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hwrng: core - Don't use a stack buffer in add_early_randomness()
[linux/fpc-iii.git] / drivers / acpi / pci_link.c
blobc983bf733ad37d7b608c9410108dcef32cdbf02b
1 /*
2 * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or (at
13 * your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21 *
22 * TBD:
23 * 1. Support more than one IRQ resource entry per link device (index).
24 * 2. Implement start/stop mechanism and use ACPI Bus Driver facilities
25 * for IRQ management (e.g. start()->_SRS).
26 */
27
28 #include <linux/syscore_ops.h>
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/types.h>
33 #include <linux/spinlock.h>
34 #include <linux/pm.h>
35 #include <linux/pci.h>
36 #include <linux/mutex.h>
37 #include <linux/slab.h>
38 #include <linux/acpi.h>
39 #include <linux/irq.h>
40
41 #include "internal.h"
42
43 #define _COMPONENT ACPI_PCI_COMPONENT
44 ACPI_MODULE_NAME("pci_link");
45 #define ACPI_PCI_LINK_CLASS "pci_irq_routing"
46 #define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
47 #define ACPI_PCI_LINK_FILE_INFO "info"
48 #define ACPI_PCI_LINK_FILE_STATUS "state"
49 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
50
51 static int acpi_pci_link_add(struct acpi_device *device,
52 const struct acpi_device_id *not_used);
53 static void acpi_pci_link_remove(struct acpi_device *device);
54
55 static const struct acpi_device_id link_device_ids[] = {
56 {"PNP0C0F", 0},
57 {"", 0},
58 };
59
60 static struct acpi_scan_handler pci_link_handler = {
61 .ids = link_device_ids,
62 .attach = acpi_pci_link_add,
63 .detach = acpi_pci_link_remove,
64 };
65
66 /*
67 * If a link is initialized, we never change its active and initialized
68 * later even the link is disable. Instead, we just repick the active irq
69 */
70 struct acpi_pci_link_irq {
71 u32 active; /* Current IRQ */
72 u8 triggering; /* All IRQs */
73 u8 polarity; /* All IRQs */
74 u8 resource_type;
75 u8 possible_count;
76 u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
77 u8 initialized:1;
78 u8 reserved:7;
79 };
80
81 struct acpi_pci_link {
82 struct list_head list;
83 struct acpi_device *device;
84 struct acpi_pci_link_irq irq;
85 int refcnt;
86 };
87
88 static LIST_HEAD(acpi_link_list);
89 static DEFINE_MUTEX(acpi_link_lock);
90
91 /* --------------------------------------------------------------------------
92 PCI Link Device Management
93 -------------------------------------------------------------------------- */
94
95 /*
96 * set context (link) possible list from resource list
97 */
98 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
99 void *context)
100 {
101 struct acpi_pci_link *link = context;
102 u32 i;
103
104 switch (resource->type) {
105 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
106 case ACPI_RESOURCE_TYPE_END_TAG:
107 return AE_OK;
108 case ACPI_RESOURCE_TYPE_IRQ:
109 {
110 struct acpi_resource_irq *p = &resource->data.irq;
111 if (!p || !p->interrupt_count) {
112 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
113 "Blank _PRS IRQ resource\n"));
114 return AE_OK;
115 }
116 for (i = 0;
117 (i < p->interrupt_count
118 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
119 if (!p->interrupts[i]) {
120 printk(KERN_WARNING PREFIX
121 "Invalid _PRS IRQ %d\n",
122 p->interrupts[i]);
123 continue;
124 }
125 link->irq.possible[i] = p->interrupts[i];
126 link->irq.possible_count++;
127 }
128 link->irq.triggering = p->triggering;
