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linux_dsm_epyc7002/drivers/pci/pci.c
Bjorn Helgaas 774800cb09 Merge branch 'pci/resource' 
- Protect pci_reassign_bridge_resources() against concurrent
    addition/removal (Benjamin Herrenschmidt)

  - Fix bridge dma_ranges resource list cleanup (Rob Herring)

  - Add PCI_STD_NUM_BARS for the number of standard BARs (Denis Efremov)

  - Add "pci=hpmmiosize" and "pci=hpmmioprefsize" parameters to control the
    MMIO and prefetchable MMIO window sizes of hotplug bridges
    independently (Nicholas Johnson)

  - Fix MMIO/MMIO_PREF window assignment that assigned more space than
    desired (Nicholas Johnson)

  - Only enforce bus numbers from bridge EA if the bridge has EA devices
    downstream (Subbaraya Sundeep)

* pci/resource:
  PCI: Do not use bus number zero from EA capability
  PCI: Avoid double hpmemsize MMIO window assignment
  PCI: Add "pci=hpmmiosize" and "pci=hpmmioprefsize" parameters
  PCI: Add PCI_STD_NUM_BARS for the number of standard BARs
  PCI: Fix missing bridge dma_ranges resource list cleanup
  PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal
2019-11-28 08:54:36 -06:00

6464 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* PCI Bus Services, see include/linux/pci.h for further explanation.
*
* Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
* David Mosberger-Tang
*
* Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
*/
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/log2.h>
#include <linux/logic_pio.h>
#include <linux/pm_wakeup.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/pci_hotplug.h>
#include <linux/vmalloc.h>
#include <linux/pci-ats.h>
#include <asm/setup.h>
#include <asm/dma.h>
#include <linux/aer.h>
#include "pci.h"
DEFINE_MUTEX(pci_slot_mutex);
const char *pci_power_names[] = {
"error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
};
EXPORT_SYMBOL_GPL(pci_power_names);
int isa_dma_bridge_buggy;
EXPORT_SYMBOL(isa_dma_bridge_buggy);
int pci_pci_problems;
EXPORT_SYMBOL(pci_pci_problems);
unsigned int pci_pm_d3_delay;
static void pci_pme_list_scan(struct work_struct *work);
static LIST_HEAD(pci_pme_list);
static DEFINE_MUTEX(pci_pme_list_mutex);
static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
struct pci_pme_device {
struct list_head list;
struct pci_dev *dev;
};
#define PME_TIMEOUT 1000 /* How long between PME checks */
static void pci_dev_d3_sleep(struct pci_dev *dev)
{
unsigned int delay = dev->d3_delay;
if (delay < pci_pm_d3_delay)
delay = pci_pm_d3_delay;
if (delay)
msleep(delay);
}
#ifdef CONFIG_PCI_DOMAINS
int pci_domains_supported = 1;
#endif
#define DEFAULT_CARDBUS_IO_SIZE (256)
#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
/* pci=cbmemsize=nnM,cbiosize=nn can override this */
unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
#define DEFAULT_HOTPLUG_IO_SIZE (256)
#define DEFAULT_HOTPLUG_MMIO_SIZE (2*1024*1024)
#define DEFAULT_HOTPLUG_MMIO_PREF_SIZE (2*1024*1024)
/* hpiosize=nn can override this */
unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
/*
* pci=hpmmiosize=nnM overrides non-prefetchable MMIO size,
* pci=hpmmioprefsize=nnM overrides prefetchable MMIO size;
* pci=hpmemsize=nnM overrides both
*/
unsigned long pci_hotplug_mmio_size = DEFAULT_HOTPLUG_MMIO_SIZE;
unsigned long pci_hotplug_mmio_pref_size = DEFAULT_HOTPLUG_MMIO_PREF_SIZE;
#define DEFAULT_HOTPLUG_BUS_SIZE 1
unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT;
/*
* The default CLS is used if arch didn't set CLS explicitly and not
* all pci devices agree on the same value. Arch can override either
* the dfl or actual value as it sees fit. Don't forget this is
* measured in 32-bit words, not bytes.
*/
u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2;
u8 pci_cache_line_size;
/*
* If we set up a device for bus mastering, we need to check the latency
* timer as certain BIOSes forget to set it properly.
*/
unsigned int pcibios_max_latency = 255;
/* If set, the PCIe ARI capability will not be used. */
static bool pcie_ari_disabled;
/* If set, the PCIe ATS capability will not be used. */
static bool pcie_ats_disabled;
/* If set, the PCI config space of each device is printed during boot. */
bool pci_early_dump;
bool pci_ats_disabled(void)
{
return pcie_ats_disabled;
}
/* Disable bridge_d3 for all PCIe ports */
static bool pci_bridge_d3_disable;
/* Force bridge_d3 for all PCIe ports */
static bool pci_bridge_d3_force;
static int __init pcie_port_pm_setup(char *str)
{
if (!strcmp(str, "off"))
pci_bridge_d3_disable = true;
else if (!strcmp(str, "force"))
pci_bridge_d3_force = true;
return 1;
}
__setup("pcie_port_pm=", pcie_port_pm_setup);
/* Time to wait after a reset for device to become responsive */
#define PCIE_RESET_READY_POLL_MS 60000
/**
* pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
* @bus: pointer to PCI bus structure to search
*
* Given a PCI bus, returns the highest PCI bus number present in the set
* including the given PCI bus and its list of child PCI buses.
*/
unsigned char pci_bus_max_busnr(struct pci_bus *bus)
{
struct pci_bus *tmp;
unsigned char max, n;
max = bus->busn_res.end;
list_for_each_entry(tmp, &bus->children, node) {
n = pci_bus_max_busnr(tmp);
if (n > max)
max = n;
}
return max;
}
EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
#ifdef CONFIG_HAS_IOMEM
void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
{
struct resource *res = &pdev->resource[bar];
/*
* Make sure the BAR is actually a memory resource, not an IO resource
*/
if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) {
pci_warn(pdev, "can't ioremap BAR %d: %pR\n", bar, res);
return NULL;
}
return ioremap_nocache(res->start, resource_size(res));
}
EXPORT_SYMBOL_GPL(pci_ioremap_bar);
void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
{
/*
* Make sure the BAR is actually a memory resource, not an IO resource
*/
if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
WARN_ON(1);
return NULL;
}
return ioremap_wc(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar));
}
EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
#endif
/**
* pci_dev_str_match_path - test if a path string matches a device
* @dev: the PCI device to test
* @path: string to match the device against
* @endptr: pointer to the string after the match
*
* Test if a string (typically from a kernel parameter) formatted as a
* path of device/function addresses matches a PCI device. The string must
* be of the form:
*
* [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
*
* A path for a device can be obtained using 'lspci -t'. Using a path
* is more robust against bus renumbering than using only a single bus,
* device and function address.
*
* Returns 1 if the string matches the device, 0 if it does not and
* a negative error code if it fails to parse the string.
*/
static int pci_dev_str_match_path(struct pci_dev *dev, const char *path,
const char **endptr)
{
int ret;
int seg, bus, slot, func;
char *wpath, *p;
char end;
*endptr = strchrnul(path, ';');
wpath = kmemdup_nul(path, *endptr - path, GFP_KERNEL);
if (!wpath)
return -ENOMEM;
while (1) {
p = strrchr(wpath, '/');
if (!p)
break;
ret = sscanf(p, "/%x.%x%c", &slot, &func, &end);
if (ret != 2) {
ret = -EINVAL;
goto free_and_exit;
}
if (dev->devfn != PCI_DEVFN(slot, func)) {
ret = 0;
goto free_and_exit;
}
/*
* Note: we don't need to get a reference to the upstream
* bridge because we hold a reference to the top level
* device which should hold a reference to the bridge,
* and so on.
*/
dev = pci_upstream_bridge(dev);
if (!dev) {
ret = 0;
goto free_and_exit;
}
*p = 0;
}
ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot,
&func, &end);
if (ret != 4) {
seg = 0;
ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end);
if (ret != 3) {
ret = -EINVAL;
goto free_and_exit;
}
}
ret = (seg == pci_domain_nr(dev->bus) &&
bus == dev->bus->number &&
dev->devfn == PCI_DEVFN(slot, func));
free_and_exit:
kfree(wpath);
return ret;
}
/**
* pci_dev_str_match - test if a string matches a device
* @dev: the PCI device to test
* @p: string to match the device against
* @endptr: pointer to the string after the match
*
* Test if a string (typically from a kernel parameter) matches a specified
* PCI device. The string may be of one of the following formats:
*
* [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*
* pci:<vendor>:<device>[:<subvendor>:<subdevice>]
*
* The first format specifies a PCI bus/device/function address which
* may change if new hardware is inserted, if motherboard firmware changes,
* or due to changes caused in kernel parameters. If the domain is
* left unspecified, it is taken to be 0. In order to be robust against
* bus renumbering issues, a path of PCI device/function numbers may be used
* to address the specific device. The path for a device can be determined
* through the use of 'lspci -t'.
*
* The second format matches devices using IDs in the configuration
* space which may match multiple devices in the system. A value of 0
* for any field will match all devices. (Note: this differs from
* in-kernel code that uses PCI_ANY_ID which is ~0; this is for
* legacy reasons and convenience so users don't have to specify
* FFFFFFFFs on the command line.)
*
* Returns 1 if the string matches the device, 0 if it does not and
* a negative error code if the string cannot be parsed.
*/
static int pci_dev_str_match(struct pci_dev *dev, const char *p,
const char **endptr)
{
int ret;
int count;
unsigned short vendor, device, subsystem_vendor, subsystem_device;
if (strncmp(p, "pci:", 4) == 0) {
/* PCI vendor/device (subvendor/subdevice) IDs are specified */
p += 4;
ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device,
&subsystem_vendor, &subsystem_device, &count);
if (ret != 4) {
ret = sscanf(p, "%hx:%hx%n", &vendor, &device, &count);
if (ret != 2)
return -EINVAL;
subsystem_vendor = 0;
subsystem_device = 0;
}
p += count;
if ((!vendor || vendor == dev->vendor) &&
(!device || device == dev->device) &&
(!subsystem_vendor ||
subsystem_vendor == dev->subsystem_vendor) &&
(!subsystem_device ||
subsystem_device == dev->subsystem_device))
goto found;
} else {
/*
* PCI Bus, Device, Function IDs are specified
* (optionally, may include a path of devfns following it)
*/
ret = pci_dev_str_match_path(dev, p, &p);
if (ret < 0)
return ret;
else if (ret)
goto found;
}
*endptr = p;
return 0;
found:
*endptr = p;
return 1;
}
static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
u8 pos, int cap, int *ttl)
{
u8 id;
u16 ent;
pci_bus_read_config_byte(bus, devfn, pos, &pos);
while ((*ttl)--) {
if (pos < 0x40)
break;
pos &= ~3;
pci_bus_read_config_word(bus, devfn, pos, &ent);
id = ent & 0xff;
if (id == 0xff)
break;
if (id == cap)
return pos;
pos = (ent >> 8);
}
return 0;
}
static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
u8 pos, int cap)
{
int ttl = PCI_FIND_CAP_TTL;
return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
}
int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
{
return __pci_find_next_cap(dev->bus, dev->devfn,
pos + PCI_CAP_LIST_NEXT, cap);
}
EXPORT_SYMBOL_GPL(pci_find_next_capability);
static int __pci_bus_find_cap_start(struct pci_bus *bus,
unsigned int devfn, u8 hdr_type)
{
u16 status;
pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
if (!(status & PCI_STATUS_CAP_LIST))
return 0;
switch (hdr_type) {
case PCI_HEADER_TYPE_NORMAL:
case PCI_HEADER_TYPE_BRIDGE:
return PCI_CAPABILITY_LIST;
case PCI_HEADER_TYPE_CARDBUS:
return PCI_CB_CAPABILITY_LIST;
}
return 0;
}
/**
* pci_find_capability - query for devices' capabilities
* @dev: PCI device to query
* @cap: capability code
*
* Tell if a device supports a given PCI capability.
* Returns the address of the requested capability structure within the
* device's PCI configuration space or 0 in case the device does not
* support it. Possible values for @cap include:
*
* %PCI_CAP_ID_PM Power Management
* %PCI_CAP_ID_AGP Accelerated Graphics Port
* %PCI_CAP_ID_VPD Vital Product Data
* %PCI_CAP_ID_SLOTID Slot Identification
* %PCI_CAP_ID_MSI Message Signalled Interrupts
* %PCI_CAP_ID_CHSWP CompactPCI HotSwap
* %PCI_CAP_ID_PCIX PCI-X
* %PCI_CAP_ID_EXP PCI Express
*/
int pci_find_capability(struct pci_dev *dev, int cap)
{
int pos;
pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
if (pos)
pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
return pos;
}
EXPORT_SYMBOL(pci_find_capability);
/**
* pci_bus_find_capability - query for devices' capabilities
* @bus: the PCI bus to query
* @devfn: PCI device to query
* @cap: capability code
*
* Like pci_find_capability() but works for PCI devices that do not have a
* pci_dev structure set up yet.
*
* Returns the address of the requested capability structure within the
* device's PCI configuration space or 0 in case the device does not
* support it.
*/
int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
{
int pos;
u8 hdr_type;
pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
if (pos)
pos = __pci_find_next_cap(bus, devfn, pos, cap);
return pos;
}
EXPORT_SYMBOL(pci_bus_find_capability);
/**
* pci_find_next_ext_capability - Find an extended capability
* @dev: PCI device to query
* @start: address at which to start looking (0 to start at beginning of list)
* @cap: capability code
*
* Returns the address of the next matching extended capability structure
* within the device's PCI configuration space or 0 if the device does
* not support it. Some capabilities can occur several times, e.g., the
* vendor-specific capability, and this provides a way to find them all.
*/
int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap)
{
u32 header;
int ttl;
int pos = PCI_CFG_SPACE_SIZE;
/* minimum 8 bytes per capability */
ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
return 0;
if (start)
pos = start;
if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
return 0;
/*
* If we have no capabilities, this is indicated by cap ID,
* cap version and next pointer all being 0.
*/
if (header == 0)
return 0;
while (ttl-- > 0) {
if (PCI_EXT_CAP_ID(header) == cap && pos != start)
return pos;
pos = PCI_EXT_CAP_NEXT(header);
if (pos < PCI_CFG_SPACE_SIZE)
break;
if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
break;
}
return 0;
}
EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
/**
* pci_find_ext_capability - Find an extended capability
* @dev: PCI device to query
* @cap: capability code
*
* Returns the address of the requested extended capability structure
* within the device's PCI configuration space or 0 if the device does
* not support it. Possible values for @cap include:
*
* %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
* %PCI_EXT_CAP_ID_VC Virtual Channel
* %PCI_EXT_CAP_ID_DSN Device Serial Number
* %PCI_EXT_CAP_ID_PWR Power Budgeting
*/
int pci_find_ext_capability(struct pci_dev *dev, int cap)
{
return pci_find_next_ext_capability(dev, 0, cap);
}
EXPORT_SYMBOL_GPL(pci_find_ext_capability);
static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
{
int rc, ttl = PCI_FIND_CAP_TTL;
u8 cap, mask;
if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
mask = HT_3BIT_CAP_MASK;
else
mask = HT_5BIT_CAP_MASK;
pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
PCI_CAP_ID_HT, &ttl);
while (pos) {
rc = pci_read_config_byte(dev, pos + 3, &cap);
if (rc != PCIBIOS_SUCCESSFUL)
return 0;
if ((cap & mask) == ht_cap)
return pos;
pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
pos + PCI_CAP_LIST_NEXT,
PCI_CAP_ID_HT, &ttl);
}
return 0;
}
/**
* pci_find_next_ht_capability - query a device's Hypertransport capabilities
* @dev: PCI device to query
* @pos: Position from which to continue searching
* @ht_cap: Hypertransport capability code
*
* To be used in conjunction with pci_find_ht_capability() to search for
* all capabilities matching @ht_cap. @pos should always be a value returned
* from pci_find_ht_capability().
*
* NB. To be 100% safe against broken PCI devices, the caller should take
* steps to avoid an infinite loop.
*/
int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
{
return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
}
EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
/**
* pci_find_ht_capability - query a device's Hypertransport capabilities
* @dev: PCI device to query
* @ht_cap: Hypertransport capability code
*
* Tell if a device supports a given Hypertransport capability.
* Returns an address within the device's PCI configuration space
* or 0 in case the device does not support the request capability.
* The address points to the PCI capability, of type PCI_CAP_ID_HT,
* which has a Hypertransport capability matching @ht_cap.
*/
int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
{
int pos;
pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
if (pos)
pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
return pos;
}
EXPORT_SYMBOL_GPL(pci_find_ht_capability);
/**
* pci_find_parent_resource - return resource region of parent bus of given
* region
* @dev: PCI device structure contains resources to be searched
* @res: child resource record for which parent is sought
*
* For given resource region of given device, return the resource region of
* parent bus the given region is contained in.
*/
struct resource *pci_find_parent_resource(const struct pci_dev *dev,
struct resource *res)
{
const struct pci_bus *bus = dev->bus;
struct resource *r;
int i;
pci_bus_for_each_resource(bus, r, i) {
if (!r)
continue;
if (resource_contains(r, res)) {
/*
* If the window is prefetchable but the BAR is
* not, the allocator made a mistake.
*/
if (r->flags & IORESOURCE_PREFETCH &&
!(res->flags & IORESOURCE_PREFETCH))
return NULL;
/*
* If we're below a transparent bridge, there may
* be both a positively-decoded aperture and a
* subtractively-decoded region that contain the BAR.
* We want the positively-decoded one, so this depends
* on pci_bus_for_each_resource() giving us those
* first.
*/
return r;
}
}
return NULL;
}
EXPORT_SYMBOL(pci_find_parent_resource);
/**
* pci_find_resource - Return matching PCI device resource
* @dev: PCI device to query
* @res: Resource to look for
*
* Goes over standard PCI resources (BARs) and checks if the given resource
* is partially or fully contained in any of them. In that case the
* matching resource is returned, %NULL otherwise.
*/
struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
{
int i;
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
struct resource *r = &dev->resource[i];
if (r->start && resource_contains(r, res))
return r;
}
return NULL;
}
EXPORT_SYMBOL(pci_find_resource);
/**
* pci_find_pcie_root_port - return PCIe Root Port
* @dev: PCI device to query
*
* Traverse up the parent chain and return the PCIe Root Port PCI Device
* for a given PCI Device.
*/
struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev)
{
struct pci_dev *bridge, *highest_pcie_bridge = dev;
bridge = pci_upstream_bridge(dev);
while (bridge && pci_is_pcie(bridge)) {
highest_pcie_bridge = bridge;
bridge = pci_upstream_bridge(bridge);
}
if (pci_pcie_type(highest_pcie_bridge) != PCI_EXP_TYPE_ROOT_PORT)
return NULL;
return highest_pcie_bridge;
}
EXPORT_SYMBOL(pci_find_pcie_root_port);
/**
* pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
* @dev: the PCI device to operate on
* @pos: config space offset of status word
* @mask: mask of bit(s) to care about in status word
*
* Return 1 when mask bit(s) in status word clear, 0 otherwise.
*/
int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)
{
int i;
/* Wait for Transaction Pending bit clean */
for (i = 0; i < 4; i++) {
u16 status;
if (i)
msleep((1 << (i - 1)) * 100);
pci_read_config_word(dev, pos, &status);
if (!(status & mask))
return 1;
}
return 0;
}
/**
* pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
* @dev: PCI device to have its BARs restored
*
* Restore the BAR values for a given device, so as to make it
* accessible by its driver.
