linux_dsm_epyc7002/drivers/pci/hotplug/shpchprm_acpi.c
rajesh.shah@intel.com 424600f970 [PATCH] shpchp: reduce dependence on ACPI
Reduce the SHPC hotplug driver's dependence on ACPI. We don't
walk the acpi namespace anymore to build a list of bridges and
devices. The remaining interaction with ACPI is to run the
_OSHP method to transition control of hotplug hardware from
system BIOS to the shpc hotplug driver, and to run the _HPP
method to get hotplug device parameters like cache line size,
latency timer and SERR/PERR enable from BIOS.

Note that one of the side effects of this patch is that shpchp
does not enable the hot-added device or its DMA bus mastering
automatically now. It expects the device driver to do that.
This may break some drivers and we will have to fix them as
they are reported.

Signed-off-by: Rajesh Shah <rajesh.shah@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28 15:37:00 -07:00

193 lines
5.2 KiB
C

/*
* SHPCHPRM 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/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/efi.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/actypes.h>
#include "shpchp.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 void 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)) {
err("%s:%s OSHP fails=0x%x\n", __FUNCTION__, path_name,
status);
} else {
dbg("%s:%s OSHP passes\n", __FUNCTION__, path_name);
}
}
int shpchprm_get_physical_slot_number(struct controller *ctrl, u32 *sun, u8 busnum, u8 devnum)
{
int offset = devnum - ctrl->slot_device_offset;
dbg("%s: ctrl->slot_num_inc %d, offset %d\n", __FUNCTION__, ctrl->slot_num_inc, offset);
*sun = (u8) (ctrl->first_slot + ctrl->slot_num_inc *offset);
return 0;
}
void get_hp_hw_control_from_firmware(struct pci_dev *dev)
{
/*
* OSHP is an optional ACPI firmware control method. If present,
* we need to run it to inform BIOS that we will control SHPC
* hardware from now on.
*/
acpi_handle handle = DEVICE_ACPI_HANDLE(&(dev->dev));
if (!handle)
return;
acpi_run_oshp(handle);
}
void 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;
}
}