129 link->irq.polarity = p->polarity;
130 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
131 break;
132 }
133 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
134 {
135 struct acpi_resource_extended_irq *p =
136 &resource->data.extended_irq;
137 if (!p || !p->interrupt_count) {
138 printk(KERN_WARNING PREFIX
139 "Blank _PRS EXT IRQ resource\n");
140 return AE_OK;
141 }
142 for (i = 0;
143 (i < p->interrupt_count
144 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
145 if (!p->interrupts[i]) {
146 printk(KERN_WARNING PREFIX
147 "Invalid _PRS IRQ %d\n",
148 p->interrupts[i]);
149 continue;
150 }
151 link->irq.possible[i] = p->interrupts[i];
152 link->irq.possible_count++;
153 }
154 link->irq.triggering = p->triggering;
155 link->irq.polarity = p->polarity;
156 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
157 break;
158 }
159 default:
160 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
161 resource->type);
162 return AE_OK;
163 }
164
165 return AE_CTRL_TERMINATE;
166 }
167
168 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
169 {
170 acpi_status status;
171
172 status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
173 acpi_pci_link_check_possible, link);
174 if (ACPI_FAILURE(status)) {
175 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
176 return -ENODEV;
177 }
178
179 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
180 "Found %d possible IRQs\n",
181 link->irq.possible_count));
182
183 return 0;
184 }
185
186 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
187 void *context)
188 {
189 int *irq = context;
190
191 switch (resource->type) {
192 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
193 case ACPI_RESOURCE_TYPE_END_TAG:
194 return AE_OK;
195 case ACPI_RESOURCE_TYPE_IRQ:
196 {
197 struct acpi_resource_irq *p = &resource->data.irq;
198 if (!p || !p->interrupt_count) {
199 /*
200 * IRQ descriptors may have no IRQ# bits set,
201 * particularly those those w/ _STA disabled
202 */
203 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
204 "Blank _CRS IRQ resource\n"));
205 return AE_OK;
206 }
207 *irq = p->interrupts[0];
208 break;
209 }
210 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
211 {
212 struct acpi_resource_extended_irq *p =
213 &resource->data.extended_irq;
214 if (!p || !p->interrupt_count) {
215 /*
216 * extended IRQ descriptors must
217 * return at least 1 IRQ
218 */
219 printk(KERN_WARNING PREFIX
220 "Blank _CRS EXT IRQ resource\n");
221 return AE_OK;
222 }
223 *irq = p->interrupts[0];
224 break;
225 }
226 break;
227 default:
228 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
229 resource->type);
230 return AE_OK;
231 }
232
233 return AE_CTRL_TERMINATE;
234 }
235
236 /*
237 * Run _CRS and set link->irq.active
238 *
239 * return value:
240 * 0 - success
241 * !0 - failure
242 */
243 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
244 {
245 int result = 0;
246 acpi_status status;
247 int irq = 0;
248
249 link->irq.active = 0;
250
251 /* in practice, status disabled is meaningless, ignore it */
252 if (acpi_strict) {
253 /* Query _STA, set link->device->status */
254 result = acpi_bus_get_status(link->device);
255 if (result) {
256 printk(KERN_ERR PREFIX "Unable to read status\n");
257 goto end;
258 }
259
260 if (!link->device->status.enabled) {
261 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
262 return 0;
263 }
264 }
265
266 /*
267 * Query and parse _CRS to get the current IRQ assignment.
