linux/drivers/pci/hotplug/acpi_pcihp.c
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   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/moduleparam.h>
  29#include <linux/kernel.h>
  30#include <linux/types.h>
  31#include <linux/pci.h>
  32#include <linux/pci_hotplug.h>
  33#include <linux/acpi.h>
  34#include <linux/pci-acpi.h>
  35#include <linux/slab.h>
  36
  37#define MY_NAME "acpi_pcihp"
  38
  39#define dbg(fmt, arg...) do { if (debug_acpi) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __func__ , ## arg); } while (0)
  40#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
  41#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
  42#define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)
  43
  44#define METHOD_NAME__SUN        "_SUN"
  45#define METHOD_NAME_OSHP        "OSHP"
  46
  47static bool debug_acpi;
  48
  49static acpi_status
  50decode_type0_hpx_record(union acpi_object *record, struct hotplug_params *hpx)
  51{
  52        int i;
  53        union acpi_object *fields = record->package.elements;
  54        u32 revision = fields[1].integer.value;
  55
  56        switch (revision) {
  57        case 1:
  58                if (record->package.count != 6)
  59                        return AE_ERROR;
  60                for (i = 2; i < 6; i++)
  61                        if (fields[i].type != ACPI_TYPE_INTEGER)
  62                                return AE_ERROR;
  63                hpx->t0 = &hpx->type0_data;
  64                hpx->t0->revision        = revision;
  65                hpx->t0->cache_line_size = fields[2].integer.value;
  66                hpx->t0->latency_timer   = fields[3].integer.value;
  67                hpx->t0->enable_serr     = fields[4].integer.value;
  68                hpx->t0->enable_perr     = fields[5].integer.value;
  69                break;
  70        default:
  71                printk(KERN_WARNING
  72                       "%s: Type 0 Revision %d record not supported\n",
  73                       __func__, revision);
  74                return AE_ERROR;
  75        }
  76        return AE_OK;
  77}
  78
  79static acpi_status
  80decode_type1_hpx_record(union acpi_object *record, struct hotplug_params *hpx)
  81{
  82        int i;
  83        union acpi_object *fields = record->package.elements;
  84        u32 revision = fields[1].integer.value;
  85
  86        switch (revision) {
  87        case 1:
  88                if (record->package.count != 5)
  89                        return AE_ERROR;
  90                for (i = 2; i < 5; i++)
  91                        if (fields[i].type != ACPI_TYPE_INTEGER)
  92                                return AE_ERROR;
  93                hpx->t1 = &hpx->type1_data;
  94                hpx->t1->revision      = revision;
  95                hpx->t1->max_mem_read  = fields[2].integer.value;
  96                hpx->t1->avg_max_split = fields[3].integer.value;
  97                hpx->t1->tot_max_split = fields[4].integer.value;
  98                break;
  99        default:
 100                printk(KERN_WARNING
 101                       "%s: Type 1 Revision %d record not supported\n",
 102                       __func__, revision);
 103                return AE_ERROR;
 104        }
 105        return AE_OK;
 106}
 107
 108static acpi_status
 109decode_type2_hpx_record(union acpi_object *record, struct hotplug_params *hpx)
 110{
 111        int i;
 112        union acpi_object *fields = record->package.elements;
 113        u32 revision = fields[1].integer.value;
 114
 115        switch (revision) {
 116        case 1:
 117                if (record->package.count != 18)
 118                        return AE_ERROR;
 119                for (i = 2; i < 18; i++)
 120                        if (fields[i].type != ACPI_TYPE_INTEGER)
 121                                return AE_ERROR;
 122                hpx->t2 = &hpx->type2_data;
 123                hpx->t2->revision      = revision;
 124                hpx->t2->unc_err_mask_and      = fields[2].integer.value;
 125                hpx->t2->unc_err_mask_or       = fields[3].integer.value;
 126                hpx->t2->unc_err_sever_and     = fields[4].integer.value;
 127                hpx->t2->unc_err_sever_or      = fields[5].integer.value;
 128                hpx->t2->cor_err_mask_and      = fields[6].integer.value;
 129                hpx->t2->cor_err_mask_or       = fields[7].integer.value;
 130                hpx->t2->adv_err_cap_and       = fields[8].integer.value;
 131                hpx->t2->adv_err_cap_or        = fields[9].integer.value;
 132                hpx->t2->pci_exp_devctl_and    = fields[10].integer.value;
 133                hpx->t2->pci_exp_devctl_or     = fields[11].integer.value;
 134                hpx->t2->pci_exp_lnkctl_and    = fields[12].integer.value;
