- Update to 2.6.25-rc3.
[linux-flexiantxendom0-3.2.10.git] / 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 #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         acpi_handle      obj_handle;
43         u8               idbuff[512];
44 };
45
46 struct ide_acpi_hwif_link {
47         ide_hwif_t                      *hwif;
48         acpi_handle                      obj_handle;
49         struct GTM_buffer                gtm;
50         struct ide_acpi_drive_link       master;
51         struct ide_acpi_drive_link       slave;
52 };
53
54 #undef DEBUGGING
55 /* note: adds function name and KERN_DEBUG */
56 #ifdef DEBUGGING
57 #define DEBPRINT(fmt, args...)  \
58                 printk(KERN_DEBUG "%s: " fmt, __FUNCTION__, ## args)
59 #else
60 #define DEBPRINT(fmt, args...)  do {} while (0)
61 #endif  /* DEBUGGING */
62
63 extern int ide_noacpi;
64 extern int ide_noacpitfs;
65 extern int ide_noacpionboot;
66
67 static bool ide_noacpi_psx;
68 static int no_acpi_psx(const struct dmi_system_id *id)
69 {
70         ide_noacpi_psx = true;
71         printk(KERN_NOTICE"%s detected - disable ACPI _PSx.\n", id->ident);
72         return 0;
73 }
74
75 static const struct dmi_system_id ide_acpi_dmi_table[] = {
76         /* Bug 9673. */
77         /* We should check if this is because ACPI NVS isn't save/restored. */
78         {
79                 .callback = no_acpi_psx,
80                 .ident    = "HP nx9005",
81                 .matches  = {
82                         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies Ltd."),
83                         DMI_MATCH(DMI_BIOS_VERSION, "KAM1.60")
84                 },
85         },
86
87         { }     /* terminate list */
88 };
89
90 static int ide_acpi_blacklist(void)
91 {
92         static int done;
93         if (done)
94                 return 0;
95         done = 1;
96         dmi_check_system(ide_acpi_dmi_table);
97         return 0;
98 }
99
100 /**
101  * ide_get_dev_handle - finds acpi_handle and PCI device.function
102  * @dev: device to locate
103  * @handle: returned acpi_handle for @dev
104  * @pcidevfn: return PCI device.func for @dev
105  *
106  * Returns the ACPI object handle to the corresponding PCI device.
107  *
108  * Returns 0 on success, <0 on error.
109  */
110 static int ide_get_dev_handle(struct device *dev, acpi_handle *handle,
111                                acpi_integer *pcidevfn)
112 {
113         struct pci_dev *pdev = to_pci_dev(dev);
114         unsigned int bus, devnum, func;
115         acpi_integer addr;
116         acpi_handle dev_handle;
117         struct acpi_buffer buffer = {.length = ACPI_ALLOCATE_BUFFER,
118                                         .pointer = NULL};
119         acpi_status status;
120         struct acpi_device_info *dinfo = NULL;
121         int ret = -ENODEV;
122
123         bus = pdev->bus->number;
124         devnum = PCI_SLOT(pdev->devfn);
125         func = PCI_FUNC(pdev->devfn);
126         /* ACPI _ADR encoding for PCI bus: */
127         addr = (acpi_integer)(devnum << 16 | func);
128
129         DEBPRINT("ENTER: pci %02x:%02x.%01x\n", bus, devnum, func);
130
131         dev_handle = DEVICE_ACPI_HANDLE(dev);
132         if (!dev_handle) {
133                 DEBPRINT("no acpi handle for device\n");
134                 goto err;
135         }
136
137         status = acpi_get_object_info(dev_handle, &buffer);
138         if (ACPI_FAILURE(status)) {
139                 DEBPRINT("get_object_info for device failed\n");
140                 goto err;
141         }
142         dinfo = buffer.pointer;
143         if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
144             dinfo->address == addr) {
145                 *pcidevfn = addr;
146                 *handle = dev_handle;
147         } else {
148                 DEBPRINT("get_object_info for device has wrong "
149                         " address: %llu, should be %u\n",
150                         dinfo ? (unsigned long long)dinfo->address : -1ULL,
151                         (unsigned int)addr);
152                 goto err;
153         }
154
155         DEBPRINT("for dev=0x%x.%x, addr=0x%llx, *handle=0x%p\n",
156                  devnum, func, (unsigned long long)addr, *handle);
157         ret = 0;
158 err:
159         kfree(dinfo);
160         return ret;
161 }
162
163 /**
164  * ide_acpi_hwif_get_handle - Get ACPI object handle for a given hwif
165  * @hwif: device to locate
166  *
167  * Retrieves the object handle for a given hwif.