268 */
269
270 status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
271 acpi_pci_link_check_current, &irq);
272 if (ACPI_FAILURE(status)) {
273 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
274 result = -ENODEV;
275 goto end;
276 }
277
278 if (acpi_strict && !irq) {
279 printk(KERN_ERR PREFIX "_CRS returned 0\n");
280 result = -ENODEV;
281 }
282
283 link->irq.active = irq;
284
285 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
286
287 end:
288 return result;
289 }
290
291 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
292 {
293 int result;
294 acpi_status status;
295 struct {
296 struct acpi_resource res;
297 struct acpi_resource end;
298 } *resource;
299 struct acpi_buffer buffer = { 0, NULL };
300
301 if (!irq)
302 return -EINVAL;
303
304 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
305 if (!resource)
306 return -ENOMEM;
307
308 buffer.length = sizeof(*resource) + 1;
309 buffer.pointer = resource;
310
311 switch (link->irq.resource_type) {
312 case ACPI_RESOURCE_TYPE_IRQ:
313 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
314 resource->res.length = sizeof(struct acpi_resource);
315 resource->res.data.irq.triggering = link->irq.triggering;
316 resource->res.data.irq.polarity =
317 link->irq.polarity;
318 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
319 resource->res.data.irq.sharable =
320 ACPI_EXCLUSIVE;
321 else
322 resource->res.data.irq.sharable = ACPI_SHARED;
323 resource->res.data.irq.interrupt_count = 1;
324 resource->res.data.irq.interrupts[0] = irq;
325 break;
326
327 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
328 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
329 resource->res.length = sizeof(struct acpi_resource);
330 resource->res.data.extended_irq.producer_consumer =
331 ACPI_CONSUMER;
332 resource->res.data.extended_irq.triggering =
333 link->irq.triggering;
334 resource->res.data.extended_irq.polarity =
335 link->irq.polarity;
336 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
337 resource->res.data.irq.sharable =
338 ACPI_EXCLUSIVE;
339 else
340 resource->res.data.irq.sharable = ACPI_SHARED;
341 resource->res.data.extended_irq.interrupt_count = 1;
342 resource->res.data.extended_irq.interrupts[0] = irq;
343 /* ignore resource_source, it's optional */
344 break;
345 default:
346 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
347 result = -EINVAL;
348 goto end;
349
350 }
351 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
352 resource->end.length = sizeof(struct acpi_resource);
353
354 /* Attempt to set the resource */
355 status = acpi_set_current_resources(link->device->handle, &buffer);
356
357 /* check for total failure */
358 if (ACPI_FAILURE(status)) {
359 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
360 result = -ENODEV;
361 goto end;
362 }
363
364 /* Query _STA, set device->status */
365 result = acpi_bus_get_status(link->device);
366 if (result) {
367 printk(KERN_ERR PREFIX "Unable to read status\n");
368 goto end;
369 }
370 if (!link->device->status.enabled) {
371 printk(KERN_WARNING PREFIX
372 "%s [%s] disabled and referenced, BIOS bug\n",
373 acpi_device_name(link->device),
374 acpi_device_bid(link->device));
375 }
376
377 /* Query _CRS, set link->irq.active */
378 result = acpi_pci_link_get_current(link);
379 if (result) {
380 goto end;
381 }
382
383 /*
384 * Is current setting not what we set?
385 * set link->irq.active
386 */
387 if (link->irq.active != irq) {
388 /*
389 * policy: when _CRS doesn't return what we just _SRS
390 * assume _SRS worked and override _CRS value.
391 */
392 printk(KERN_WARNING PREFIX
393 "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
394 acpi_device_name(link->device),
395 acpi_device_bid(link->device), link->irq.active, irq);
396 link->irq.active = irq;
397 }
398
399 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
400
401 end:
402 kfree(resource);
403 return result;
404 }
405
406 /* --------------------------------------------------------------------------
407 PCI Link IRQ Management
408 -------------------------------------------------------------------------- */
409
410 /*
411 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
412 * Link Devices to move the PIRQs around to minimize sharing.
413 *
414 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
415 * that the BIOS has already set to active. This is necessary because
416 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
417 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
418 * even if acpi_irq_nobalance is set.
419 *
420 * A tables of penalties avoids directing PCI interrupts to well known
421 * ISA IRQs. Boot params are available to over-ride the default table:
422 *
423 * List interrupts that are free for PCI use.
424 * acpi_irq_pci=n[,m]
425 *
426 * List interrupts that should not be used for PCI:
427 * acpi_irq_isa=n[,m]
428 *
429 * Note that PCI IRQ routers have a list of possible IRQs,
430 * which may not include the IRQs this table says are available.
431 *
432 * Since this heuristic can't tell the difference between a link
433 * that no device will attach to, vs. a link which may be shared
434 * by multiple active devices -- it is not optimal.
435 *
436 * If interrupt performance is that important, get an IO-APIC system
437 * with a pin dedicated to each device. Or for that matter, an MSI
438 * enabled system.