*/
static void pci_restore_bars(struct pci_dev *dev)
{
int i;
for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
pci_update_resource(dev, i);
}
static const struct pci_platform_pm_ops *pci_platform_pm;
int pci_set_platform_pm(const struct pci_platform_pm_ops *ops)
{
if (!ops->is_manageable || !ops->set_state || !ops->get_state ||
!ops->choose_state || !ops->set_wakeup || !ops->need_resume)
return -EINVAL;
pci_platform_pm = ops;
return 0;
}
static inline bool platform_pci_power_manageable(struct pci_dev *dev)
{
return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
}
static inline int platform_pci_set_power_state(struct pci_dev *dev,
pci_power_t t)
{
return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
}
static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
{
return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN;
}
static inline void platform_pci_refresh_power_state(struct pci_dev *dev)
{
if (pci_platform_pm && pci_platform_pm->refresh_state)
pci_platform_pm->refresh_state(dev);
}
static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
{
return pci_platform_pm ?
pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
}
static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
{
return pci_platform_pm ?
pci_platform_pm->set_wakeup(dev, enable) : -ENODEV;
}
static inline bool platform_pci_need_resume(struct pci_dev *dev)
{
return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false;
}
static inline bool platform_pci_bridge_d3(struct pci_dev *dev)
{
return pci_platform_pm ? pci_platform_pm->bridge_d3(dev) : false;
}
/**
* pci_raw_set_power_state - Use PCI PM registers to set the power state of
* given PCI device
* @dev: PCI device to handle.
* @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
*
* RETURN VALUE:
* -EINVAL if the requested state is invalid.
* -EIO if device does not support PCI PM or its PM capabilities register has a
* wrong version, or device doesn't support the requested state.
* 0 if device already is in the requested state.
* 0 if device's power state has been successfully changed.
*/
static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
{
u16 pmcsr;
bool need_restore = false;
/* Check if we're already there */
if (dev->current_state == state)
return 0;
if (!dev->pm_cap)
return -EIO;
if (state < PCI_D0 || state > PCI_D3hot)
return -EINVAL;
/*
* Validate transition: We can enter D0 from any state, but if
* we're already in a low-power state, we can only go deeper. E.g.,
* we can go from D1 to D3, but we can't go directly from D3 to D1;
* we'd have to go from D3 to D0, then to D1.
*/
if (state != PCI_D0 && dev->current_state <= PCI_D3cold
&& dev->current_state > state) {
pci_err(dev, "invalid power transition (from %s to %s)\n",
pci_power_name(dev->current_state),
pci_power_name(state));
return -EINVAL;
}
/* Check if this device supports the desired state */
if ((state == PCI_D1 && !dev->d1_support)
|| (state == PCI_D2 && !dev->d2_support))
return -EIO;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
if (pmcsr == (u16) ~0) {
pci_err(dev, "can't change power state from %s to %s (config space inaccessible)\n",
pci_power_name(dev->current_state),
pci_power_name(state));
return -EIO;
}
/*
* If we're (effectively) in D3, force entire word to 0.
* This doesn't affect PME_Status, disables PME_En, and
* sets PowerState to 0.
*/
switch (dev->current_state) {
case PCI_D0:
case PCI_D1:
case PCI_D2:
pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
pmcsr |= state;
break;
case PCI_D3hot:
case PCI_D3cold:
case PCI_UNKNOWN: /* Boot-up */
if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
&& !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
need_restore = true;
/* Fall-through - force to D0 */
default:
pmcsr = 0;
break;
}
/* Enter specified state */
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
/*
* Mandatory power management transition delays; see PCI PM 1.1
* 5.6.1 table 18
*/
if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
pci_dev_d3_sleep(dev);
else if (state == PCI_D2 || dev->current_state == PCI_D2)
msleep(PCI_PM_D2_DELAY);
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
if (dev->current_state != state)
pci_info_ratelimited(dev, "refused to change power state from %s to %s\n",
pci_power_name(dev->current_state),
pci_power_name(state));
/*
* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
* INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
* from D3hot to D0 _may_ perform an internal reset, thereby
* going to "D0 Uninitialized" rather than "D0 Initialized".
* For example, at least some versions of the 3c905B and the
* 3c556B exhibit this behaviour.
*
* At least some laptop BIOSen (e.g. the Thinkpad T21) leave
* devices in a D3hot state at boot. Consequently, we need to
* restore at least the BARs so that the device will be
* accessible to its driver.
*/
if (need_restore)
pci_restore_bars(dev);
if (dev->bus->self)
pcie_aspm_pm_state_change(dev->bus->self);
return 0;
}
/**
* pci_update_current_state - Read power state of given device and cache it
* @dev: PCI device to handle.
* @state: State to cache in case the device doesn't have the PM capability
*
* The power state is read from the PMCSR register, which however is
* inaccessible in D3cold. The platform firmware is therefore queried first
* to detect accessibility of the register. In case the platform firmware
* reports an incorrect state or the device isn't power manageable by the
* platform at all, we try to detect D3cold by testing accessibility of the
* vendor ID in config space.
*/
void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
{
if (platform_pci_get_power_state(dev) == PCI_D3cold ||
!pci_device_is_present(dev)) {
dev->current_state = PCI_D3cold;
} else if (dev->pm_cap) {
u16 pmcsr;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
} else {
dev->current_state = state;
}
}
/**
* pci_refresh_power_state - Refresh the given device's power state data
* @dev: Target PCI device.
*
* Ask the platform to refresh the devices power state information and invoke
* pci_update_current_state() to update its current PCI power state.
*/
void pci_refresh_power_state(struct pci_dev *dev)
{
if (platform_pci_power_manageable(dev))
platform_pci_refresh_power_state(dev);
pci_update_current_state(dev, dev->current_state);
}
/**
* pci_platform_power_transition - Use platform to change device power state
* @dev: PCI device to handle.
* @state: State to put the device into.
*/
int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
{
int error;
if (platform_pci_power_manageable(dev)) {
error = platform_pci_set_power_state(dev, state);
if (!error)
pci_update_current_state(dev, state);
} else
error = -ENODEV;
if (error && !dev->pm_cap) /* Fall back to PCI_D0 */
dev->current_state = PCI_D0;
return error;
}
EXPORT_SYMBOL_GPL(pci_platform_power_transition);
/**
* pci_wakeup - Wake up a PCI device
* @pci_dev: Device to handle.
* @ign: ignored parameter
*/
static int pci_wakeup(struct pci_dev *pci_dev, void *ign)
{
pci_wakeup_event(pci_dev);
pm_request_resume(&pci_dev->dev);
return 0;
}
/**
* pci_wakeup_bus - Walk given bus and wake up devices on it
* @bus: Top bus of the subtree to walk.
*/
void pci_wakeup_bus(struct pci_bus *bus)
{
if (bus)
pci_walk_bus(bus, pci_wakeup, NULL);
}
static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
{
int delay = 1;
u32 id;
/*
* After reset, the device should not silently discard config
* requests, but it may still indicate that it needs more time by
* responding to them with CRS completions. The Root Port will
* generally synthesize ~0 data to complete the read (except when
* CRS SV is enabled and the read was for the Vendor ID; in that
* case it synthesizes 0x0001 data).
*
* Wait for the device to return a non-CRS completion. Read the
* Command register instead of Vendor ID so we don't have to
* contend with the CRS SV value.
*/
pci_read_config_dword(dev, PCI_COMMAND, &id);
while (id == ~0) {
if (delay > timeout) {
pci_warn(dev, "not ready %dms after %s; giving up\n",
delay - 1, reset_type);
return -ENOTTY;
}
if (delay > 1000)
pci_info(dev, "not ready %dms after %s; waiting\n",
delay - 1, reset_type);
msleep(delay);
delay *= 2;
pci_read_config_dword(dev, PCI_COMMAND, &id);
}
if (delay > 1000)
pci_info(dev, "ready %dms after %s\n", delay - 1,
reset_type);
return 0;
}
/**
* pci_power_up - Put the given device into D0
* @dev: PCI device to power up
*/
int pci_power_up(struct pci_dev *dev)
{
pci_platform_power_transition(dev, PCI_D0);
/*
* Mandatory power management transition delays are handled in
* pci_pm_resume_noirq() and pci_pm_runtime_resume() of the
* corresponding bridge.
*/
if (dev->runtime_d3cold) {
/*
* When powering on a bridge from D3cold, the whole hierarchy
* may be powered on into D0uninitialized state, resume them to
* give them a chance to suspend again
*/
pci_wakeup_bus(dev->subordinate);
}
return pci_raw_set_power_state(dev, PCI_D0);
}
/**
* __pci_dev_set_current_state - Set current state of a PCI device
* @dev: Device to handle
* @data: pointer to state to be set
*/
static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
{
pci_power_t state = *(pci_power_t *)data;
dev->current_state = state;
return 0;
}
/**
* pci_bus_set_current_state - Walk given bus and set current state of devices
* @bus: Top bus of the subtree to walk.
* @state: state to be set
*/
void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
{
if (bus)
pci_walk_bus(bus, __pci_dev_set_current_state, &state);
}
/**
* pci_set_power_state - Set the power state of a PCI device
* @dev: PCI device to handle.
* @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
*
* Transition a device to a new power state, using the platform firmware and/or
* the device's PCI PM registers.
*
* RETURN VALUE:
* -EINVAL if the requested state is invalid.
* -EIO if device does not support PCI PM or its PM capabilities register has a
* wrong version, or device doesn't support the requested state.
* 0 if the transition is to D1 or D2 but D1 and D2 are not supported.
* 0 if device already is in the requested state.
* 0 if the transition is to D3 but D3 is not supported.
* 0 if device's power state has been successfully changed.
*/
int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
int error;
/* Bound the state we're entering */
if (state > PCI_D3cold)
state = PCI_D3cold;
else if (state < PCI_D0)
state = PCI_D0;
else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
/*
* If the device or the parent bridge do not support PCI
* PM, ignore the request if we're doing anything other
* than putting it into D0 (which would only happen on
* boot).
*/
return 0;
/* Check if we're already there */
if (dev->current_state == state)
return 0;
if (state == PCI_D0)
return pci_power_up(dev);
/*
* This device is quirked not to be put into D3, so don't put it in
* D3
*/
if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
return 0;
/*
* To put device in D3cold, we put device into D3hot in native
* way, then put device into D3cold with platform ops
*/
error = pci_raw_set_power_state(dev, state > PCI_D3hot ?
PCI_D3hot : state);
if (pci_platform_power_transition(dev, state))
return error;
/* Powering off a bridge may power off the whole hierarchy */
if (state == PCI_D3cold)
pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
return 0;
}
EXPORT_SYMBOL(pci_set_power_state);
/**
* pci_choose_state - Choose the power state of a PCI device
* @dev: PCI device to be suspended
* @state: target sleep state for the whole system. This is the value
* that is passed to suspend() function.
*
* Returns PCI power state suitable for given device and given system
* message.
*/
pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
{
pci_power_t ret;
if (!dev->pm_cap)
return PCI_D0;
ret = platform_pci_choose_state(dev);
if (ret != PCI_POWER_ERROR)
return ret;
switch (state.event) {
case PM_EVENT_ON:
return PCI_D0;
case PM_EVENT_FREEZE:
case PM_EVENT_PRETHAW:
/* REVISIT both freeze and pre-thaw "should" use D0 */
case PM_EVENT_SUSPEND:
case PM_EVENT_HIBERNATE:
return PCI_D3hot;
default:
pci_info(dev, "unrecognized suspend event %d\n",
state.event);
BUG();
}
return PCI_D0;
}
EXPORT_SYMBOL(pci_choose_state);
#define PCI_EXP_SAVE_REGS 7
static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
u16 cap, bool extended)
{
struct pci_cap_saved_state *tmp;
hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) {
if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap)
return tmp;
}
return NULL;
}
struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap)
{
return _pci_find_saved_cap(dev, cap, false);
}
struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap)
{
return _pci_find_saved_cap(dev, cap, true);
}
static int pci_save_pcie_state(struct pci_dev *dev)
{
int i = 0;
struct pci_cap_saved_state *save_state;
u16 *cap;
if (!pci_is_pcie(dev))
return 0;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
if (!save_state) {
pci_err(dev, "buffer not found in %s\n", __func__);
return -ENOMEM;
}
cap = (u16 *)&save_state->cap.data[0];
pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
return 0;
}
static void pci_restore_pcie_state(struct pci_dev *dev)
{
int i = 0;
struct pci_cap_saved_state *save_state;
u16 *cap;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
if (!save_state)
return;
cap = (u16 *)&save_state->cap.data[0];
pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
}
static int pci_save_pcix_state(struct pci_dev *dev)
{
int pos;
struct pci_cap_saved_state *save_state;
pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!pos)
return 0;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
if (!save_state) {
pci_err(dev, "buffer not found in %s\n", __func__);
return -ENOMEM;
}
pci_read_config_word(dev, pos + PCI_X_CMD,
(u16 *)save_state->cap.data);
return 0;
}
static void pci_restore_pcix_state(struct pci_dev *dev)
{
int i = 0, pos;
struct pci_cap_saved_state *save_state;
u16 *cap;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!save_state || !pos)
return;
cap = (u16 *)&save_state->cap.data[0];
pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
}
static void pci_save_ltr_state(struct pci_dev *dev)
{
int ltr;
struct pci_cap_saved_state *save_state;
u16 *cap;
if (!pci_is_pcie(dev))
return;
ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
if (!ltr)
return;
save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
if (!save_state) {
pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n");
return;
}
cap = (u16 *)&save_state->cap.data[0];
pci_read_config_word(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap++);
pci_read_config_word(dev, ltr + PCI_LTR_MAX_NOSNOOP_LAT, cap++);
}
static void pci_restore_ltr_state(struct pci_dev *dev)
{
struct pci_cap_saved_state *save_state;
int ltr;
u16 *cap;
save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
if (!save_state || !ltr)
return;
cap = (u16 *)&save_state->cap.data[0];
pci_write_config_word(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap++);
pci_write_config_word(dev, ltr + PCI_LTR_MAX_NOSNOOP_LAT, *cap++);
}
/**
* pci_save_state - save the PCI configuration space of a device before
* suspending
* @dev: PCI device that we're dealing with
*/
int pci_save_state(struct pci_dev *dev)
{
int i;
/* XXX: 100% dword access ok here? */
for (i = 0; i < 16; i++)
pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
dev->state_saved = true;
i = pci_save_pcie_state(dev);
if (i != 0)
return i;
i = pci_save_pcix_state(dev);
if (i != 0)
return i;
pci_save_ltr_state(dev);
pci_save_dpc_state(dev);
pci_save_aer_state(dev);
return pci_save_vc_state(dev);
}
EXPORT_SYMBOL(pci_save_state);
static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
u32 saved_val, int retry, bool force)
{
u32 val;
pci_read_config_dword(pdev, offset, &val);
if (!force && val == saved_val)
return;
for (;;) {
pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n",
offset, val, saved_val);
pci_write_config_dword(pdev, offset, saved_val);
if (retry-- <= 0)
return;
pci_read_config_dword(pdev, offset, &val);
if (val == saved_val)
return;
mdelay(1);
}
}
static void pci_restore_config_space_range(struct pci_dev *pdev,
int start, int end, int retry,
bool force)
{
int index;
for (index = end; index >= start; index--)
pci_restore_config_dword(pdev, 4 * index,
pdev->saved_config_space[index],
retry, force);
}
static void pci_restore_config_space(struct pci_dev *pdev)
{
if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
pci_restore_config_space_range(pdev, 10, 15, 0, false);
/* Restore BARs before the command register. */
pci_restore_config_space_range(pdev, 4, 9, 10, false);
pci_restore_config_space_range(pdev, 0, 3, 0, false);
} else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
pci_restore_config_space_range(pdev, 12, 15, 0, false);
/*
* Force rewriting of prefetch registers to avoid S3 resume
* issues on Intel PCI bridges that occur when these
* registers are not explicitly written.
*/
pci_restore_config_space_range(pdev, 9, 11, 0, true);
pci_restore_config_space_range(pdev, 0, 8, 0, false);
} else {
pci_restore_config_space_range(pdev, 0, 15, 0, false);
}
}
static void pci_restore_rebar_state(struct pci_dev *pdev)
{
unsigned int pos, nbars, i;
u32 ctrl;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
if (!pos)
return;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
PCI_REBAR_CTRL_NBAR_SHIFT;
for (i = 0; i < nbars; i++, pos += 8) {
struct resource *res;
int bar_idx, size;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
res = pdev->resource + bar_idx;
size = ilog2(resource_size(res)) - 20;
ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
}
}
/**
* pci_restore_state - Restore the saved state of a PCI device
* @dev: PCI device that we're dealing with
*/
void pci_restore_state(struct pci_dev *dev)
{
if (!dev->state_saved)
return;
/*
* Restore max latencies (in the LTR capability) before enabling
* LTR itself (in the PCIe capability).
*/
pci_restore_ltr_state(dev);
pci_restore_pcie_state(dev);
pci_restore_pasid_state(dev);
pci_restore_pri_state(dev);
pci_restore_ats_state(dev);
pci_restore_vc_state(dev);
pci_restore_rebar_state(dev);
pci_restore_dpc_state(dev);
pci_cleanup_aer_error_status_regs(dev);
pci_restore_aer_state(dev);
pci_restore_config_space(dev);
pci_restore_pcix_state(dev);
pci_restore_msi_state(dev);
/* Restore ACS and IOV configuration state */
pci_enable_acs(dev);
pci_restore_iov_state(dev);
dev->state_saved = false;
}
EXPORT_SYMBOL(pci_restore_state);
struct pci_saved_state {
u32 config_space[16];
struct pci_cap_saved_data cap[0];
};
/**
* pci_store_saved_state - Allocate and return an opaque struct containing
* the device saved state.
* @dev: PCI device that we're dealing with
*
* Return NULL if no state or error.
*/
struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
{
struct pci_saved_state *state;
struct pci_cap_saved_state *tmp;
struct pci_cap_saved_data *cap;
size_t size;
if (!dev->state_saved)
return NULL;
size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
hlist_for_each_entry(tmp, &dev->saved_cap_space, next)
size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
state = kzalloc(size, GFP_KERNEL);
if (!state)
return NULL;
memcpy(state->config_space, dev->saved_config_space,
sizeof(state->config_space));
cap = state->cap;
hlist_for_each_entry(tmp, &dev->saved_cap_space, next) {
size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
memcpy(cap, &tmp->cap, len);
cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
}
/* Empty cap_save terminates list */
return state;
}
EXPORT_SYMBOL_GPL(pci_store_saved_state);
/**
* pci_load_saved_state - Reload the provided save state into struct pci_dev.
* @dev: PCI device that we're dealing with
* @state: Saved state returned from pci_store_saved_state()
*/
int pci_load_saved_state(struct pci_dev *dev,
struct pci_saved_state *state)
{
struct pci_cap_saved_data *cap;
dev->state_saved = false;
if (!state)
return 0;
memcpy(dev->saved_config_space, state->config_space,
sizeof(state->config_space));
cap = state->cap;
while (cap->size) {
struct pci_cap_saved_state *tmp;
tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended);
if (!tmp || tmp->cap.size != cap->size)
return -EINVAL;
memcpy(tmp->cap.data, cap->data, tmp->cap.size);
cap = (struct pci_cap_saved_data *)((u8 *)cap +
sizeof(struct pci_cap_saved_data) + cap->size);
}
dev->state_saved = true;
return 0;
}
EXPORT_SYMBOL_GPL(pci_load_saved_state);
/**
* pci_load_and_free_saved_state - Reload the save state pointed to by state,
* and free the memory allocated for it.
