SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/ide/ide-acpi.c

   1 /*
   2  * Provides ACPI support for IDE drives.
   3  *
   4  * Copyright (C) 2005 Intel Corp.
   5  * Copyright (C) 2005 Randy Dunlap
   6  * Copyright (C) 2006 SUSE Linux Products GmbH
   7  * Copyright (C) 2006 Hannes Reinecke
   8  */
   9
  10 #include <linux/ata.h>
  11 #include <linux/delay.h>
  12 #include <linux/device.h>
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <acpi/acpi.h>
  16 #include <linux/ide.h>
  17 #include <linux/pci.h>
  18 #include <linux/dmi.h>
  19
  20 #include <acpi/acpi_bus.h>
  21
  22 #define REGS_PER_GTF            7
  23 struct taskfile_array {
  24         u8      tfa[REGS_PER_GTF];      /* regs. 0x1f1 - 0x1f7 */
  25 };
  26
  27 struct GTM_buffer {
  28         u32     PIO_speed0;
  29         u32     DMA_speed0;
  30         u32     PIO_speed1;
  31         u32     DMA_speed1;
  32         u32     GTM_flags;
  33 };
  34
  35 struct ide_acpi_drive_link {
  36         acpi_handle      obj_handle;
  37         u8               idbuff[512];
  38 };
  39
  40 struct ide_acpi_hwif_link {
  41         ide_hwif_t                      *hwif;
  42         acpi_handle                      obj_handle;
  43         struct GTM_buffer                gtm;
  44         struct ide_acpi_drive_link       master;
  45         struct ide_acpi_drive_link       slave;
  46 };
  47
  48 #undef DEBUGGING
  49 /* note: adds function name and KERN_DEBUG */
  50 #ifdef DEBUGGING
  51 #define DEBPRINT(fmt, args...)  \
  52                 printk(KERN_DEBUG "%s: " fmt, __func__, ## args)
  53 #else
  54 #define DEBPRINT(fmt, args...)  do {} while (0)
  55 #endif  /* DEBUGGING */
  56
  57 static int ide_noacpi;
  58 module_param_named(noacpi, ide_noacpi, bool, 0);
  59 MODULE_PARM_DESC(noacpi, "disable IDE ACPI support");
  60
  61 static int ide_acpigtf;
  62 module_param_named(acpigtf, ide_acpigtf, bool, 0);
  63 MODULE_PARM_DESC(acpigtf, "enable IDE ACPI _GTF support");
  64
  65 static int ide_acpionboot;
  66 module_param_named(acpionboot, ide_acpionboot, bool, 0);
  67 MODULE_PARM_DESC(acpionboot, "call IDE ACPI methods on boot");
  68
  69 static bool ide_noacpi_psx;
  70 static int no_acpi_psx(const struct dmi_system_id *id)
  71 {
  72         ide_noacpi_psx = true;
  73         printk(KERN_NOTICE"%s detected - disable ACPI _PSx.\n", id->ident);
  74         return 0;
  75 }
  76
  77 static const struct dmi_system_id ide_acpi_dmi_table[] = {
  78         /* Bug 9673. */
  79         /* We should check if this is because ACPI NVS isn't save/restored. */
  80         {
  81                 .callback = no_acpi_psx,
  82                 .ident    = "HP nx9005",
  83                 .matches  = {
  84                         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies Ltd."),
  85                         DMI_MATCH(DMI_BIOS_VERSION, "KAM1.60")
  86                 },
  87         },
  88
  89         { }     /* terminate list */
  90 };
  91
  92 int ide_acpi_init(void)
  93 {
  94         dmi_check_system(ide_acpi_dmi_table);
  95         return 0;
  96 }
  97
  98 /**
  99  * ide_get_dev_handle - finds acpi_handle and PCI device.function
 100  * @dev: device to locate
 101  * @handle: returned acpi_handle for @dev
 102  * @pcidevfn: return PCI device.func for @dev
 103  *
 104  * Returns the ACPI object handle to the corresponding PCI device.
 105  *
 106  * Returns 0 on success, <0 on error.
