linux_dsm_epyc7002/arch/x86/pci/i386.c
Dave Airlie 6c00a61e1b intel-agp: add chipset flushing support
This adds support for flushing the chipsets on the 915, 945, 965 and G33
families of Intel chips.

The BIOS doesn't seem to always allocate the BAR on the 965 chipsets
so I have to use pci resource code to create a resource

It adds an export for pcibios_align_resource.
2008-02-05 14:33:32 +10:00

329 lines
9.0 KiB
C

/*
* Low-Level PCI Access for i386 machines
*
* Copyright 1993, 1994 Drew Eckhardt
* Visionary Computing
* (Unix and Linux consulting and custom programming)
* Drew@Colorado.EDU
* +1 (303) 786-7975
*
* Drew's work was sponsored by:
* iX Multiuser Multitasking Magazine
* Hannover, Germany
* hm@ix.de
*
* Copyright 1997--2000 Martin Mares <mj@ucw.cz>
*
* For more information, please consult the following manuals (look at
* http://www.pcisig.com/ for how to get them):
*
* PCI BIOS Specification
* PCI Local Bus Specification
* PCI to PCI Bridge Specification
* PCI System Design Guide
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include "pci.h"
static int
skip_isa_ioresource_align(struct pci_dev *dev) {
if ((pci_probe & PCI_CAN_SKIP_ISA_ALIGN) &&
!(dev->bus->bridge_ctl & PCI_BRIDGE_CTL_ISA))
return 1;
return 0;
}
/*
* We need to avoid collisions with `mirrored' VGA ports
* and other strange ISA hardware, so we always want the
* addresses to be allocated in the 0x000-0x0ff region
* modulo 0x400.
*
* Why? Because some silly external IO cards only decode
* the low 10 bits of the IO address. The 0x00-0xff region
* is reserved for motherboard devices that decode all 16
* bits, so it's ok to allocate at, say, 0x2800-0x28ff,
* but we want to try to avoid allocating at 0x2900-0x2bff
* which might have be mirrored at 0x0100-0x03ff..
*/
void
pcibios_align_resource(void *data, struct resource *res,
resource_size_t size, resource_size_t align)
{
struct pci_dev *dev = data;
if (res->flags & IORESOURCE_IO) {
resource_size_t start = res->start;
if (skip_isa_ioresource_align(dev))
return;
if (start & 0x300) {
start = (start + 0x3ff) & ~0x3ff;
res->start = start;
}
}
}
EXPORT_SYMBOL(pcibios_align_resource);
/*
* Handle resources of PCI devices. If the world were perfect, we could
* just allocate all the resource regions and do nothing more. It isn't.
* On the other hand, we cannot just re-allocate all devices, as it would
* require us to know lots of host bridge internals. So we attempt to
* keep as much of the original configuration as possible, but tweak it
* when it's found to be wrong.
*
* Known BIOS problems we have to work around:
* - I/O or memory regions not configured
* - regions configured, but not enabled in the command register
* - bogus I/O addresses above 64K used
* - expansion ROMs left enabled (this may sound harmless, but given
* the fact the PCI specs explicitly allow address decoders to be
* shared between expansion ROMs and other resource regions, it's
* at least dangerous)
*
* Our solution:
* (1) Allocate resources for all buses behind PCI-to-PCI bridges.
* This gives us fixed barriers on where we can allocate.
* (2) Allocate resources for all enabled devices. If there is
* a collision, just mark the resource as unallocated. Also
* disable expansion ROMs during this step.
* (3) Try to allocate resources for disabled devices. If the
* resources were assigned correctly, everything goes well,
* if they weren't, they won't disturb allocation of other
* resources.
* (4) Assign new addresses to resources which were either
* not configured at all or misconfigured. If explicitly
* requested by the user, configure expansion ROM address
* as well.
*/
static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
{
struct pci_bus *bus;
struct pci_dev *dev;
int idx;
struct resource *r, *pr;
/* Depth-First Search on bus tree */
list_for_each_entry(bus, bus_list, node) {
if ((dev = bus->self)) {
for (idx = PCI_BRIDGE_RESOURCES;
idx < PCI_NUM_RESOURCES; idx++) {
r = &dev->resource[idx];
if (!r->flags)
continue;
pr = pci_find_parent_resource(dev, r);
if (!r->start || !pr ||
request_resource(pr, r) < 0) {
printk(KERN_ERR "PCI: Cannot allocate "
"resource region %d "
"of bridge %s\n",
idx, pci_name(dev));
/*
* Something is wrong with the region.