* @dev: PCI device that we're dealing with
* @state: Pointer to saved state returned from pci_store_saved_state()
*/
int pci_load_and_free_saved_state(struct pci_dev *dev,
struct pci_saved_state **state)
{
int ret = pci_load_saved_state(dev, *state);
kfree(*state);
*state = NULL;
return ret;
}
EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
int __weak pcibios_enable_device(struct pci_dev *dev, int bars)
{
return pci_enable_resources(dev, bars);
}
static int do_pci_enable_device(struct pci_dev *dev, int bars)
{
int err;
struct pci_dev *bridge;
u16 cmd;
u8 pin;
err = pci_set_power_state(dev, PCI_D0);
if (err < 0 && err != -EIO)
return err;
bridge = pci_upstream_bridge(dev);
if (bridge)
pcie_aspm_powersave_config_link(bridge);
err = pcibios_enable_device(dev, bars);
if (err < 0)
return err;
pci_fixup_device(pci_fixup_enable, dev);
if (dev->msi_enabled || dev->msix_enabled)
return 0;
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
if (pin) {
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (cmd & PCI_COMMAND_INTX_DISABLE)
pci_write_config_word(dev, PCI_COMMAND,
cmd & ~PCI_COMMAND_INTX_DISABLE);
}
return 0;
}
/**
* pci_reenable_device - Resume abandoned device
* @dev: PCI device to be resumed
*
* NOTE: This function is a backend of pci_default_resume() and is not supposed
* to be called by normal code, write proper resume handler and use it instead.
*/
int pci_reenable_device(struct pci_dev *dev)
{
if (pci_is_enabled(dev))
return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
return 0;
}
EXPORT_SYMBOL(pci_reenable_device);
static void pci_enable_bridge(struct pci_dev *dev)
{
struct pci_dev *bridge;
int retval;
bridge = pci_upstream_bridge(dev);
if (bridge)
pci_enable_bridge(bridge);
if (pci_is_enabled(dev)) {
if (!dev->is_busmaster)
pci_set_master(dev);
return;
}
retval = pci_enable_device(dev);
if (retval)
pci_err(dev, "Error enabling bridge (%d), continuing\n",
retval);
pci_set_master(dev);
}
static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
{
struct pci_dev *bridge;
int err;
int i, bars = 0;
/*
* Power state could be unknown at this point, either due to a fresh
* boot or a device removal call. So get the current power state
* so that things like MSI message writing will behave as expected
* (e.g. if the device really is in D0 at enable time).
*/
if (dev->pm_cap) {
u16 pmcsr;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
}
if (atomic_inc_return(&dev->enable_cnt) > 1)
return 0; /* already enabled */
bridge = pci_upstream_bridge(dev);
if (bridge)
pci_enable_bridge(bridge);
/* only skip sriov related */
for (i = 0; i <= PCI_ROM_RESOURCE; i++)
if (dev->resource[i].flags & flags)
bars |= (1 << i);
for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
if (dev->resource[i].flags & flags)
bars |= (1 << i);
err = do_pci_enable_device(dev, bars);
if (err < 0)
atomic_dec(&dev->enable_cnt);
return err;
}
/**
* pci_enable_device_io - Initialize a device for use with IO space
* @dev: PCI device to be initialized
*
* Initialize device before it's used by a driver. Ask low-level code
* to enable I/O resources. Wake up the device if it was suspended.
* Beware, this function can fail.
*/
int pci_enable_device_io(struct pci_dev *dev)
{
return pci_enable_device_flags(dev, IORESOURCE_IO);
}
EXPORT_SYMBOL(pci_enable_device_io);
/**
* pci_enable_device_mem - Initialize a device for use with Memory space
* @dev: PCI device to be initialized
*
* Initialize device before it's used by a driver. Ask low-level code
* to enable Memory resources. Wake up the device if it was suspended.
* Beware, this function can fail.
*/
int pci_enable_device_mem(struct pci_dev *dev)
{
return pci_enable_device_flags(dev, IORESOURCE_MEM);
}
EXPORT_SYMBOL(pci_enable_device_mem);
/**
* pci_enable_device - Initialize device before it's used by a driver.
* @dev: PCI device to be initialized
*
* Initialize device before it's used by a driver. Ask low-level code
* to enable I/O and memory. Wake up the device if it was suspended.
* Beware, this function can fail.
*
* Note we don't actually enable the device many times if we call
* this function repeatedly (we just increment the count).
*/
int pci_enable_device(struct pci_dev *dev)
{
return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
}
EXPORT_SYMBOL(pci_enable_device);
/*
* Managed PCI resources. This manages device on/off, INTx/MSI/MSI-X
* on/off and BAR regions. pci_dev itself records MSI/MSI-X status, so
* there's no need to track it separately. pci_devres is initialized
* when a device is enabled using managed PCI device enable interface.
*/
struct pci_devres {
unsigned int enabled:1;
unsigned int pinned:1;
unsigned int orig_intx:1;
unsigned int restore_intx:1;
unsigned int mwi:1;
u32 region_mask;
};
static void pcim_release(struct device *gendev, void *res)
{
struct pci_dev *dev = to_pci_dev(gendev);
struct pci_devres *this = res;
int i;
if (dev->msi_enabled)
pci_disable_msi(dev);
if (dev->msix_enabled)
pci_disable_msix(dev);
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
if (this->region_mask & (1 << i))
pci_release_region(dev, i);
if (this->mwi)
pci_clear_mwi(dev);
if (this->restore_intx)
pci_intx(dev, this->orig_intx);
if (this->enabled && !this->pinned)
pci_disable_device(dev);
}
static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
{
struct pci_devres *dr, *new_dr;
dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
if (dr)
return dr;
new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
if (!new_dr)
return NULL;
return devres_get(&pdev->dev, new_dr, NULL, NULL);
}
static struct pci_devres *find_pci_dr(struct pci_dev *pdev)
{
if (pci_is_managed(pdev))
return devres_find(&pdev->dev, pcim_release, NULL, NULL);
return NULL;
}
/**
* pcim_enable_device - Managed pci_enable_device()
* @pdev: PCI device to be initialized
*
* Managed pci_enable_device().
*/
int pcim_enable_device(struct pci_dev *pdev)
{
struct pci_devres *dr;
int rc;
dr = get_pci_dr(pdev);
if (unlikely(!dr))
return -ENOMEM;
if (dr->enabled)
return 0;
rc = pci_enable_device(pdev);
if (!rc) {
pdev->is_managed = 1;
dr->enabled = 1;
}
return rc;
}
EXPORT_SYMBOL(pcim_enable_device);
/**
* pcim_pin_device - Pin managed PCI device
* @pdev: PCI device to pin
*
* Pin managed PCI device @pdev. Pinned device won't be disabled on
* driver detach. @pdev must have been enabled with
* pcim_enable_device().
*/
void pcim_pin_device(struct pci_dev *pdev)
{
struct pci_devres *dr;
dr = find_pci_dr(pdev);
WARN_ON(!dr || !dr->enabled);
if (dr)
dr->pinned = 1;
}
EXPORT_SYMBOL(pcim_pin_device);
/*
* pcibios_add_device - provide arch specific hooks when adding device dev
* @dev: the PCI device being added
*
* Permits the platform to provide architecture specific functionality when
* devices are added. This is the default implementation. Architecture
* implementations can override this.
*/
int __weak pcibios_add_device(struct pci_dev *dev)
{
return 0;
}
/**
* pcibios_release_device - provide arch specific hooks when releasing
* device dev
* @dev: the PCI device being released
*
* Permits the platform to provide architecture specific functionality when
* devices are released. This is the default implementation. Architecture
* implementations can override this.
*/
void __weak pcibios_release_device(struct pci_dev *dev) {}
/**
* pcibios_disable_device - disable arch specific PCI resources for device dev
* @dev: the PCI device to disable
*
* Disables architecture specific PCI resources for the device. This
* is the default implementation. Architecture implementations can
* override this.
*/
void __weak pcibios_disable_device(struct pci_dev *dev) {}
/**
* pcibios_penalize_isa_irq - penalize an ISA IRQ
* @irq: ISA IRQ to penalize
* @active: IRQ active or not
*
* Permits the platform to provide architecture-specific functionality when
* penalizing ISA IRQs. This is the default implementation. Architecture
* implementations can override this.
*/
void __weak pcibios_penalize_isa_irq(int irq, int active) {}
static void do_pci_disable_device(struct pci_dev *dev)
{
u16 pci_command;
pci_read_config_word(dev, PCI_COMMAND, &pci_command);
if (pci_command & PCI_COMMAND_MASTER) {
pci_command &= ~PCI_COMMAND_MASTER;
pci_write_config_word(dev, PCI_COMMAND, pci_command);
}
pcibios_disable_device(dev);
}
/**
* pci_disable_enabled_device - Disable device without updating enable_cnt
* @dev: PCI device to disable
*
* NOTE: This function is a backend of PCI power management routines and is
* not supposed to be called drivers.
*/
void pci_disable_enabled_device(struct pci_dev *dev)
{
if (pci_is_enabled(dev))
do_pci_disable_device(dev);
}
/**
* pci_disable_device - Disable PCI device after use
* @dev: PCI device to be disabled
*
* Signal to the system that the PCI device is not in use by the system
* anymore. This only involves disabling PCI bus-mastering, if active.
*
* Note we don't actually disable the device until all callers of
* pci_enable_device() have called pci_disable_device().
*/
void pci_disable_device(struct pci_dev *dev)
{
struct pci_devres *dr;
dr = find_pci_dr(dev);
if (dr)
dr->enabled = 0;
dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
"disabling already-disabled device");
if (atomic_dec_return(&dev->enable_cnt) != 0)
return;
do_pci_disable_device(dev);
dev->is_busmaster = 0;
}
EXPORT_SYMBOL(pci_disable_device);
/**
* pcibios_set_pcie_reset_state - set reset state for device dev
* @dev: the PCIe device reset
* @state: Reset state to enter into
*
* Set the PCIe reset state for the device. This is the default
* implementation. Architecture implementations can override this.
*/
int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
enum pcie_reset_state state)
{
return -EINVAL;
}
/**
* pci_set_pcie_reset_state - set reset state for device dev
* @dev: the PCIe device reset
* @state: Reset state to enter into
*
* Sets the PCI reset state for the device.
*/
int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
{
return pcibios_set_pcie_reset_state(dev, state);
}
EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
/**
* pcie_clear_root_pme_status - Clear root port PME interrupt status.
* @dev: PCIe root port or event collector.
*/
void pcie_clear_root_pme_status(struct pci_dev *dev)
{
pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
}
/**
* pci_check_pme_status - Check if given device has generated PME.
* @dev: Device to check.
*
* Check the PME status of the device and if set, clear it and clear PME enable
* (if set). Return 'true' if PME status and PME enable were both set or
* 'false' otherwise.
*/
bool pci_check_pme_status(struct pci_dev *dev)
{
int pmcsr_pos;
u16 pmcsr;
bool ret = false;
if (!dev->pm_cap)
return false;
pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
pci_read_config_word(dev, pmcsr_pos, &pmcsr);
if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
return false;
/* Clear PME status. */
pmcsr |= PCI_PM_CTRL_PME_STATUS;
if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
/* Disable PME to avoid interrupt flood. */
pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
ret = true;
}
pci_write_config_word(dev, pmcsr_pos, pmcsr);
return ret;
}
/**
* pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
* @dev: Device to handle.
* @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
*
* Check if @dev has generated PME and queue a resume request for it in that
* case.
*/
static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
{
if (pme_poll_reset && dev->pme_poll)
dev->pme_poll = false;
if (pci_check_pme_status(dev)) {
pci_wakeup_event(dev);
pm_request_resume(&dev->dev);
}
return 0;
}
/**
* pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
* @bus: Top bus of the subtree to walk.
*/
void pci_pme_wakeup_bus(struct pci_bus *bus)
{
if (bus)
pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
}
/**
* pci_pme_capable - check the capability of PCI device to generate PME#
* @dev: PCI device to handle.
* @state: PCI state from which device will issue PME#.
*/
bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
{
if (!dev->pm_cap)
return false;
return !!(dev->pme_support & (1 << state));
}
EXPORT_SYMBOL(pci_pme_capable);
static void pci_pme_list_scan(struct work_struct *work)
{
struct pci_pme_device *pme_dev, *n;
mutex_lock(&pci_pme_list_mutex);
list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
if (pme_dev->dev->pme_poll) {
struct pci_dev *bridge;
bridge = pme_dev->dev->bus->self;
/*
* If bridge is in low power state, the
* configuration space of subordinate devices
* may be not accessible
*/
if (bridge && bridge->current_state != PCI_D0)
continue;
/*
* If the device is in D3cold it should not be
* polled either.
*/
if (pme_dev->dev->current_state == PCI_D3cold)
continue;
pci_pme_wakeup(pme_dev->dev, NULL);
} else {
list_del(&pme_dev->list);
kfree(pme_dev);
}
}
if (!list_empty(&pci_pme_list))
queue_delayed_work(system_freezable_wq, &pci_pme_work,
msecs_to_jiffies(PME_TIMEOUT));
mutex_unlock(&pci_pme_list_mutex);
}
static void __pci_pme_active(struct pci_dev *dev, bool enable)
{
u16 pmcsr;
if (!dev->pme_support)
return;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
/* Clear PME_Status by writing 1 to it and enable PME# */
pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
if (!enable)
pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
}
/**
* pci_pme_restore - Restore PME configuration after config space restore.
* @dev: PCI device to update.
*/
void pci_pme_restore(struct pci_dev *dev)
{
u16 pmcsr;
if (!dev->pme_support)
return;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
if (dev->wakeup_prepared) {
pmcsr |= PCI_PM_CTRL_PME_ENABLE;
pmcsr &= ~PCI_PM_CTRL_PME_STATUS;
} else {
pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
pmcsr |= PCI_PM_CTRL_PME_STATUS;
}
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
}
/**
* pci_pme_active - enable or disable PCI device's PME# function
* @dev: PCI device to handle.
* @enable: 'true' to enable PME# generation; 'false' to disable it.
*
* The caller must verify that the device is capable of generating PME# before
* calling this function with @enable equal to 'true'.
*/
void pci_pme_active(struct pci_dev *dev, bool enable)
{
__pci_pme_active(dev, enable);
/*
* PCI (as opposed to PCIe) PME requires that the device have
* its PME# line hooked up correctly. Not all hardware vendors
* do this, so the PME never gets delivered and the device
* remains asleep. The easiest way around this is to
* periodically walk the list of suspended devices and check
* whether any have their PME flag set. The assumption is that
* we'll wake up often enough anyway that this won't be a huge
* hit, and the power savings from the devices will still be a
* win.
*
* Although PCIe uses in-band PME message instead of PME# line
* to report PME, PME does not work for some PCIe devices in
* reality. For example, there are devices that set their PME
* status bits, but don't really bother to send a PME message;
* there are PCI Express Root Ports that don't bother to
* trigger interrupts when they receive PME messages from the
* devices below. So PME poll is used for PCIe devices too.
*/
if (dev->pme_poll) {
struct pci_pme_device *pme_dev;
if (enable) {
pme_dev = kmalloc(sizeof(struct pci_pme_device),
GFP_KERNEL);
if (!pme_dev) {
pci_warn(dev, "can't enable PME#\n");
return;
}
pme_dev->dev = dev;
mutex_lock(&pci_pme_list_mutex);
list_add(&pme_dev->list, &pci_pme_list);
if (list_is_singular(&pci_pme_list))
queue_delayed_work(system_freezable_wq,
&pci_pme_work,
msecs_to_jiffies(PME_TIMEOUT));
mutex_unlock(&pci_pme_list_mutex);
} else {
mutex_lock(&pci_pme_list_mutex);
list_for_each_entry(pme_dev, &pci_pme_list, list) {
if (pme_dev->dev == dev) {
list_del(&pme_dev->list);
kfree(pme_dev);
break;
}
}
mutex_unlock(&pci_pme_list_mutex);
}
}
pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled");
}
EXPORT_SYMBOL(pci_pme_active);
/**
* __pci_enable_wake - enable PCI device as wakeup event source
* @dev: PCI device affected
* @state: PCI state from which device will issue wakeup events
* @enable: True to enable event generation; false to disable
*
* This enables the device as a wakeup event source, or disables it.
* When such events involves platform-specific hooks, those hooks are
* called automatically by this routine.
*
* Devices with legacy power management (no standard PCI PM capabilities)
* always require such platform hooks.
*
* RETURN VALUE:
* 0 is returned on success
* -EINVAL is returned if device is not supposed to wake up the system
* Error code depending on the platform is returned if both the platform and
* the native mechanism fail to enable the generation of wake-up events
*/
static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
{
int ret = 0;
/*
* Bridges that are not power-manageable directly only signal
* wakeup on behalf of subordinate devices which is set up
* elsewhere, so skip them. However, bridges that are
* power-manageable may signal wakeup for themselves (for example,
* on a hotplug event) and they need to be covered here.
*/
if (!pci_power_manageable(dev))
return 0;
/* Don't do the same thing twice in a row for one device. */
if (!!enable == !!dev->wakeup_prepared)
return 0;
/*
* According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
* Anderson we should be doing PME# wake enable followed by ACPI wake
* enable. To disable wake-up we call the platform first, for symmetry.
*/
if (enable) {
int error;
if (pci_pme_capable(dev, state))
pci_pme_active(dev, true);
else
ret = 1;
error = platform_pci_set_wakeup(dev, true);
if (ret)
ret = error;
if (!ret)
dev->wakeup_prepared = true;
} else {
platform_pci_set_wakeup(dev, false);
pci_pme_active(dev, false);
dev->wakeup_prepared = false;
}
return ret;
}
/**
* pci_enable_wake - change wakeup settings for a PCI device
* @pci_dev: Target device
* @state: PCI state from which device will issue wakeup events
* @enable: Whether or not to enable event generation
*
* If @enable is set, check device_may_wakeup() for the device before calling
* __pci_enable_wake() for it.
*/
int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable)
{
if (enable && !device_may_wakeup(&pci_dev->dev))
return -EINVAL;
return __pci_enable_wake(pci_dev, state, enable);
}
EXPORT_SYMBOL(pci_enable_wake);
/**
* pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
* @dev: PCI device to prepare
* @enable: True to enable wake-up event generation; false to disable
*
* Many drivers want the device to wake up the system from D3_hot or D3_cold
* and this function allows them to set that up cleanly - pci_enable_wake()
* should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
* ordering constraints.
*
* This function only returns error code if the device is not allowed to wake
* up the system from sleep or it is not capable of generating PME# from both
* D3_hot and D3_cold and the platform is unable to enable wake-up power for it.
*/
int pci_wake_from_d3(struct pci_dev *dev, bool enable)
{
return pci_pme_capable(dev, PCI_D3cold) ?
pci_enable_wake(dev, PCI_D3cold, enable) :
pci_enable_wake(dev, PCI_D3hot, enable);
}
EXPORT_SYMBOL(pci_wake_from_d3);
/**
* pci_target_state - find an appropriate low power state for a given PCI dev
* @dev: PCI device
* @wakeup: Whether or not wakeup functionality will be enabled for the device.
*
* Use underlying platform code to find a supported low power state for @dev.
* If the platform can't manage @dev, return the deepest state from which it
* can generate wake events, based on any available PME info.
*/
static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
{
pci_power_t target_state = PCI_D3hot;
if (platform_pci_power_manageable(dev)) {
/*
* Call the platform to find the target state for the device.
