drivers/pci/hotplug/acpi_pcihp.c

   1 /*
   2  * Common ACPI functions for hot plug platforms
   3  *
   4  * Copyright (C) 2006 Intel Corporation
   5  *
   6  * All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or (at
  11  * your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  16  * NON INFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  * Send feedback to <kristen.c.accardi@intel.com>
  24  *
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/kernel.h>
  29 #include <linux/types.h>
  30 #include <linux/pci.h>
  31 #include <acpi/acpi.h>
  32 #include <acpi/acpi_bus.h>
  33 #include <acpi/actypes.h>
  34 #include "pci_hotplug.h"
  35
  36 #define METHOD_NAME__SUN        "_SUN"
  37 #define METHOD_NAME__HPP        "_HPP"
  38 #define METHOD_NAME_OSHP        "OSHP"
  39
  40
  41 static acpi_status
  42 acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
  43 {
  44         acpi_status             status;
  45         u8                      nui[4];
  46         struct acpi_buffer      ret_buf = { 0, NULL};
  47         struct acpi_buffer      string = { ACPI_ALLOCATE_BUFFER, NULL };
  48         union acpi_object       *ext_obj, *package;
  49         int                     i, len = 0;
  50
  51         acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
  52
  53         /* get _hpp */
  54         status = acpi_evaluate_object(handle, METHOD_NAME__HPP, NULL, &ret_buf);
  55         switch (status) {
  56         case AE_BUFFER_OVERFLOW:
  57                 ret_buf.pointer = kmalloc (ret_buf.length, GFP_KERNEL);
  58                 if (!ret_buf.pointer) {
  59                         printk(KERN_ERR "%s:%s alloc for _HPP fail\n",
  60                                 __FUNCTION__, (char *)string.pointer);
  61                         acpi_os_free(string.pointer);
  62                         return AE_NO_MEMORY;
  63                 }
  64                 status = acpi_evaluate_object(handle, METHOD_NAME__HPP,
  65                                 NULL, &ret_buf);
  66                 if (ACPI_SUCCESS(status))
  67                         break;
  68         default:
  69                 if (ACPI_FAILURE(status)) {
  70                         pr_debug("%s:%s _HPP fail=0x%x\n", __FUNCTION__,
  71                                 (char *)string.pointer, status);
  72                         acpi_os_free(string.pointer);
  73                         return status;
  74                 }
  75         }
  76
  77         ext_obj = (union acpi_object *) ret_buf.pointer;
  78         if (ext_obj->type != ACPI_TYPE_PACKAGE) {
  79                 printk(KERN_ERR "%s:%s _HPP obj not a package\n", __FUNCTION__,
  80                                 (char *)string.pointer);
  81                 status = AE_ERROR;
  82                 goto free_and_return;
  83         }
  84
  85         len = ext_obj->package.count;
  86         package = (union acpi_object *) ret_buf.pointer;
  87         for ( i = 0; (i < len) || (i < 4); i++) {
  88                 ext_obj = (union acpi_object *) &package->package.elements[i];
  89                 switch (ext_obj->type) {
  90                 case ACPI_TYPE_INTEGER:
  91                         nui[i] = (u8)ext_obj->integer.value;
  92                         break;
  93                 default:
  94                         printk(KERN_ERR "%s:%s _HPP obj type incorrect\n",
  95                                 __FUNCTION__, (char *)string.pointer);
  96                         status = AE_ERROR;
  97                         goto free_and_return;
  98                 }
  99         }
 100
 101         hpp->cache_line_size = nui[0];
 102         hpp->latency_timer = nui[1];
 103         hpp->enable_serr = nui[2];
 104         hpp->enable_perr = nui[3];
 105
 106         pr_debug("  _HPP: cache_line_size=0x%x\n", hpp->cache_line_size);
 107         pr_debug("  _HPP: latency timer  =0x%x\n", hpp->latency_timer);
 108         pr_debug("  _HPP: enable SERR    =0x%x\n", hpp->enable_serr);
 109         pr_debug("  _HPP: enable PERR    =0x%x\n", hpp->enable_perr);
 110
 111 free_and_return:
 112         acpi_os_free(string.pointer);
 113         acpi_os_free(ret_buf.pointer);
 114         return status;
 115 }
 116
 117
 118
 119 /* acpi_run_oshp - get control of hotplug from the firmware
 120  *
 121  * @handle - the handle of the hotplug controller.
