drivers/ide/ide-acpi.c

   1 /*
   2  * ide-acpi.c
   3  * Provides ACPI support for IDE drives.
   4  *
   5  * Copyright (C) 2005 Intel Corp.
   6  * Copyright (C) 2005 Randy Dunlap
   7  * Copyright (C) 2006 SUSE Linux Products GmbH
   8  * Copyright (C) 2006 Hannes Reinecke
   9  */
  10
  11 #include <linux/ata.h>
  12 #include <linux/delay.h>
  13 #include <linux/device.h>
  14 #include <linux/errno.h>
  15 #include <linux/kernel.h>
  16 #include <acpi/acpi.h>
  17 #include <linux/ide.h>
  18 #include <linux/pci.h>
  19
  20 #include <acpi/acpi_bus.h>
  21 #include <acpi/acnames.h>
  22 #include <acpi/acnamesp.h>
  23 #include <acpi/acparser.h>
  24 #include <acpi/acexcep.h>
  25 #include <acpi/acmacros.h>
  26 #include <acpi/actypes.h>
  27
  28 #define REGS_PER_GTF            7
  29 struct taskfile_array {
  30         u8      tfa[REGS_PER_GTF];      /* regs. 0x1f1 - 0x1f7 */
  31 };
  32
  33 struct GTM_buffer {
  34         u32     PIO_speed0;
  35         u32     DMA_speed0;
  36         u32     PIO_speed1;
  37         u32     DMA_speed1;
  38         u32     GTM_flags;
  39 };
  40
  41 struct ide_acpi_drive_link {
  42         ide_drive_t     *drive;
  43         acpi_handle      obj_handle;
  44         u8               idbuff[512];
  45 };
  46
  47 struct ide_acpi_hwif_link {
  48         ide_hwif_t                      *hwif;
  49         acpi_handle                      obj_handle;
  50         struct GTM_buffer                gtm;
  51         struct ide_acpi_drive_link       master;
  52         struct ide_acpi_drive_link       slave;
  53 };
  54
  55 #undef DEBUGGING
  56 /* note: adds function name and KERN_DEBUG */
  57 #ifdef DEBUGGING
  58 #define DEBPRINT(fmt, args...)  \
  59                 printk(KERN_DEBUG "%s: " fmt, __FUNCTION__, ## args)
  60 #else
  61 #define DEBPRINT(fmt, args...)  do {} while (0)
  62 #endif  /* DEBUGGING */
  63
  64 extern int ide_noacpi;
  65 extern int ide_noacpitfs;
  66 extern int ide_noacpionboot;
  67
  68 /**
  69  * ide_get_dev_handle - finds acpi_handle and PCI device.function
  70  * @dev: device to locate
  71  * @handle: returned acpi_handle for @dev
  72  * @pcidevfn: return PCI device.func for @dev
  73  *
  74  * Returns the ACPI object handle to the corresponding PCI device.
  75  *
  76  * Returns 0 on success, <0 on error.