168  *
169  * Returns handle on success, 0 on error.
170  */
171 static acpi_handle ide_acpi_hwif_get_handle(ide_hwif_t *hwif)
172 {
173         struct device           *dev = hwif->gendev.parent;
174         acpi_handle             uninitialized_var(dev_handle);
175         acpi_integer            pcidevfn;
176         acpi_handle             chan_handle;
177         int                     err;
178
179         DEBPRINT("ENTER: device %s\n", hwif->name);
180
181         if (!dev) {
182                 DEBPRINT("no PCI device for %s\n", hwif->name);
183                 return NULL;
184         }
185
186         err = ide_get_dev_handle(dev, &dev_handle, &pcidevfn);
187         if (err < 0) {
188                 DEBPRINT("ide_get_dev_handle failed (%d)\n", err);
189                 return NULL;
190         }
191
192         /* get child objects of dev_handle == channel objects,
193          * + _their_ children == drive objects */
194         /* channel is hwif->channel */
195         chan_handle = acpi_get_child(dev_handle, hwif->channel);
196         DEBPRINT("chan adr=%d: handle=0x%p\n",
197                  hwif->channel, chan_handle);
198
199         return chan_handle;
200 }
201
202 /**
203  * ide_acpi_drive_get_handle - Get ACPI object handle for a given drive
204  * @drive: device to locate
205  *
206  * Retrieves the object handle of a given drive. According to the ACPI
207  * spec the drive is a child of the hwif.
208  *
209  * Returns handle on success, 0 on error.
210  */
211 static acpi_handle ide_acpi_drive_get_handle(ide_drive_t *drive)
212 {
213         ide_hwif_t      *hwif = HWIF(drive);
214         int              port;
215         acpi_handle      drive_handle;
216
217         if (!hwif->acpidata)
218                 return NULL;
219
220         if (!hwif->acpidata->obj_handle)
221                 return NULL;
222
223         port = hwif->channel ? drive->dn - 2: drive->dn;
224
225         DEBPRINT("ENTER: %s at channel#: %d port#: %d\n",
226                  drive->name, hwif->channel, port);
227
228
229         /* TBD: could also check ACPI object VALID bits */
230         drive_handle = acpi_get_child(hwif->acpidata->obj_handle, port);
231         DEBPRINT("drive %s handle 0x%p\n", drive->name, drive_handle);
232
233         return drive_handle;
234 }
235
236 /**
237  * do_drive_get_GTF - get the drive bootup default taskfile settings
238  * @drive: the drive for which the taskfile settings should be retrieved
239  * @gtf_length: number of bytes of _GTF data returned at @gtf_address
240  * @gtf_address: buffer containing _GTF taskfile arrays
241  *
242  * The _GTF method has no input parameters.
243  * It returns a variable number of register set values (registers
244  * hex 1F1..1F7, taskfiles).
245  * The <variable number> is not known in advance, so have ACPI-CA
246  * allocate the buffer as needed and return it, then free it later.
247  *
248  * The returned @gtf_length and @gtf_address are only valid if the
249  * function return value is 0.