 135                hpx->t2->pci_exp_lnkctl_or     = fields[13].integer.value;
 136                hpx->t2->sec_unc_err_sever_and = fields[14].integer.value;
 137                hpx->t2->sec_unc_err_sever_or  = fields[15].integer.value;
 138                hpx->t2->sec_unc_err_mask_and  = fields[16].integer.value;
 139                hpx->t2->sec_unc_err_mask_or   = fields[17].integer.value;
 140                break;
 141        default:
 142                printk(KERN_WARNING
 143                       "%s: Type 2 Revision %d record not supported\n",
 144                       __func__, revision);
 145                return AE_ERROR;
 146        }
 147        return AE_OK;
 148}
 149
 150static acpi_status
 151acpi_run_hpx(acpi_handle handle, struct hotplug_params *hpx)
 152{
 153        acpi_status status;
 154        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 155        union acpi_object *package, *record, *fields;
 156        u32 type;
 157        int i;
 158
 159        /* Clear the return buffer with zeros */
 160        memset(hpx, 0, sizeof(struct hotplug_params));
 161
 162        status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
 163        if (ACPI_FAILURE(status))
 164                return status;
 165
 166        package = (union acpi_object *)buffer.pointer;
 167        if (package->type != ACPI_TYPE_PACKAGE) {
 168                status = AE_ERROR;
 169                goto exit;
 170        }
 171
 172        for (i = 0; i < package->package.count; i++) {
 173                record = &package->package.elements[i];
 174                if (record->type != ACPI_TYPE_PACKAGE) {
 175                        status = AE_ERROR;
 176                        goto exit;
 177                }
 178
 179                fields = record->package.elements;
 180                if (fields[0].type != ACPI_TYPE_INTEGER ||
 181                    fields[1].type != ACPI_TYPE_INTEGER) {
 182                        status = AE_ERROR;
 183                        goto exit;
 184                }
 185
 186                type = fields[0].integer.value;
 187                switch (type) {
 188                case 0:
 189                        status = decode_type0_hpx_record(record, hpx);
 190                        if (ACPI_FAILURE(status))
 191                                goto exit;
 192                        break;
 193                case 1:
 194                        status = decode_type1_hpx_record(record, hpx);
 195                        if (ACPI_FAILURE(status))
 196                                goto exit;
 197                        break;
 198                case 2:
 199                        status = decode_type2_hpx_record(record, hpx);
 200                        if (ACPI_FAILURE(status))
 201                                goto exit;
 202                        break;
 203                default:
 204                        printk(KERN_ERR "%s: Type %d record not supported\n",
 205                               __func__, type);
 206                        status = AE_ERROR;
 207                        goto exit;
 208                }
 209        }
 210 exit:
 211        kfree(buffer.pointer);
 212        return status;
 213}
 214
 215static acpi_status
 216acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
 217{
 218        acpi_status status;
 219        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 220        union acpi_object *package, *fields;
 221        int i;
 222
 223        memset(hpp, 0, sizeof(struct hotplug_params));
 224
 225        status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
 226        if (ACPI_FAILURE(status))
 227                return status;
 228
 229        package = (union acpi_object *) buffer.pointer;
 230        if (package->type != ACPI_TYPE_PACKAGE ||
 231            package->package.count != 4) {
 232                status = AE_ERROR;
 233                goto exit;
 234        }
 235
 236        fields = package->package.elements;
 237        for (i = 0; i < 4; i++) {
 238                if (fields[i].type != ACPI_TYPE_INTEGER) {
 239                        status = AE_ERROR;
 240                        goto exit;
 241                }
 242        }
 243
 244        hpp->t0 = &hpp->type0_data;
 245        hpp->t0->revision        = 1;
 246        hpp->t0->cache_line_size = fields[0].integer.value;
 247        hpp->t0->latency_timer   = fields[1].integer.value;
 248        hpp->t0->enable_serr     = fields[2].integer.value;
 249        hpp->t0->enable_perr     = fields[3].integer.value;
 250
 251exit:
 252        kfree(buffer.pointer);
 253        return status;
 254}
 255
 256
 257
 258/* acpi_run_oshp - get control of hotplug from the firmware
 259 *
 260 * @handle - the handle of the hotplug controller.
