kernel-ark/drivers/acpi/glue.c
rajesh.shah@intel.com a3a45ec8f8 [PATCH] pciehp: clean-up how we request control of hotplug hardware
This patch further tweaks how we request control of hotplug
controller hardware from BIOS. We first search the ACPI namespace
corresponding to a specific hotplug controller looking for an
_OSC or OSHP method. On failure, we successively move to the
ACPI parent object, till we hit the highest level host bridge
in the hierarchy. This allows for different types of BIOS's
which place the _OSC/OSHP methods at various places in the acpi
namespace, while still not encroaching on the namespace of
some other root level host bridge.

This patch also introduces a new load time option (pciehp_force)
that allows us to bypass all _OSC/OSHP checking. Not supporting
these methods seems to be be the most common ACPI firmware problem
we've run into. This will still _not_ allow the pciehp driver to
work correctly if the BIOS really doesn't support pciehp (i.e. if
it doesn't generate a hotplug interrupt). Use this option with
caution.  Some BIOS's may deliberately not build any _OSC/OSHP
methods to make sure it retains control the hotplug hardware.
Using the pciehp_force parameter for such systems can lead to
two separate entities trying to control the same hardware.

Signed-off-by: Rajesh Shah <rajesh.shah@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-10 16:09:15 -08:00

