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