 261 */
 262static acpi_status acpi_run_oshp(acpi_handle handle)
 263{
 264        acpi_status             status;
 265        struct acpi_buffer      string = { ACPI_ALLOCATE_BUFFER, NULL };
 266
 267        acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
 268
 269        /* run OSHP */
 270        status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
 271        if (ACPI_FAILURE(status))
 272                if (status != AE_NOT_FOUND)
 273                        printk(KERN_ERR "%s:%s OSHP fails=0x%x\n",
 274                               __func__, (char *)string.pointer, status);
 275                else
 276                        dbg("%s:%s OSHP not found\n",
 277                            __func__, (char *)string.pointer);
 278        else
 279                pr_debug("%s:%s OSHP passes\n", __func__,
 280                        (char *)string.pointer);
 281
 282        kfree(string.pointer);
 283        return status;
 284}
 285
 286/* pci_get_hp_params
 287 *
 288 * @dev - the pci_dev for which we want parameters
 289 * @hpp - allocated by the caller
 290 */
 291int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp)
 292{
 293        acpi_status status;
 294        acpi_handle handle, phandle;
 295        struct pci_bus *pbus;
 296
 297        handle = NULL;
 298        for (pbus = dev->bus; pbus; pbus = pbus->parent) {
 299                handle = acpi_pci_get_bridge_handle(pbus);
 300                if (handle)
 301                        break;
 302        }
 303
 304        /*
 305         * _HPP settings apply to all child buses, until another _HPP is
 306         * encountered. If we don't find an _HPP for the input pci dev,
 307         * look for it in the parent device scope since that would apply to
 308         * this pci dev.
 309         */
 310        while (handle) {
 311                status = acpi_run_hpx(handle, hpp);
 312                if (ACPI_SUCCESS(status))
 313                        return 0;
 314                status = acpi_run_hpp(handle, hpp);
 315                if (ACPI_SUCCESS(status))
 316                        return 0;
 317                if (acpi_is_root_bridge(handle))
 318                        break;
 319                status = acpi_get_parent(handle, &phandle);
 320                if (ACPI_FAILURE(status))
 321                        break;
 322                handle = phandle;
 323        }
 324        return -ENODEV;
 325}
 326EXPORT_SYMBOL_GPL(pci_get_hp_params);
 327
 328/**
 329 * acpi_get_hp_hw_control_from_firmware
 330 * @dev: the pci_dev of the bridge that has a hotplug controller
 331 * @flags: requested control bits for _OSC
 332 *
 333 * Attempt to take hotplug control from firmware.
 334 */
 335int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
 336{
 337        acpi_status status;
 338        acpi_handle chandle, handle;
 339        struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
 340
 341        flags &= OSC_SHPC_NATIVE_HP_CONTROL;
 342        if (!flags) {
 343                err("Invalid flags %u specified!\n", flags);
 344                return -EINVAL;
 345        }
 346
 347        /*
 348         * Per PCI firmware specification, we should run the ACPI _OSC
 349         * method to get control of hotplug hardware before using it. If
 350         * an _OSC is missing, we look for an OSHP to do the same thing.
 351         * To handle different BIOS behavior, we look for _OSC on a root
 352         * bridge preferentially (according to PCI fw spec). Later for
 353         * OSHP within the scope of the hotplug controller and its parents,
 354         * up to the host bridge under which this controller exists.