 122  */
 123 acpi_status acpi_run_oshp(acpi_handle handle)
 124 {
 125         acpi_status             status;
 126         struct acpi_buffer      string = { ACPI_ALLOCATE_BUFFER, NULL };
 127
 128         acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
 129
 130         /* run OSHP */
 131         status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
 132         if (ACPI_FAILURE(status))
 133                 printk(KERN_ERR "%s:%s OSHP fails=0x%x\n", __FUNCTION__,
 134                         (char *)string.pointer, status);
 135         else
 136                 pr_debug("%s:%s OSHP passes\n", __FUNCTION__,
 137                         (char *)string.pointer);
 138
 139         acpi_os_free(string.pointer);
 140         return status;
 141 }
 142 EXPORT_SYMBOL_GPL(acpi_run_oshp);
 143
 144
 145
 146 /* acpi_get_hp_params_from_firmware
 147  *
 148  * @dev - the pci_dev of the newly added device
 149  * @hpp - allocated by the caller
 150  */
 151 acpi_status acpi_get_hp_params_from_firmware(struct pci_dev *dev,
 152                 struct hotplug_params *hpp)
 153 {
 154         acpi_status status = AE_NOT_FOUND;
 155         struct pci_dev *pdev = dev;
 156
 157         /*
 158          * _HPP settings apply to all child buses, until another _HPP is
 159          * encountered. If we don't find an _HPP for the input pci dev,
 160          * look for it in the parent device scope since that would apply to
 161          * this pci dev. If we don't find any _HPP, use hardcoded defaults
 162          */
 163         while (pdev && (ACPI_FAILURE(status))) {
 164                 acpi_handle handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
 165                 if (!handle)
 166                         break;
 167                 status = acpi_run_hpp(handle, hpp);
 168                 if (!(pdev->bus->parent))
 169                         break;
 170                 /* Check if a parent object supports _HPP */
 171                 pdev = pdev->bus->parent->self;
 172         }
 173         return status;
 174 }
 175 EXPORT_SYMBOL_GPL(acpi_get_hp_params_from_firmware);
 176
 177
 178 /* acpi_root_bridge - check to see if this acpi object is a root bridge
 179  *
 180  * @handle - the acpi object in question.
 181  */
 182 int acpi_root_bridge(acpi_handle handle)
 183 {
 184         acpi_status status;
 185         struct acpi_device_info *info;
 186         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 187         int i;
 188
 189         status = acpi_get_object_info(handle, &buffer);
 190         if (ACPI_SUCCESS(status)) {
 191                 info = buffer.pointer;
 192                 if ((info->valid & ACPI_VALID_HID) &&
 193                         !strcmp(PCI_ROOT_HID_STRING,
 194                                         info->hardware_id.value)) {
 195                         acpi_os_free(buffer.pointer);
 196                         return 1;
 197                 }
 198                 if (info->valid & ACPI_VALID_CID) {
 199                         for (i=0; i < info->compatibility_id.count; i++) {
 200                                 if (!strcmp(PCI_ROOT_HID_STRING,
 201                                         info->compatibility_id.id[i].value)) {
 202                                         acpi_os_free(buffer.pointer);
 203                                         return 1;
 204                                 }
 205                         }
 206                 }
 207                 acpi_os_free(buffer.pointer);
 208         }
 209         return 0;
 210 }
 211 EXPORT_SYMBOL_GPL(acpi_root_bridge);