drivers/acpi/acpica/hwpci.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: hwpci - Obtain PCI bus, device, and function numbers
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2012, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include "accommon.h"
  46
  47 #define _COMPONENT          ACPI_NAMESPACE
  48 ACPI_MODULE_NAME("hwpci")
  49
  50 /* PCI configuration space values */
  51 #define PCI_CFG_HEADER_TYPE_REG             0x0E
  52 #define PCI_CFG_PRIMARY_BUS_NUMBER_REG      0x18
  53 #define PCI_CFG_SECONDARY_BUS_NUMBER_REG    0x19
  54 /* PCI header values */
  55 #define PCI_HEADER_TYPE_MASK                0x7F
  56 #define PCI_TYPE_BRIDGE                     0x01
  57 #define PCI_TYPE_CARDBUS_BRIDGE             0x02
  58 typedef struct acpi_pci_device {
  59         acpi_handle device;
  60         struct acpi_pci_device *next;
  61
  62 } acpi_pci_device;
  63
  64 /* Local prototypes */
  65
  66 static acpi_status
  67 acpi_hw_build_pci_list(acpi_handle root_pci_device,
  68                        acpi_handle pci_region,
  69                        struct acpi_pci_device **return_list_head);
  70
  71 static acpi_status
  72 acpi_hw_process_pci_list(struct acpi_pci_id *pci_id,
  73                          struct acpi_pci_device *list_head);
  74
  75 static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head);
  76
  77 static acpi_status
  78 acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id,
  79                             acpi_handle pci_device,
  80                             u16 *bus_number, u8 *is_bridge);
  81
  82 /*******************************************************************************
  83  *
  84  * FUNCTION:    acpi_hw_derive_pci_id
  85  *
  86  * PARAMETERS:  pci_id              - Initial values for the PCI ID. May be
  87  *                                    modified by this function.
  88  *              root_pci_device     - A handle to a PCI device object. This
  89  *                                    object must be a PCI Root Bridge having a
  90  *                                    _HID value of either PNP0A03 or PNP0A08
  91  *              pci_region          - A handle to a PCI configuration space
  92  *                                    Operation Region being initialized
  93  *
  94  * RETURN:      Status
  95  *
  96  * DESCRIPTION: This function derives a full PCI ID for a PCI device,
  97  *              consisting of a Segment number, Bus number, Device number,
  98  *              and function code.
  99  *
 100  *              The PCI hardware dynamically configures PCI bus numbers
 101  *              depending on the bus topology discovered during system
 102  *              initialization. This function is invoked during configuration
 103  *              of a PCI_Config Operation Region in order to (possibly) update
 104  *              the Bus/Device/Function numbers in the pci_id with the actual
 105  *              values as determined by the hardware and operating system
 106  *              configuration.
 107  *
 108  *              The pci_id parameter is initially populated during the Operation
 109  *              Region initialization. This function is then called, and is
 110  *              will make any necessary modifications to the Bus, Device, or
 111  *              Function number PCI ID subfields as appropriate for the
 112  *              current hardware and OS configuration.
 113  *
 114  * NOTE:        Created 08/2010. Replaces the previous OSL acpi_os_derive_pci_id
 115  *              interface since this feature is OS-independent. This module
 116  *              specifically avoids any use of recursion by building a local
 117  *              temporary device list.
 118  *
 119  ******************************************************************************/
 120
 121 acpi_status
 122 acpi_hw_derive_pci_id(struct acpi_pci_id *pci_id,
 123                       acpi_handle root_pci_device, acpi_handle pci_region)
 124 {
 125         acpi_status status;
 126         struct acpi_pci_device *list_head = NULL;
 127
 128         ACPI_FUNCTION_TRACE(hw_derive_pci_id);
 129
 130         if (!pci_id) {
 131                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 132         }
 133
 134         /* Build a list of PCI devices, from pci_region up to root_pci_device */
 135
 136         status =
 137             acpi_hw_build_pci_list(root_pci_device, pci_region, &list_head);
 138         if (ACPI_SUCCESS(status)) {
 139
 140                 /* Walk the list, updating the PCI device/function/bus numbers */
 141
 142                 status = acpi_hw_process_pci_list(pci_id, list_head);
 143         }
 144
 145         /* Always delete the list */
 146
 147         acpi_hw_delete_pci_list(list_head);
 148         return_ACPI_STATUS(status);
 149 }
 150
 151 /*******************************************************************************
 152  *
 153  * FUNCTION:    acpi_hw_build_pci_list
 154  *
 155  * PARAMETERS:  root_pci_device     - A handle to a PCI device object. This
 156  *                                    object is guaranteed to be a PCI Root
 157  *                                    Bridge having a _HID value of either
 158  *                                    PNP0A03 or PNP0A08
 159  *              pci_region          - A handle to the PCI configuration space
 160  *                                    Operation Region
 161  *              return_list_head    - Where the PCI device list is returned
 162  *
 163  * RETURN:      Status
 164  *
 165  * DESCRIPTION: Builds a list of devices from the input PCI region up to the
 166  *              Root PCI device for this namespace subtree.