*/
pci_power_t state = platform_pci_choose_state(dev);
switch (state) {
case PCI_POWER_ERROR:
case PCI_UNKNOWN:
break;
case PCI_D1:
case PCI_D2:
if (pci_no_d1d2(dev))
break;
/* else, fall through */
default:
target_state = state;
}
return target_state;
}
if (!dev->pm_cap)
target_state = PCI_D0;
/*
* If the device is in D3cold even though it's not power-manageable by
* the platform, it may have been powered down by non-standard means.
* Best to let it slumber.
*/
if (dev->current_state == PCI_D3cold)
target_state = PCI_D3cold;
if (wakeup) {
/*
* Find the deepest state from which the device can generate
* PME#.
*/
if (dev->pme_support) {
while (target_state
&& !(dev->pme_support & (1 << target_state)))
target_state--;
}
}
return target_state;
}
/**
* pci_prepare_to_sleep - prepare PCI device for system-wide transition
* into a sleep state
* @dev: Device to handle.
*
* Choose the power state appropriate for the device depending on whether
* it can wake up the system and/or is power manageable by the platform
* (PCI_D3hot is the default) and put the device into that state.
*/
int pci_prepare_to_sleep(struct pci_dev *dev)
{
bool wakeup = device_may_wakeup(&dev->dev);
pci_power_t target_state = pci_target_state(dev, wakeup);
int error;
if (target_state == PCI_POWER_ERROR)
return -EIO;
pci_enable_wake(dev, target_state, wakeup);
error = pci_set_power_state(dev, target_state);
if (error)
pci_enable_wake(dev, target_state, false);
return error;
}
EXPORT_SYMBOL(pci_prepare_to_sleep);
/**
* pci_back_from_sleep - turn PCI device on during system-wide transition
* into working state
* @dev: Device to handle.
*
* Disable device's system wake-up capability and put it into D0.
*/
int pci_back_from_sleep(struct pci_dev *dev)
{
pci_enable_wake(dev, PCI_D0, false);
return pci_set_power_state(dev, PCI_D0);
}
EXPORT_SYMBOL(pci_back_from_sleep);
/**
* pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
* @dev: PCI device being suspended.
*
* Prepare @dev to generate wake-up events at run time and put it into a low
* power state.
*/
int pci_finish_runtime_suspend(struct pci_dev *dev)
{
pci_power_t target_state;
int error;
target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
if (target_state == PCI_POWER_ERROR)
return -EIO;
dev->runtime_d3cold = target_state == PCI_D3cold;
__pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
error = pci_set_power_state(dev, target_state);
if (error) {
pci_enable_wake(dev, target_state, false);
dev->runtime_d3cold = false;
}
return error;
}
/**
* pci_dev_run_wake - Check if device can generate run-time wake-up events.
* @dev: Device to check.
*
* Return true if the device itself is capable of generating wake-up events
* (through the platform or using the native PCIe PME) or if the device supports
* PME and one of its upstream bridges can generate wake-up events.
*/
bool pci_dev_run_wake(struct pci_dev *dev)
{
struct pci_bus *bus = dev->bus;
if (!dev->pme_support)
return false;
/* PME-capable in principle, but not from the target power state */
if (!pci_pme_capable(dev, pci_target_state(dev, true)))
return false;
if (device_can_wakeup(&dev->dev))
return true;
while (bus->parent) {
struct pci_dev *bridge = bus->self;
if (device_can_wakeup(&bridge->dev))
return true;
bus = bus->parent;
}
/* We have reached the root bus. */
if (bus->bridge)
return device_can_wakeup(bus->bridge);
return false;
}
EXPORT_SYMBOL_GPL(pci_dev_run_wake);
/**
* pci_dev_need_resume - Check if it is necessary to resume the device.
* @pci_dev: Device to check.
*
* Return 'true' if the device is not runtime-suspended or it has to be
* reconfigured due to wakeup settings difference between system and runtime
* suspend, or the current power state of it is not suitable for the upcoming
* (system-wide) transition.
*/
bool pci_dev_need_resume(struct pci_dev *pci_dev)
{
struct device *dev = &pci_dev->dev;
pci_power_t target_state;
if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev))
return true;
target_state = pci_target_state(pci_dev, device_may_wakeup(dev));
/*
* If the earlier platform check has not triggered, D3cold is just power
* removal on top of D3hot, so no need to resume the device in that
* case.
*/
return target_state != pci_dev->current_state &&
target_state != PCI_D3cold &&
pci_dev->current_state != PCI_D3hot;
}
/**
* pci_dev_adjust_pme - Adjust PME setting for a suspended device.
* @pci_dev: Device to check.
*
* If the device is suspended and it is not configured for system wakeup,
* disable PME for it to prevent it from waking up the system unnecessarily.
*
* Note that if the device's power state is D3cold and the platform check in
* pci_dev_need_resume() has not triggered, the device's configuration need not
* be changed.
*/
void pci_dev_adjust_pme(struct pci_dev *pci_dev)
{
struct device *dev = &pci_dev->dev;
spin_lock_irq(&dev->power.lock);
if (pm_runtime_suspended(dev) && !device_may_wakeup(dev) &&
pci_dev->current_state < PCI_D3cold)
__pci_pme_active(pci_dev, false);
spin_unlock_irq(&dev->power.lock);
}
/**
* pci_dev_complete_resume - Finalize resume from system sleep for a device.
* @pci_dev: Device to handle.
*
* If the device is runtime suspended and wakeup-capable, enable PME for it as
* it might have been disabled during the prepare phase of system suspend if
* the device was not configured for system wakeup.
*/
void pci_dev_complete_resume(struct pci_dev *pci_dev)
{
struct device *dev = &pci_dev->dev;
if (!pci_dev_run_wake(pci_dev))
return;
spin_lock_irq(&dev->power.lock);
if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold)
__pci_pme_active(pci_dev, true);
spin_unlock_irq(&dev->power.lock);
}
void pci_config_pm_runtime_get(struct pci_dev *pdev)
{
struct device *dev = &pdev->dev;
struct device *parent = dev->parent;
if (parent)
pm_runtime_get_sync(parent);
pm_runtime_get_noresume(dev);
/*
* pdev->current_state is set to PCI_D3cold during suspending,
* so wait until suspending completes
*/
pm_runtime_barrier(dev);
/*
* Only need to resume devices in D3cold, because config
* registers are still accessible for devices suspended but
* not in D3cold.
*/
if (pdev->current_state == PCI_D3cold)
pm_runtime_resume(dev);
}
void pci_config_pm_runtime_put(struct pci_dev *pdev)
{
struct device *dev = &pdev->dev;
struct device *parent = dev->parent;
pm_runtime_put(dev);
if (parent)
pm_runtime_put_sync(parent);
}
static const struct dmi_system_id bridge_d3_blacklist[] = {
#ifdef CONFIG_X86
{
/*
* Gigabyte X299 root port is not marked as hotplug capable
* which allows Linux to power manage it. However, this
* confuses the BIOS SMI handler so don't power manage root
* ports on that system.
*/
.ident = "X299 DESIGNARE EX-CF",
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
DMI_MATCH(DMI_BOARD_NAME, "X299 DESIGNARE EX-CF"),
},
},
#endif
{ }
};
/**
* pci_bridge_d3_possible - Is it possible to put the bridge into D3
* @bridge: Bridge to check
*
* This function checks if it is possible to move the bridge to D3.
* Currently we only allow D3 for recent enough PCIe ports and Thunderbolt.
*/
bool pci_bridge_d3_possible(struct pci_dev *bridge)
{
if (!pci_is_pcie(bridge))
return false;
switch (pci_pcie_type(bridge)) {
case PCI_EXP_TYPE_ROOT_PORT:
case PCI_EXP_TYPE_UPSTREAM:
case PCI_EXP_TYPE_DOWNSTREAM:
if (pci_bridge_d3_disable)
return false;
/*
* Hotplug ports handled by firmware in System Management Mode
* may not be put into D3 by the OS (Thunderbolt on non-Macs).
*/
if (bridge->is_hotplug_bridge && !pciehp_is_native(bridge))
return false;
if (pci_bridge_d3_force)
return true;
/* Even the oldest 2010 Thunderbolt controller supports D3. */
if (bridge->is_thunderbolt)
return true;
/* Platform might know better if the bridge supports D3 */
if (platform_pci_bridge_d3(bridge))
return true;
/*
* Hotplug ports handled natively by the OS were not validated
* by vendors for runtime D3 at least until 2018 because there
* was no OS support.
*/
if (bridge->is_hotplug_bridge)
return false;
if (dmi_check_system(bridge_d3_blacklist))
return false;
/*
* It should be safe to put PCIe ports from 2015 or newer
* to D3.
*/
if (dmi_get_bios_year() >= 2015)
return true;
break;
}
return false;
}
static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
{
bool *d3cold_ok = data;
if (/* The device needs to be allowed to go D3cold ... */
dev->no_d3cold || !dev->d3cold_allowed ||
/* ... and if it is wakeup capable to do so from D3cold. */
(device_may_wakeup(&dev->dev) &&
!pci_pme_capable(dev, PCI_D3cold)) ||
/* If it is a bridge it must be allowed to go to D3. */
!pci_power_manageable(dev))
*d3cold_ok = false;
return !*d3cold_ok;
}
/*
* pci_bridge_d3_update - Update bridge D3 capabilities
* @dev: PCI device which is changed
*
* Update upstream bridge PM capabilities accordingly depending on if the
* device PM configuration was changed or the device is being removed. The
* change is also propagated upstream.
*/
void pci_bridge_d3_update(struct pci_dev *dev)
{
bool remove = !device_is_registered(&dev->dev);
struct pci_dev *bridge;
bool d3cold_ok = true;
bridge = pci_upstream_bridge(dev);
if (!bridge || !pci_bridge_d3_possible(bridge))
return;
/*
* If D3 is currently allowed for the bridge, removing one of its
* children won't change that.
*/
if (remove && bridge->bridge_d3)
return;
/*
* If D3 is currently allowed for the bridge and a child is added or
* changed, disallowance of D3 can only be caused by that child, so
* we only need to check that single device, not any of its siblings.
*
* If D3 is currently not allowed for the bridge, checking the device
* first may allow us to skip checking its siblings.
*/
if (!remove)
pci_dev_check_d3cold(dev, &d3cold_ok);
/*
* If D3 is currently not allowed for the bridge, this may be caused
* either by the device being changed/removed or any of its siblings,
* so we need to go through all children to find out if one of them
* continues to block D3.
*/
if (d3cold_ok && !bridge->bridge_d3)
pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
&d3cold_ok);
if (bridge->bridge_d3 != d3cold_ok) {
bridge->bridge_d3 = d3cold_ok;
/* Propagate change to upstream bridges */
pci_bridge_d3_update(bridge);
}
}
/**
* pci_d3cold_enable - Enable D3cold for device
* @dev: PCI device to handle
*
* This function can be used in drivers to enable D3cold from the device
* they handle. It also updates upstream PCI bridge PM capabilities
* accordingly.
*/
void pci_d3cold_enable(struct pci_dev *dev)
{
if (dev->no_d3cold) {
dev->no_d3cold = false;
pci_bridge_d3_update(dev);
}
}
EXPORT_SYMBOL_GPL(pci_d3cold_enable);
/**
* pci_d3cold_disable - Disable D3cold for device
* @dev: PCI device to handle
*
* This function can be used in drivers to disable D3cold from the device
* they handle. It also updates upstream PCI bridge PM capabilities
* accordingly.
*/
void pci_d3cold_disable(struct pci_dev *dev)
{
if (!dev->no_d3cold) {
dev->no_d3cold = true;
pci_bridge_d3_update(dev);
}
}
EXPORT_SYMBOL_GPL(pci_d3cold_disable);
/**
* pci_pm_init - Initialize PM functions of given PCI device
* @dev: PCI device to handle.
*/
void pci_pm_init(struct pci_dev *dev)
{
int pm;
u16 status;
u16 pmc;
pm_runtime_forbid(&dev->dev);
pm_runtime_set_active(&dev->dev);
pm_runtime_enable(&dev->dev);
device_enable_async_suspend(&dev->dev);
dev->wakeup_prepared = false;
dev->pm_cap = 0;
dev->pme_support = 0;
/* find PCI PM capability in list */
pm = pci_find_capability(dev, PCI_CAP_ID_PM);
if (!pm)
return;
/* Check device's ability to generate PME# */
pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
pci_err(dev, "unsupported PM cap regs version (%u)\n",
pmc & PCI_PM_CAP_VER_MASK);
return;
}
dev->pm_cap = pm;
dev->d3_delay = PCI_PM_D3_WAIT;
dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
dev->bridge_d3 = pci_bridge_d3_possible(dev);
dev->d3cold_allowed = true;
dev->d1_support = false;
dev->d2_support = false;
if (!pci_no_d1d2(dev)) {
if (pmc & PCI_PM_CAP_D1)
dev->d1_support = true;
if (pmc & PCI_PM_CAP_D2)
dev->d2_support = true;
if (dev->d1_support || dev->d2_support)
pci_info(dev, "supports%s%s\n",
dev->d1_support ? " D1" : "",
dev->d2_support ? " D2" : "");
}
pmc &= PCI_PM_CAP_PME_MASK;
if (pmc) {
pci_info(dev, "PME# supported from%s%s%s%s%s\n",
(pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
(pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
(pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
(pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
(pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
dev->pme_poll = true;
/*
* Make device's PM flags reflect the wake-up capability, but
* let the user space enable it to wake up the system as needed.
*/
device_set_wakeup_capable(&dev->dev, true);
/* Disable the PME# generation functionality */
pci_pme_active(dev, false);
}
pci_read_config_word(dev, PCI_STATUS, &status);
if (status & PCI_STATUS_IMM_READY)
dev->imm_ready = 1;
}
static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
{
unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI;
switch (prop) {
case PCI_EA_P_MEM:
case PCI_EA_P_VF_MEM:
flags |= IORESOURCE_MEM;
break;
case PCI_EA_P_MEM_PREFETCH:
case PCI_EA_P_VF_MEM_PREFETCH:
flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
break;
case PCI_EA_P_IO:
flags |= IORESOURCE_IO;
break;
default:
return 0;
}
return flags;
}
static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei,
u8 prop)
{
if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO)
return &dev->resource[bei];
#ifdef CONFIG_PCI_IOV
else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 &&
(prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH))
return &dev->resource[PCI_IOV_RESOURCES +
bei - PCI_EA_BEI_VF_BAR0];
#endif
else if (bei == PCI_EA_BEI_ROM)
return &dev->resource[PCI_ROM_RESOURCE];
else
return NULL;
}
/* Read an Enhanced Allocation (EA) entry */
static int pci_ea_read(struct pci_dev *dev, int offset)
{
struct resource *res;
int ent_size, ent_offset = offset;
resource_size_t start, end;
unsigned long flags;
u32 dw0, bei, base, max_offset;
u8 prop;
bool support_64 = (sizeof(resource_size_t) >= 8);
pci_read_config_dword(dev, ent_offset, &dw0);
ent_offset += 4;
/* Entry size field indicates DWORDs after 1st */
ent_size = ((dw0 & PCI_EA_ES) + 1) << 2;
if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
goto out;
bei = (dw0 & PCI_EA_BEI) >> 4;
prop = (dw0 & PCI_EA_PP) >> 8;
/*
* If the Property is in the reserved range, try the Secondary
* Property instead.
*/
if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
prop = (dw0 & PCI_EA_SP) >> 16;
if (prop > PCI_EA_P_BRIDGE_IO)
goto out;
res = pci_ea_get_resource(dev, bei, prop);
if (!res) {
pci_err(dev, "Unsupported EA entry BEI: %u\n", bei);
goto out;
}
flags = pci_ea_flags(dev, prop);
if (!flags) {
pci_err(dev, "Unsupported EA properties: %#x\n", prop);
goto out;
}
/* Read Base */
pci_read_config_dword(dev, ent_offset, &base);
start = (base & PCI_EA_FIELD_MASK);
ent_offset += 4;
/* Read MaxOffset */
pci_read_config_dword(dev, ent_offset, &max_offset);
ent_offset += 4;
/* Read Base MSBs (if 64-bit entry) */
if (base & PCI_EA_IS_64) {
u32 base_upper;
pci_read_config_dword(dev, ent_offset, &base_upper);
ent_offset += 4;
flags |= IORESOURCE_MEM_64;
/* entry starts above 32-bit boundary, can't use */
if (!support_64 && base_upper)
goto out;
if (support_64)
start |= ((u64)base_upper << 32);
}
end = start + (max_offset | 0x03);
/* Read MaxOffset MSBs (if 64-bit entry) */
if (max_offset & PCI_EA_IS_64) {
u32 max_offset_upper;
pci_read_config_dword(dev, ent_offset, &max_offset_upper);
ent_offset += 4;
flags |= IORESOURCE_MEM_64;
/* entry too big, can't use */
if (!support_64 && max_offset_upper)
goto out;
if (support_64)
end += ((u64)max_offset_upper << 32);
}
if (end < start) {
pci_err(dev, "EA Entry crosses address boundary\n");
goto out;
}
if (ent_size != ent_offset - offset) {
pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n",
ent_size, ent_offset - offset);
goto out;
}
res->name = pci_name(dev);
res->start = start;
res->end = end;
res->flags = flags;
if (bei <= PCI_EA_BEI_BAR5)
pci_info(dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
bei, res, prop);
else if (bei == PCI_EA_BEI_ROM)
pci_info(dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n",
res, prop);
else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5)
pci_info(dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
bei - PCI_EA_BEI_VF_BAR0, res, prop);
else
pci_info(dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n",
bei, res, prop);
out:
return offset + ent_size;
}
/* Enhanced Allocation Initialization */
void pci_ea_init(struct pci_dev *dev)
{
int ea;
u8 num_ent;
int offset;
int i;
/* find PCI EA capability in list */
ea = pci_find_capability(dev, PCI_CAP_ID_EA);
if (!ea)
return;
/* determine the number of entries */
pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT,
&num_ent);
num_ent &= PCI_EA_NUM_ENT_MASK;
offset = ea + PCI_EA_FIRST_ENT;
/* Skip DWORD 2 for type 1 functions */
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
offset += 4;
/* parse each EA entry */
for (i = 0; i < num_ent; ++i)
offset = pci_ea_read(dev, offset);
}
static void pci_add_saved_cap(struct pci_dev *pci_dev,
struct pci_cap_saved_state *new_cap)
{
hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
}
/**
* _pci_add_cap_save_buffer - allocate buffer for saving given
* capability registers
* @dev: the PCI device
* @cap: the capability to allocate the buffer for
* @extended: Standard or Extended capability ID
* @size: requested size of the buffer
*/
static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap,
bool extended, unsigned int size)
{
int pos;
struct pci_cap_saved_state *save_state;
if (extended)
pos = pci_find_ext_capability(dev, cap);
else
pos = pci_find_capability(dev, cap);
if (!pos)
return 0;
save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
if (!save_state)
return -ENOMEM;
save_state->cap.cap_nr = cap;
save_state->cap.cap_extended = extended;
save_state->cap.size = size;
pci_add_saved_cap(dev, save_state);
return 0;
}
int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size)
{
return _pci_add_cap_save_buffer(dev, cap, false, size);
}
int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size)
{
return _pci_add_cap_save_buffer(dev, cap, true, size);
}
/**
* pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
* @dev: the PCI device
*/
void pci_allocate_cap_save_buffers(struct pci_dev *dev)
{
int error;
error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
PCI_EXP_SAVE_REGS * sizeof(u16));
if (error)
pci_err(dev, "unable to preallocate PCI Express save buffer\n");
error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
if (error)
pci_err(dev, "unable to preallocate PCI-X save buffer\n");
error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR,
2 * sizeof(u16));
if (error)
pci_err(dev, "unable to allocate suspend buffer for LTR\n");
pci_allocate_vc_save_buffers(dev);
}
void pci_free_cap_save_buffers(struct pci_dev *dev)
{
struct pci_cap_saved_state *tmp;
struct hlist_node *n;
hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next)
kfree(tmp);
}
/**
* pci_configure_ari - enable or disable ARI forwarding
* @dev: the PCI device
*
* If @dev and its upstream bridge both support ARI, enable ARI in the
* bridge. Otherwise, disable ARI in the bridge.