* Invalidate the resource to prevent
* child resource allocations in this
* range.
*/
r->flags = 0;
}
}
}
pcibios_allocate_bus_resources(&bus->children);
}
}
static void __init pcibios_allocate_resources(int pass)
{
struct pci_dev *dev = NULL;
int idx, disabled;
u16 command;
struct resource *r, *pr;
for_each_pci_dev(dev) {
pci_read_config_word(dev, PCI_COMMAND, &command);
for (idx = 0; idx < PCI_ROM_RESOURCE; idx++) {
r = &dev->resource[idx];
if (r->parent) /* Already allocated */
continue;
if (!r->start) /* Address not assigned at all */
continue;
if (r->flags & IORESOURCE_IO)
disabled = !(command & PCI_COMMAND_IO);
else
disabled = !(command & PCI_COMMAND_MEMORY);
if (pass == disabled) {
DBG("PCI: Resource %08lx-%08lx "
"(f=%lx, d=%d, p=%d)\n",
r->start, r->end, r->flags, disabled, pass);
pr = pci_find_parent_resource(dev, r);
if (!pr || request_resource(pr, r) < 0) {
printk(KERN_ERR "PCI: Cannot allocate "
"resource region %d "
"of device %s\n",
idx, pci_name(dev));
/* We'll assign a new address later */
r->end -= r->start;
r->start = 0;
}
}
}
if (!pass) {
r = &dev->resource[PCI_ROM_RESOURCE];
if (r->flags & IORESOURCE_ROM_ENABLE) {
/* Turn the ROM off, leave the resource region,
* but keep it unregistered. */
u32 reg;
DBG("PCI: Switching off ROM of %s\n",
pci_name(dev));
r->flags &= ~IORESOURCE_ROM_ENABLE;
pci_read_config_dword(dev,
dev->rom_base_reg, &reg);
pci_write_config_dword(dev, dev->rom_base_reg,
reg & ~PCI_ROM_ADDRESS_ENABLE);
}
}
}
}
static int __init pcibios_assign_resources(void)
{
struct pci_dev *dev = NULL;
struct resource *r, *pr;
if (!(pci_probe & PCI_ASSIGN_ROMS)) {
/*
* Try to use BIOS settings for ROMs, otherwise let
* pci_assign_unassigned_resources() allocate the new
* addresses.
*/
for_each_pci_dev(dev) {
r = &dev->resource[PCI_ROM_RESOURCE];
if (!r->flags || !r->start)
continue;
pr = pci_find_parent_resource(dev, r);
if (!pr || request_resource(pr, r) < 0) {
r->end -= r->start;
r->start = 0;
}
}
}
pci_assign_unassigned_resources();
return 0;
}
void __init pcibios_resource_survey(void)
{
DBG("PCI: Allocating resources\n");
pcibios_allocate_bus_resources(&pci_root_buses);
pcibios_allocate_resources(0);
pcibios_allocate_resources(1);
}
/**
* called in fs_initcall (one below subsys_initcall),
* give a chance for motherboard reserve resources
*/
fs_initcall(pcibios_assign_resources);
int pcibios_enable_resources(struct pci_dev *dev, int mask)
{
u16 cmd, old_cmd;
int idx;
struct resource *r;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
old_cmd = cmd;
for (idx = 0; idx < PCI_NUM_RESOURCES; idx++) {
/* Only set up the requested stuff */
if (!(mask & (1 << idx)))
continue;
r = &dev->resource[idx];
if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
continue;
if ((idx == PCI_ROM_RESOURCE) &&
(!(r->flags & IORESOURCE_ROM_ENABLE)))
continue;
if (!r->start && r->end) {
printk(KERN_ERR "PCI: Device %s not available "
"because of resource %d collisions\n",
pci_name(dev), idx);
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (cmd != old_cmd) {
printk("PCI: Enabling device %s (%04x -> %04x)\n",
pci_name(dev), old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
/*
* If we set up a device for bus mastering, we need to check the latency
* timer as certain crappy BIOSes forget to set it properly.
*/
unsigned int pcibios_max_latency = 255;
void pcibios_set_master(struct pci_dev *dev)
{
u8 lat;
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;
printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n",
pci_name(dev), lat);
pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
}
int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
unsigned long prot;
/* I/O space cannot be accessed via normal processor loads and
* stores on this platform.
*/
if (mmap_state == pci_mmap_io)
return -EINVAL;
/* Leave vm_pgoff as-is, the PCI space address is the physical
* address on this platform.
*/
prot = pgprot_val(vma->vm_page_prot);
if (boot_cpu_data.x86 > 3)
prot |= _PAGE_PCD | _PAGE_PWT;
vma->vm_page_prot = __pgprot(prot);
/* Write-combine setting is ignored, it is changed via the mtrr
* interfaces on this platform.
*/
if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot))
return -EAGAIN;
return 0;
}