drivers/pci/hotplug/pciehprm_acpi.c

   1 /*
   2  * PCIEHPRM ACPI: PHP Resource Manager for ACPI platform
   3  *
   4  * Copyright (C) 2003-2004 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 <linux/acpi.h>
  32 #include <linux/pci-acpi.h>
  33 #include <acpi/acpi_bus.h>
  34 #include <acpi/actypes.h>
  35 #include "pciehp.h"
  36
  37 #define METHOD_NAME__SUN        "_SUN"
  38 #define METHOD_NAME__HPP        "_HPP"
  39 #define METHOD_NAME_OSHP        "OSHP"
  40
  41 static u8 * acpi_path_name( acpi_handle handle)
  42 {
  43         acpi_status             status;
  44         static u8               path_name[ACPI_PATHNAME_MAX];
  45         struct acpi_buffer      ret_buf = { ACPI_PATHNAME_MAX, path_name };
  46
  47         memset(path_name, 0, sizeof (path_name));
  48         status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &ret_buf);
  49
  50         if (ACPI_FAILURE(status))
  51                 return NULL;
  52         else
  53                 return path_name;
  54 }
  55
  56 static acpi_status
  57 acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
  58 {
  59         acpi_status             status;
  60         u8                      nui[4];
  61         struct acpi_buffer      ret_buf = { 0, NULL};
  62         union acpi_object       *ext_obj, *package;
  63         u8                      *path_name = acpi_path_name(handle);
  64         int                     i, len = 0;
  65
  66         /* get _hpp */
  67         status = acpi_evaluate_object(handle, METHOD_NAME__HPP, NULL, &ret_buf);
  68         switch (status) {
  69         case AE_BUFFER_OVERFLOW:
  70                 ret_buf.pointer = kmalloc (ret_buf.length, GFP_KERNEL);
  71                 if (!ret_buf.pointer) {
  72                         err ("%s:%s alloc for _HPP fail\n", __FUNCTION__,
  73                                         path_name);
  74                         return AE_NO_MEMORY;
  75                 }
  76                 status = acpi_evaluate_object(handle, METHOD_NAME__HPP,
  77                                 NULL, &ret_buf);
  78                 if (ACPI_SUCCESS(status))
  79                         break;
  80         default:
  81                 if (ACPI_FAILURE(status)) {
  82                         dbg("%s:%s _HPP fail=0x%x\n", __FUNCTION__,
  83                                         path_name, status);
  84                         return status;
  85                 }
  86         }
  87
  88         ext_obj = (union acpi_object *) ret_buf.pointer;
  89         if (ext_obj->type != ACPI_TYPE_PACKAGE) {
  90                 err ("%s:%s _HPP obj not a package\n", __FUNCTION__,
  91                                 path_name);
  92                 status = AE_ERROR;
  93                 goto free_and_return;
  94         }
  95
  96         len = ext_obj->package.count;
  97         package = (union acpi_object *) ret_buf.pointer;
  98         for ( i = 0; (i < len) || (i < 4); i++) {
  99                 ext_obj = (union acpi_object *) &package->package.elements[i];
 100                 switch (ext_obj->type) {
 101                 case ACPI_TYPE_INTEGER:
 102                         nui[i] = (u8)ext_obj->integer.value;
 103                         break;
 104                 default:
 105                         err ("%s:%s _HPP obj type incorrect\n", __FUNCTION__,
 106                                         path_name);
 107                         status = AE_ERROR;
 108                         goto free_and_return;
 109                 }
 110         }
 111
 112         hpp->cache_line_size = nui[0];
 113         hpp->latency_timer = nui[1];
 114         hpp->enable_serr = nui[2];
 115         hpp->enable_perr = nui[3];
 116
 117         dbg("  _HPP: cache_line_size=0x%x\n", hpp->cache_line_size);
 118         dbg("  _HPP: latency timer  =0x%x\n", hpp->latency_timer);
 119         dbg("  _HPP: enable SERR    =0x%x\n", hpp->enable_serr);
 120         dbg("  _HPP: enable PERR    =0x%x\n", hpp->enable_perr);
 121
 122 free_and_return:
 123         kfree(ret_buf.pointer);
 124         return status;
 125 }
 126
 127 static acpi_status acpi_run_oshp(acpi_handle handle)
 128 {
 129         acpi_status             status;
 130         u8                      *path_name = acpi_path_name(handle);
 131
 132         /* run OSHP */
 133         status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
 134         if (ACPI_FAILURE(status)) {
 135                 dbg("%s:%s OSHP fails=0x%x\n", __FUNCTION__, path_name,
 136                                 status);
 137         } else {
 138                 dbg("%s:%s OSHP passes\n", __FUNCTION__, path_name);
 139         }
 140         return status;
 141 }
 142
 143 static int is_root_bridge(acpi_handle handle)
 144 {
 145         acpi_status status;
 146         struct acpi_device_info *info;
 147         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 148         int i;
 149
 150         status = acpi_get_object_info(handle, &buffer);