 107  */
 108 static int ide_get_dev_handle(struct device *dev, acpi_handle *handle,
 109                                acpi_integer *pcidevfn)
 110 {
 111         struct pci_dev *pdev = to_pci_dev(dev);
 112         unsigned int bus, devnum, func;
 113         acpi_integer addr;
 114         acpi_handle dev_handle;
 115         struct acpi_buffer buffer = {.length = ACPI_ALLOCATE_BUFFER,
 116                                         .pointer = NULL};
 117         acpi_status status;
 118         struct acpi_device_info *dinfo = NULL;
 119         int ret = -ENODEV;
 120
 121         bus = pdev->bus->number;
 122         devnum = PCI_SLOT(pdev->devfn);
 123         func = PCI_FUNC(pdev->devfn);
 124         /* ACPI _ADR encoding for PCI bus: */
 125         addr = (acpi_integer)(devnum << 16 | func);
 126
 127         DEBPRINT("ENTER: pci %02x:%02x.%01x\n", bus, devnum, func);
 128
 129         dev_handle = DEVICE_ACPI_HANDLE(dev);
 130         if (!dev_handle) {
 131                 DEBPRINT("no acpi handle for device\n");
 132                 goto err;
 133         }
 134
 135         status = acpi_get_object_info(dev_handle, &buffer);
 136         if (ACPI_FAILURE(status)) {
 137                 DEBPRINT("get_object_info for device failed\n");
 138                 goto err;
 139         }
 140         dinfo = buffer.pointer;
 141         if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
 142             dinfo->address == addr) {
 143                 *pcidevfn = addr;
 144                 *handle = dev_handle;
 145         } else {
 146                 DEBPRINT("get_object_info for device has wrong "
 147                         " address: %llu, should be %u\n",
 148                         dinfo ? (unsigned long long)dinfo->address : -1ULL,
 149                         (unsigned int)addr);
 150                 goto err;
 151         }
 152
 153         DEBPRINT("for dev=0x%x.%x, addr=0x%llx, *handle=0x%p\n",
 154                  devnum, func, (unsigned long long)addr, *handle);
 155         ret = 0;
 156 err:
 157         kfree(dinfo);
 158         return ret;
 159 }
 160
 161 /**
 162  * ide_acpi_hwif_get_handle - Get ACPI object handle for a given hwif
 163  * @hwif: device to locate
 164  *
 165  * Retrieves the object handle for a given hwif.
 166  *
 167  * Returns handle on success, 0 on error.
 168  */
 169 static acpi_handle ide_acpi_hwif_get_handle(ide_hwif_t *hwif)
 170 {
 171         struct device           *dev = hwif->gendev.parent;
 172         acpi_handle             uninitialized_var(dev_handle);
 173         acpi_integer            pcidevfn;
 174         acpi_handle             chan_handle;
 175         int                     err;
 176
 177         DEBPRINT("ENTER: device %s\n", hwif->name);
 178
 179         if (!dev) {
 180                 DEBPRINT("no PCI device for %s\n", hwif->name);
 181                 return NULL;
 182         }
 183
 184         err = ide_get_dev_handle(dev, &dev_handle, &pcidevfn);
 185         if (err < 0) {
 186                 DEBPRINT("ide_get_dev_handle failed (%d)\n", err);
 187                 return NULL;
 188         }
 189
 190         /* get child objects of dev_handle == channel objects,
 191          * + _their_ children == drive objects */
 192         /* channel is hwif->channel */
 193         chan_handle = acpi_get_child(dev_handle, hwif->channel);
 194         DEBPRINT("chan adr=%d: handle=0x%p\n",
 195                  hwif->channel, chan_handle);
 196
 197         return chan_handle;
 198 }
 199
 200 /**
 201  * do_drive_get_GTF - get the drive bootup default taskfile settings
 202  * @drive: the drive for which the taskfile settings should be retrieved
 203  * @gtf_length: number of bytes of _GTF data returned at @gtf_address
 204  * @gtf_address: buffer containing _GTF taskfile arrays
 205  *
 206  * The _GTF method has no input parameters.
 207  * It returns a variable number of register set values (registers
 208  * hex 1F1..1F7, taskfiles).
 209  * The <variable number> is not known in advance, so have ACPI-CA
 210  * allocate the buffer as needed and return it, then free it later.
 211  *
 212  * The returned @gtf_length and @gtf_address are only valid if the
 213  * function return value is 0.