  77  */
  78 static int ide_get_dev_handle(struct device *dev, acpi_handle *handle,
  79                                acpi_integer *pcidevfn)
  80 {
  81         struct pci_dev *pdev = to_pci_dev(dev);
  82         unsigned int bus, devnum, func;
  83         acpi_integer addr;
  84         acpi_handle dev_handle;
  85         struct acpi_buffer buffer = {.length = ACPI_ALLOCATE_BUFFER,
  86                                         .pointer = NULL};
  87         acpi_status status;
  88         struct acpi_device_info *dinfo = NULL;
  89         int ret = -ENODEV;
  90
  91         bus = pdev->bus->number;
  92         devnum = PCI_SLOT(pdev->devfn);
  93         func = PCI_FUNC(pdev->devfn);
  94         /* ACPI _ADR encoding for PCI bus: */
  95         addr = (acpi_integer)(devnum << 16 | func);
  96
  97         DEBPRINT("ENTER: pci %02x:%02x.%01x\n", bus, devnum, func);
  98
  99         dev_handle = DEVICE_ACPI_HANDLE(dev);
 100         if (!dev_handle) {
 101                 DEBPRINT("no acpi handle for device\n");
 102                 goto err;
 103         }
 104
 105         status = acpi_get_object_info(dev_handle, &buffer);
 106         if (ACPI_FAILURE(status)) {
 107                 DEBPRINT("get_object_info for device failed\n");
 108                 goto err;
 109         }
 110         dinfo = buffer.pointer;
 111         if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
 112             dinfo->address == addr) {
 113                 *pcidevfn = addr;
 114                 *handle = dev_handle;
 115         } else {
 116                 DEBPRINT("get_object_info for device has wrong "
 117                         " address: %llu, should be %u\n",
 118                         dinfo ? (unsigned long long)dinfo->address : -1ULL,
 119                         (unsigned int)addr);
 120                 goto err;
 121         }
 122
 123         DEBPRINT("for dev=0x%x.%x, addr=0x%llx, *handle=0x%p\n",
 124                  devnum, func, (unsigned long long)addr, *handle);
 125         ret = 0;
 126 err:
 127         kfree(dinfo);
 128         return ret;
 129 }
 130
 131 /**
 132  * ide_acpi_hwif_get_handle - Get ACPI object handle for a given hwif
 133  * @hwif: device to locate
 134  *
 135  * Retrieves the object handle for a given hwif.
 136  *
 137  * Returns handle on success, 0 on error.
 138  */
 139 static acpi_handle ide_acpi_hwif_get_handle(ide_hwif_t *hwif)
 140 {
 141         struct device           *dev = hwif->gendev.parent;
 142         acpi_handle             dev_handle;
 143         acpi_integer            pcidevfn;
 144         acpi_handle             chan_handle;
 145         int                     err;
 146
 147         DEBPRINT("ENTER: device %s\n", hwif->name);
 148
 149         if (!dev) {
 150                 DEBPRINT("no PCI device for %s\n", hwif->name);
 151                 return NULL;
 152         }
 153
 154         err = ide_get_dev_handle(dev, &dev_handle, &pcidevfn);
 155         if (err < 0) {
 156                 DEBPRINT("ide_get_dev_handle failed (%d)\n", err);
 157                 return NULL;
 158         }
 159
 160         /* get child objects of dev_handle == channel objects,
 161          * + _their_ children == drive objects */
 162         /* channel is hwif->channel */
 163         chan_handle = acpi_get_child(dev_handle, hwif->channel);
 164         DEBPRINT("chan adr=%d: handle=0x%p\n",
 165                  hwif->channel, chan_handle);
 166
 167         return chan_handle;
 168 }
 169
 170 /**
 171  * ide_acpi_drive_get_handle - Get ACPI object handle for a given drive
 172  * @drive: device to locate
 173  *
 174  * Retrieves the object handle of a given drive. According to the ACPI
 175  * spec the drive is a child of the hwif.
 176  *
 177  * Returns handle on success, 0 on error.
 178  */
 179 static acpi_handle ide_acpi_drive_get_handle(ide_drive_t *drive)
 180 {
 181         ide_hwif_t      *hwif = HWIF(drive);
 182         int              port;
 183         acpi_handle      drive_handle;
 184
 185         if (!hwif->acpidata)
 186                 return NULL;
 187
 188         if (!hwif->acpidata->obj_handle)
 189                 return NULL;
 190
 191         port = hwif->channel ? drive->dn - 2: drive->dn;
 192
 193         DEBPRINT("ENTER: %s at channel#: %d port#: %d\n",
 194                  drive->name, hwif->channel, port);
 195
 196
 197         /* TBD: could also check ACPI object VALID bits */
 198         drive_handle = acpi_get_child(hwif->acpidata->obj_handle, port);
 199         DEBPRINT("drive %s handle 0x%p\n", drive->name, drive_handle);
 200
 201         return drive_handle;
 202 }
 203
 204 /**
 205  * do_drive_get_GTF - get the drive bootup default taskfile settings
 206  * @drive: the drive for which the taskfile settings should be retrieved
 207  * @gtf_length: number of bytes of _GTF data returned at @gtf_address
 208  * @gtf_address: buffer containing _GTF taskfile arrays
 209  *
 210  * The _GTF method has no input parameters.