 167  *
 168  ******************************************************************************/
 169
 170 static acpi_status
 171 acpi_hw_build_pci_list(acpi_handle root_pci_device,
 172                        acpi_handle pci_region,
 173                        struct acpi_pci_device **return_list_head)
 174 {
 175         acpi_handle current_device;
 176         acpi_handle parent_device;
 177         acpi_status status;
 178         struct acpi_pci_device *list_element;
 179         struct acpi_pci_device *list_head = NULL;
 180
 181         /*
 182          * Ascend namespace branch until the root_pci_device is reached, building
 183          * a list of device nodes. Loop will exit when either the PCI device is
 184          * found, or the root of the namespace is reached.
 185          */
 186         current_device = pci_region;
 187         while (1) {
 188                 status = acpi_get_parent(current_device, &parent_device);
 189                 if (ACPI_FAILURE(status)) {
 190                         return (status);
 191                 }
 192
 193                 /* Finished when we reach the PCI root device (PNP0A03 or PNP0A08) */
 194
 195                 if (parent_device == root_pci_device) {
 196                         *return_list_head = list_head;
 197                         return (AE_OK);
 198                 }
 199
 200                 list_element = ACPI_ALLOCATE(sizeof(struct acpi_pci_device));
 201                 if (!list_element) {
 202                         return (AE_NO_MEMORY);
 203                 }
 204
 205                 /* Put new element at the head of the list */
 206
 207                 list_element->next = list_head;
 208                 list_element->device = parent_device;
 209                 list_head = list_element;
 210
 211                 current_device = parent_device;
 212         }
 213 }
 214
 215 /*******************************************************************************
 216  *
 217  * FUNCTION:    acpi_hw_process_pci_list
 218  *
 219  * PARAMETERS:  pci_id              - Initial values for the PCI ID. May be
 220  *                                    modified by this function.
 221  *              list_head           - Device list created by
 222  *                                    acpi_hw_build_pci_list
 223  *
 224  * RETURN:      Status
 225  *
 226  * DESCRIPTION: Walk downward through the PCI device list, getting the device
 227  *              info for each, via the PCI configuration space and updating
 228  *              the PCI ID as necessary. Deletes the list during traversal.
 229  *
 230  ******************************************************************************/
 231
 232 static acpi_status
 233 acpi_hw_process_pci_list(struct acpi_pci_id *pci_id,
 234                          struct acpi_pci_device *list_head)
 235 {
 236         acpi_status status = AE_OK;
 237         struct acpi_pci_device *info;
 238         u16 bus_number;
 239         u8 is_bridge = TRUE;
 240
 241         ACPI_FUNCTION_NAME(hw_process_pci_list);
 242
 243         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 244                           "Input PciId:  Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X\n",
 245                           pci_id->segment, pci_id->bus, pci_id->device,
 246                           pci_id->function));
 247
 248         bus_number = pci_id->bus;
 249
 250         /*
 251          * Descend down the namespace tree, collecting PCI device, function,
 252          * and bus numbers. bus_number is only important for PCI bridges.
 253          * Algorithm: As we descend the tree, use the last valid PCI device,
 254          * function, and bus numbers that are discovered, and assign them
 255          * to the PCI ID for the target device.
 256          */
 257         info = list_head;
 258         while (info) {
 259                 status = acpi_hw_get_pci_device_info(pci_id, info->device,
 260                                                      &bus_number, &is_bridge);
 261                 if (ACPI_FAILURE(status)) {
 262                         return_ACPI_STATUS(status);
 263                 }
 264
 265                 info = info->next;
 266         }
 267
 268         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
 269                           "Output PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X "
 270                           "Status %X BusNumber %X IsBridge %X\n",
 271                           pci_id->segment, pci_id->bus, pci_id->device,
 272                           pci_id->function, status, bus_number, is_bridge));
 273
 274         return_ACPI_STATUS(AE_OK);
 275 }
 276
 277 /*******************************************************************************
 278  *
 279  * FUNCTION:    acpi_hw_delete_pci_list
 280  *
 281  * PARAMETERS:  list_head           - Device list created by
 282  *                                    acpi_hw_build_pci_list
 283  *
 284  * RETURN:      None
 285  *
 286  * DESCRIPTION: Free the entire PCI list.
