/*
* PCIEHPRM ACPI: PHP Resource Manager for ACPI platform
*
* Copyright (C) 2003-2004 Intel Corporation
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send feedback to <kristen.c.accardi@intel.com>
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/pci-acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/actypes.h>
#include "pciehp.h"
#define METHOD_NAME__SUN "_SUN"
#define METHOD_NAME__HPP "_HPP"
#define METHOD_NAME_OSHP "OSHP"
static u8 * acpi_path_name( acpi_handle handle)
{
acpi_status status;
static u8 path_name[ACPI_PATHNAME_MAX];
struct acpi_buffer ret_buf = { ACPI_PATHNAME_MAX, path_name };
memset(path_name, 0, sizeof (path_name));
status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &ret_buf);
if (ACPI_FAILURE(status))
return NULL;
else
return path_name;
}
static acpi_status
acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
{
acpi_status status;
u8 nui[4];
struct acpi_buffer ret_buf = { 0, NULL};
union acpi_object *ext_obj, *package;
u8 *path_name = acpi_path_name(handle);
int i, len = 0;
/* get _hpp */
status = acpi_evaluate_object(handle, METHOD_NAME__HPP, NULL, &ret_buf);
switch (status) {
case AE_BUFFER_OVERFLOW:
ret_buf.pointer = kmalloc (ret_buf.length, GFP_KERNEL);
if (!ret_buf.pointer) {
err ("%s:%s alloc for _HPP fail\n", __FUNCTION__,
path_name);
return AE_NO_MEMORY;
}
status = acpi_evaluate_object(handle, METHOD_NAME__HPP,
NULL, &ret_buf);
if (ACPI_SUCCESS(status))
break;
default:
if (ACPI_FAILURE(status)) {
dbg("%s:%s _HPP fail=0x%x\n", __FUNCTION__,
path_name, status);
return status;
}
}
ext_obj = (union acpi_object *) ret_buf.pointer;
if (ext_obj->type != ACPI_TYPE_PACKAGE) {
err ("%s:%s _HPP obj not a package\n", __FUNCTION__,
path_name);
status = AE_ERROR;
goto free_and_return;
}
len = ext_obj->package.count;
package = (union acpi_object *) ret_buf.pointer;
for ( i = 0; (i < len) || (i < 4); i++) {
ext_obj = (union acpi_object *) &package->package.elements[i];
switch (ext_obj->type) {
case ACPI_TYPE_INTEGER:
nui[i] = (u8)ext_obj->integer.value;
break;
default:
err ("%s:%s _HPP obj type incorrect\n", __FUNCTION__,
path_name);
status = AE_ERROR;
goto free_and_return;
}
}
hpp->cache_line_size = nui[0];
hpp->latency_timer = nui[1];
hpp->enable_serr = nui[2];
hpp->enable_perr = nui[3];
dbg(" _HPP: cache_line_size=0x%x\n", hpp->cache_line_size);
dbg(" _HPP: latency timer =0x%x\n", hpp->latency_timer);
dbg(" _HPP: enable SERR =0x%x\n", hpp->enable_serr);
dbg(" _HPP: enable PERR =0x%x\n", hpp->enable_perr);
free_and_return:
kfree(ret_buf.pointer);
return status;
}
static acpi_status acpi_run_oshp(acpi_handle handle)
{
acpi_status status;
u8 *path_name = acpi_path_name(handle);
/* run OSHP */
status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
if (ACPI_FAILURE(status)) {
dbg("%s:%s OSHP fails=0x%x\n", __FUNCTION__, path_name,
status);
} else {
dbg("%s:%s OSHP passes\n", __FUNCTION__, path_name);
}
return status;
}
static int is_root_bridge(acpi_handle handle)
{
acpi_status status;
struct acpi_device_info *info;
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
int i;
status = acpi_get_object_info(handle, &buffer);
if (ACPI_SUCCESS(status)) {
info = buffer.pointer;
if ((info->valid & ACPI_VALID_HID) &&
!strcmp(PCI_ROOT_HID_STRING,
info->hardware_id.value)) {
acpi_os_free(buffer.pointer);
return 1;
}
if (info->valid & ACPI_VALID_CID) {
for (i=0; i < info->compatibility_id.count; i++) {
if (!strcmp(PCI_ROOT_HID_STRING,
info->compatibility_id.id[i].value)) {
acpi_os_free(buffer.pointer);
return 1;
}
}
}
}
return 0;
}
int pciehp_get_hp_hw_control_from_firmware(struct pci_dev *dev)
{
acpi_status status;
acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
struct pci_dev *pdev = dev;
u8 *path_name;
/*
* Per PCI firmware specification, we should run the ACPI _OSC
* method to get control of hotplug hardware before using it.
* If an _OSC is missing, we look for an OSHP to do the same thing.
* To handle different BIOS behavior, we look for _OSC and OSHP
* within the scope of the hotplug controller and its parents, upto
* the host bridge under which this controller exists.
*/
while (!handle) {
/*
* This hotplug controller was not listed in the ACPI name
* space at all. Try to get acpi handle of parent pci bus.
*/
if (!pdev || !pdev->bus->parent)
break;
dbg("Could not find %s in acpi namespace, trying parent\n",
pci_name(pdev));
if (!pdev->bus->parent->self)
/* Parent must be a host bridge */
handle = acpi_get_pci_rootbridge_handle(
pci_domain_nr(pdev->bus->parent),
pdev->bus->parent->number);
else
handle = DEVICE_ACPI_HANDLE(
&(pdev->bus->parent->self->dev));
pdev = pdev->bus->parent->self;
}
while (handle) {
path_name = acpi_path_name(handle);
dbg("Trying to get hotplug control for %s \n", path_name);
status = pci_osc_control_set(handle,
OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
if (status == AE_NOT_FOUND)
status = acpi_run_oshp(handle);
if (ACPI_SUCCESS(status)) {
dbg("Gained control for hotplug HW for pci %s (%s)\n",
pci_name(dev), path_name);
return 0;
}
if (is_root_bridge(handle))
break;
chandle = handle;
status = acpi_get_parent(chandle, &handle);
if (ACPI_FAILURE(status))
break;
}
err("Cannot get control of hotplug hardware for pci %s\n",
pci_name(dev));
return -1;
}
void pciehp_get_hp_params_from_firmware(struct pci_dev *dev,
struct hotplug_params *hpp)
{
acpi_status status = AE_NOT_FOUND;
struct pci_dev *pdev = dev;
/*
* _HPP settings apply to all child buses, until another _HPP is
* encountered. If we don't find an _HPP for the input pci dev,
* look for it in the parent device scope since that would apply to
* this pci dev. If we don't find any _HPP, use hardcoded defaults
*/
while (pdev && (ACPI_FAILURE(status))) {
acpi_handle handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
if (!handle)
break;
status = acpi_run_hpp(handle, hpp);
if (!(pdev->bus->parent))
break;
/* Check if a parent object supports _HPP */
pdev = pdev->bus->parent->self;
}
}