 355         */
 356        handle = acpi_find_root_bridge_handle(pdev);
 357        if (handle) {
 358                acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
 359                dbg("Trying to get hotplug control for %s\n",
 360                                (char *)string.pointer);
 361                status = acpi_pci_osc_control_set(handle, &flags, flags);
 362                if (ACPI_SUCCESS(status))
 363                        goto got_one;
 364                if (status == AE_SUPPORT)
 365                        goto no_control;
 366                kfree(string.pointer);
 367                string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
 368        }
 369
 370        handle = DEVICE_ACPI_HANDLE(&pdev->dev);
 371        if (!handle) {
 372                /*
 373                 * This hotplug controller was not listed in the ACPI name
 374                 * space at all. Try to get acpi handle of parent pci bus.
 375                 */
 376                struct pci_bus *pbus;
 377                for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
 378                        handle = acpi_pci_get_bridge_handle(pbus);
 379                        if (handle)
 380                                break;
 381                }
 382        }
 383
 384        while (handle) {
 385                acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
 386                dbg("Trying to get hotplug control for %s \n",
 387                    (char *)string.pointer);
 388                status = acpi_run_oshp(handle);
 389                if (ACPI_SUCCESS(status))
 390                        goto got_one;
 391                if (acpi_is_root_bridge(handle))
 392                        break;
 393                chandle = handle;
 394                status = acpi_get_parent(chandle, &handle);
 395                if (ACPI_FAILURE(status))
 396                        break;
 397        }
 398no_control:
 399        dbg("Cannot get control of hotplug hardware for pci %s\n",
 400            pci_name(pdev));
 401        kfree(string.pointer);
 402        return -ENODEV;
 403got_one:
 404        dbg("Gained control for hotplug HW for pci %s (%s)\n",
 405            pci_name(pdev), (char *)string.pointer);
 406        kfree(string.pointer);
 407        return 0;
 408}
 409EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);
 410
 411static int pcihp_is_ejectable(acpi_handle handle)
 412{
 413        acpi_status status;
 414        acpi_handle tmp;
 415        unsigned long long removable;
 416        status = acpi_get_handle(handle, "_ADR", &tmp);
 417        if (ACPI_FAILURE(status))
 418                return 0;
 419        status = acpi_get_handle(handle, "_EJ0", &tmp);
 420        if (ACPI_SUCCESS(status))
 421                return 1;
 422        status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
 423        if (ACPI_SUCCESS(status) && removable)
 424                return 1;
 425        return 0;
 426}
 427
 428/**
 429 * acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
 430 * @pbus: the PCI bus of the PCI slot corresponding to 'handle'
 431 * @handle: ACPI handle to check
 432 *
 433 * Return 1 if handle is ejectable PCI slot, 0 otherwise.
 434 */
 435int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
 436{
 437        acpi_handle bridge_handle, parent_handle;
 438
 439        if (!(bridge_handle = acpi_pci_get_bridge_handle(pbus)))
 440                return 0;
 441        if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
 442                return 0;
 443        if (bridge_handle != parent_handle)
 444                return 0;
 445        return pcihp_is_ejectable(handle);
 446}
 447EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable);
 448
 449static acpi_status
 450check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
 451{
 452        int *found = (int *)context;
 453        if (pcihp_is_ejectable(handle)) {
 454                *found = 1;
 455                return AE_CTRL_TERMINATE;
 456        }
 457        return AE_OK;
 458}
 459
 460/**
 461 * acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
 462 * @handle - handle of the PCI bus to scan
 463 *
 464 * Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
 465 */
 466int acpi_pci_detect_ejectable(acpi_handle handle)
 467{
 468        int found = 0;
 469
 470        if (!handle)
 471                return found;
 472
 473        acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 474                            check_hotplug, NULL, (void *)&found, NULL);
 475        return found;
 476}
 477EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable);
 478
 479module_param(debug_acpi, bool, 0644);
 480MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not");
 481