 211  * It returns a variable number of register set values (registers
 212  * hex 1F1..1F7, taskfiles).
 213  * The <variable number> is not known in advance, so have ACPI-CA
 214  * allocate the buffer as needed and return it, then free it later.
 215  *
 216  * The returned @gtf_length and @gtf_address are only valid if the
 217  * function return value is 0.
 218  */
 219 static int do_drive_get_GTF(ide_drive_t *drive,
 220                      unsigned int *gtf_length, unsigned long *gtf_address,
 221                      unsigned long *obj_loc)
 222 {
 223         acpi_status                     status;
 224         struct acpi_buffer              output;
 225         union acpi_object               *out_obj;
 226         ide_hwif_t                      *hwif = HWIF(drive);
 227         struct device                   *dev = hwif->gendev.parent;
 228         int                             err = -ENODEV;
 229         int                             port;
 230
 231         *gtf_length = 0;
 232         *gtf_address = 0UL;
 233         *obj_loc = 0UL;
 234
 235         if (ide_noacpi)
 236                 return 0;
 237
 238         if (!dev) {
 239                 DEBPRINT("no PCI device for %s\n", hwif->name);
 240                 goto out;
 241         }
 242
 243         if (!hwif->acpidata) {
 244                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 245                 goto out;
 246         }
 247
 248         port = hwif->channel ? drive->dn - 2: drive->dn;
 249
 250         if (!drive->acpidata) {
 251                 if (port == 0) {
 252                         drive->acpidata = &hwif->acpidata->master;
 253                         hwif->acpidata->master.drive = drive;
 254                 } else {
 255                         drive->acpidata = &hwif->acpidata->slave;
 256                         hwif->acpidata->slave.drive = drive;
 257                 }
 258         }
 259
 260         DEBPRINT("ENTER: %s at %s, port#: %d, hard_port#: %d\n",
 261                  hwif->name, dev->bus_id, port, hwif->channel);
 262
 263         if (!drive->present) {
 264                 DEBPRINT("%s drive %d:%d not present\n",
 265                          hwif->name, hwif->channel, port);
 266                 goto out;
 267         }
 268
 269         /* Get this drive's _ADR info. if not already known. */
 270         if (!drive->acpidata->obj_handle) {
 271                 drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
 272                 if (!drive->acpidata->obj_handle) {
 273                         DEBPRINT("No ACPI object found for %s\n",
 274                                  drive->name);
 275                         goto out;
 276                 }
 277         }
 278
 279         /* Setting up output buffer */
 280         output.length = ACPI_ALLOCATE_BUFFER;
 281         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
 282
 283         /* _GTF has no input parameters */
 284         err = -EIO;
 285         status = acpi_evaluate_object(drive->acpidata->obj_handle, "_GTF",
 286                                       NULL, &output);
 287         if (ACPI_FAILURE(status)) {
 288                 printk(KERN_DEBUG
 289                        "%s: Run _GTF error: status = 0x%x\n",
 290                        __FUNCTION__, status);
 291                 goto out;
 292         }
 293
 294         if (!output.length || !output.pointer) {
 295                 DEBPRINT("Run _GTF: "
 296                        "length or ptr is NULL (0x%llx, 0x%p)\n",