361 lines
8.4 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/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>
#define ACPI_GLUE_DEBUG 0
#if ACPI_GLUE_DEBUG
#define DBG(x...) printk(PREFIX x)
#else
#define DBG(x...)
#endif
static LIST_HEAD(bus_type_list);
static DECLARE_RWSEM(bus_type_sem);
int register_acpi_bus_type(struct acpi_bus_type *type)
{
if (acpi_disabled)
return -ENODEV;
if (type && type->bus && 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->bus->name);
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL(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 "ACPI bus type %s unregistered\n",
type->bus->name);
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL(unregister_acpi_bus_type);
static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
{
struct acpi_bus_type *tmp, *ret = NULL;
down_read(&bus_type_sem);
list_for_each_entry(tmp, &bus_type_list, list) {
if (tmp->bus == type) {
ret = tmp;
break;
}
}
up_read(&bus_type_sem);
return ret;
}
static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
{
struct acpi_bus_type *tmp;
int ret = -ENODEV;
down_read(&bus_type_sem);
list_for_each_entry(tmp, &bus_type_list, list) {
if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
ret = 0;
break;
}
}
up_read(&bus_type_sem);
return ret;
}
/* Get PCI root bridge's handle from its segment and bus number */
struct acpi_find_pci_root {
unsigned int seg;
unsigned int bus;
acpi_handle handle;
};
static acpi_status
do_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
{
unsigned long *busnr = (unsigned long *)data;
struct acpi_resource_address64 address;
if (resource->id != ACPI_RSTYPE_ADDRESS16 &&
resource->id != ACPI_RSTYPE_ADDRESS32 &&
resource->id != ACPI_RSTYPE_ADDRESS64)
return AE_OK;
acpi_resource_to_address64(resource, &address);
if ((address.address_length > 0) &&
(address.resource_type == ACPI_BUS_NUMBER_RANGE))
*busnr = address.min_address_range;
return AE_OK;
}
static int get_root_bridge_busnr(acpi_handle handle)
{
acpi_status status;
unsigned long bus, bbn;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
status = acpi_evaluate_integer(handle, METHOD_NAME__BBN, NULL,
&bbn);
if (status == AE_NOT_FOUND) {
/* Assume bus = 0 */
printk(KERN_INFO PREFIX
"Assume root bridge [%s] bus is 0\n",
(char *)buffer.pointer);
status = AE_OK;
bbn = 0;
}
if (ACPI_FAILURE(status)) {
bbn = -ENODEV;
goto exit;
}
if (bbn > 0)
goto exit;
/* _BBN in some systems return 0 for all root bridges */
bus = -1;
status = acpi_walk_resources(handle, METHOD_NAME__CRS,
do_root_bridge_busnr_callback, &bus);
/* If _CRS failed, we just use _BBN */
if (ACPI_FAILURE(status) || (bus == -1))
goto exit;
/* We select _CRS */
if (bbn != bus) {
printk(KERN_INFO PREFIX
"_BBN and _CRS returns different value for %s. Select _CRS\n",
(char *)buffer.pointer);
bbn = bus;
}
exit:
acpi_os_free(buffer.pointer);
return (int)bbn;
}
static acpi_status
find_pci_rootbridge(acpi_handle handle, u32 lvl, void *context, void **rv)
{
struct acpi_find_pci_root *find = (struct acpi_find_pci_root *)context;
unsigned long seg, bus;
acpi_status status;
int tmp;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL, &seg);
if (status == AE_NOT_FOUND) {
/* Assume seg = 0 */
status = AE_OK;
seg = 0;
}
if (ACPI_FAILURE(status)) {
status = AE_CTRL_DEPTH;
goto exit;
}
tmp = get_root_bridge_busnr(handle);
if (tmp < 0) {
printk(KERN_ERR PREFIX
"Find root bridge failed for %s\n",
(char *)buffer.pointer);
status = AE_CTRL_DEPTH;
goto exit;
}
bus = tmp;
if (seg == find->seg && bus == find->bus)
find->handle = handle;
status = AE_OK;
exit:
acpi_os_free(buffer.pointer);
return status;
}
acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
{
struct acpi_find_pci_root find = { seg, bus, NULL };
acpi_get_devices(PCI_ROOT_HID_STRING, find_pci_rootbridge, &find, NULL);
return find.handle;
}
EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
/* Get device's handler per its address under its parent */
struct acpi_find_child {
acpi_handle handle;
acpi_integer address;
};
static acpi_status
do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
{
acpi_status status;
struct acpi_device_info *info;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_find_child *find = (struct acpi_find_child *)context;
status = acpi_get_object_info(handle, &buffer);
if (ACPI_SUCCESS(status)) {
info = buffer.pointer;
if (info->address == find->address)
find->handle = handle;
acpi_os_free(buffer.pointer);
}
return AE_OK;
}
acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
{
struct acpi_find_child find = { NULL, address };
if (!parent)
return NULL;
acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
1, do_acpi_find_child, &find, NULL);
return find.handle;
}
EXPORT_SYMBOL(acpi_get_child);
/* Link ACPI devices with physical devices */
static void acpi_glue_data_handler(acpi_handle handle,
u32 function, void *context)
{
/* we provide an empty handler */
}
/* Note: a success call will increase reference count by one */
struct device *acpi_get_physical_device(acpi_handle handle)
{
acpi_status status;
struct device *dev;
status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
if (ACPI_SUCCESS(status))
return get_device(dev);
return NULL;
}
EXPORT_SYMBOL(acpi_get_physical_device);
static int acpi_bind_one(struct device *dev, acpi_handle handle)
{
acpi_status status;
if (dev->firmware_data) {
printk(KERN_WARNING PREFIX
"Drivers changed 'firmware_data' for %s\n", dev->bus_id);
return -EINVAL;
}
get_device(dev);
status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
if (ACPI_FAILURE(status)) {
put_device(dev);
return -EINVAL;
}
dev->firmware_data = handle;
return 0;
}
static int acpi_unbind_one(struct device *dev)
{
if (!dev->firmware_data)
return 0;
if (dev == acpi_get_physical_device(dev->firmware_data)) {
/* acpi_get_physical_device increase refcnt by one */
put_device(dev);
acpi_detach_data(dev->firmware_data, acpi_glue_data_handler);
dev->firmware_data = NULL;
/* acpi_bind_one increase refcnt by one */
put_device(dev);
} else {
printk(KERN_ERR PREFIX
"Oops, 'firmware_data' corrupt for %s\n", dev->bus_id);
}
return 0;
}
static int acpi_platform_notify(struct device *dev)
{
struct acpi_bus_type *type;
acpi_handle handle;
int ret = -EINVAL;
if (!dev->bus || !dev->parent) {
/* bridge devices genernally haven't bus or parent */
ret = acpi_find_bridge_device(dev, &handle);
goto end;
}
type = acpi_get_bus_type(dev->bus);
if (!type) {
DBG("No ACPI bus support for %s\n", dev->bus_id);
ret = -EINVAL;
goto end;
}
if ((ret = type->find_device(dev, &handle)) != 0)
DBG("Can't get handler for %s\n", dev->bus_id);
end:
if (!ret)
acpi_bind_one(dev, handle);
#if ACPI_GLUE_DEBUG
if (!ret) {
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(dev->firmware_data, ACPI_FULL_PATHNAME, &buffer);
DBG("Device %s -> %s\n", dev->bus_id, (char *)buffer.pointer);
acpi_os_free(buffer.pointer);
} else
DBG("Device %s -> No ACPI support\n", dev->bus_id);
#endif
return ret;
}
static int acpi_platform_notify_remove(struct device *dev)
{
acpi_unbind_one(dev);
return 0;
}
static int __init init_acpi_device_notify(void)
{
if (acpi_disabled)
return 0;
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;
}
arch_initcall(init_acpi_device_notify);