 214  */
 215 static int do_drive_get_GTF(ide_drive_t *drive,
 216                      unsigned int *gtf_length, unsigned long *gtf_address,
 217                      unsigned long *obj_loc)
 218 {
 219         acpi_status                     status;
 220         struct acpi_buffer              output;
 221         union acpi_object               *out_obj;
 222         int                             err = -ENODEV;
 223
 224         *gtf_length = 0;
 225         *gtf_address = 0UL;
 226         *obj_loc = 0UL;
 227
 228         if (!drive->acpidata->obj_handle) {
 229                 DEBPRINT("No ACPI object found for %s\n", drive->name);
 230                 goto out;
 231         }
 232
 233         /* Setting up output buffer */
 234         output.length = ACPI_ALLOCATE_BUFFER;
 235         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
 236
 237         /* _GTF has no input parameters */
 238         err = -EIO;
 239         status = acpi_evaluate_object(drive->acpidata->obj_handle, "_GTF",
 240                                       NULL, &output);
 241         if (ACPI_FAILURE(status)) {
 242                 printk(KERN_DEBUG
 243                        "%s: Run _GTF error: status = 0x%x\n",
 244                        __func__, status);
 245                 goto out;
 246         }
 247
 248         if (!output.length || !output.pointer) {
 249                 DEBPRINT("Run _GTF: "
 250                        "length or ptr is NULL (0x%llx, 0x%p)\n",
 251                        (unsigned long long)output.length,
 252                        output.pointer);
 253                 goto out;
 254         }
 255
 256         out_obj = output.pointer;
 257         if (out_obj->type != ACPI_TYPE_BUFFER) {
 258                 DEBPRINT("Run _GTF: error: "
 259                        "expected object type of ACPI_TYPE_BUFFER, "
 260                        "got 0x%x\n", out_obj->type);
 261                 err = -ENOENT;
 262                 kfree(output.pointer);
 263                 goto out;
 264         }
 265
 266         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
 267             out_obj->buffer.length % REGS_PER_GTF) {
 268                 printk(KERN_ERR
 269                        "%s: unexpected GTF length (%d) or addr (0x%p)\n",
 270                        __func__, out_obj->buffer.length,
 271                        out_obj->buffer.pointer);
 272                 err = -ENOENT;
 273                 kfree(output.pointer);
 274                 goto out;
 275         }
 276
 277         *gtf_length = out_obj->buffer.length;
 278         *gtf_address = (unsigned long)out_obj->buffer.pointer;
 279         *obj_loc = (unsigned long)out_obj;
 280         DEBPRINT("returning gtf_length=%d, gtf_address=0x%lx, obj_loc=0x%lx\n",
 281                  *gtf_length, *gtf_address, *obj_loc);
 282         err = 0;
 283 out:
 284         return err;
 285 }
 286
 287 /**
 288  * taskfile_load_raw - send taskfile registers to drive
 289  * @drive: drive to which output is sent
 290  * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
 291  *
 292  * Outputs IDE taskfile to the drive.
 293  */
 294 static int taskfile_load_raw(ide_drive_t *drive,
 295                               const struct taskfile_array *gtf)
 296 {
 297         ide_task_t args;
 298         int err = 0;
 299
 300         DEBPRINT("(0x1f1-1f7): hex: "
 301                "%02x %02x %02x %02x %02x %02x %02x\n",
 302                gtf->tfa[0], gtf->tfa[1], gtf->tfa[2],
 303                gtf->tfa[3], gtf->tfa[4], gtf->tfa[5], gtf->tfa[6]);
 304
 305         memset(&args, 0, sizeof(ide_task_t));
 306
 307         /* convert gtf to IDE Taskfile */
 308         memcpy(&args.tf_array[7], &gtf->tfa, 7);
 309         args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
 310
 311         if (!ide_acpigtf) {
 312                 DEBPRINT("_GTF execution disabled\n");
 313                 return err;
 314         }
 315
 316         err = ide_no_data_taskfile(drive, &args);
 317         if (err)
 318                 printk(KERN_ERR "%s: ide_no_data_taskfile failed: %u\n",
 319                        __func__, err);
 320
 321         return err;
 322 }
 323
 324 /**
 325  * do_drive_set_taskfiles - write the drive taskfile settings from _GTF
 326  * @drive: the drive to which the taskfile command should be sent
 327  * @gtf_length: total number of bytes of _GTF taskfiles
 328  * @gtf_address: location of _GTF taskfile arrays
 329  *
 330  * Write {gtf_address, length gtf_length} in groups of
 331  * REGS_PER_GTF bytes.