 297                        (unsigned long long)output.length,
 298                        output.pointer);
 299                 goto out;
 300         }
 301
 302         out_obj = output.pointer;
 303         if (out_obj->type != ACPI_TYPE_BUFFER) {
 304                 DEBPRINT("Run _GTF: error: "
 305                        "expected object type of ACPI_TYPE_BUFFER, "
 306                        "got 0x%x\n", out_obj->type);
 307                 err = -ENOENT;
 308                 kfree(output.pointer);
 309                 goto out;
 310         }
 311
 312         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
 313             out_obj->buffer.length % REGS_PER_GTF) {
 314                 printk(KERN_ERR
 315                        "%s: unexpected GTF length (%d) or addr (0x%p)\n",
 316                        __FUNCTION__, out_obj->buffer.length,
 317                        out_obj->buffer.pointer);
 318                 err = -ENOENT;
 319                 kfree(output.pointer);
 320                 goto out;
 321         }
 322
 323         *gtf_length = out_obj->buffer.length;
 324         *gtf_address = (unsigned long)out_obj->buffer.pointer;
 325         *obj_loc = (unsigned long)out_obj;
 326         DEBPRINT("returning gtf_length=%d, gtf_address=0x%lx, obj_loc=0x%lx\n",
 327                  *gtf_length, *gtf_address, *obj_loc);
 328         err = 0;
 329 out:
 330         return err;
 331 }
 332
 333 /**
 334  * taskfile_load_raw - send taskfile registers to drive
 335  * @drive: drive to which output is sent
 336  * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
 337  *
 338  * Outputs IDE taskfile to the drive.
 339  */
 340 static int taskfile_load_raw(ide_drive_t *drive,
 341                               const struct taskfile_array *gtf)
 342 {
 343         ide_task_t args;
 344         int err = 0;
 345
 346         DEBPRINT("(0x1f1-1f7): hex: "
 347                "%02x %02x %02x %02x %02x %02x %02x\n",
 348                gtf->tfa[0], gtf->tfa[1], gtf->tfa[2],
 349                gtf->tfa[3], gtf->tfa[4], gtf->tfa[5], gtf->tfa[6]);
 350
 351         memset(&args, 0, sizeof(ide_task_t));
 352         args.command_type = IDE_DRIVE_TASK_NO_DATA;
 353         args.data_phase   = TASKFILE_IN;
 354         args.handler      = &task_no_data_intr;
 355
 356         /* convert gtf to IDE Taskfile */
 357         args.tfRegister[1] = gtf->tfa[0];       /* 0x1f1 */
 358         args.tfRegister[2] = gtf->tfa[1];       /* 0x1f2 */
 359         args.tfRegister[3] = gtf->tfa[2];       /* 0x1f3 */
 360         args.tfRegister[4] = gtf->tfa[3];       /* 0x1f4 */
 361         args.tfRegister[5] = gtf->tfa[4];       /* 0x1f5 */
 362         args.tfRegister[6] = gtf->tfa[5];       /* 0x1f6 */
 363         args.tfRegister[7] = gtf->tfa[6];       /* 0x1f7 */
 364
 365         if (ide_noacpitfs) {
 366                 DEBPRINT("_GTF execution disabled\n");
 367                 return err;
 368         }
 369
 370         err = ide_raw_taskfile(drive, &args, NULL);
 371         if (err)
 372                 printk(KERN_ERR "%s: ide_raw_taskfile failed: %u\n",
 373                        __FUNCTION__, err);
 374
 375         return err;
 376 }
 377
 378 /**
 379  * do_drive_set_taskfiles - write the drive taskfile settings from _GTF
 380  * @drive: the drive to which the taskfile command should be sent
 381  * @gtf_length: total number of bytes of _GTF taskfiles
 382  * @gtf_address: location of _GTF taskfile arrays
 383  *
 384  * Write {gtf_address, length gtf_length} in groups of
 385  * REGS_PER_GTF bytes.