 287  *
 288  ******************************************************************************/
 289
 290 static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head)
 291 {
 292         struct acpi_pci_device *next;
 293         struct acpi_pci_device *previous;
 294
 295         next = list_head;
 296         while (next) {
 297                 previous = next;
 298                 next = previous->next;
 299                 ACPI_FREE(previous);
 300         }
 301 }
 302
 303 /*******************************************************************************
 304  *
 305  * FUNCTION:    acpi_hw_get_pci_device_info
 306  *
 307  * PARAMETERS:  pci_id              - Initial values for the PCI ID. May be
 308  *                                    modified by this function.
 309  *              pci_device          - Handle for the PCI device object
 310  *              bus_number          - Where a PCI bridge bus number is returned
 311  *              is_bridge           - Return value, indicates if this PCI
 312  *                                    device is a PCI bridge
 313  *
 314  * RETURN:      Status
 315  *
 316  * DESCRIPTION: Get the device info for a single PCI device object. Get the
 317  *              _ADR (contains PCI device and function numbers), and for PCI
 318  *              bridge devices, get the bus number from PCI configuration
 319  *              space.
 320  *
 321  ******************************************************************************/
 322
 323 static acpi_status
 324 acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id,
 325                             acpi_handle pci_device,
 326                             u16 *bus_number, u8 *is_bridge)
 327 {
 328         acpi_status status;
 329         acpi_object_type object_type;
 330         u64 return_value;
 331         u64 pci_value;
 332
 333         /* We only care about objects of type Device */
 334
 335         status = acpi_get_type(pci_device, &object_type);
 336         if (ACPI_FAILURE(status)) {
 337                 return (status);
 338         }
 339
 340         if (object_type != ACPI_TYPE_DEVICE) {
 341                 return (AE_OK);
 342         }
 343
 344         /* We need an _ADR. Ignore device if not present */
 345
 346         status = acpi_ut_evaluate_numeric_object(METHOD_NAME__ADR,
 347                                                  pci_device, &return_value);
 348         if (ACPI_FAILURE(status)) {
 349                 return (AE_OK);
 350         }
 351
 352         /*
 353          * From _ADR, get the PCI Device and Function and
 354          * update the PCI ID.
 355          */
 356         pci_id->device = ACPI_HIWORD(ACPI_LODWORD(return_value));
 357         pci_id->function = ACPI_LOWORD(ACPI_LODWORD(return_value));
 358
 359         /*
 360          * If the previous device was a bridge, use the previous
 361          * device bus number
 362          */
 363         if (*is_bridge) {
 364                 pci_id->bus = *bus_number;
 365         }
 366
 367         /*
 368          * Get the bus numbers from PCI Config space:
 369          *
 370          * First, get the PCI header_type
 371          */
 372         *is_bridge = FALSE;
 373         status = acpi_os_read_pci_configuration(pci_id,
 374                                                 PCI_CFG_HEADER_TYPE_REG,
 375                                                 &pci_value, 8);
 376         if (ACPI_FAILURE(status)) {
 377                 return (status);
 378         }
 379
 380         /* We only care about bridges (1=pci_bridge, 2=card_bus_bridge) */
 381
 382         pci_value &= PCI_HEADER_TYPE_MASK;
 383
 384         if ((pci_value != PCI_TYPE_BRIDGE) &&
 385             (pci_value != PCI_TYPE_CARDBUS_BRIDGE)) {
 386                 return (AE_OK);
 387         }
 388
 389         /* Bridge: Get the Primary bus_number */
 390
 391         status = acpi_os_read_pci_configuration(pci_id,
 392                                                 PCI_CFG_PRIMARY_BUS_NUMBER_REG,
 393                                                 &pci_value, 8);
 394         if (ACPI_FAILURE(status)) {
 395                 return (status);
 396         }
 397
 398         *is_bridge = TRUE;
 399         pci_id->bus = (u16)pci_value;
 400
 401         /* Bridge: Get the Secondary bus_number */
 402
 403         status = acpi_os_read_pci_configuration(pci_id,
 404                                                 PCI_CFG_SECONDARY_BUS_NUMBER_REG,
 405                                                 &pci_value, 8);
 406         if (ACPI_FAILURE(status)) {
 407                 return (status);
 408         }
 409
 410         *bus_number = (u16)pci_value;
 411         return (AE_OK);
 412 }