1 /*******************************************************************************
   2  *
   3  * Module Name: hwpci - Obtain PCI bus, device, and function numbers
   4  *
   5  ******************************************************************************/
   6 
   7 /*
   8  * Copyright (C) 2000 - 2014, 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 #define __HWPCI_C__
  45 
  46 #include "acpi.h"
  47 #include "accommon.h"
  48 
  49 
  50 #define _COMPONENT          ACPI_NAMESPACE
  51         ACPI_MODULE_NAME    ("hwpci")
  52 
  53 
  54 /* PCI configuration space values */
  55 
  56 #define PCI_CFG_HEADER_TYPE_REG             0x0E
  57 #define PCI_CFG_PRIMARY_BUS_NUMBER_REG      0x18
  58 #define PCI_CFG_SECONDARY_BUS_NUMBER_REG    0x19
  59 
  60 /* PCI header values */
  61 
  62 #define PCI_HEADER_TYPE_MASK                0x7F
  63 #define PCI_TYPE_BRIDGE                     0x01
  64 #define PCI_TYPE_CARDBUS_BRIDGE             0x02
  65 
  66 typedef struct acpi_pci_device
  67 {
  68     ACPI_HANDLE             Device;
  69     struct acpi_pci_device  *Next;
  70 
  71 } ACPI_PCI_DEVICE;
  72 
  73 
  74 /* Local prototypes */
  75 
  76 static ACPI_STATUS
  77 AcpiHwBuildPciList (
  78     ACPI_HANDLE             RootPciDevice,
  79     ACPI_HANDLE             PciRegion,
  80     ACPI_PCI_DEVICE         **ReturnListHead);
  81 
  82 static ACPI_STATUS
  83 AcpiHwProcessPciList (
  84     ACPI_PCI_ID             *PciId,
  85     ACPI_PCI_DEVICE         *ListHead);
  86 
  87 static void
  88 AcpiHwDeletePciList (
  89     ACPI_PCI_DEVICE         *ListHead);
  90 
  91 static ACPI_STATUS
  92 AcpiHwGetPciDeviceInfo (
  93     ACPI_PCI_ID             *PciId,
  94     ACPI_HANDLE             PciDevice,
  95     UINT16                  *BusNumber,
  96     BOOLEAN                 *IsBridge);
  97 
  98 
  99 /*******************************************************************************
 100  *
 101  * FUNCTION:    AcpiHwDerivePciId
 102  *
 103  * PARAMETERS:  PciId               - Initial values for the PCI ID. May be
 104  *                                    modified by this function.
 105  *              RootPciDevice       - A handle to a PCI device object. This
 106  *                                    object must be a PCI Root Bridge having a
 107  *                                    _HID value of either PNP0A03 or PNP0A08
 108  *              PciRegion           - A handle to a PCI configuration space
 109  *                                    Operation Region being initialized
 110  *
 111  * RETURN:      Status
 112  *
 113  * DESCRIPTION: This function derives a full PCI ID for a PCI device,
 114  *              consisting of a Segment number, Bus number, Device number,
 115  *              and function code.
 116  *
 117  *              The PCI hardware dynamically configures PCI bus numbers
 118  *              depending on the bus topology discovered during system
 119  *              initialization. This function is invoked during configuration
 120  *              of a PCI_Config Operation Region in order to (possibly) update
 121  *              the Bus/Device/Function numbers in the PciId with the actual
 122  *              values as determined by the hardware and operating system
 123  *              configuration.
 124  *
 125  *              The PciId parameter is initially populated during the Operation
 126  *              Region initialization. This function is then called, and is
 127  *              will make any necessary modifications to the Bus, Device, or
 128  *              Function number PCI ID subfields as appropriate for the
 129  *              current hardware and OS configuration.
 130  *
 131  * NOTE:        Created 08/2010. Replaces the previous OSL AcpiOsDerivePciId
 132  *              interface since this feature is OS-independent. This module
 133  *              specifically avoids any use of recursion by building a local
 134  *              temporary device list.
