linux_dsm_epyc7002/drivers/acpi/glue.c
Rafael J. Wysocki ac212b6980 ACPI / processor: Use common hotplug infrastructure
Split the ACPI processor driver into two parts, one that is
non-modular, resides in the ACPI core and handles the enumeration
and hotplug of processors and one that implements the rest of the
existing processor driver functionality.

The non-modular part uses an ACPI scan handler object to enumerate
processors on the basis of information provided by the ACPI namespace
and to hook up with the common ACPI hotplug infrastructure.  It also
populates the ACPI handle of each processor device having a
corresponding object in the ACPI namespace, which allows the driver
proper to bind to those devices, and makes the driver bind to them
if it is readily available (i.e. loaded) when the scan handler's
.attach() routine is running.

There are a few reasons to make this change.

First, switching the ACPI processor driver to using the common ACPI
hotplug infrastructure reduces code duplication and size considerably,
even though a new file is created along with a header comment etc.

Second, since the common hotplug code attempts to offline devices
before starting the (non-reversible) removal procedure, it will abort
(and possibly roll back) hot-remove operations involving processors
if cpu_down() returns an error code for one of them instead of
continuing them blindly (if /sys/firmware/acpi/hotplug/force_remove
is unset).  That is a more desirable behavior than what the current
code does.

Finally, the separation of the scan/hotplug part from the driver
proper makes it possible to simplify the driver's .remove() routine,
because it doesn't need to worry about the possible cleanup related
to processor removal any more (the scan/hotplug part is responsible
for that now) and can handle device removal and driver removal
symmetricaly (i.e. as appropriate).

Some user-visible changes in sysfs are made (for example, the
'sysdev' link from the ACPI device node to the processor device's
directory is gone and a 'physical_node' link is present instead
and a corresponding 'firmware_node' is present in the processor
device's directory, the processor driver is now visible under
/sys/bus/cpu/drivers/ and bound to the processor device), but
that shouldn't affect the functionality that users care about
(frequency scaling, C-states and thermal management).

Tested on my venerable Toshiba Portege R500.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
2013-05-12 14:14:32 +02:00