250  */
251 static int do_drive_get_GTF(ide_drive_t *drive,
252                      unsigned int *gtf_length, unsigned long *gtf_address,
253                      unsigned long *obj_loc)
254 {
255         acpi_status                     status;
256         struct acpi_buffer              output;
257         union acpi_object               *out_obj;
258         ide_hwif_t                      *hwif = HWIF(drive);
259         struct device                   *dev = hwif->gendev.parent;
260         int                             err = -ENODEV;
261         int                             port;
262
263         *gtf_length = 0;
264         *gtf_address = 0UL;
265         *obj_loc = 0UL;
266
267         if (ide_noacpi)
268                 return 0;
269
270         if (!dev) {
271                 DEBPRINT("no PCI device for %s\n", hwif->name);
272                 goto out;
273         }
274
275         if (!hwif->acpidata) {
276                 DEBPRINT("no ACPI data for %s\n", hwif->name);
277                 goto out;
278         }
279
280         port = hwif->channel ? drive->dn - 2: drive->dn;
281
282         DEBPRINT("ENTER: %s at %s, port#: %d, hard_port#: %d\n",
283                  hwif->name, dev->bus_id, port, hwif->channel);
284
285         if (!drive->present) {
286                 DEBPRINT("%s drive %d:%d not present\n",
287                          hwif->name, hwif->channel, port);
288                 goto out;
289         }
290
291         /* Get this drive's _ADR info. if not already known. */
292         if (!drive->acpidata->obj_handle) {
293                 drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
294                 if (!drive->acpidata->obj_handle) {
295                         DEBPRINT("No ACPI object found for %s\n",
296                                  drive->name);
297                         goto out;
298                 }
299         }
300
301         /* Setting up output buffer */
302         output.length = ACPI_ALLOCATE_BUFFER;
303         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
304
305         /* _GTF has no input parameters */
306         err = -EIO;
307         status = acpi_evaluate_object(drive->acpidata->obj_handle, "_GTF",
308                                       NULL, &output);
309         if (ACPI_FAILURE(status)) {
310                 printk(KERN_DEBUG
311                        "%s: Run _GTF error: status = 0x%x\n",
312                        __FUNCTION__, status);
313                 goto out;
314         }
315
316         if (!output.length || !output.pointer) {
317                 DEBPRINT("Run _GTF: "
318                        "length or ptr is NULL (0x%llx, 0x%p)\n",
319                        (unsigned long long)output.length,
320                        output.pointer);
321                 goto out;
322         }
323
324         out_obj = output.pointer;
325         if (out_obj->type != ACPI_TYPE_BUFFER) {
326                 DEBPRINT("Run _GTF: error: "
327                        "expected object type of ACPI_TYPE_BUFFER, "
328                        "got 0x%x\n", out_obj->type);
329                 err = -ENOENT;
330                 kfree(output.pointer);
331                 goto out;
332         }
333
334         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
335             out_obj->buffer.length % REGS_PER_GTF) {
336                 printk(KERN_ERR
337                        "%s: unexpected GTF length (%d) or addr (0x%p)\n",
338                        __FUNCTION__, out_obj->buffer.length,
339                        out_obj->buffer.pointer);
340                 err = -ENOENT;
341                 kfree(output.pointer);
342                 goto out;
343         }
344
345         *gtf_length = out_obj->buffer.length;
346         *gtf_address = (unsigned long)out_obj->buffer.pointer;
347         *obj_loc = (unsigned long)out_obj;
348         DEBPRINT("returning gtf_length=%d, gtf_address=0x%lx, obj_loc=0x%lx\n",
349                  *gtf_length, *gtf_address, *obj_loc);
350         err = 0;
351 out:
352         return err;
353 }
354
355 /**
356  * taskfile_load_raw - send taskfile registers to drive
357  * @drive: drive to which output is sent
358  * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
359  *
360  * Outputs IDE taskfile to the drive.
361  */
362 static int taskfile_load_raw(ide_drive_t *drive,
363                               const struct taskfile_array *gtf)
364 {
365         ide_task_t args;
366         int err = 0;
367
368         DEBPRINT("(0x1f1-1f7): hex: "
369                "%02x %02x %02x %02x %02x %02x %02x\n",
370                gtf->tfa[0], gtf->tfa[1], gtf->tfa[2],
371                gtf->tfa[3], gtf->tfa[4], gtf->tfa[5], gtf->tfa[6]);
372
373         memset(&args, 0, sizeof(ide_task_t));
374
375         /* convert gtf to IDE Taskfile */
376         memcpy(&args.tf_array[7], &gtf->tfa, 7);
377         args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
378
379         if (ide_noacpitfs) {
380                 DEBPRINT("_GTF execution disabled\n");
381                 return err;
382         }
383
384         err = ide_no_data_taskfile(drive, &args);
385         if (err)
386                 printk(KERN_ERR "%s: ide_no_data_taskfile failed: %u\n",
387                        __FUNCTION__, err);
388
389         return err;
390 }
391
392 /**
393  * do_drive_set_taskfiles - write the drive taskfile settings from _GTF
394  * @drive: the drive to which the taskfile command should be sent
395  * @gtf_length: total number of bytes of _GTF taskfiles
396  * @gtf_address: location of _GTF taskfile arrays
397  *
398  * Write {gtf_address, length gtf_length} in groups of
399  * REGS_PER_GTF bytes.