 135  *
 136  ******************************************************************************/
 137 
 138 ACPI_STATUS
 139 AcpiHwDerivePciId (
 140     ACPI_PCI_ID             *PciId,
 141     ACPI_HANDLE             RootPciDevice,
 142     ACPI_HANDLE             PciRegion)
 143 {
 144     ACPI_STATUS             Status;
 145     ACPI_PCI_DEVICE         *ListHead = NULL;
 146 
 147 
 148     ACPI_FUNCTION_TRACE (HwDerivePciId);
 149 
 150 
 151     if (!PciId)
 152     {
 153         return_ACPI_STATUS (AE_BAD_PARAMETER);
 154     }
 155 
 156     /* Build a list of PCI devices, from PciRegion up to RootPciDevice */
 157 
 158     Status = AcpiHwBuildPciList (RootPciDevice, PciRegion, &ListHead);
 159     if (ACPI_SUCCESS (Status))
 160     {
 161         /* Walk the list, updating the PCI device/function/bus numbers */
 162 
 163         Status = AcpiHwProcessPciList (PciId, ListHead);
 164     }
 165 
 166     /* Always delete the list */
 167 
 168     AcpiHwDeletePciList (ListHead);
 169     return_ACPI_STATUS (Status);
 170 }
 171 
 172 
 173 /*******************************************************************************
 174  *
 175  * FUNCTION:    AcpiHwBuildPciList
 176  *
 177  * PARAMETERS:  RootPciDevice       - A handle to a PCI device object. This
 178  *                                    object is guaranteed to be a PCI Root
 179  *                                    Bridge having a _HID value of either
 180  *                                    PNP0A03 or PNP0A08
 181  *              PciRegion           - A handle to the PCI configuration space
 182  *                                    Operation Region
 183  *              ReturnListHead      - Where the PCI device list is returned
 184  *
 185  * RETURN:      Status
 186  *
 187  * DESCRIPTION: Builds a list of devices from the input PCI region up to the
 188  *              Root PCI device for this namespace subtree.
 189  *
 190  ******************************************************************************/
 191 
 192 static ACPI_STATUS
 193 AcpiHwBuildPciList (
 194     ACPI_HANDLE             RootPciDevice,
 195     ACPI_HANDLE             PciRegion,
 196     ACPI_PCI_DEVICE         **ReturnListHead)
 197 {
 198     ACPI_HANDLE             CurrentDevice;
 199     ACPI_HANDLE             ParentDevice;
 200     ACPI_STATUS             Status;
 201     ACPI_PCI_DEVICE         *ListElement;
 202     ACPI_PCI_DEVICE         *ListHead = NULL;
 203 
 204 
 205     /*
 206      * Ascend namespace branch until the RootPciDevice is reached, building
 207      * a list of device nodes. Loop will exit when either the PCI device is
 208      * found, or the root of the namespace is reached.
 209      */
 210     CurrentDevice = PciRegion;
 211     while (1)
 212     {
 213         Status = AcpiGetParent (CurrentDevice, &ParentDevice);
 214         if (ACPI_FAILURE (Status))
 215         {
 216             return (Status);
 217         }
 218 
 219         /* Finished when we reach the PCI root device (PNP0A03 or PNP0A08) */
 220 
 221         if (ParentDevice == RootPciDevice)
 222         {
 223             *ReturnListHead = ListHead;
 224             return (AE_OK);
 225         }
 226 
 227         ListElement = ACPI_ALLOCATE (sizeof (ACPI_PCI_DEVICE));
 228         if (!ListElement)
 229         {
 230             return (AE_NO_MEMORY);
 231         }
 232 
 233         /* Put new element at the head of the list */
 234 
 235         ListElement->Next = ListHead;
 236         ListElement->Device = ParentDevice;
 237         ListHead = ListElement;
 238 
 239         CurrentDevice = ParentDevice;
 240     }
 241 }
 242 
 243 
 244 /*******************************************************************************
 245  *
 246  * FUNCTION:    AcpiHwProcessPciList
 247  *
 248  * PARAMETERS:  PciId               - Initial values for the PCI ID. May be
 249  *                                    modified by this function.