 332  */
 333 static int do_drive_set_taskfiles(ide_drive_t *drive,
 334                                   unsigned int gtf_length,
 335                                   unsigned long gtf_address)
 336 {
 337         int                     rc = -ENODEV, err;
 338         int                     gtf_count = gtf_length / REGS_PER_GTF;
 339         int                     ix;
 340         struct taskfile_array   *gtf;
 341
 342         if (ide_noacpi)
 343                 return 0;
 344
 345         DEBPRINT("ENTER: %s, hard_port#: %d\n", drive->name, drive->dn);
 346
 347         if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)
 348                 goto out;
 349
 350         if (!gtf_count)         /* shouldn't be here */
 351                 goto out;
 352
 353         DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx\n",
 354                  gtf_length, gtf_length, gtf_count, gtf_address);
 355
 356         if (gtf_length % REGS_PER_GTF) {
 357                 printk(KERN_ERR "%s: unexpected GTF length (%d)\n",
 358                        __func__, gtf_length);
 359                 goto out;
 360         }
 361
 362         rc = 0;
 363         for (ix = 0; ix < gtf_count; ix++) {
 364                 gtf = (struct taskfile_array *)
 365                         (gtf_address + ix * REGS_PER_GTF);
 366
 367                 /* send all TaskFile registers (0x1f1-0x1f7) *in*that*order* */
 368                 err = taskfile_load_raw(drive, gtf);
 369                 if (err)
 370                         rc = err;
 371         }
 372
 373 out:
 374         return rc;
 375 }
 376
 377 /**
 378  * ide_acpi_exec_tfs - get then write drive taskfile settings
 379  * @drive: the drive for which the taskfile settings should be
 380  *         written.
 381  *
 382  * According to the ACPI spec this should be called after _STM
 383  * has been evaluated for the interface. Some ACPI vendors interpret
 384  * that as a hard requirement and modify the taskfile according
 385  * to the Identify Drive information passed down with _STM.
 386  * So one should really make sure to call this only after _STM has
 387  * been executed.
 388  */
 389 int ide_acpi_exec_tfs(ide_drive_t *drive)
 390 {
 391         int             ret;
 392         unsigned int    gtf_length;
 393         unsigned long   gtf_address;
 394         unsigned long   obj_loc;
 395
 396         if (ide_noacpi)
 397                 return 0;
 398
 399         DEBPRINT("call get_GTF, drive=%s port=%d\n", drive->name, drive->dn);
 400
 401         ret = do_drive_get_GTF(drive, &gtf_length, &gtf_address, &obj_loc);
 402         if (ret < 0) {
 403                 DEBPRINT("get_GTF error (%d)\n", ret);
 404                 return ret;
 405         }
 406
 407         DEBPRINT("call set_taskfiles, drive=%s\n", drive->name);
 408
 409         ret = do_drive_set_taskfiles(drive, gtf_length, gtf_address);
 410         kfree((void *)obj_loc);
 411         if (ret < 0) {
 412                 DEBPRINT("set_taskfiles error (%d)\n", ret);
 413         }
 414
 415         DEBPRINT("ret=%d\n", ret);
 416
 417         return ret;
 418 }
 419
 420 /**
 421  * ide_acpi_get_timing - get the channel (controller) timings
 422  * @hwif: target IDE interface (channel)
 423  *
 424  * This function executes the _GTM ACPI method for the target channel.