302 lines
6.9 KiB
C

/*
* Link physical devices with ACPI devices support
*
* Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
* Copyright (c) 2005 Intel Corp.
*
* This file is released under the GPLv2.
*/
#include <linux/export.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>
#include "internal.h"
#define ACPI_GLUE_DEBUG 0
#if ACPI_GLUE_DEBUG
#define DBG(fmt, ...) \
printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
#else
#define DBG(fmt, ...) \
do { \
if (0) \
printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__); \
} while (0)
#endif
static LIST_HEAD(bus_type_list);
static DECLARE_RWSEM(bus_type_sem);
#define PHYSICAL_NODE_STRING "physical_node"
int register_acpi_bus_type(struct acpi_bus_type *type)
{
if (acpi_disabled)
return -ENODEV;
if (type && type->match && type->find_device) {
down_write(&bus_type_sem);
list_add_tail(&type->list, &bus_type_list);
up_write(&bus_type_sem);
printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL_GPL(register_acpi_bus_type);
int unregister_acpi_bus_type(struct acpi_bus_type *type)
{
if (acpi_disabled)
return 0;
if (type) {
down_write(&bus_type_sem);
list_del_init(&type->list);
up_write(&bus_type_sem);
printk(KERN_INFO PREFIX "bus type %s unregistered\n",
type->name);
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
{
struct acpi_bus_type *tmp, *ret = NULL;
down_read(&bus_type_sem);
list_for_each_entry(tmp, &bus_type_list, list) {
if (tmp->match(dev)) {
ret = tmp;
break;
}
}
up_read(&bus_type_sem);
return ret;
}
static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used,
void *addr_p, void **ret_p)
{
unsigned long long addr;
acpi_status status;
status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) {
*ret_p = handle;
return AE_CTRL_TERMINATE;
}
return AE_OK;
}
acpi_handle acpi_get_child(acpi_handle parent, u64 address)
{
void *ret = NULL;
if (!parent)
return NULL;
acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, NULL,
do_acpi_find_child, &address, &ret);
return (acpi_handle)ret;
}
EXPORT_SYMBOL(acpi_get_child);
int acpi_bind_one(struct device *dev, acpi_handle handle)
{
struct acpi_device *acpi_dev;
acpi_status status;
struct acpi_device_physical_node *physical_node, *pn;
char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
int retval = -EINVAL;
if (ACPI_HANDLE(dev)) {
if (handle) {
dev_warn(dev, "ACPI handle is already set\n");
return -EINVAL;
} else {
handle = ACPI_HANDLE(dev);
}
}
if (!handle)
return -EINVAL;
get_device(dev);
status = acpi_bus_get_device(handle, &acpi_dev);
if (ACPI_FAILURE(status))
goto err;
physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
if (!physical_node) {
retval = -ENOMEM;
goto err;
}
mutex_lock(&acpi_dev->physical_node_lock);
/* Sanity check. */
list_for_each_entry(pn, &acpi_dev->physical_node_list, node)
if (pn->dev == dev) {
dev_warn(dev, "Already associated with ACPI node\n");
goto err_free;
}
/* allocate physical node id according to physical_node_id_bitmap */
physical_node->node_id =
find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
ACPI_MAX_PHYSICAL_NODE);
if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
retval = -ENOSPC;
goto err_free;
}
set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
physical_node->dev = dev;
list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
acpi_dev->physical_node_count++;
mutex_unlock(&acpi_dev->physical_node_lock);
if (!ACPI_HANDLE(dev))
ACPI_HANDLE_SET(dev, acpi_dev->handle);
if (!physical_node->node_id)
strcpy(physical_node_name, PHYSICAL_NODE_STRING);
else
sprintf(physical_node_name,
"physical_node%d", physical_node->node_id);
retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
physical_node_name);
retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
"firmware_node");
if (acpi_dev->wakeup.flags.valid)
device_set_wakeup_capable(dev, true);
return 0;
err:
ACPI_HANDLE_SET(dev, NULL);
put_device(dev);
return retval;
err_free:
mutex_unlock(&acpi_dev->physical_node_lock);
kfree(physical_node);
goto err;
}
EXPORT_SYMBOL_GPL(acpi_bind_one);
int acpi_unbind_one(struct device *dev)
{
struct acpi_device_physical_node *entry;
struct acpi_device *acpi_dev;
acpi_status status;
struct list_head *node, *next;
if (!ACPI_HANDLE(dev))
return 0;
status = acpi_bus_get_device(ACPI_HANDLE(dev), &acpi_dev);
if (ACPI_FAILURE(status))
goto err;
mutex_lock(&acpi_dev->physical_node_lock);
list_for_each_safe(node, next, &acpi_dev->physical_node_list) {
char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
entry = list_entry(node, struct acpi_device_physical_node,
node);
if (entry->dev != dev)
continue;
list_del(node);
clear_bit(entry->node_id, acpi_dev->physical_node_id_bitmap);
acpi_dev->physical_node_count--;
if (!entry->node_id)
strcpy(physical_node_name, PHYSICAL_NODE_STRING);
else
sprintf(physical_node_name,
"physical_node%d", entry->node_id);
sysfs_remove_link(&acpi_dev->dev.kobj, physical_node_name);
sysfs_remove_link(&dev->kobj, "firmware_node");
ACPI_HANDLE_SET(dev, NULL);
/* acpi_bind_one increase refcnt by one */
put_device(dev);
kfree(entry);
}
mutex_unlock(&acpi_dev->physical_node_lock);
return 0;
err:
dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
return -EINVAL;
}
EXPORT_SYMBOL_GPL(acpi_unbind_one);
static int acpi_platform_notify(struct device *dev)
{
struct acpi_bus_type *type = acpi_get_bus_type(dev);
acpi_handle handle;
int ret;
ret = acpi_bind_one(dev, NULL);
if (ret && type) {
ret = type->find_device(dev, &handle);
if (ret) {
DBG("Unable to get handle for %s\n", dev_name(dev));
goto out;
}
ret = acpi_bind_one(dev, handle);
if (ret)
goto out;
}
if (type && type->setup)
type->setup(dev);
out:
#if ACPI_GLUE_DEBUG
if (!ret) {
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
kfree(buffer.pointer);
} else
DBG("Device %s -> No ACPI support\n", dev_name(dev));
#endif
return ret;
}
static int acpi_platform_notify_remove(struct device *dev)
{
struct acpi_bus_type *type;
type = acpi_get_bus_type(dev);
if (type && type->cleanup)
type->cleanup(dev);
acpi_unbind_one(dev);
return 0;
}
int __init init_acpi_device_notify(void)
{
if (platform_notify || platform_notify_remove) {
printk(KERN_ERR PREFIX "Can't use platform_notify\n");
return 0;
}
platform_notify = acpi_platform_notify;
platform_notify_remove = acpi_platform_notify_remove;
return 0;
}