 250  *              ListHead            - Device list created by
 251  *                                    AcpiHwBuildPciList
 252  *
 253  * RETURN:      Status
 254  *
 255  * DESCRIPTION: Walk downward through the PCI device list, getting the device
 256  *              info for each, via the PCI configuration space and updating
 257  *              the PCI ID as necessary. Deletes the list during traversal.
 258  *
 259  ******************************************************************************/
 260 
 261 static ACPI_STATUS
 262 AcpiHwProcessPciList (
 263     ACPI_PCI_ID             *PciId,
 264     ACPI_PCI_DEVICE         *ListHead)
 265 {
 266     ACPI_STATUS             Status = AE_OK;
 267     ACPI_PCI_DEVICE         *Info;
 268     UINT16                  BusNumber;
 269     BOOLEAN                 IsBridge = TRUE;
 270 
 271 
 272     ACPI_FUNCTION_NAME (HwProcessPciList);
 273 
 274 
 275     ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
 276         "Input PciId:  Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X\n",
 277         PciId->Segment, PciId->Bus, PciId->Device, PciId->Function));
 278 
 279     BusNumber = PciId->Bus;
 280 
 281     /*
 282      * Descend down the namespace tree, collecting PCI device, function,
 283      * and bus numbers. BusNumber is only important for PCI bridges.
 284      * Algorithm: As we descend the tree, use the last valid PCI device,
 285      * function, and bus numbers that are discovered, and assign them
 286      * to the PCI ID for the target device.
 287      */
 288     Info = ListHead;
 289     while (Info)
 290     {
 291         Status = AcpiHwGetPciDeviceInfo (PciId, Info->Device,
 292             &BusNumber, &IsBridge);
 293         if (ACPI_FAILURE (Status))
 294         {
 295             return (Status);
 296         }
 297 
 298         Info = Info->Next;
 299     }
 300 
 301     ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
 302         "Output PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X "
 303         "Status %X BusNumber %X IsBridge %X\n",
 304         PciId->Segment, PciId->Bus, PciId->Device, PciId->Function,
 305         Status, BusNumber, IsBridge));
 306 
 307     return (AE_OK);
 308 }
 309 
 310 
 311 /*******************************************************************************
 312  *
 313  * FUNCTION:    AcpiHwDeletePciList
 314  *
 315  * PARAMETERS:  ListHead            - Device list created by
 316  *                                    AcpiHwBuildPciList
 317  *
 318  * RETURN:      None
 319  *
 320  * DESCRIPTION: Free the entire PCI list.
 321  *
 322  ******************************************************************************/
 323 
 324 static void
 325 AcpiHwDeletePciList (
 326     ACPI_PCI_DEVICE         *ListHead)
 327 {
 328     ACPI_PCI_DEVICE         *Next;
 329     ACPI_PCI_DEVICE         *Previous;
 330 
 331 
 332     Next = ListHead;
 333     while (Next)
 334     {
 335         Previous = Next;
 336         Next = Previous->Next;
 337         ACPI_FREE (Previous);
 338     }
 339 }
 340 
 341 
 342 /*******************************************************************************
 343  *
 344  * FUNCTION:    AcpiHwGetPciDeviceInfo
 345  *
 346  * PARAMETERS:  PciId               - Initial values for the PCI ID. May be
 347  *                                    modified by this function.