400  */
401 static int do_drive_set_taskfiles(ide_drive_t *drive,
402                                   unsigned int gtf_length,
403                                   unsigned long gtf_address)
404 {
405         int                     rc = -ENODEV, err;
406         int                     gtf_count = gtf_length / REGS_PER_GTF;
407         int                     ix;
408         struct taskfile_array   *gtf;
409
410         if (ide_noacpi)
411                 return 0;
412
413         DEBPRINT("ENTER: %s, hard_port#: %d\n", drive->name, drive->dn);
414
415         if (!drive->present)
416                 goto out;
417         if (!gtf_count)         /* shouldn't be here */
418                 goto out;
419
420         DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx\n",
421                  gtf_length, gtf_length, gtf_count, gtf_address);
422
423         if (gtf_length % REGS_PER_GTF) {
424                 printk(KERN_ERR "%s: unexpected GTF length (%d)\n",
425                        __FUNCTION__, gtf_length);
426                 goto out;
427         }
428
429         rc = 0;
430         for (ix = 0; ix < gtf_count; ix++) {
431                 gtf = (struct taskfile_array *)
432                         (gtf_address + ix * REGS_PER_GTF);
433
434                 /* send all TaskFile registers (0x1f1-0x1f7) *in*that*order* */
435                 err = taskfile_load_raw(drive, gtf);
436                 if (err)
437                         rc = err;
438         }
439
440 out:
441         return rc;
442 }
443
444 /**
445  * ide_acpi_exec_tfs - get then write drive taskfile settings
446  * @drive: the drive for which the taskfile settings should be
447  *         written.
448  *
449  * According to the ACPI spec this should be called after _STM
450  * has been evaluated for the interface. Some ACPI vendors interpret
451  * that as a hard requirement and modify the taskfile according
452  * to the Identify Drive information passed down with _STM.
453  * So one should really make sure to call this only after _STM has
454  * been executed.
455  */
456 int ide_acpi_exec_tfs(ide_drive_t *drive)
457 {
458         int             ret;
459         unsigned int    gtf_length;
460         unsigned long   gtf_address;
461         unsigned long   obj_loc;
462
463         if (ide_noacpi)
464                 return 0;
465
466         DEBPRINT("call get_GTF, drive=%s port=%d\n", drive->name, drive->dn);
467
468         ret = do_drive_get_GTF(drive, &gtf_length, &gtf_address, &obj_loc);
469         if (ret < 0) {
470                 DEBPRINT("get_GTF error (%d)\n", ret);
471                 return ret;
472         }
473
474         DEBPRINT("call set_taskfiles, drive=%s\n", drive->name);
475
476         ret = do_drive_set_taskfiles(drive, gtf_length, gtf_address);
477         kfree((void *)obj_loc);
478         if (ret < 0) {
479                 DEBPRINT("set_taskfiles error (%d)\n", ret);
480         }
481
482         DEBPRINT("ret=%d\n", ret);
483
484         return ret;
485 }
486
487 /**
488  * ide_acpi_get_timing - get the channel (controller) timings
489  * @hwif: target IDE interface (channel)
490  *
491  * This function executes the _GTM ACPI method for the target channel.