*/
void pci_configure_ari(struct pci_dev *dev)
{
u32 cap;
struct pci_dev *bridge;
if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
return;
bridge = dev->bus->self;
if (!bridge)
return;
pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
if (!(cap & PCI_EXP_DEVCAP2_ARI))
return;
if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_ARI);
bridge->ari_enabled = 1;
} else {
pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_ARI);
bridge->ari_enabled = 0;
}
}
static int pci_acs_enable;
/**
* pci_request_acs - ask for ACS to be enabled if supported
*/
void pci_request_acs(void)
{
pci_acs_enable = 1;
}
static const char *disable_acs_redir_param;
/**
* pci_disable_acs_redir - disable ACS redirect capabilities
* @dev: the PCI device
*
* For only devices specified in the disable_acs_redir parameter.
*/
static void pci_disable_acs_redir(struct pci_dev *dev)
{
int ret = 0;
const char *p;
int pos;
u16 ctrl;
if (!disable_acs_redir_param)
return;
p = disable_acs_redir_param;
while (*p) {
ret = pci_dev_str_match(dev, p, &p);
if (ret < 0) {
pr_info_once("PCI: Can't parse disable_acs_redir parameter: %s\n",
disable_acs_redir_param);
break;
} else if (ret == 1) {
/* Found a match */
break;
}
if (*p != ';' && *p != ',') {
/* End of param or invalid format */
break;
}
p++;
}
if (ret != 1)
return;
if (!pci_dev_specific_disable_acs_redir(dev))
return;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
if (!pos) {
pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n");
return;
}
pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
/* P2P Request & Completion Redirect */
ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC);
pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
pci_info(dev, "disabled ACS redirect\n");
}
/**
* pci_std_enable_acs - enable ACS on devices using standard ACS capabilities
* @dev: the PCI device
*/
static void pci_std_enable_acs(struct pci_dev *dev)
{
int pos;
u16 cap;
u16 ctrl;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
if (!pos)
return;
pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
/* Source Validation */
ctrl |= (cap & PCI_ACS_SV);
/* P2P Request Redirect */
ctrl |= (cap & PCI_ACS_RR);
/* P2P Completion Redirect */
ctrl |= (cap & PCI_ACS_CR);
/* Upstream Forwarding */
ctrl |= (cap & PCI_ACS_UF);
pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
}
/**
* pci_enable_acs - enable ACS if hardware support it
* @dev: the PCI device
*/
void pci_enable_acs(struct pci_dev *dev)
{
if (!pci_acs_enable)
goto disable_acs_redir;
if (!pci_dev_specific_enable_acs(dev))
goto disable_acs_redir;
pci_std_enable_acs(dev);
disable_acs_redir:
/*
* Note: pci_disable_acs_redir() must be called even if ACS was not
* enabled by the kernel because it may have been enabled by
* platform firmware. So if we are told to disable it, we should
* always disable it after setting the kernel's default
* preferences.
*/
pci_disable_acs_redir(dev);
}
static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
{
int pos;
u16 cap, ctrl;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
if (!pos)
return false;
/*
* Except for egress control, capabilities are either required
* or only required if controllable. Features missing from the
* capability field can therefore be assumed as hard-wired enabled.
*/
pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap);
acs_flags &= (cap | PCI_ACS_EC);
pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
return (ctrl & acs_flags) == acs_flags;
}
/**
* pci_acs_enabled - test ACS against required flags for a given device
* @pdev: device to test
* @acs_flags: required PCI ACS flags
*
* Return true if the device supports the provided flags. Automatically
* filters out flags that are not implemented on multifunction devices.
*
* Note that this interface checks the effective ACS capabilities of the
* device rather than the actual capabilities. For instance, most single
* function endpoints are not required to support ACS because they have no
* opportunity for peer-to-peer access. We therefore return 'true'
* regardless of whether the device exposes an ACS capability. This makes
* it much easier for callers of this function to ignore the actual type
* or topology of the device when testing ACS support.
*/
bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
{
int ret;
ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
if (ret >= 0)
return ret > 0;
/*
* Conventional PCI and PCI-X devices never support ACS, either
* effectively or actually. The shared bus topology implies that
* any device on the bus can receive or snoop DMA.
*/
if (!pci_is_pcie(pdev))
return false;
switch (pci_pcie_type(pdev)) {
/*
* PCI/X-to-PCIe bridges are not specifically mentioned by the spec,
* but since their primary interface is PCI/X, we conservatively
* handle them as we would a non-PCIe device.
*/
case PCI_EXP_TYPE_PCIE_BRIDGE:
/*
* PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never
* applicable... must never implement an ACS Extended Capability...".
* This seems arbitrary, but we take a conservative interpretation
* of this statement.
*/
case PCI_EXP_TYPE_PCI_BRIDGE:
case PCI_EXP_TYPE_RC_EC:
return false;
/*
* PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should
* implement ACS in order to indicate their peer-to-peer capabilities,
* regardless of whether they are single- or multi-function devices.
*/
case PCI_EXP_TYPE_DOWNSTREAM:
case PCI_EXP_TYPE_ROOT_PORT:
return pci_acs_flags_enabled(pdev, acs_flags);
/*
* PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be
* implemented by the remaining PCIe types to indicate peer-to-peer
* capabilities, but only when they are part of a multifunction
* device. The footnote for section 6.12 indicates the specific
* PCIe types included here.
*/
case PCI_EXP_TYPE_ENDPOINT:
case PCI_EXP_TYPE_UPSTREAM:
case PCI_EXP_TYPE_LEG_END:
case PCI_EXP_TYPE_RC_END:
if (!pdev->multifunction)
break;
return pci_acs_flags_enabled(pdev, acs_flags);
}
/*
* PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable
* to single function devices with the exception of downstream ports.
*/
return true;
}
/**
* pci_acs_path_enable - test ACS flags from start to end in a hierarchy
* @start: starting downstream device
* @end: ending upstream device or NULL to search to the root bus
* @acs_flags: required flags
*
* Walk up a device tree from start to end testing PCI ACS support. If
* any step along the way does not support the required flags, return false.
*/
bool pci_acs_path_enabled(struct pci_dev *start,
struct pci_dev *end, u16 acs_flags)
{
struct pci_dev *pdev, *parent = start;
do {
pdev = parent;
if (!pci_acs_enabled(pdev, acs_flags))
return false;
if (pci_is_root_bus(pdev->bus))
return (end == NULL);
parent = pdev->bus->self;
} while (pdev != end);
return true;
}
/**
* pci_rebar_find_pos - find position of resize ctrl reg for BAR
* @pdev: PCI device
* @bar: BAR to find
*
* Helper to find the position of the ctrl register for a BAR.
* Returns -ENOTSUPP if resizable BARs are not supported at all.
* Returns -ENOENT if no ctrl register for the BAR could be found.
*/
static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
{
unsigned int pos, nbars, i;
u32 ctrl;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
if (!pos)
return -ENOTSUPP;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
PCI_REBAR_CTRL_NBAR_SHIFT;
for (i = 0; i < nbars; i++, pos += 8) {
int bar_idx;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
if (bar_idx == bar)
return pos;
}
return -ENOENT;
}
/**
* pci_rebar_get_possible_sizes - get possible sizes for BAR
* @pdev: PCI device
* @bar: BAR to query
*
* Get the possible sizes of a resizable BAR as bitmask defined in the spec
* (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable.
*/
u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar)
{
int pos;
u32 cap;
pos = pci_rebar_find_pos(pdev, bar);
if (pos < 0)
return 0;
pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
return (cap & PCI_REBAR_CAP_SIZES) >> 4;
}
/**
* pci_rebar_get_current_size - get the current size of a BAR
* @pdev: PCI device
* @bar: BAR to set size to
*
* Read the size of a BAR from the resizable BAR config.
* Returns size if found or negative error code.
*/
int pci_rebar_get_current_size(struct pci_dev *pdev, int bar)
{
int pos;
u32 ctrl;
pos = pci_rebar_find_pos(pdev, bar);
if (pos < 0)
return pos;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> PCI_REBAR_CTRL_BAR_SHIFT;
}
/**
* pci_rebar_set_size - set a new size for a BAR
* @pdev: PCI device
* @bar: BAR to set size to
* @size: new size as defined in the spec (0=1MB, 19=512GB)
*
* Set the new size of a BAR as defined in the spec.
* Returns zero if resizing was successful, error code otherwise.
*/
int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size)
{
int pos;
u32 ctrl;
pos = pci_rebar_find_pos(pdev, bar);
if (pos < 0)
return pos;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
return 0;
}
/**
* pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port
* @dev: the PCI device
* @cap_mask: mask of desired AtomicOp sizes, including one or more of:
* PCI_EXP_DEVCAP2_ATOMIC_COMP32
* PCI_EXP_DEVCAP2_ATOMIC_COMP64
* PCI_EXP_DEVCAP2_ATOMIC_COMP128
*
* Return 0 if all upstream bridges support AtomicOp routing, egress
* blocking is disabled on all upstream ports, and the root port supports
* the requested completion capabilities (32-bit, 64-bit and/or 128-bit
* AtomicOp completion), or negative otherwise.
*/
int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
{
struct pci_bus *bus = dev->bus;
struct pci_dev *bridge;
u32 cap, ctl2;
if (!pci_is_pcie(dev))
return -EINVAL;
/*
* Per PCIe r4.0, sec 6.15, endpoints and root ports may be
* AtomicOp requesters. For now, we only support endpoints as
* requesters and root ports as completers. No endpoints as
* completers, and no peer-to-peer.
*/
switch (pci_pcie_type(dev)) {
case PCI_EXP_TYPE_ENDPOINT:
case PCI_EXP_TYPE_LEG_END:
case PCI_EXP_TYPE_RC_END:
break;
default:
return -EINVAL;
}
while (bus->parent) {
bridge = bus->self;
pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
switch (pci_pcie_type(bridge)) {
/* Ensure switch ports support AtomicOp routing */
case PCI_EXP_TYPE_UPSTREAM:
case PCI_EXP_TYPE_DOWNSTREAM:
if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
return -EINVAL;
break;
/* Ensure root port supports all the sizes we care about */
case PCI_EXP_TYPE_ROOT_PORT:
if ((cap & cap_mask) != cap_mask)
return -EINVAL;
break;
}
/* Ensure upstream ports don't block AtomicOps on egress */
if (pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM) {
pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2,
&ctl2);
if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK)
return -EINVAL;
}
bus = bus->parent;
}
pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_ATOMIC_REQ);
return 0;
}
EXPORT_SYMBOL(pci_enable_atomic_ops_to_root);
/**
* pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
* @dev: the PCI device
* @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
*
* Perform INTx swizzling for a device behind one level of bridge. This is
* required by section 9.1 of the PCI-to-PCI bridge specification for devices
* behind bridges on add-in cards. For devices with ARI enabled, the slot
* number is always 0 (see the Implementation Note in section 2.2.8.1 of
* the PCI Express Base Specification, Revision 2.1)
*/
u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
{
int slot;
if (pci_ari_enabled(dev->bus))
slot = 0;
else
slot = PCI_SLOT(dev->devfn);
return (((pin - 1) + slot) % 4) + 1;
}
int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
{
u8 pin;
pin = dev->pin;
if (!pin)
return -1;
while (!pci_is_root_bus(dev->bus)) {
pin = pci_swizzle_interrupt_pin(dev, pin);
dev = dev->bus->self;
}
*bridge = dev;
return pin;
}
/**
* pci_common_swizzle - swizzle INTx all the way to root bridge
* @dev: the PCI device
* @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
*
* Perform INTx swizzling for a device. This traverses through all PCI-to-PCI
* bridges all the way up to a PCI root bus.
*/
u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
{
u8 pin = *pinp;
while (!pci_is_root_bus(dev->bus)) {
pin = pci_swizzle_interrupt_pin(dev, pin);
dev = dev->bus->self;
}
*pinp = pin;
return PCI_SLOT(dev->devfn);
}
EXPORT_SYMBOL_GPL(pci_common_swizzle);
/**
* pci_release_region - Release a PCI bar
* @pdev: PCI device whose resources were previously reserved by
* pci_request_region()
* @bar: BAR to release
*
* Releases the PCI I/O and memory resources previously reserved by a
* successful call to pci_request_region(). Call this function only
* after all use of the PCI regions has ceased.
*/
void pci_release_region(struct pci_dev *pdev, int bar)
{
struct pci_devres *dr;
if (pci_resource_len(pdev, bar) == 0)
return;
if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
release_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar));
else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
release_mem_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar));
dr = find_pci_dr(pdev);
if (dr)
dr->region_mask &= ~(1 << bar);
}
EXPORT_SYMBOL(pci_release_region);
/**
* __pci_request_region - Reserved PCI I/O and memory resource
* @pdev: PCI device whose resources are to be reserved
* @bar: BAR to be reserved
* @res_name: Name to be associated with resource.
* @exclusive: whether the region access is exclusive or not
*
* Mark the PCI region associated with PCI device @pdev BAR @bar as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* If @exclusive is set, then the region is marked so that userspace
* is explicitly not allowed to map the resource via /dev/mem or
* sysfs MMIO access.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*/
static int __pci_request_region(struct pci_dev *pdev, int bar,
const char *res_name, int exclusive)
{
struct pci_devres *dr;
if (pci_resource_len(pdev, bar) == 0)
return 0;
if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
if (!request_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar), res_name))
goto err_out;
} else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
if (!__request_mem_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar), res_name,
exclusive))
goto err_out;
}
dr = find_pci_dr(pdev);
if (dr)
dr->region_mask |= 1 << bar;
return 0;
err_out:
pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar,
&pdev->resource[bar]);
return -EBUSY;
}
/**
* pci_request_region - Reserve PCI I/O and memory resource
* @pdev: PCI device whose resources are to be reserved
* @bar: BAR to be reserved
* @res_name: Name to be associated with resource
*
* Mark the PCI region associated with PCI device @pdev BAR @bar as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*/
int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
{
return __pci_request_region(pdev, bar, res_name, 0);
}
EXPORT_SYMBOL(pci_request_region);
/**
* pci_release_selected_regions - Release selected PCI I/O and memory resources
* @pdev: PCI device whose resources were previously reserved
* @bars: Bitmask of BARs to be released
*
* Release selected PCI I/O and memory resources previously reserved.
* Call this function only after all use of the PCI regions has ceased.
*/
void pci_release_selected_regions(struct pci_dev *pdev, int bars)
{
int i;
for (i = 0; i < PCI_STD_NUM_BARS; i++)
if (bars & (1 << i))
pci_release_region(pdev, i);
}
EXPORT_SYMBOL(pci_release_selected_regions);
static int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
const char *res_name, int excl)
{
int i;
for (i = 0; i < PCI_STD_NUM_BARS; i++)
if (bars & (1 << i))
if (__pci_request_region(pdev, i, res_name, excl))
goto err_out;
return 0;
err_out:
while (--i >= 0)
if (bars & (1 << i))
pci_release_region(pdev, i);
return -EBUSY;
}
/**
* pci_request_selected_regions - Reserve selected PCI I/O and memory resources
* @pdev: PCI device whose resources are to be reserved
* @bars: Bitmask of BARs to be requested
* @res_name: Name to be associated with resource
*/
int pci_request_selected_regions(struct pci_dev *pdev, int bars,
const char *res_name)
{
return __pci_request_selected_regions(pdev, bars, res_name, 0);
}
EXPORT_SYMBOL(pci_request_selected_regions);
int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars,
const char *res_name)
{
return __pci_request_selected_regions(pdev, bars, res_name,
IORESOURCE_EXCLUSIVE);
}
EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
/**
* pci_release_regions - Release reserved PCI I/O and memory resources
* @pdev: PCI device whose resources were previously reserved by
* pci_request_regions()
*
* Releases all PCI I/O and memory resources previously reserved by a
* successful call to pci_request_regions(). Call this function only
* after all use of the PCI regions has ceased.
*/
void pci_release_regions(struct pci_dev *pdev)
{
pci_release_selected_regions(pdev, (1 << PCI_STD_NUM_BARS) - 1);
}
EXPORT_SYMBOL(pci_release_regions);
/**
* pci_request_regions - Reserve PCI I/O and memory resources
* @pdev: PCI device whose resources are to be reserved
* @res_name: Name to be associated with resource.
*
* Mark all PCI regions associated with PCI device @pdev as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*/
int pci_request_regions(struct pci_dev *pdev, const char *res_name)
{
return pci_request_selected_regions(pdev,
((1 << PCI_STD_NUM_BARS) - 1), res_name);
}
EXPORT_SYMBOL(pci_request_regions);
/**
* pci_request_regions_exclusive - Reserve PCI I/O and memory resources
* @pdev: PCI device whose resources are to be reserved
* @res_name: Name to be associated with resource.
*
* Mark all PCI regions associated with PCI device @pdev as being reserved
* by owner @res_name. Do not access any address inside the PCI regions
* unless this call returns successfully.
*
* pci_request_regions_exclusive() will mark the region so that /dev/mem
* and the sysfs MMIO access will not be allowed.
*
* Returns 0 on success, or %EBUSY on error. A warning message is also
* printed on failure.
*/
int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
{
return pci_request_selected_regions_exclusive(pdev,
((1 << PCI_STD_NUM_BARS) - 1), res_name);
}
EXPORT_SYMBOL(pci_request_regions_exclusive);
/*
* Record the PCI IO range (expressed as CPU physical address + size).
* Return a negative value if an error has occurred, zero otherwise
*/
int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr,
resource_size_t size)
{
int ret = 0;
#ifdef PCI_IOBASE
struct logic_pio_hwaddr *range;
if (!size || addr + size < addr)
return -EINVAL;
range = kzalloc(sizeof(*range), GFP_ATOMIC);
if (!range)
return -ENOMEM;
range->fwnode = fwnode;
range->size = size;
range->hw_start = addr;
range->flags = LOGIC_PIO_CPU_MMIO;
ret = logic_pio_register_range(range);
if (ret)
kfree(range);
#endif
return ret;
}
phys_addr_t pci_pio_to_address(unsigned long pio)
{
phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
#ifdef PCI_IOBASE
if (pio >= MMIO_UPPER_LIMIT)
return address;
address = logic_pio_to_hwaddr(pio);
#endif
return address;
}
unsigned long __weak pci_address_to_pio(phys_addr_t address)
{
#ifdef PCI_IOBASE
return logic_pio_trans_cpuaddr(address);
#else
if (address > IO_SPACE_LIMIT)
return (unsigned long)-1;
return (unsigned long) address;
#endif
}
/**
* pci_remap_iospace - Remap the memory mapped I/O space
* @res: Resource describing the I/O space
* @phys_addr: physical address of range to be mapped
*
* Remap the memory mapped I/O space described by the @res and the CPU
* physical address @phys_addr into virtual address space. Only
* architectures that have memory mapped IO functions defined (and the
* PCI_IOBASE value defined) should call this function.