 348  *              PciDevice           - Handle for the PCI device object
 349  *              BusNumber           - Where a PCI bridge bus number is returned
 350  *              IsBridge            - Return value, indicates if this PCI
 351  *                                    device is a PCI bridge
 352  *
 353  * RETURN:      Status
 354  *
 355  * DESCRIPTION: Get the device info for a single PCI device object. Get the
 356  *              _ADR (contains PCI device and function numbers), and for PCI
 357  *              bridge devices, get the bus number from PCI configuration
 358  *              space.
 359  *
 360  ******************************************************************************/
 361 
 362 static ACPI_STATUS
 363 AcpiHwGetPciDeviceInfo (
 364     ACPI_PCI_ID             *PciId,
 365     ACPI_HANDLE             PciDevice,
 366     UINT16                  *BusNumber,
 367     BOOLEAN                 *IsBridge)
 368 {
 369     ACPI_STATUS             Status;
 370     ACPI_OBJECT_TYPE        ObjectType;
 371     UINT64                  ReturnValue;
 372     UINT64                  PciValue;
 373 
 374 
 375     /* We only care about objects of type Device */
 376 
 377     Status = AcpiGetType (PciDevice, &ObjectType);
 378     if (ACPI_FAILURE (Status))
 379     {
 380         return (Status);
 381     }
 382 
 383     if (ObjectType != ACPI_TYPE_DEVICE)
 384     {
 385         return (AE_OK);
 386     }
 387 
 388     /* We need an _ADR. Ignore device if not present */
 389 
 390     Status = AcpiUtEvaluateNumericObject (METHOD_NAME__ADR,
 391         PciDevice, &ReturnValue);
 392     if (ACPI_FAILURE (Status))
 393     {
 394         return (AE_OK);
 395     }
 396 
 397     /*
 398      * From _ADR, get the PCI Device and Function and
 399      * update the PCI ID.
 400      */
 401     PciId->Device = ACPI_HIWORD (ACPI_LODWORD (ReturnValue));
 402     PciId->Function = ACPI_LOWORD (ACPI_LODWORD (ReturnValue));
 403 
 404     /*
 405      * If the previous device was a bridge, use the previous
 406      * device bus number
 407      */
 408     if (*IsBridge)
 409     {
 410         PciId->Bus = *BusNumber;
 411     }
 412 
 413     /*
 414      * Get the bus numbers from PCI Config space:
 415      *
 416      * First, get the PCI HeaderType
 417      */
 418     *IsBridge = FALSE;
 419     Status = AcpiOsReadPciConfiguration (PciId,
 420         PCI_CFG_HEADER_TYPE_REG, &PciValue, 8);
 421     if (ACPI_FAILURE (Status))
 422     {
 423         return (Status);
 424     }
 425 
 426     /* We only care about bridges (1=PciBridge, 2=CardBusBridge) */
 427 
 428     PciValue &= PCI_HEADER_TYPE_MASK;
 429 
 430     if ((PciValue != PCI_TYPE_BRIDGE) &&
 431         (PciValue != PCI_TYPE_CARDBUS_BRIDGE))
 432     {
 433         return (AE_OK);
 434     }
 435 
 436     /* Bridge: Get the Primary BusNumber */
 437 
 438     Status = AcpiOsReadPciConfiguration (PciId,
 439         PCI_CFG_PRIMARY_BUS_NUMBER_REG, &PciValue, 8);
 440     if (ACPI_FAILURE (Status))
 441     {
 442         return (Status);
 443     }
 444 
 445     *IsBridge = TRUE;
 446     PciId->Bus = (UINT16) PciValue;
 447 
 448     /* Bridge: Get the Secondary BusNumber */
 449 
 450     Status = AcpiOsReadPciConfiguration (PciId,
 451         PCI_CFG_SECONDARY_BUS_NUMBER_REG, &PciValue, 8);
 452     if (ACPI_FAILURE (Status))
 453     {
 454         return (Status);
 455     }
 456 
 457     *BusNumber = (UINT16) PciValue;
 458     return (AE_OK);
 459 }