 386  */
 387 static int do_drive_set_taskfiles(ide_drive_t *drive,
 388                                   unsigned int gtf_length,
 389                                   unsigned long gtf_address)
 390 {
 391         int                     rc = -ENODEV, err;
 392         int                     gtf_count = gtf_length / REGS_PER_GTF;
 393         int                     ix;
 394         struct taskfile_array   *gtf;
 395
 396         if (ide_noacpi)
 397                 return 0;
 398
 399         DEBPRINT("ENTER: %s, hard_port#: %d\n", drive->name, drive->dn);
 400
 401         if (!drive->present)
 402                 goto out;
 403         if (!gtf_count)         /* shouldn't be here */
 404                 goto out;
 405
 406         DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx\n",
 407                  gtf_length, gtf_length, gtf_count, gtf_address);
 408
 409         if (gtf_length % REGS_PER_GTF) {
 410                 printk(KERN_ERR "%s: unexpected GTF length (%d)\n",
 411                        __FUNCTION__, gtf_length);
 412                 goto out;
 413         }
 414
 415         rc = 0;
 416         for (ix = 0; ix < gtf_count; ix++) {
 417                 gtf = (struct taskfile_array *)
 418                         (gtf_address + ix * REGS_PER_GTF);
 419
 420                 /* send all TaskFile registers (0x1f1-0x1f7) *in*that*order* */
 421                 err = taskfile_load_raw(drive, gtf);
 422                 if (err)
 423                         rc = err;
 424         }
 425
 426 out:
 427         return rc;
 428 }
 429
 430 /**
 431  * ide_acpi_exec_tfs - get then write drive taskfile settings
 432  * @drive: the drive for which the taskfile settings should be
 433  *         written.
 434  *
 435  * According to the ACPI spec this should be called after _STM
 436  * has been evaluated for the interface. Some ACPI vendors interpret
 437  * that as a hard requirement and modify the taskfile according
 438  * to the Identify Drive information passed down with _STM.
 439  * So one should really make sure to call this only after _STM has
 440  * been executed.
 441  */
 442 int ide_acpi_exec_tfs(ide_drive_t *drive)
 443 {
 444         int             ret;
 445         unsigned int    gtf_length;
 446         unsigned long   gtf_address;
 447         unsigned long   obj_loc;
 448
 449         if (ide_noacpi)
 450                 return 0;
 451
 452         DEBPRINT("call get_GTF, drive=%s port=%d\n", drive->name, drive->dn);
 453
 454         ret = do_drive_get_GTF(drive, &gtf_length, &gtf_address, &obj_loc);
 455         if (ret < 0) {
 456                 DEBPRINT("get_GTF error (%d)\n", ret);
 457                 return ret;
 458         }
 459
 460         DEBPRINT("call set_taskfiles, drive=%s\n", drive->name);
 461
 462         ret = do_drive_set_taskfiles(drive, gtf_length, gtf_address);
 463         kfree((void *)obj_loc);
 464         if (ret < 0) {
 465                 DEBPRINT("set_taskfiles error (%d)\n", ret);
 466         }
 467
 468         DEBPRINT("ret=%d\n", ret);
 469
 470         return ret;
 471 }
 472 EXPORT_SYMBOL_GPL(ide_acpi_exec_tfs);
 473
 474 /**
 475  * ide_acpi_get_timing - get the channel (controller) timings
 476  * @hwif: target IDE interface (channel)
 477  *
 478  * This function executes the _GTM ACPI method for the target channel.