 425  *
 426  */
 427 void ide_acpi_get_timing(ide_hwif_t *hwif)
 428 {
 429         acpi_status             status;
 430         struct acpi_buffer      output;
 431         union acpi_object       *out_obj;
 432
 433         if (ide_noacpi)
 434                 return;
 435
 436         DEBPRINT("ENTER:\n");
 437
 438         if (!hwif->acpidata) {
 439                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 440                 return;
 441         }
 442
 443         /* Setting up output buffer for _GTM */
 444         output.length = ACPI_ALLOCATE_BUFFER;
 445         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
 446
 447         /* _GTM has no input parameters */
 448         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_GTM",
 449                                       NULL, &output);
 450
 451         DEBPRINT("_GTM status: %d, outptr: 0x%p, outlen: 0x%llx\n",
 452                  status, output.pointer,
 453                  (unsigned long long)output.length);
 454
 455         if (ACPI_FAILURE(status)) {
 456                 DEBPRINT("Run _GTM error: status = 0x%x\n", status);
 457                 return;
 458         }
 459
 460         if (!output.length || !output.pointer) {
 461                 DEBPRINT("Run _GTM: length or ptr is NULL (0x%llx, 0x%p)\n",
 462                        (unsigned long long)output.length,
 463                        output.pointer);
 464                 kfree(output.pointer);
 465                 return;
 466         }
 467
 468         out_obj = output.pointer;
 469         if (out_obj->type != ACPI_TYPE_BUFFER) {
 470                 kfree(output.pointer);
 471                 DEBPRINT("Run _GTM: error: "
 472                        "expected object type of ACPI_TYPE_BUFFER, "
 473                        "got 0x%x\n", out_obj->type);
 474                 return;
 475         }
 476
 477         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
 478             out_obj->buffer.length != sizeof(struct GTM_buffer)) {
 479                 kfree(output.pointer);
 480                 printk(KERN_ERR
 481                         "%s: unexpected _GTM length (0x%x)[should be 0x%zx] or "
 482                         "addr (0x%p)\n",
 483                         __func__, out_obj->buffer.length,
 484                         sizeof(struct GTM_buffer), out_obj->buffer.pointer);
 485                 return;
 486         }
 487
 488         memcpy(&hwif->acpidata->gtm, out_obj->buffer.pointer,
 489                sizeof(struct GTM_buffer));
 490
 491         DEBPRINT("_GTM info: ptr: 0x%p, len: 0x%x, exp.len: 0x%Zx\n",
 492                  out_obj->buffer.pointer, out_obj->buffer.length,
 493                  sizeof(struct GTM_buffer));
 494
 495         DEBPRINT("_GTM fields: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
 496                  hwif->acpidata->gtm.PIO_speed0,
 497                  hwif->acpidata->gtm.DMA_speed0,
 498                  hwif->acpidata->gtm.PIO_speed1,
 499                  hwif->acpidata->gtm.DMA_speed1,
 500                  hwif->acpidata->gtm.GTM_flags);
 501
 502         kfree(output.pointer);
 503 }
 504
 505 /**
 506  * ide_acpi_push_timing - set the channel (controller) timings
 507  * @hwif: target IDE interface (channel)
 508  *
 509  * This function executes the _STM ACPI method for the target channel.
 510  *
 511  * _STM requires Identify Drive data, which has to passed as an argument.
 512  * Unfortunately drive->id is a mangled version which we can't readily
 513  * use; hence we'll get the information afresh.
 514  */
 515 void ide_acpi_push_timing(ide_hwif_t *hwif)
 516 {
 517         acpi_status             status;
 518         struct acpi_object_list input;
 519         union acpi_object       in_params[3];
 520         struct ide_acpi_drive_link      *master = &hwif->acpidata->master;
 521         struct ide_acpi_drive_link      *slave = &hwif->acpidata->slave;
 522
 523         if (ide_noacpi)
 524                 return;
 525
 526         DEBPRINT("ENTER:\n");
 527
 528         if (!hwif->acpidata) {
 529                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 530                 return;
 531         }
 532
 533         /* Give the GTM buffer + drive Identify data to the channel via the
 534          * _STM method: */
 535         /* setup input parameters buffer for _STM */
 536         input.count = 3;
 537         input.pointer = in_params;
 538         in_params[0].type = ACPI_TYPE_BUFFER;
 539         in_params[0].buffer.length = sizeof(struct GTM_buffer);
 540         in_params[0].buffer.pointer = (u8 *)&hwif->acpidata->gtm;
 541         in_params[1].type = ACPI_TYPE_BUFFER;
 542         in_params[1].buffer.length = ATA_ID_WORDS * 2;
 543         in_params[1].buffer.pointer = (u8 *)&master->idbuff;
 544         in_params[2].type = ACPI_TYPE_BUFFER;
 545         in_params[2].buffer.length = ATA_ID_WORDS * 2;
 546         in_params[2].buffer.pointer = (u8 *)&slave->idbuff;
 547         /* Output buffer: _STM has no output */
 548
 549         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_STM",
 550                                       &input, NULL);
 551
 552         if (ACPI_FAILURE(status)) {
 553                 DEBPRINT("Run _STM error: status = 0x%x\n", status);
 554         }
 555         DEBPRINT("_STM status: %d\n", status);
 556 }
 557
 558 /**
 559  * ide_acpi_set_state - set the channel power state
 560  * @hwif: target IDE interface
 561  * @on: state, on/off
 562  *
 563  * This function executes the _PS0/_PS3 ACPI method to set the power state.