492  *
493  */
494 void ide_acpi_get_timing(ide_hwif_t *hwif)
495 {
496         acpi_status             status;
497         struct acpi_buffer      output;
498         union acpi_object       *out_obj;
499
500         if (ide_noacpi)
501                 return;
502
503         DEBPRINT("ENTER:\n");
504
505         if (!hwif->acpidata) {
506                 DEBPRINT("no ACPI data for %s\n", hwif->name);
507                 return;
508         }
509
510         /* Setting up output buffer for _GTM */
511         output.length = ACPI_ALLOCATE_BUFFER;
512         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
513
514         /* _GTM has no input parameters */
515         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_GTM",
516                                       NULL, &output);
517
518         DEBPRINT("_GTM status: %d, outptr: 0x%p, outlen: 0x%llx\n",
519                  status, output.pointer,
520                  (unsigned long long)output.length);
521
522         if (ACPI_FAILURE(status)) {
523                 DEBPRINT("Run _GTM error: status = 0x%x\n", status);
524                 return;
525         }
526
527         if (!output.length || !output.pointer) {
528                 DEBPRINT("Run _GTM: length or ptr is NULL (0x%llx, 0x%p)\n",
529                        (unsigned long long)output.length,
530                        output.pointer);
531                 kfree(output.pointer);
532                 return;
533         }
534
535         out_obj = output.pointer;
536         if (out_obj->type != ACPI_TYPE_BUFFER) {
537                 kfree(output.pointer);
538                 DEBPRINT("Run _GTM: error: "
539                        "expected object type of ACPI_TYPE_BUFFER, "
540                        "got 0x%x\n", out_obj->type);
541                 return;
542         }
543
544         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
545             out_obj->buffer.length != sizeof(struct GTM_buffer)) {
546                 kfree(output.pointer);
547                 printk(KERN_ERR
548                         "%s: unexpected _GTM length (0x%x)[should be 0x%zx] or "
549                         "addr (0x%p)\n",
550                         __FUNCTION__, out_obj->buffer.length,
551                         sizeof(struct GTM_buffer), out_obj->buffer.pointer);
552                 return;
553         }
554
555         memcpy(&hwif->acpidata->gtm, out_obj->buffer.pointer,
556                sizeof(struct GTM_buffer));
557
558         DEBPRINT("_GTM info: ptr: 0x%p, len: 0x%x, exp.len: 0x%Zx\n",
559                  out_obj->buffer.pointer, out_obj->buffer.length,
560                  sizeof(struct GTM_buffer));
561
562         DEBPRINT("_GTM fields: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
563                  hwif->acpidata->gtm.PIO_speed0,
564                  hwif->acpidata->gtm.DMA_speed0,
565                  hwif->acpidata->gtm.PIO_speed1,
566                  hwif->acpidata->gtm.DMA_speed1,
567                  hwif->acpidata->gtm.GTM_flags);
568
569         kfree(output.pointer);
570 }
571
572 /**
573  * ide_acpi_push_timing - set the channel (controller) timings
574  * @hwif: target IDE interface (channel)
575  *
576  * This function executes the _STM ACPI method for the target channel.
577  *
578  * _STM requires Identify Drive data, which has to passed as an argument.
579  * Unfortunately hd_driveid is a mangled version which we can't readily
580  * use; hence we'll get the information afresh.
581  */
582 void ide_acpi_push_timing(ide_hwif_t *hwif)
583 {
584         acpi_status             status;
585         struct acpi_object_list input;
586         union acpi_object       in_params[3];
587         struct ide_acpi_drive_link      *master = &hwif->acpidata->master;
588         struct ide_acpi_drive_link      *slave = &hwif->acpidata->slave;
589
590         if (ide_noacpi)
591                 return;
592
593         DEBPRINT("ENTER:\n");
594
595         if (!hwif->acpidata) {
596                 DEBPRINT("no ACPI data for %s\n", hwif->name);
597                 return;
598         }
599
600         /* Give the GTM buffer + drive Identify data to the channel via the
601          * _STM method: */
602         /* setup input parameters buffer for _STM */
603         input.count = 3;
604         input.pointer = in_params;
605         in_params[0].type = ACPI_TYPE_BUFFER;
606         in_params[0].buffer.length = sizeof(struct GTM_buffer);
607         in_params[0].buffer.pointer = (u8 *)&hwif->acpidata->gtm;
608         in_params[1].type = ACPI_TYPE_BUFFER;
609         in_params[1].buffer.length = sizeof(struct hd_driveid);
610         in_params[1].buffer.pointer = (u8 *)&master->idbuff;
611         in_params[2].type = ACPI_TYPE_BUFFER;
612         in_params[2].buffer.length = sizeof(struct hd_driveid);
613         in_params[2].buffer.pointer = (u8 *)&slave->idbuff;
614         /* Output buffer: _STM has no output */
615
616         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_STM",
617                                       &input, NULL);
618
619         if (ACPI_FAILURE(status)) {
620                 DEBPRINT("Run _STM error: status = 0x%x\n", status);
621         }
622         DEBPRINT("_STM status: %d\n", status);
623 }
624
625 /**
626  * ide_acpi_set_state - set the channel power state
627  * @hwif: target IDE interface
628  * @on: state, on/off
629  *
630  * This function executes the _PS0/_PS3 ACPI method to set the power state.