 479  *
 480  */
 481 void ide_acpi_get_timing(ide_hwif_t *hwif)
 482 {
 483         acpi_status             status;
 484         struct acpi_buffer      output;
 485         union acpi_object       *out_obj;
 486
 487         if (ide_noacpi)
 488                 return;
 489
 490         DEBPRINT("ENTER:\n");
 491
 492         if (!hwif->acpidata) {
 493                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 494                 return;
 495         }
 496
 497         /* Setting up output buffer for _GTM */
 498         output.length = ACPI_ALLOCATE_BUFFER;
 499         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
 500
 501         /* _GTM has no input parameters */
 502         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_GTM",
 503                                       NULL, &output);
 504
 505         DEBPRINT("_GTM status: %d, outptr: 0x%p, outlen: 0x%llx\n",
 506                  status, output.pointer,
 507                  (unsigned long long)output.length);
 508
 509         if (ACPI_FAILURE(status)) {
 510                 DEBPRINT("Run _GTM error: status = 0x%x\n", status);
 511                 return;
 512         }
 513
 514         if (!output.length || !output.pointer) {
 515                 DEBPRINT("Run _GTM: length or ptr is NULL (0x%llx, 0x%p)\n",
 516                        (unsigned long long)output.length,
 517                        output.pointer);
 518                 kfree(output.pointer);
 519                 return;
 520         }
 521
 522         out_obj = output.pointer;
 523         if (out_obj->type != ACPI_TYPE_BUFFER) {
 524                 kfree(output.pointer);
 525                 DEBPRINT("Run _GTM: error: "
 526                        "expected object type of ACPI_TYPE_BUFFER, "
 527                        "got 0x%x\n", out_obj->type);
 528                 return;
 529         }
 530
 531         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
 532             out_obj->buffer.length != sizeof(struct GTM_buffer)) {
 533                 kfree(output.pointer);
 534                 printk(KERN_ERR
 535                         "%s: unexpected _GTM length (0x%x)[should be 0x%zx] or "
 536                         "addr (0x%p)\n",
 537                         __FUNCTION__, out_obj->buffer.length,
 538                         sizeof(struct GTM_buffer), out_obj->buffer.pointer);
 539                 return;
 540         }
 541
 542         memcpy(&hwif->acpidata->gtm, out_obj->buffer.pointer,
 543                sizeof(struct GTM_buffer));
 544
 545         DEBPRINT("_GTM info: ptr: 0x%p, len: 0x%x, exp.len: 0x%Zx\n",
 546                  out_obj->buffer.pointer, out_obj->buffer.length,
 547                  sizeof(struct GTM_buffer));
 548
 549         DEBPRINT("_GTM fields: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
 550                  hwif->acpidata->gtm.PIO_speed0,
 551                  hwif->acpidata->gtm.DMA_speed0,
 552                  hwif->acpidata->gtm.PIO_speed1,
 553                  hwif->acpidata->gtm.DMA_speed1,
 554                  hwif->acpidata->gtm.GTM_flags);
 555
 556         kfree(output.pointer);
 557 }
 558 EXPORT_SYMBOL_GPL(ide_acpi_get_timing);
 559
 560 /**
 561  * ide_acpi_push_timing - set the channel (controller) timings
 562  * @hwif: target IDE interface (channel)
 563  *
 564  * This function executes the _STM ACPI method for the target channel.
 565  *
 566  * _STM requires Identify Drive data, which has to passed as an argument.
 567  * Unfortunately hd_driveid is a mangled version which we can't readily
 568  * use; hence we'll get the information afresh.
 569  */
 570 void ide_acpi_push_timing(ide_hwif_t *hwif)
 571 {
 572         acpi_status             status;
 573         struct acpi_object_list input;
 574         union acpi_object       in_params[3];
 575         struct ide_acpi_drive_link      *master = &hwif->acpidata->master;
 576         struct ide_acpi_drive_link      *slave = &hwif->acpidata->slave;
 577
 578         if (ide_noacpi)
 579                 return;
 580
 581         DEBPRINT("ENTER:\n");
 582
 583         if (!hwif->acpidata) {
 584                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 585                 return;
 586         }
 587
 588         /* Give the GTM buffer + drive Identify data to the channel via the
 589          * _STM method: */
 590         /* setup input parameters buffer for _STM */
 591         input.count = 3;
 592         input.pointer = in_params;
 593         in_params[0].type = ACPI_TYPE_BUFFER;
 594         in_params[0].buffer.length = sizeof(struct GTM_buffer);
 595         in_params[0].buffer.pointer = (u8 *)&hwif->acpidata->gtm;
 596         in_params[1].type = ACPI_TYPE_BUFFER;
 597         in_params[1].buffer.length = sizeof(struct hd_driveid);
 598         in_params[1].buffer.pointer = (u8 *)&master->idbuff;
 599         in_params[2].type = ACPI_TYPE_BUFFER;
 600         in_params[2].buffer.length = sizeof(struct hd_driveid);
 601         in_params[2].buffer.pointer = (u8 *)&slave->idbuff;
 602         /* Output buffer: _STM has no output */
 603
 604         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_STM",
 605                                       &input, NULL);
 606
 607         if (ACPI_FAILURE(status)) {
 608                 DEBPRINT("Run _STM error: status = 0x%x\n", status);
 609         }
 610         DEBPRINT("_STM status: %d\n", status);
 611 }
 612 EXPORT_SYMBOL_GPL(ide_acpi_push_timing);
 613
 614 /**
 615  * ide_acpi_init - initialize the ACPI link for an IDE interface
 616  * @hwif: target IDE interface (channel)
 617  *
 618  * The ACPI spec is not quite clear when the drive identify buffer
 619  * should be obtained. Calling IDENTIFY DEVICE during shutdown
 620  * is not the best of ideas as the drive might already being put to
 621  * sleep. And obviously we can't call it during resume.