*/
int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
{
#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
if (!(res->flags & IORESOURCE_IO))
return -EINVAL;
if (res->end > IO_SPACE_LIMIT)
return -EINVAL;
return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
pgprot_device(PAGE_KERNEL));
#else
/*
* This architecture does not have memory mapped I/O space,
* so this function should never be called
*/
WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
return -ENODEV;
#endif
}
EXPORT_SYMBOL(pci_remap_iospace);
/**
* pci_unmap_iospace - Unmap the memory mapped I/O space
* @res: resource to be unmapped
*
* Unmap the CPU virtual address @res from virtual address space. Only
* architectures that have memory mapped IO functions defined (and the
* PCI_IOBASE value defined) should call this function.
*/
void pci_unmap_iospace(struct resource *res)
{
#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
unmap_kernel_range(vaddr, resource_size(res));
#endif
}
EXPORT_SYMBOL(pci_unmap_iospace);
static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
{
struct resource **res = ptr;
pci_unmap_iospace(*res);
}
/**
* devm_pci_remap_iospace - Managed pci_remap_iospace()
* @dev: Generic device to remap IO address for
* @res: Resource describing the I/O space
* @phys_addr: physical address of range to be mapped
*
* Managed pci_remap_iospace(). Map is automatically unmapped on driver
* detach.
*/
int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
phys_addr_t phys_addr)
{
const struct resource **ptr;
int error;
ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return -ENOMEM;
error = pci_remap_iospace(res, phys_addr);
if (error) {
devres_free(ptr);
} else {
*ptr = res;
devres_add(dev, ptr);
}
return error;
}
EXPORT_SYMBOL(devm_pci_remap_iospace);
/**
* devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
* @dev: Generic device to remap IO address for
* @offset: Resource address to map
* @size: Size of map
*
* Managed pci_remap_cfgspace(). Map is automatically unmapped on driver
* detach.
*/
void __iomem *devm_pci_remap_cfgspace(struct device *dev,
resource_size_t offset,
resource_size_t size)
{
void __iomem **ptr, *addr;
ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return NULL;
addr = pci_remap_cfgspace(offset, size);
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
} else
devres_free(ptr);
return addr;
}
EXPORT_SYMBOL(devm_pci_remap_cfgspace);
/**
* devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
* @dev: generic device to handle the resource for
* @res: configuration space resource to be handled
*
* Checks that a resource is a valid memory region, requests the memory
* region and ioremaps with pci_remap_cfgspace() API that ensures the
* proper PCI configuration space memory attributes are guaranteed.
*
* All operations are managed and will be undone on driver detach.
*
* Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
* on failure. Usage example::
*
* res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
* base = devm_pci_remap_cfg_resource(&pdev->dev, res);
* if (IS_ERR(base))
* return PTR_ERR(base);
*/
void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
struct resource *res)
{
resource_size_t size;
const char *name;
void __iomem *dest_ptr;
BUG_ON(!dev);
if (!res || resource_type(res) != IORESOURCE_MEM) {
dev_err(dev, "invalid resource\n");
return IOMEM_ERR_PTR(-EINVAL);
}
size = resource_size(res);
name = res->name ?: dev_name(dev);
if (!devm_request_mem_region(dev, res->start, size, name)) {
dev_err(dev, "can't request region for resource %pR\n", res);
return IOMEM_ERR_PTR(-EBUSY);
}
dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
if (!dest_ptr) {
dev_err(dev, "ioremap failed for resource %pR\n", res);
devm_release_mem_region(dev, res->start, size);
dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
}
return dest_ptr;
}
EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
static void __pci_set_master(struct pci_dev *dev, bool enable)
{
u16 old_cmd, cmd;
pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
if (enable)
cmd = old_cmd | PCI_COMMAND_MASTER;
else
cmd = old_cmd & ~PCI_COMMAND_MASTER;
if (cmd != old_cmd) {
pci_dbg(dev, "%s bus mastering\n",
enable ? "enabling" : "disabling");
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
dev->is_busmaster = enable;
}
/**
* pcibios_setup - process "pci=" kernel boot arguments
* @str: string used to pass in "pci=" kernel boot arguments
*
* Process kernel boot arguments. This is the default implementation.
* Architecture specific implementations can override this as necessary.
*/
char * __weak __init pcibios_setup(char *str)
{
return str;
}
/**
* pcibios_set_master - enable PCI bus-mastering for device dev
* @dev: the PCI device to enable
*
* Enables PCI bus-mastering for the device. This is the default
* implementation. Architecture specific implementations can override
* this if necessary.
*/
void __weak pcibios_set_master(struct pci_dev *dev)
{
u8 lat;
/* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
if (pci_is_pcie(dev))
return;
pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
if (lat < 16)
lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
else if (lat > pcibios_max_latency)
lat = pcibios_max_latency;
else
return;
pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
}
/**
* pci_set_master - enables bus-mastering for device dev
* @dev: the PCI device to enable
*
* Enables bus-mastering on the device and calls pcibios_set_master()
* to do the needed arch specific settings.
*/
void pci_set_master(struct pci_dev *dev)
{
__pci_set_master(dev, true);
pcibios_set_master(dev);
}
EXPORT_SYMBOL(pci_set_master);
/**
* pci_clear_master - disables bus-mastering for device dev
* @dev: the PCI device to disable
*/
void pci_clear_master(struct pci_dev *dev)
{
__pci_set_master(dev, false);
}
EXPORT_SYMBOL(pci_clear_master);
/**
* pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
* @dev: the PCI device for which MWI is to be enabled
*
* Helper function for pci_set_mwi.
* Originally copied from drivers/net/acenic.c.
* Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pci_set_cacheline_size(struct pci_dev *dev)
{
u8 cacheline_size;
if (!pci_cache_line_size)
return -EINVAL;
/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
equal to or multiple of the right value. */
pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
if (cacheline_size >= pci_cache_line_size &&
(cacheline_size % pci_cache_line_size) == 0)
return 0;
/* Write the correct value. */
pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
/* Read it back. */
pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
if (cacheline_size == pci_cache_line_size)
return 0;
pci_info(dev, "cache line size of %d is not supported\n",
pci_cache_line_size << 2);
return -EINVAL;
}
EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
/**
* pci_set_mwi - enables memory-write-invalidate PCI transaction
* @dev: the PCI device for which MWI is enabled
*
* Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pci_set_mwi(struct pci_dev *dev)
{
#ifdef PCI_DISABLE_MWI
return 0;
#else
int rc;
u16 cmd;
rc = pci_set_cacheline_size(dev);
if (rc)
return rc;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (!(cmd & PCI_COMMAND_INVALIDATE)) {
pci_dbg(dev, "enabling Mem-Wr-Inval\n");
cmd |= PCI_COMMAND_INVALIDATE;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
#endif
}
EXPORT_SYMBOL(pci_set_mwi);
/**
* pcim_set_mwi - a device-managed pci_set_mwi()
* @dev: the PCI device for which MWI is enabled
*
* Managed pci_set_mwi().
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pcim_set_mwi(struct pci_dev *dev)
{
struct pci_devres *dr;
dr = find_pci_dr(dev);
if (!dr)
return -ENOMEM;
dr->mwi = 1;
return pci_set_mwi(dev);
}
EXPORT_SYMBOL(pcim_set_mwi);
/**
* pci_try_set_mwi - enables memory-write-invalidate PCI transaction
* @dev: the PCI device for which MWI is enabled
*
* Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
* Callers are not required to check the return value.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pci_try_set_mwi(struct pci_dev *dev)
{
#ifdef PCI_DISABLE_MWI
return 0;
#else
return pci_set_mwi(dev);
#endif
}
EXPORT_SYMBOL(pci_try_set_mwi);
/**
* pci_clear_mwi - disables Memory-Write-Invalidate for device dev
* @dev: the PCI device to disable
*
* Disables PCI Memory-Write-Invalidate transaction on the device
*/
void pci_clear_mwi(struct pci_dev *dev)
{
#ifndef PCI_DISABLE_MWI
u16 cmd;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (cmd & PCI_COMMAND_INVALIDATE) {
cmd &= ~PCI_COMMAND_INVALIDATE;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
#endif
}
EXPORT_SYMBOL(pci_clear_mwi);
/**
* pci_intx - enables/disables PCI INTx for device dev
* @pdev: the PCI device to operate on
* @enable: boolean: whether to enable or disable PCI INTx
*
* Enables/disables PCI INTx for device @pdev
*/
void pci_intx(struct pci_dev *pdev, int enable)
{
u16 pci_command, new;
pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
if (enable)
new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
else
new = pci_command | PCI_COMMAND_INTX_DISABLE;
if (new != pci_command) {
struct pci_devres *dr;
pci_write_config_word(pdev, PCI_COMMAND, new);
dr = find_pci_dr(pdev);
if (dr && !dr->restore_intx) {
dr->restore_intx = 1;
dr->orig_intx = !enable;
}
}
}
EXPORT_SYMBOL_GPL(pci_intx);
static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
{
struct pci_bus *bus = dev->bus;
bool mask_updated = true;
u32 cmd_status_dword;
u16 origcmd, newcmd;
unsigned long flags;
bool irq_pending;
/*
* We do a single dword read to retrieve both command and status.
* Document assumptions that make this possible.
*/
BUILD_BUG_ON(PCI_COMMAND % 4);
BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
raw_spin_lock_irqsave(&pci_lock, flags);
bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
/*
* Check interrupt status register to see whether our device
* triggered the interrupt (when masking) or the next IRQ is
* already pending (when unmasking).
*/
if (mask != irq_pending) {
mask_updated = false;
goto done;
}
origcmd = cmd_status_dword;
newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
if (mask)
newcmd |= PCI_COMMAND_INTX_DISABLE;
if (newcmd != origcmd)
bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
done:
raw_spin_unlock_irqrestore(&pci_lock, flags);
return mask_updated;
}
/**
* pci_check_and_mask_intx - mask INTx on pending interrupt
* @dev: the PCI device to operate on
*
* Check if the device dev has its INTx line asserted, mask it and return
* true in that case. False is returned if no interrupt was pending.
*/
bool pci_check_and_mask_intx(struct pci_dev *dev)
{
return pci_check_and_set_intx_mask(dev, true);
}
EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
/**
* pci_check_and_unmask_intx - unmask INTx if no interrupt is pending
* @dev: the PCI device to operate on
*
* Check if the device dev has its INTx line asserted, unmask it if not and
* return true. False is returned and the mask remains active if there was
* still an interrupt pending.
*/
bool pci_check_and_unmask_intx(struct pci_dev *dev)
{
return pci_check_and_set_intx_mask(dev, false);
}
EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
/**
* pci_wait_for_pending_transaction - wait for pending transaction
* @dev: the PCI device to operate on
*
* Return 0 if transaction is pending 1 otherwise.
*/
int pci_wait_for_pending_transaction(struct pci_dev *dev)
{
if (!pci_is_pcie(dev))
return 1;
return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA,
PCI_EXP_DEVSTA_TRPND);
}
EXPORT_SYMBOL(pci_wait_for_pending_transaction);
/**
* pcie_has_flr - check if a device supports function level resets
* @dev: device to check
*
* Returns true if the device advertises support for PCIe function level
* resets.
*/
bool pcie_has_flr(struct pci_dev *dev)
{
u32 cap;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
return false;
pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
return cap & PCI_EXP_DEVCAP_FLR;
}
EXPORT_SYMBOL_GPL(pcie_has_flr);
/**
* pcie_flr - initiate a PCIe function level reset
* @dev: device to reset
*
* Initiate a function level reset on @dev. The caller should ensure the
* device supports FLR before calling this function, e.g. by using the
* pcie_has_flr() helper.
*/
int pcie_flr(struct pci_dev *dev)
{
if (!pci_wait_for_pending_transaction(dev))
pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
if (dev->imm_ready)
return 0;
/*
* Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within
* 100ms, but may silently discard requests while the FLR is in
* progress. Wait 100ms before trying to access the device.
*/
msleep(100);
return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
}
EXPORT_SYMBOL_GPL(pcie_flr);
static int pci_af_flr(struct pci_dev *dev, int probe)
{
int pos;
u8 cap;
pos = pci_find_capability(dev, PCI_CAP_ID_AF);
if (!pos)
return -ENOTTY;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
return -ENOTTY;
pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
return -ENOTTY;
if (probe)
return 0;
/*
* Wait for Transaction Pending bit to clear. A word-aligned test
* is used, so we use the control offset rather than status and shift
* the test bit to match.
*/
if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL,
PCI_AF_STATUS_TP << 8))
pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");
pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
if (dev->imm_ready)
return 0;
/*
* Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006,
* updated 27 July 2006; a device must complete an FLR within
* 100ms, but may silently discard requests while the FLR is in
* progress. Wait 100ms before trying to access the device.
*/
msleep(100);
return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS);
}
/**
* pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
* @dev: Device to reset.
* @probe: If set, only check if the device can be reset this way.
*
* If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
* unset, it will be reinitialized internally when going from PCI_D3hot to
* PCI_D0. If that's the case and the device is not in a low-power state
* already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
*
* NOTE: This causes the caller to sleep for twice the device power transition
* cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
* by default (i.e. unless the @dev's d3_delay field has a different value).
* Moreover, only devices in D0 can be reset by this function.
*/
static int pci_pm_reset(struct pci_dev *dev, int probe)
{
u16 csr;
if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
return -ENOTTY;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
return -ENOTTY;
if (probe)
return 0;
if (dev->current_state != PCI_D0)
return -EINVAL;
csr &= ~PCI_PM_CTRL_STATE_MASK;
csr |= PCI_D3hot;
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
pci_dev_d3_sleep(dev);
csr &= ~PCI_PM_CTRL_STATE_MASK;
csr |= PCI_D0;
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
pci_dev_d3_sleep(dev);
return pci_dev_wait(dev, "PM D3hot->D0", PCIE_RESET_READY_POLL_MS);
}
/**
* pcie_wait_for_link_delay - Wait until link is active or inactive
* @pdev: Bridge device
* @active: waiting for active or inactive?
* @delay: Delay to wait after link has become active (in ms)
*
* Use this to wait till link becomes active or inactive.
*/
static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
int delay)
{
int timeout = 1000;
bool ret;
u16 lnk_status;
/*
* Some controllers might not implement link active reporting. In this
* case, we wait for 1000 + 100 ms.
*/
if (!pdev->link_active_reporting) {
msleep(1100);
return true;
}
/*
* PCIe r4.0 sec 6.6.1, a component must enter LTSSM Detect within 20ms,
* after which we should expect an link active if the reset was
* successful. If so, software must wait a minimum 100ms before sending
* configuration requests to devices downstream this port.
*
* If the link fails to activate, either the device was physically
* removed or the link is permanently failed.
*/
if (active)
msleep(20);
for (;;) {
pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
if (ret == active)
break;
if (timeout <= 0)
break;
msleep(10);
timeout -= 10;
}
if (active && ret)
msleep(delay);
else if (ret != active)
pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n",
active ? "set" : "cleared");
return ret == active;
}
/**
* pcie_wait_for_link - Wait until link is active or inactive
* @pdev: Bridge device
* @active: waiting for active or inactive?
*
* Use this to wait till link becomes active or inactive.
*/
bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
{
return pcie_wait_for_link_delay(pdev, active, 100);
}
/*
* Find maximum D3cold delay required by all the devices on the bus. The
* spec says 100 ms, but firmware can lower it and we allow drivers to
* increase it as well.
*
* Called with @pci_bus_sem locked for reading.
*/
static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
{
const struct pci_dev *pdev;
int min_delay = 100;
int max_delay = 0;
list_for_each_entry(pdev, &bus->devices, bus_list) {
if (pdev->d3cold_delay < min_delay)
min_delay = pdev->d3cold_delay;
if (pdev->d3cold_delay > max_delay)
max_delay = pdev->d3cold_delay;
}
return max(min_delay, max_delay);
}
/**
* pci_bridge_wait_for_secondary_bus - Wait for secondary bus to be accessible
* @dev: PCI bridge
*
* Handle necessary delays before access to the devices on the secondary
* side of the bridge are permitted after D3cold to D0 transition.
*
* For PCIe this means the delays in PCIe 5.0 section 6.6.1. For
* conventional PCI it means Tpvrh + Trhfa specified in PCI 3.0 section
* 4.3.2.
*/
void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev)
{
struct pci_dev *child;
int delay;
if (pci_dev_is_disconnected(dev))
return;
if (!pci_is_bridge(dev) || !dev->bridge_d3)
return;
down_read(&pci_bus_sem);
/*
* We only deal with devices that are present currently on the bus.
* For any hot-added devices the access delay is handled in pciehp
* board_added(). In case of ACPI hotplug the firmware is expected
* to configure the devices before OS is notified.
*/
if (!dev->subordinate || list_empty(&dev->subordinate->devices)) {
up_read(&pci_bus_sem);
return;
}
/* Take d3cold_delay requirements into account */
delay = pci_bus_max_d3cold_delay(dev->subordinate);
if (!delay) {
up_read(&pci_bus_sem);
return;
}
child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
bus_list);
up_read(&pci_bus_sem);
/*
* Conventional PCI and PCI-X we need to wait Tpvrh + Trhfa before
* accessing the device after reset (that is 1000 ms + 100 ms). In
* practice this should not be needed because we don't do power
* management for them (see pci_bridge_d3_possible()).
*/
if (!pci_is_pcie(dev)) {
pci_dbg(dev, "waiting %d ms for secondary bus\n", 1000 + delay);
msleep(1000 + delay);
return;
}
/*
* For PCIe downstream and root ports that do not support speeds
* greater than 5 GT/s need to wait minimum 100 ms. For higher
* speeds (gen3) we need to wait first for the data link layer to
* become active.
*
* However, 100 ms is the minimum and the PCIe spec says the
* software must allow at least 1s before it can determine that the
* device that did not respond is a broken device. There is
* evidence that 100 ms is not always enough, for example certain
* Titan Ridge xHCI controller does not always respond to
* configuration requests if we only wait for 100 ms (see
* https://bugzilla.kernel.org/show_bug.cgi?id=203885).
*
* Therefore we wait for 100 ms and check for the device presence.
* If it is still not present give it an additional 100 ms.
*/
if (!pcie_downstream_port(dev))
return;
if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) {
pci_dbg(dev, "waiting %d ms for downstream link\n", delay);
msleep(delay);
} else {
pci_dbg(dev, "waiting %d ms for downstream link, after activation\n",
delay);
if (!pcie_wait_for_link_delay(dev, true, delay)) {
/* Did not train, no need to wait any further */
return;
}
}
if (!pci_device_is_present(child)) {
pci_dbg(child, "waiting additional %d ms to become accessible\n", delay);
msleep(delay);
}
}
void pci_reset_secondary_bus(struct pci_dev *dev)
{
u16 ctrl;
pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
/*
* PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double
* this to 2ms to ensure that we meet the minimum requirement.
*/
msleep(2);
ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
/*
* Trhfa for conventional PCI is 2^25 clock cycles.
* Assuming a minimum 33MHz clock this results in a 1s
* delay before we can consider subordinate devices to
* be re-initialized. PCIe has some ways to shorten this,
* but we don't make use of them yet.
*/
ssleep(1);
}
void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
{
pci_reset_secondary_bus(dev);
}
/**
* pci_bridge_secondary_bus_reset - Reset the secondary bus on a PCI bridge.
* @dev: Bridge device
*
* Use the bridge control register to assert reset on the secondary bus.
* Devices on the secondary bus are left in power-on state.