 151         if (ACPI_SUCCESS(status)) {
 152                 info = buffer.pointer;
 153                 if ((info->valid & ACPI_VALID_HID) &&
 154                         !strcmp(PCI_ROOT_HID_STRING,
 155                                         info->hardware_id.value)) {
 156                         acpi_os_free(buffer.pointer);
 157                         return 1;
 158                 }
 159                 if (info->valid & ACPI_VALID_CID) {
 160                         for (i=0; i < info->compatibility_id.count; i++) {
 161                                 if (!strcmp(PCI_ROOT_HID_STRING,
 162                                         info->compatibility_id.id[i].value)) {
 163                                         acpi_os_free(buffer.pointer);
 164                                         return 1;
 165                                 }
 166                         }
 167                 }
 168         }
 169         return 0;
 170 }
 171
 172 int pciehp_get_hp_hw_control_from_firmware(struct pci_dev *dev)
 173 {
 174         acpi_status status;
 175         acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
 176         struct pci_dev *pdev = dev;
 177         struct pci_bus *parent;
 178         u8 *path_name;
 179
 180         /*
 181          * Per PCI firmware specification, we should run the ACPI _OSC
 182          * method to get control of hotplug hardware before using it.
 183          * If an _OSC is missing, we look for an OSHP to do the same thing.
 184          * To handle different BIOS behavior, we look for _OSC and OSHP
 185          * within the scope of the hotplug controller and its parents, upto
 186          * the host bridge under which this controller exists.
 187          */
 188         while (!handle) {
 189                 /*
 190                  * This hotplug controller was not listed in the ACPI name
 191                  * space at all. Try to get acpi handle of parent pci bus.
 192                  */
 193                 if (!pdev || !pdev->bus->parent)
 194                         break;
 195                 parent = pdev->bus->parent;
 196                 dbg("Could not find %s in acpi namespace, trying parent\n",
 197                                 pci_name(pdev));
 198                 if (!parent->self)
 199                         /* Parent must be a host bridge */
 200                         handle = acpi_get_pci_rootbridge_handle(
 201                                         pci_domain_nr(parent),
 202                                         parent->number);
 203                 else
 204                         handle = DEVICE_ACPI_HANDLE(
 205                                         &(parent->self->dev));
 206                 pdev = parent->self;
 207         }
 208
 209         while (handle) {
 210                 path_name = acpi_path_name(handle);
 211                 dbg("Trying to get hotplug control for %s \n", path_name);
 212                 status = pci_osc_control_set(handle,
 213                                 OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
 214                 if (status == AE_NOT_FOUND)
 215                         status = acpi_run_oshp(handle);
 216                 if (ACPI_SUCCESS(status)) {
 217                         dbg("Gained control for hotplug HW for pci %s (%s)\n",
 218                                 pci_name(dev), path_name);
 219                         return 0;
 220                 }
 221                 if (is_root_bridge(handle))
 222                         break;
 223                 chandle = handle;
 224                 status = acpi_get_parent(chandle, &handle);
 225                 if (ACPI_FAILURE(status))
 226                         break;
 227         }
 228
 229         err("Cannot get control of hotplug hardware for pci %s\n",
 230                         pci_name(dev));
 231         return -1;
 232 }
 233
 234 void pciehp_get_hp_params_from_firmware(struct pci_dev *dev,
 235                 struct hotplug_params *hpp)
 236 {
 237         acpi_status status = AE_NOT_FOUND;
 238         struct pci_dev *pdev = dev;
 239
 240         /*
 241          * _HPP settings apply to all child buses, until another _HPP is
 242          * encountered. If we don't find an _HPP for the input pci dev,
 243          * look for it in the parent device scope since that would apply to
 244          * this pci dev. If we don't find any _HPP, use hardcoded defaults
 245          */
 246         while (pdev && (ACPI_FAILURE(status))) {
 247                 acpi_handle handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
 248                 if (!handle)
 249                         break;
 250                 status = acpi_run_hpp(handle, hpp);
 251                 if (!(pdev->bus->parent))
 252                         break;
 253                 /* Check if a parent object supports _HPP */
 254                 pdev = pdev->bus->parent->self;
 255         }
 256 }
 257