 622  * So we get the information during startup; but this means that
 623  * any changes during run-time will be lost after resume.
 624  */
 625 void ide_acpi_init(ide_hwif_t *hwif)
 626 {
 627         int unit;
 628         int                     err;
 629         struct ide_acpi_drive_link      *master;
 630         struct ide_acpi_drive_link      *slave;
 631
 632         hwif->acpidata = kzalloc(sizeof(struct ide_acpi_hwif_link), GFP_KERNEL);
 633         if (!hwif->acpidata)
 634                 return;
 635
 636         hwif->acpidata->obj_handle = ide_acpi_hwif_get_handle(hwif);
 637         if (!hwif->acpidata->obj_handle) {
 638                 DEBPRINT("no ACPI object for %s found\n", hwif->name);
 639                 kfree(hwif->acpidata);
 640                 hwif->acpidata = NULL;
 641                 return;
 642         }
 643
 644         /*
 645          * The ACPI spec mandates that we send information
 646          * for both drives, regardless whether they are connected
 647          * or not.
 648          */
 649         hwif->acpidata->master.drive = &hwif->drives[0];
 650         hwif->drives[0].acpidata = &hwif->acpidata->master;
 651         master = &hwif->acpidata->master;
 652
 653         hwif->acpidata->slave.drive = &hwif->drives[1];
 654         hwif->drives[1].acpidata = &hwif->acpidata->slave;
 655         slave = &hwif->acpidata->slave;
 656
 657
 658         /*
 659          * Send IDENTIFY for each drive
 660          */
 661         if (master->drive->present) {
 662                 err = taskfile_lib_get_identify(master->drive, master->idbuff);
 663                 if (err) {
 664                         DEBPRINT("identify device %s failed (%d)\n",
 665                                  master->drive->name, err);
 666                 }
 667         }
 668
 669         if (slave->drive->present) {
 670                 err = taskfile_lib_get_identify(slave->drive, slave->idbuff);
 671                 if (err) {
 672                         DEBPRINT("identify device %s failed (%d)\n",
 673                                  slave->drive->name, err);
 674                 }
 675         }
 676
 677         if (ide_noacpionboot) {
 678                 DEBPRINT("ACPI methods disabled on boot\n");
 679                 return;
 680         }
 681
 682         /*
 683          * ACPI requires us to call _STM on startup
 684          */
 685         ide_acpi_get_timing(hwif);
 686         ide_acpi_push_timing(hwif);
 687
 688         for (unit = 0; unit < MAX_DRIVES; ++unit) {
 689                 ide_drive_t *drive = &hwif->drives[unit];
 690
 691                 if (drive->present) {
 692                         /* Execute ACPI startup code */
 693                         ide_acpi_exec_tfs(drive);
 694                 }
 695         }
 696 }
 697 EXPORT_SYMBOL_GPL(ide_acpi_init);