*/
int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
{
pcibios_reset_secondary_bus(dev);
return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
}
EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
{
struct pci_dev *pdev;
if (pci_is_root_bus(dev->bus) || dev->subordinate ||
!dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
return -ENOTTY;
list_for_each_entry(pdev, &dev->bus->devices, bus_list)
if (pdev != dev)
return -ENOTTY;
if (probe)
return 0;
return pci_bridge_secondary_bus_reset(dev->bus->self);
}
static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
{
int rc = -ENOTTY;
if (!hotplug || !try_module_get(hotplug->owner))
return rc;
if (hotplug->ops->reset_slot)
rc = hotplug->ops->reset_slot(hotplug, probe);
module_put(hotplug->owner);
return rc;
}
static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
{
struct pci_dev *pdev;
if (dev->subordinate || !dev->slot ||
dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
return -ENOTTY;
list_for_each_entry(pdev, &dev->bus->devices, bus_list)
if (pdev != dev && pdev->slot == dev->slot)
return -ENOTTY;
return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
}
static void pci_dev_lock(struct pci_dev *dev)
{
pci_cfg_access_lock(dev);
/* block PM suspend, driver probe, etc. */
device_lock(&dev->dev);
}
/* Return 1 on successful lock, 0 on contention */
static int pci_dev_trylock(struct pci_dev *dev)
{
if (pci_cfg_access_trylock(dev)) {
if (device_trylock(&dev->dev))
return 1;
pci_cfg_access_unlock(dev);
}
return 0;
}
static void pci_dev_unlock(struct pci_dev *dev)
{
device_unlock(&dev->dev);
pci_cfg_access_unlock(dev);
}
static void pci_dev_save_and_disable(struct pci_dev *dev)
{
const struct pci_error_handlers *err_handler =
dev->driver ? dev->driver->err_handler : NULL;
/*
* dev->driver->err_handler->reset_prepare() is protected against
* races with ->remove() by the device lock, which must be held by
* the caller.
*/
if (err_handler && err_handler->reset_prepare)
err_handler->reset_prepare(dev);
/*
* Wake-up device prior to save. PM registers default to D0 after
* reset and a simple register restore doesn't reliably return
* to a non-D0 state anyway.
*/
pci_set_power_state(dev, PCI_D0);
pci_save_state(dev);
/*
* Disable the device by clearing the Command register, except for
* INTx-disable which is set. This not only disables MMIO and I/O port
* BARs, but also prevents the device from being Bus Master, preventing
* DMA from the device including MSI/MSI-X interrupts. For PCI 2.3
* compliant devices, INTx-disable prevents legacy interrupts.
*/
pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
}
static void pci_dev_restore(struct pci_dev *dev)
{
const struct pci_error_handlers *err_handler =
dev->driver ? dev->driver->err_handler : NULL;
pci_restore_state(dev);
/*
* dev->driver->err_handler->reset_done() is protected against
* races with ->remove() by the device lock, which must be held by
* the caller.
*/
if (err_handler && err_handler->reset_done)
err_handler->reset_done(dev);
}
/**
* __pci_reset_function_locked - reset a PCI device function while holding
* the @dev mutex lock.
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* The device function is presumed to be unused and the caller is holding
* the device mutex lock when this function is called.
*
* Resetting the device will make the contents of PCI configuration space
* random, so any caller of this must be prepared to reinitialise the
* device including MSI, bus mastering, BARs, decoding IO and memory spaces,
* etc.
*
* Returns 0 if the device function was successfully reset or negative if the
* device doesn't support resetting a single function.
*/
int __pci_reset_function_locked(struct pci_dev *dev)
{
int rc;
might_sleep();
/*
* A reset method returns -ENOTTY if it doesn't support this device
* and we should try the next method.
*
* If it returns 0 (success), we're finished. If it returns any
* other error, we're also finished: this indicates that further
* reset mechanisms might be broken on the device.
*/
rc = pci_dev_specific_reset(dev, 0);
if (rc != -ENOTTY)
return rc;
if (pcie_has_flr(dev)) {
rc = pcie_flr(dev);
if (rc != -ENOTTY)
return rc;
}
rc = pci_af_flr(dev, 0);
if (rc != -ENOTTY)
return rc;
rc = pci_pm_reset(dev, 0);
if (rc != -ENOTTY)
return rc;
rc = pci_dev_reset_slot_function(dev, 0);
if (rc != -ENOTTY)
return rc;
return pci_parent_bus_reset(dev, 0);
}
EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
/**
* pci_probe_reset_function - check whether the device can be safely reset
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* Returns 0 if the device function can be reset or negative if the
* device doesn't support resetting a single function.
*/
int pci_probe_reset_function(struct pci_dev *dev)
{
int rc;
might_sleep();
rc = pci_dev_specific_reset(dev, 1);
if (rc != -ENOTTY)
return rc;
if (pcie_has_flr(dev))
return 0;
rc = pci_af_flr(dev, 1);
if (rc != -ENOTTY)
return rc;
rc = pci_pm_reset(dev, 1);
if (rc != -ENOTTY)
return rc;
rc = pci_dev_reset_slot_function(dev, 1);
if (rc != -ENOTTY)
return rc;
return pci_parent_bus_reset(dev, 1);
}
/**
* pci_reset_function - quiesce and reset a PCI device function
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* This function does not just reset the PCI portion of a device, but
* clears all the state associated with the device. This function differs
* from __pci_reset_function_locked() in that it saves and restores device state
* over the reset and takes the PCI device lock.
*
* Returns 0 if the device function was successfully reset or negative if the
* device doesn't support resetting a single function.
*/
int pci_reset_function(struct pci_dev *dev)
{
int rc;
if (!dev->reset_fn)
return -ENOTTY;
pci_dev_lock(dev);
pci_dev_save_and_disable(dev);
rc = __pci_reset_function_locked(dev);
pci_dev_restore(dev);
pci_dev_unlock(dev);
return rc;
}
EXPORT_SYMBOL_GPL(pci_reset_function);
/**
* pci_reset_function_locked - quiesce and reset a PCI device function
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* This function does not just reset the PCI portion of a device, but
* clears all the state associated with the device. This function differs
* from __pci_reset_function_locked() in that it saves and restores device state
* over the reset. It also differs from pci_reset_function() in that it
* requires the PCI device lock to be held.
*
* Returns 0 if the device function was successfully reset or negative if the
* device doesn't support resetting a single function.
*/
int pci_reset_function_locked(struct pci_dev *dev)
{
int rc;
if (!dev->reset_fn)
return -ENOTTY;
pci_dev_save_and_disable(dev);
rc = __pci_reset_function_locked(dev);
pci_dev_restore(dev);
return rc;
}
EXPORT_SYMBOL_GPL(pci_reset_function_locked);
/**
* pci_try_reset_function - quiesce and reset a PCI device function
* @dev: PCI device to reset
*
* Same as above, except return -EAGAIN if unable to lock device.
*/
int pci_try_reset_function(struct pci_dev *dev)
{
int rc;
if (!dev->reset_fn)
return -ENOTTY;
if (!pci_dev_trylock(dev))
return -EAGAIN;
pci_dev_save_and_disable(dev);
rc = __pci_reset_function_locked(dev);
pci_dev_restore(dev);
pci_dev_unlock(dev);
return rc;
}
EXPORT_SYMBOL_GPL(pci_try_reset_function);
/* Do any devices on or below this bus prevent a bus reset? */
static bool pci_bus_resetable(struct pci_bus *bus)
{
struct pci_dev *dev;
if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
return false;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
(dev->subordinate && !pci_bus_resetable(dev->subordinate)))
return false;
}
return true;
}
/* Lock devices from the top of the tree down */
static void pci_bus_lock(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
pci_dev_lock(dev);
if (dev->subordinate)
pci_bus_lock(dev->subordinate);
}
}
/* Unlock devices from the bottom of the tree up */
static void pci_bus_unlock(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
}
/* Return 1 on successful lock, 0 on contention */
static int pci_bus_trylock(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (!pci_dev_trylock(dev))
goto unlock;
if (dev->subordinate) {
if (!pci_bus_trylock(dev->subordinate)) {
pci_dev_unlock(dev);
goto unlock;
}
}
}
return 1;
unlock:
list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
return 0;
}
/* Do any devices on or below this slot prevent a bus reset? */
static bool pci_slot_resetable(struct pci_slot *slot)
{
struct pci_dev *dev;
if (slot->bus->self &&
(slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
return false;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
(dev->subordinate && !pci_bus_resetable(dev->subordinate)))
return false;
}
return true;
}
/* Lock devices from the top of the tree down */
static void pci_slot_lock(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
pci_dev_lock(dev);
if (dev->subordinate)
pci_bus_lock(dev->subordinate);
}
}
/* Unlock devices from the bottom of the tree up */
static void pci_slot_unlock(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
}
/* Return 1 on successful lock, 0 on contention */
static int pci_slot_trylock(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (!pci_dev_trylock(dev))
goto unlock;
if (dev->subordinate) {
if (!pci_bus_trylock(dev->subordinate)) {
pci_dev_unlock(dev);
goto unlock;
}
}
}
return 1;
unlock:
list_for_each_entry_continue_reverse(dev,
&slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
return 0;
}
/*
* Save and disable devices from the top of the tree down while holding
* the @dev mutex lock for the entire tree.
*/
static void pci_bus_save_and_disable_locked(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
pci_dev_save_and_disable(dev);
if (dev->subordinate)
pci_bus_save_and_disable_locked(dev->subordinate);
}
}
/*
* Restore devices from top of the tree down while holding @dev mutex lock
* for the entire tree. Parent bridges need to be restored before we can
* get to subordinate devices.
*/
static void pci_bus_restore_locked(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
pci_dev_restore(dev);
if (dev->subordinate)
pci_bus_restore_locked(dev->subordinate);
}
}
/*
* Save and disable devices from the top of the tree down while holding
* the @dev mutex lock for the entire tree.
*/
static void pci_slot_save_and_disable_locked(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
pci_dev_save_and_disable(dev);
if (dev->subordinate)
pci_bus_save_and_disable_locked(dev->subordinate);
}
}
/*
* Restore devices from top of the tree down while holding @dev mutex lock
* for the entire tree. Parent bridges need to be restored before we can
* get to subordinate devices.
*/
static void pci_slot_restore_locked(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
pci_dev_restore(dev);
if (dev->subordinate)
pci_bus_restore_locked(dev->subordinate);
}
}
static int pci_slot_reset(struct pci_slot *slot, int probe)
{
int rc;
if (!slot || !pci_slot_resetable(slot))
return -ENOTTY;
if (!probe)
pci_slot_lock(slot);
might_sleep();
rc = pci_reset_hotplug_slot(slot->hotplug, probe);
if (!probe)
pci_slot_unlock(slot);
return rc;
}
/**
* pci_probe_reset_slot - probe whether a PCI slot can be reset
* @slot: PCI slot to probe
*
* Return 0 if slot can be reset, negative if a slot reset is not supported.
*/
int pci_probe_reset_slot(struct pci_slot *slot)
{
return pci_slot_reset(slot, 1);
}
EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
/**
* __pci_reset_slot - Try to reset a PCI slot
* @slot: PCI slot to reset
*
* A PCI bus may host multiple slots, each slot may support a reset mechanism
* independent of other slots. For instance, some slots may support slot power
* control. In the case of a 1:1 bus to slot architecture, this function may
* wrap the bus reset to avoid spurious slot related events such as hotplug.
* Generally a slot reset should be attempted before a bus reset. All of the
* function of the slot and any subordinate buses behind the slot are reset
* through this function. PCI config space of all devices in the slot and
* behind the slot is saved before and restored after reset.
*
* Same as above except return -EAGAIN if the slot cannot be locked
*/
static int __pci_reset_slot(struct pci_slot *slot)
{
int rc;
rc = pci_slot_reset(slot, 1);
if (rc)
return rc;
if (pci_slot_trylock(slot)) {
pci_slot_save_and_disable_locked(slot);
might_sleep();
rc = pci_reset_hotplug_slot(slot->hotplug, 0);
pci_slot_restore_locked(slot);
pci_slot_unlock(slot);
} else
rc = -EAGAIN;
return rc;
}
static int pci_bus_reset(struct pci_bus *bus, int probe)
{
int ret;
if (!bus->self || !pci_bus_resetable(bus))
return -ENOTTY;
if (probe)
return 0;
pci_bus_lock(bus);
might_sleep();
ret = pci_bridge_secondary_bus_reset(bus->self);
pci_bus_unlock(bus);
return ret;
}
/**
* pci_bus_error_reset - reset the bridge's subordinate bus
* @bridge: The parent device that connects to the bus to reset
*
* This function will first try to reset the slots on this bus if the method is
* available. If slot reset fails or is not available, this will fall back to a
* secondary bus reset.
*/
int pci_bus_error_reset(struct pci_dev *bridge)
{
struct pci_bus *bus = bridge->subordinate;
struct pci_slot *slot;
if (!bus)
return -ENOTTY;
mutex_lock(&pci_slot_mutex);
if (list_empty(&bus->slots))
goto bus_reset;
list_for_each_entry(slot, &bus->slots, list)
if (pci_probe_reset_slot(slot))
goto bus_reset;
list_for_each_entry(slot, &bus->slots, list)
if (pci_slot_reset(slot, 0))
goto bus_reset;
mutex_unlock(&pci_slot_mutex);
return 0;
bus_reset:
mutex_unlock(&pci_slot_mutex);
return pci_bus_reset(bridge->subordinate, 0);
}
/**
* pci_probe_reset_bus - probe whether a PCI bus can be reset
* @bus: PCI bus to probe
*
* Return 0 if bus can be reset, negative if a bus reset is not supported.
*/
int pci_probe_reset_bus(struct pci_bus *bus)
{
return pci_bus_reset(bus, 1);
}
EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
/**
* __pci_reset_bus - Try to reset a PCI bus
* @bus: top level PCI bus to reset
*
* Same as above except return -EAGAIN if the bus cannot be locked
*/
static int __pci_reset_bus(struct pci_bus *bus)
{
int rc;
rc = pci_bus_reset(bus, 1);
if (rc)
return rc;
if (pci_bus_trylock(bus)) {
pci_bus_save_and_disable_locked(bus);
might_sleep();
rc = pci_bridge_secondary_bus_reset(bus->self);
pci_bus_restore_locked(bus);
pci_bus_unlock(bus);
} else
rc = -EAGAIN;
return rc;
}
/**
* pci_reset_bus - Try to reset a PCI bus
* @pdev: top level PCI device to reset via slot/bus
*
* Same as above except return -EAGAIN if the bus cannot be locked
*/
int pci_reset_bus(struct pci_dev *pdev)
{
return (!pci_probe_reset_slot(pdev->slot)) ?
__pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus);
}
EXPORT_SYMBOL_GPL(pci_reset_bus);
/**
* pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
* @dev: PCI device to query
*
* Returns mmrbc: maximum designed memory read count in bytes or
* appropriate error value.
*/
int pcix_get_max_mmrbc(struct pci_dev *dev)
{
int cap;
u32 stat;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
return -EINVAL;
return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
}
EXPORT_SYMBOL(pcix_get_max_mmrbc);
/**
* pcix_get_mmrbc - get PCI-X maximum memory read byte count
* @dev: PCI device to query
*
* Returns mmrbc: maximum memory read count in bytes or appropriate error
* value.
*/
int pcix_get_mmrbc(struct pci_dev *dev)
{
int cap;
u16 cmd;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
return -EINVAL;
return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
}
EXPORT_SYMBOL(pcix_get_mmrbc);
/**
* pcix_set_mmrbc - set PCI-X maximum memory read byte count
* @dev: PCI device to query
* @mmrbc: maximum memory read count in bytes
* valid values are 512, 1024, 2048, 4096
*
* If possible sets maximum memory read byte count, some bridges have errata
* that prevent this.
*/
int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
{
int cap;
u32 stat, v, o;
u16 cmd;
if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
return -EINVAL;
v = ffs(mmrbc) - 10;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
return -EINVAL;
if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
return -E2BIG;
if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
return -EINVAL;
o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
if (o != v) {
if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
return -EIO;
cmd &= ~PCI_X_CMD_MAX_READ;
cmd |= v << 2;
if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
return -EIO;
}
return 0;
}
EXPORT_SYMBOL(pcix_set_mmrbc);
/**
* pcie_get_readrq - get PCI Express read request size
* @dev: PCI device to query
*
* Returns maximum memory read request in bytes or appropriate error value.
*/
int pcie_get_readrq(struct pci_dev *dev)
{
u16 ctl;
pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
}
EXPORT_SYMBOL(pcie_get_readrq);
/**
* pcie_set_readrq - set PCI Express maximum memory read request
* @dev: PCI device to query
* @rq: maximum memory read count in bytes
* valid values are 128, 256, 512, 1024, 2048, 4096
*
* If possible sets maximum memory read request in bytes
*/
int pcie_set_readrq(struct pci_dev *dev, int rq)
{
u16 v;
if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
return -EINVAL;
/*
* If using the "performance" PCIe config, we clamp the read rq
* size to the max packet size to keep the host bridge from
* generating requests larger than we can cope with.
*/
if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
int mps = pcie_get_mps(dev);
if (mps < rq)
rq = mps;
}
v = (ffs(rq) - 8) << 12;
return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_READRQ, v);
}
EXPORT_SYMBOL(pcie_set_readrq);
/**
* pcie_get_mps - get PCI Express maximum payload size
* @dev: PCI device to query
*
* Returns maximum payload size in bytes
*/
int pcie_get_mps(struct pci_dev *dev)
{
u16 ctl;
pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
}
EXPORT_SYMBOL(pcie_get_mps);
/**
* pcie_set_mps - set PCI Express maximum payload size
* @dev: PCI device to query
* @mps: maximum payload size in bytes
* valid values are 128, 256, 512, 1024, 2048, 4096
*
* If possible sets maximum payload size
*/
int pcie_set_mps(struct pci_dev *dev, int mps)
{
u16 v;
if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
return -EINVAL;
v = ffs(mps) - 8;
if (v > dev->pcie_mpss)
return -EINVAL;
v <<= 5;
return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_PAYLOAD, v);
}
EXPORT_SYMBOL(pcie_set_mps);
/**
* pcie_bandwidth_available - determine minimum link settings of a PCIe
* device and its bandwidth limitation
* @dev: PCI device to query
* @limiting_dev: storage for device causing the bandwidth limitation
* @speed: storage for speed of limiting device
* @width: storage for width of limiting device
*
* Walk up the PCI device chain and find the point where the minimum
* bandwidth is available. Return the bandwidth available there and (if
* limiting_dev, speed, and width pointers are supplied) information about
* that point. The bandwidth returned is in Mb/s, i.e., megabits/second of
* raw bandwidth.
*/
u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
enum pci_bus_speed *speed,
enum pcie_link_width *width)
{
u16 lnksta;
enum pci_bus_speed next_speed;
enum pcie_link_width next_width;
u32 bw, next_bw;
if (speed)
*speed = PCI_SPEED_UNKNOWN;
if (width)
*width = PCIE_LNK_WIDTH_UNKNOWN;
bw = 0;
while (dev) {
pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
PCI_EXP_LNKSTA_NLW_SHIFT;
next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed);
/* Check if current device limits the total bandwidth */
if (!bw || next_bw <= bw) {
bw = next_bw;
if (limiting_dev)
*limiting_dev = dev;
if (speed)
*speed = next_speed;
if (width)
*width = next_width;
}
dev = pci_upstream_bridge(dev);
}
return bw;
}
EXPORT_SYMBOL(pcie_bandwidth_available);
/**
* pcie_get_speed_cap - query for the PCI device's link speed capability
* @dev: PCI device to query
*
* Query the PCI device speed capability. Return the maximum link speed
* supported by the device.