631  * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
632  */
633 void ide_acpi_set_state(ide_hwif_t *hwif, int on)
634 {
635         int unit;
636
637         if (ide_noacpi || ide_noacpi_psx)
638                 return;
639
640         DEBPRINT("ENTER:\n");
641
642         if (!hwif->acpidata) {
643                 DEBPRINT("no ACPI data for %s\n", hwif->name);
644                 return;
645         }
646         /* channel first and then drives for power on and verse versa for power off */
647         if (on)
648                 acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);
649         for (unit = 0; unit < MAX_DRIVES; ++unit) {
650                 ide_drive_t *drive = &hwif->drives[unit];
651
652                 if (!drive->acpidata->obj_handle)
653                         drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
654
655                 if (drive->acpidata->obj_handle && drive->present) {
656                         acpi_bus_set_power(drive->acpidata->obj_handle,
657                                 on? ACPI_STATE_D0: ACPI_STATE_D3);
658                 }
659         }
660         if (!on)
661                 acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D3);
662 }
663
664 /**
665  * ide_acpi_init - initialize the ACPI link for an IDE interface
666  * @hwif: target IDE interface (channel)
667  *
668  * The ACPI spec is not quite clear when the drive identify buffer
669  * should be obtained. Calling IDENTIFY DEVICE during shutdown
670  * is not the best of ideas as the drive might already being put to
671  * sleep. And obviously we can't call it during resume.
672  * So we get the information during startup; but this means that
673  * any changes during run-time will be lost after resume.
674  */
675 void ide_acpi_init(ide_hwif_t *hwif)
676 {
677         ide_acpi_blacklist();
678
679         hwif->acpidata = kzalloc(sizeof(struct ide_acpi_hwif_link), GFP_KERNEL);
680         if (!hwif->acpidata)
681                 return;
682
683         hwif->acpidata->obj_handle = ide_acpi_hwif_get_handle(hwif);
684         if (!hwif->acpidata->obj_handle) {
685                 DEBPRINT("no ACPI object for %s found\n", hwif->name);
686                 kfree(hwif->acpidata);
687                 hwif->acpidata = NULL;
688         }
689 }
690
691 void ide_acpi_port_init_devices(ide_hwif_t *hwif)
692 {
693         ide_drive_t *drive;
694         int i, err;
695
696         if (hwif->acpidata == NULL)
697                 return;
698
699         /*
700          * The ACPI spec mandates that we send information
701          * for both drives, regardless whether they are connected
702          * or not.
703          */
704         hwif->drives[0].acpidata = &hwif->acpidata->master;
705         hwif->drives[1].acpidata = &hwif->acpidata->slave;
706
707         /*
708          * Send IDENTIFY for each drive
709          */
710         for (i = 0; i < MAX_DRIVES; i++) {
711                 drive = &hwif->drives[i];
712
713                 if (!drive->present)
714                         continue;
715
716                 err = taskfile_lib_get_identify(drive, drive->acpidata->idbuff);
717                 if (err)
718                         DEBPRINT("identify device %s failed (%d)\n",
719                                  drive->name, err);
720         }
721
722         if (ide_noacpionboot) {
723                 DEBPRINT("ACPI methods disabled on boot\n");
724                 return;
725         }
726
727         /* ACPI _PS0 before _STM */
728         ide_acpi_set_state(hwif, 1);
729         /*
730          * ACPI requires us to call _STM on startup
731          */
732         ide_acpi_get_timing(hwif);
733         ide_acpi_push_timing(hwif);
734
735         for (i = 0; i < MAX_DRIVES; i++) {
736                 drive = &hwif->drives[i];
737
738                 if (drive->present)
739                         /* Execute ACPI startup code */
740                         ide_acpi_exec_tfs(drive);
741         }
742 }