 564  * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
 565  */
 566 void ide_acpi_set_state(ide_hwif_t *hwif, int on)
 567 {
 568         ide_drive_t *drive;
 569         int i;
 570
 571         if (ide_noacpi || ide_noacpi_psx)
 572                 return;
 573
 574         DEBPRINT("ENTER:\n");
 575
 576         if (!hwif->acpidata) {
 577                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 578                 return;
 579         }
 580
 581         /* channel first and then drives for power on and verse versa for power off */
 582         if (on)
 583                 acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);
 584
 585         ide_port_for_each_present_dev(i, drive, hwif) {
 586                 if (drive->acpidata->obj_handle)
 587                         acpi_bus_set_power(drive->acpidata->obj_handle,
 588                                            on ? ACPI_STATE_D0 : ACPI_STATE_D3);
 589         }
 590
 591         if (!on)
 592                 acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D3);
 593 }
 594
 595 /**
 596  * ide_acpi_init_port - initialize the ACPI link for an IDE interface
 597  * @hwif: target IDE interface (channel)
 598  *
 599  * The ACPI spec is not quite clear when the drive identify buffer
 600  * should be obtained. Calling IDENTIFY DEVICE during shutdown
 601  * is not the best of ideas as the drive might already being put to
 602  * sleep. And obviously we can't call it during resume.
 603  * So we get the information during startup; but this means that
 604  * any changes during run-time will be lost after resume.
 605  */
 606 void ide_acpi_init_port(ide_hwif_t *hwif)
 607 {
 608         hwif->acpidata = kzalloc(sizeof(struct ide_acpi_hwif_link), GFP_KERNEL);
 609         if (!hwif->acpidata)
 610                 return;
 611
 612         hwif->acpidata->obj_handle = ide_acpi_hwif_get_handle(hwif);
 613         if (!hwif->acpidata->obj_handle) {
 614                 DEBPRINT("no ACPI object for %s found\n", hwif->name);
 615                 kfree(hwif->acpidata);
 616                 hwif->acpidata = NULL;
 617         }
 618 }
 619
 620 void ide_acpi_port_init_devices(ide_hwif_t *hwif)
 621 {
 622         ide_drive_t *drive;
 623         int i, err;
 624
 625         if (hwif->acpidata == NULL)
 626                 return;
 627
 628         /*
 629          * The ACPI spec mandates that we send information
 630          * for both drives, regardless whether they are connected
 631          * or not.
 632          */
 633         hwif->devices[0]->acpidata = &hwif->acpidata->master;
 634         hwif->devices[1]->acpidata = &hwif->acpidata->slave;
 635
 636         /* get _ADR info for each device */
 637         ide_port_for_each_present_dev(i, drive, hwif) {
 638                 acpi_handle dev_handle;
 639
 640                 DEBPRINT("ENTER: %s at channel#: %d port#: %d\n",
 641                          drive->name, hwif->channel, drive->dn & 1);
 642
 643                 /* TBD: could also check ACPI object VALID bits */
 644                 dev_handle = acpi_get_child(hwif->acpidata->obj_handle,
 645                                             drive->dn & 1);
 646
 647                 DEBPRINT("drive %s handle 0x%p\n", drive->name, dev_handle);
 648
 649                 drive->acpidata->obj_handle = dev_handle;
 650         }
 651
 652         /* send IDENTIFY for each device */
 653         ide_port_for_each_present_dev(i, drive, hwif) {
 654                 err = taskfile_lib_get_identify(drive, drive->acpidata->idbuff);
 655                 if (err)
 656                         DEBPRINT("identify device %s failed (%d)\n",
 657                                  drive->name, err);
 658         }
 659
 660         if (!ide_acpionboot) {
 661                 DEBPRINT("ACPI methods disabled on boot\n");
 662                 return;
 663         }
 664
 665         /* ACPI _PS0 before _STM */
 666         ide_acpi_set_state(hwif, 1);
 667         /*
 668          * ACPI requires us to call _STM on startup
 669          */
 670         ide_acpi_get_timing(hwif);
 671         ide_acpi_push_timing(hwif);
 672
 673         ide_port_for_each_present_dev(i, drive, hwif) {
 674                 ide_acpi_exec_tfs(drive);
 675         }
 676 }