ide-acpi.c revision 5e32132befa5d2cefadf3141fee0bbb40cd11f0e
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
29struct taskfile_array {
30	u8	tfa[REGS_PER_GTF];	/* regs. 0x1f1 - 0x1f7 */
31};
32
33struct GTM_buffer {
34	u32	PIO_speed0;
35	u32	DMA_speed0;
36	u32	PIO_speed1;
37	u32	DMA_speed1;
38	u32	GTM_flags;
39};
40
41struct ide_acpi_drive_link {
42	ide_drive_t	*drive;
43	acpi_handle	 obj_handle;
44	u8		 idbuff[512];
45};
46
47struct 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
64extern int ide_noacpi;
65extern int ide_noacpitfs;
66extern 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 */
78static 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;
126err:
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 */
139static 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 */
179static 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 */
219static 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;
329out:
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 */
340static 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 */
387static 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
426out:
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 */
442int 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}
472EXPORT_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 */
481void 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}
558EXPORT_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 */
570void 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}
612EXPORT_SYMBOL_GPL(ide_acpi_push_timing);
613
614/**
615 * ide_acpi_set_state - set the channel power state
616 * @hwif: target IDE interface
617 * @on: state, on/off
618 *
619 * This function executes the _PS0/_PS3 ACPI method to set the power state.
620 * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
621 */
622void ide_acpi_set_state(ide_hwif_t *hwif, int on)
623{
624	int unit;
625
626	if (ide_noacpi)
627		return;
628
629	DEBPRINT("ENTER:\n");
630
631	if (!hwif->acpidata) {
632		DEBPRINT("no ACPI data for %s\n", hwif->name);
633		return;
634	}
635	/* channel first and then drives for power on and verse versa for power off */
636	if (on)
637		acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);
638	for (unit = 0; unit < MAX_DRIVES; ++unit) {
639		ide_drive_t *drive = &hwif->drives[unit];
640
641		if (!drive->acpidata->obj_handle)
642			drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
643
644		if (drive->acpidata->obj_handle && drive->present) {
645			acpi_bus_set_power(drive->acpidata->obj_handle,
646				on? ACPI_STATE_D0: ACPI_STATE_D3);
647		}
648	}
649	if (!on)
650		acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D3);
651}
652EXPORT_SYMBOL_GPL(ide_acpi_set_state);
653
654/**
655 * ide_acpi_init - initialize the ACPI link for an IDE interface
656 * @hwif: target IDE interface (channel)
657 *
658 * The ACPI spec is not quite clear when the drive identify buffer
659 * should be obtained. Calling IDENTIFY DEVICE during shutdown
660 * is not the best of ideas as the drive might already being put to
661 * sleep. And obviously we can't call it during resume.
662 * So we get the information during startup; but this means that
663 * any changes during run-time will be lost after resume.
664 */
665void ide_acpi_init(ide_hwif_t *hwif)
666{
667	int unit;
668	int			err;
669	struct ide_acpi_drive_link	*master;
670	struct ide_acpi_drive_link	*slave;
671
672	hwif->acpidata = kzalloc(sizeof(struct ide_acpi_hwif_link), GFP_KERNEL);
673	if (!hwif->acpidata)
674		return;
675
676	hwif->acpidata->obj_handle = ide_acpi_hwif_get_handle(hwif);
677	if (!hwif->acpidata->obj_handle) {
678		DEBPRINT("no ACPI object for %s found\n", hwif->name);
679		kfree(hwif->acpidata);
680		hwif->acpidata = NULL;
681		return;
682	}
683
684	/*
685	 * The ACPI spec mandates that we send information
686	 * for both drives, regardless whether they are connected
687	 * or not.
688	 */
689	hwif->acpidata->master.drive = &hwif->drives[0];
690	hwif->drives[0].acpidata = &hwif->acpidata->master;
691	master = &hwif->acpidata->master;
692
693	hwif->acpidata->slave.drive = &hwif->drives[1];
694	hwif->drives[1].acpidata = &hwif->acpidata->slave;
695	slave = &hwif->acpidata->slave;
696
697
698	/*
699	 * Send IDENTIFY for each drive
700	 */
701	if (master->drive->present) {
702		err = taskfile_lib_get_identify(master->drive, master->idbuff);
703		if (err) {
704			DEBPRINT("identify device %s failed (%d)\n",
705				 master->drive->name, err);
706		}
707	}
708
709	if (slave->drive->present) {
710		err = taskfile_lib_get_identify(slave->drive, slave->idbuff);
711		if (err) {
712			DEBPRINT("identify device %s failed (%d)\n",
713				 slave->drive->name, err);
714		}
715	}
716
717	if (ide_noacpionboot) {
718		DEBPRINT("ACPI methods disabled on boot\n");
719		return;
720	}
721
722	/* ACPI _PS0 before _STM */
723	ide_acpi_set_state(hwif, 1);
724	/*
725	 * ACPI requires us to call _STM on startup
726	 */
727	ide_acpi_get_timing(hwif);
728	ide_acpi_push_timing(hwif);
729
730	for (unit = 0; unit < MAX_DRIVES; ++unit) {
731		ide_drive_t *drive = &hwif->drives[unit];
732
733		if (drive->present) {
734			/* Execute ACPI startup code */
735			ide_acpi_exec_tfs(drive);
736		}
737	}
738}
739EXPORT_SYMBOL_GPL(ide_acpi_init);
740