*/
enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
{
u32 lnkcap2, lnkcap;
/*
* Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The
* implementation note there recommends using the Supported Link
* Speeds Vector in Link Capabilities 2 when supported.
*
* Without Link Capabilities 2, i.e., prior to PCIe r3.0, software
* should use the Supported Link Speeds field in Link Capabilities,
* where only 2.5 GT/s and 5.0 GT/s speeds were defined.
*/
pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
if (lnkcap2) { /* PCIe r3.0-compliant */
if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB)
return PCIE_SPEED_32_0GT;
else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
return PCIE_SPEED_16_0GT;
else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
return PCIE_SPEED_8_0GT;
else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
return PCIE_SPEED_5_0GT;
else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
return PCIE_SPEED_2_5GT;
return PCI_SPEED_UNKNOWN;
}
pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
return PCIE_SPEED_5_0GT;
else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB)
return PCIE_SPEED_2_5GT;
return PCI_SPEED_UNKNOWN;
}
EXPORT_SYMBOL(pcie_get_speed_cap);
/**
* pcie_get_width_cap - query for the PCI device's link width capability
* @dev: PCI device to query
*
* Query the PCI device width capability. Return the maximum link width
* supported by the device.
*/
enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
{
u32 lnkcap;
pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
if (lnkcap)
return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;
return PCIE_LNK_WIDTH_UNKNOWN;
}
EXPORT_SYMBOL(pcie_get_width_cap);
/**
* pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability
* @dev: PCI device
* @speed: storage for link speed
* @width: storage for link width
*
* Calculate a PCI device's link bandwidth by querying for its link speed
* and width, multiplying them, and applying encoding overhead. The result
* is in Mb/s, i.e., megabits/second of raw bandwidth.
*/
u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
enum pcie_link_width *width)
{
*speed = pcie_get_speed_cap(dev);
*width = pcie_get_width_cap(dev);
if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN)
return 0;
return *width * PCIE_SPEED2MBS_ENC(*speed);
}
/**
* __pcie_print_link_status - Report the PCI device's link speed and width
* @dev: PCI device to query
* @verbose: Print info even when enough bandwidth is available
*
* If the available bandwidth at the device is less than the device is
* capable of, report the device's maximum possible bandwidth and the
* upstream link that limits its performance. If @verbose, always print
* the available bandwidth, even if the device isn't constrained.
*/
void __pcie_print_link_status(struct pci_dev *dev, bool verbose)
{
enum pcie_link_width width, width_cap;
enum pci_bus_speed speed, speed_cap;
struct pci_dev *limiting_dev = NULL;
u32 bw_avail, bw_cap;
bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap);
bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width);
if (bw_avail >= bw_cap && verbose)
pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
bw_cap / 1000, bw_cap % 1000,
PCIE_SPEED2STR(speed_cap), width_cap);
else if (bw_avail < bw_cap)
pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
bw_avail / 1000, bw_avail % 1000,
PCIE_SPEED2STR(speed), width,
limiting_dev ? pci_name(limiting_dev) : "<unknown>",
bw_cap / 1000, bw_cap % 1000,
PCIE_SPEED2STR(speed_cap), width_cap);
}
/**
* pcie_print_link_status - Report the PCI device's link speed and width
* @dev: PCI device to query
*
* Report the available bandwidth at the device.
*/
void pcie_print_link_status(struct pci_dev *dev)
{
__pcie_print_link_status(dev, true);
}
EXPORT_SYMBOL(pcie_print_link_status);
/**
* pci_select_bars - Make BAR mask from the type of resource
* @dev: the PCI device for which BAR mask is made
* @flags: resource type mask to be selected
*
* This helper routine makes bar mask from the type of resource.
*/
int pci_select_bars(struct pci_dev *dev, unsigned long flags)
{
int i, bars = 0;
for (i = 0; i < PCI_NUM_RESOURCES; i++)
if (pci_resource_flags(dev, i) & flags)
bars |= (1 << i);
return bars;
}
EXPORT_SYMBOL(pci_select_bars);
/* Some architectures require additional programming to enable VGA */
static arch_set_vga_state_t arch_set_vga_state;
void __init pci_register_set_vga_state(arch_set_vga_state_t func)
{
arch_set_vga_state = func; /* NULL disables */
}
static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
unsigned int command_bits, u32 flags)
{
if (arch_set_vga_state)
return arch_set_vga_state(dev, decode, command_bits,
flags);
return 0;
}
/**
* pci_set_vga_state - set VGA decode state on device and parents if requested
* @dev: the PCI device
* @decode: true = enable decoding, false = disable decoding
* @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
* @flags: traverse ancestors and change bridges
* CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
*/
int pci_set_vga_state(struct pci_dev *dev, bool decode,
unsigned int command_bits, u32 flags)
{
struct pci_bus *bus;
struct pci_dev *bridge;
u16 cmd;
int rc;
WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
/* ARCH specific VGA enables */
rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
if (rc)
return rc;
if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (decode == true)
cmd |= command_bits;
else
cmd &= ~command_bits;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
return 0;
bus = dev->bus;
while (bus) {
bridge = bus->self;
if (bridge) {
pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
&cmd);
if (decode == true)
cmd |= PCI_BRIDGE_CTL_VGA;
else
cmd &= ~PCI_BRIDGE_CTL_VGA;
pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
cmd);
}
bus = bus->parent;
}
return 0;
}
/**
* pci_add_dma_alias - Add a DMA devfn alias for a device
* @dev: the PCI device for which alias is added
* @devfn: alias slot and function
*
* This helper encodes an 8-bit devfn as a bit number in dma_alias_mask
* which is used to program permissible bus-devfn source addresses for DMA
* requests in an IOMMU. These aliases factor into IOMMU group creation
* and are useful for devices generating DMA requests beyond or different
* from their logical bus-devfn. Examples include device quirks where the
* device simply uses the wrong devfn, as well as non-transparent bridges
* where the alias may be a proxy for devices in another domain.
*
* IOMMU group creation is performed during device discovery or addition,
* prior to any potential DMA mapping and therefore prior to driver probing
* (especially for userspace assigned devices where IOMMU group definition
* cannot be left as a userspace activity). DMA aliases should therefore
* be configured via quirks, such as the PCI fixup header quirk.
*/
void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
{
if (!dev->dma_alias_mask)
dev->dma_alias_mask = bitmap_zalloc(U8_MAX, GFP_KERNEL);
if (!dev->dma_alias_mask) {
pci_warn(dev, "Unable to allocate DMA alias mask\n");
return;
}
set_bit(devfn, dev->dma_alias_mask);
pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
PCI_SLOT(devfn), PCI_FUNC(devfn));
}
bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2)
{
return (dev1->dma_alias_mask &&
test_bit(dev2->devfn, dev1->dma_alias_mask)) ||
(dev2->dma_alias_mask &&
test_bit(dev1->devfn, dev2->dma_alias_mask));
}
bool pci_device_is_present(struct pci_dev *pdev)
{
u32 v;
if (pci_dev_is_disconnected(pdev))
return false;
return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
}
EXPORT_SYMBOL_GPL(pci_device_is_present);
void pci_ignore_hotplug(struct pci_dev *dev)
{
struct pci_dev *bridge = dev->bus->self;
dev->ignore_hotplug = 1;
/* Propagate the "ignore hotplug" setting to the parent bridge. */
if (bridge)
bridge->ignore_hotplug = 1;
}
EXPORT_SYMBOL_GPL(pci_ignore_hotplug);
resource_size_t __weak pcibios_default_alignment(void)
{
return 0;
}
/*
* Arches that don't want to expose struct resource to userland as-is in
* sysfs and /proc can implement their own pci_resource_to_user().
*/
void __weak pci_resource_to_user(const struct pci_dev *dev, int bar,
const struct resource *rsrc,
resource_size_t *start, resource_size_t *end)
{
*start = rsrc->start;
*end = rsrc->end;
}
static char *resource_alignment_param;
static DEFINE_SPINLOCK(resource_alignment_lock);
/**
* pci_specified_resource_alignment - get resource alignment specified by user.
* @dev: the PCI device to get
* @resize: whether or not to change resources' size when reassigning alignment
*
* RETURNS: Resource alignment if it is specified.
* Zero if it is not specified.
*/
static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
bool *resize)
{
int align_order, count;
resource_size_t align = pcibios_default_alignment();
const char *p;
int ret;
spin_lock(&resource_alignment_lock);
p = resource_alignment_param;
if (!p || !*p)
goto out;
if (pci_has_flag(PCI_PROBE_ONLY)) {
align = 0;
pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n");
goto out;
}
while (*p) {
count = 0;
if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
p[count] == '@') {
p += count + 1;
} else {
align_order = -1;
}
ret = pci_dev_str_match(dev, p, &p);
if (ret == 1) {
*resize = true;
if (align_order == -1)
align = PAGE_SIZE;
else
align = 1 << align_order;
break;
} else if (ret < 0) {
pr_err("PCI: Can't parse resource_alignment parameter: %s\n",
p);
break;
}
if (*p != ';' && *p != ',') {
/* End of param or invalid format */
break;
}
p++;
}
out:
spin_unlock(&resource_alignment_lock);
return align;
}
static void pci_request_resource_alignment(struct pci_dev *dev, int bar,
resource_size_t align, bool resize)
{
struct resource *r = &dev->resource[bar];
resource_size_t size;
if (!(r->flags & IORESOURCE_MEM))
return;
if (r->flags & IORESOURCE_PCI_FIXED) {
pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n",
bar, r, (unsigned long long)align);
return;
}
size = resource_size(r);
if (size >= align)
return;
/*
* Increase the alignment of the resource. There are two ways we
* can do this:
*
* 1) Increase the size of the resource. BARs are aligned on their
* size, so when we reallocate space for this resource, we'll
* allocate it with the larger alignment. This also prevents
* assignment of any other BARs inside the alignment region, so
* if we're requesting page alignment, this means no other BARs
* will share the page.
*
* The disadvantage is that this makes the resource larger than
* the hardware BAR, which may break drivers that compute things
* based on the resource size, e.g., to find registers at a
* fixed offset before the end of the BAR.
*
* 2) Retain the resource size, but use IORESOURCE_STARTALIGN and
* set r->start to the desired alignment. By itself this
* doesn't prevent other BARs being put inside the alignment
* region, but if we realign *every* resource of every device in
* the system, none of them will share an alignment region.
*
* When the user has requested alignment for only some devices via
* the "pci=resource_alignment" argument, "resize" is true and we
* use the first method. Otherwise we assume we're aligning all
* devices and we use the second.
*/
pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n",
bar, r, (unsigned long long)align);
if (resize) {
r->start = 0;
r->end = align - 1;
} else {
r->flags &= ~IORESOURCE_SIZEALIGN;
r->flags |= IORESOURCE_STARTALIGN;
r->start = align;
r->end = r->start + size - 1;
}
r->flags |= IORESOURCE_UNSET;
}
/*
* This function disables memory decoding and releases memory resources
* of the device specified by kernel's boot parameter 'pci=resource_alignment='.
* It also rounds up size to specified alignment.
* Later on, the kernel will assign page-aligned memory resource back
* to the device.
*/
void pci_reassigndev_resource_alignment(struct pci_dev *dev)
{
int i;
struct resource *r;
resource_size_t align;
u16 command;
bool resize = false;
/*
* VF BARs are read-only zero according to SR-IOV spec r1.1, sec
* 3.4.1.11. Their resources are allocated from the space
* described by the VF BARx register in the PF's SR-IOV capability.
* We can't influence their alignment here.
*/
if (dev->is_virtfn)
return;
/* check if specified PCI is target device to reassign */
align = pci_specified_resource_alignment(dev, &resize);
if (!align)
return;
if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
(dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
pci_warn(dev, "Can't reassign resources to host bridge\n");
return;
}
pci_read_config_word(dev, PCI_COMMAND, &command);
command &= ~PCI_COMMAND_MEMORY;
pci_write_config_word(dev, PCI_COMMAND, command);
for (i = 0; i <= PCI_ROM_RESOURCE; i++)
pci_request_resource_alignment(dev, i, align, resize);
/*
* Need to disable bridge's resource window,
* to enable the kernel to reassign new resource
* window later on.
*/
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
r = &dev->resource[i];
if (!(r->flags & IORESOURCE_MEM))
continue;
r->flags |= IORESOURCE_UNSET;
r->end = resource_size(r) - 1;
r->start = 0;
}
pci_disable_bridge_window(dev);
}
}
static ssize_t resource_alignment_show(struct bus_type *bus, char *buf)
{
size_t count = 0;
spin_lock(&resource_alignment_lock);
if (resource_alignment_param)
count = snprintf(buf, PAGE_SIZE, "%s", resource_alignment_param);
spin_unlock(&resource_alignment_lock);
/*
* When set by the command line, resource_alignment_param will not
* have a trailing line feed, which is ugly. So conditionally add
* it here.
*/
if (count >= 2 && buf[count - 2] != '\n' && count < PAGE_SIZE - 1) {
buf[count - 1] = '\n';
buf[count++] = 0;
}
return count;
}
static ssize_t resource_alignment_store(struct bus_type *bus,
const char *buf, size_t count)
{
char *param = kstrndup(buf, count, GFP_KERNEL);
if (!param)
return -ENOMEM;
spin_lock(&resource_alignment_lock);
kfree(resource_alignment_param);
resource_alignment_param = param;
spin_unlock(&resource_alignment_lock);
return count;
}
static BUS_ATTR_RW(resource_alignment);
static int __init pci_resource_alignment_sysfs_init(void)
{
return bus_create_file(&pci_bus_type,
&bus_attr_resource_alignment);
}
late_initcall(pci_resource_alignment_sysfs_init);
static void pci_no_domains(void)
{
#ifdef CONFIG_PCI_DOMAINS
pci_domains_supported = 0;
#endif
}
#ifdef CONFIG_PCI_DOMAINS_GENERIC
static atomic_t __domain_nr = ATOMIC_INIT(-1);
static int pci_get_new_domain_nr(void)
{
return atomic_inc_return(&__domain_nr);
}
static int of_pci_bus_find_domain_nr(struct device *parent)
{
static int use_dt_domains = -1;
int domain = -1;
if (parent)
domain = of_get_pci_domain_nr(parent->of_node);
/*
* Check DT domain and use_dt_domains values.
*
* If DT domain property is valid (domain >= 0) and
* use_dt_domains != 0, the DT assignment is valid since this means
* we have not previously allocated a domain number by using
* pci_get_new_domain_nr(); we should also update use_dt_domains to
* 1, to indicate that we have just assigned a domain number from
* DT.
*
* If DT domain property value is not valid (ie domain < 0), and we
* have not previously assigned a domain number from DT
* (use_dt_domains != 1) we should assign a domain number by
* using the:
*
* pci_get_new_domain_nr()
*
* API and update the use_dt_domains value to keep track of method we
* are using to assign domain numbers (use_dt_domains = 0).
*
* All other combinations imply we have a platform that is trying
* to mix domain numbers obtained from DT and pci_get_new_domain_nr(),
* which is a recipe for domain mishandling and it is prevented by
* invalidating the domain value (domain = -1) and printing a
* corresponding error.
*/
if (domain >= 0 && use_dt_domains) {
use_dt_domains = 1;
} else if (domain < 0 && use_dt_domains != 1) {
use_dt_domains = 0;
domain = pci_get_new_domain_nr();
} else {
if (parent)
pr_err("Node %pOF has ", parent->of_node);
pr_err("Inconsistent \"linux,pci-domain\" property in DT\n");
domain = -1;
}
return domain;
}
int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
{
return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
acpi_pci_bus_find_domain_nr(bus);
}
#endif
/**
* pci_ext_cfg_avail - can we access extended PCI config space?
*
* Returns 1 if we can access PCI extended config space (offsets
* greater than 0xff). This is the default implementation. Architecture
* implementations can override this.
*/
int __weak pci_ext_cfg_avail(void)
{
return 1;
}
void __weak pci_fixup_cardbus(struct pci_bus *bus)
{
}
EXPORT_SYMBOL(pci_fixup_cardbus);
static int __init pci_setup(char *str)
{
while (str) {
char *k = strchr(str, ',');
if (k)
*k++ = 0;
if (*str && (str = pcibios_setup(str)) && *str) {
if (!strcmp(str, "nomsi")) {
pci_no_msi();
} else if (!strncmp(str, "noats", 5)) {
pr_info("PCIe: ATS is disabled\n");
pcie_ats_disabled = true;
} else if (!strcmp(str, "noaer")) {
pci_no_aer();
} else if (!strcmp(str, "earlydump")) {
pci_early_dump = true;
} else if (!strncmp(str, "realloc=", 8)) {
pci_realloc_get_opt(str + 8);
} else if (!strncmp(str, "realloc", 7)) {
pci_realloc_get_opt("on");
} else if (!strcmp(str, "nodomains")) {
pci_no_domains();
} else if (!strncmp(str, "noari", 5)) {
pcie_ari_disabled = true;
} else if (!strncmp(str, "cbiosize=", 9)) {
pci_cardbus_io_size = memparse(str + 9, &str);
} else if (!strncmp(str, "cbmemsize=", 10)) {
pci_cardbus_mem_size = memparse(str + 10, &str);
} else if (!strncmp(str, "resource_alignment=", 19)) {
resource_alignment_param = str + 19;
} else if (!strncmp(str, "ecrc=", 5)) {
pcie_ecrc_get_policy(str + 5);
} else if (!strncmp(str, "hpiosize=", 9)) {
pci_hotplug_io_size = memparse(str + 9, &str);
} else if (!strncmp(str, "hpmmiosize=", 11)) {
pci_hotplug_mmio_size = memparse(str + 11, &str);
} else if (!strncmp(str, "hpmmioprefsize=", 15)) {
pci_hotplug_mmio_pref_size = memparse(str + 15, &str);
} else if (!strncmp(str, "hpmemsize=", 10)) {
pci_hotplug_mmio_size = memparse(str + 10, &str);
pci_hotplug_mmio_pref_size = pci_hotplug_mmio_size;
} else if (!strncmp(str, "hpbussize=", 10)) {
pci_hotplug_bus_size =
simple_strtoul(str + 10, &str, 0);
if (pci_hotplug_bus_size > 0xff)
pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
} else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
pcie_bus_config = PCIE_BUS_TUNE_OFF;
} else if (!strncmp(str, "pcie_bus_safe", 13)) {
pcie_bus_config = PCIE_BUS_SAFE;
} else if (!strncmp(str, "pcie_bus_perf", 13)) {
pcie_bus_config = PCIE_BUS_PERFORMANCE;
} else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
pcie_bus_config = PCIE_BUS_PEER2PEER;
} else if (!strncmp(str, "pcie_scan_all", 13)) {
pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
} else if (!strncmp(str, "disable_acs_redir=", 18)) {
disable_acs_redir_param = str + 18;
} else {
pr_err("PCI: Unknown option `%s'\n", str);
}
}
str = k;
}
return 0;
}
early_param("pci", pci_setup);
/*
* 'resource_alignment_param' and 'disable_acs_redir_param' are initialized
* in pci_setup(), above, to point to data in the __initdata section which
* will be freed after the init sequence is complete. We can't allocate memory
* in pci_setup() because some architectures do not have any memory allocation
* service available during an early_param() call. So we allocate memory and
* copy the variable here before the init section is freed.
*
*/
static int __init pci_realloc_setup_params(void)
{
resource_alignment_param = kstrdup(resource_alignment_param,
GFP_KERNEL);
disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL);
return 0;
}
pure_initcall(pci_realloc_setup_params);
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