439 */
440
441 #define ACPI_MAX_ISA_IRQS 16
442
443 #define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
444 #define PIRQ_PENALTY_PCI_USING (16*16*16)
445 #define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
446 #define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
447 #define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
448
449 static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = {
450 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
451 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
452 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
453 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
454 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
455 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
456 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
457 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
458 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
459 0, /* IRQ9 PCI, often acpi */
460 0, /* IRQ10 PCI */
461 0, /* IRQ11 PCI */
462 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
463 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
464 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
465 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
466 /* >IRQ15 */
467 };
468
469 static int acpi_irq_pci_sharing_penalty(int irq)
470 {
471 struct acpi_pci_link *link;
472 int penalty = 0;
473 int i;
474
475 list_for_each_entry(link, &acpi_link_list, list) {
476 /*
477 * If a link is active, penalize its IRQ heavily
478 * so we try to choose a different IRQ.
479 */
480 if (link->irq.active && link->irq.active == irq)
481 penalty += PIRQ_PENALTY_PCI_USING;
482
483 /*
484 * penalize the IRQs PCI might use, but not as severely.
485 */
486 for (i = 0; i < link->irq.possible_count; i++)
487 if (link->irq.possible[i] == irq)
488 penalty += PIRQ_PENALTY_PCI_POSSIBLE /
489 link->irq.possible_count;
490 }
491
492 return penalty;
493 }
494
495 static int acpi_irq_get_penalty(int irq)
496 {
497 int penalty = 0;
498
499 /*
500 * Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict
501 * with PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be
502 * use for PCI IRQs.
503 */
504 if (irq == acpi_gbl_FADT.sci_interrupt) {
505 u32 type = irq_get_trigger_type(irq) & IRQ_TYPE_SENSE_MASK;
506
507 if (type != IRQ_TYPE_LEVEL_LOW)
508 penalty += PIRQ_PENALTY_ISA_ALWAYS;
509 else
510 penalty += PIRQ_PENALTY_PCI_USING;
511 }
512
513 if (irq < ACPI_MAX_ISA_IRQS)
514 return penalty + acpi_isa_irq_penalty[irq];
515
516 penalty += acpi_irq_pci_sharing_penalty(irq);
517 return penalty;
518 }
519
520 int __init acpi_irq_penalty_init(void)
521 {
522 struct acpi_pci_link *link;
523 int i;
524
525 /*
526 * Update penalties to facilitate IRQ balancing.
527 */
528 list_for_each_entry(link, &acpi_link_list, list) {
529
530 /*
531 * reflect the possible and active irqs in the penalty table --
532 * useful for breaking ties.
533 */
534 if (link->irq.possible_count) {
535 int penalty =
536 PIRQ_PENALTY_PCI_POSSIBLE /
537 link->irq.possible_count;
538
539 for (i = 0; i < link->irq.possible_count; i++) {
540 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
541 acpi_isa_irq_penalty[link->irq.
542 possible[i]] +=
543 penalty;
544 }
545
546 } else if (link->irq.active &&
547 (link->irq.active < ACPI_MAX_ISA_IRQS)) {
548 acpi_isa_irq_penalty[link->irq.active] +=
549 PIRQ_PENALTY_PCI_POSSIBLE;
550 }
551 }
552
553 return 0;
554 }
555
556 static int acpi_irq_balance = -1; /* 0: static, 1: balance */
557
558 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
559 {
560 int irq;
561 int i;
562
563 if (link->irq.initialized) {
564 if (link->refcnt == 0)
565 /* This means the link is disabled but initialized */
566 acpi_pci_link_set(link, link->irq.active);
567 return 0;
568 }
569
570 /*
571 * search for active IRQ in list of possible IRQs.
572 */
573 for (i = 0; i < link->irq.possible_count; ++i) {
574 if (link->irq.active == link->irq.possible[i])
575 break;
576 }
577 /*
578 * forget active IRQ that is not in possible list
579 */
580 if (i == link->irq.possible_count) {
581 if (acpi_strict)
582 printk(KERN_WARNING PREFIX "_CRS %d not found"
583 " in _PRS\n", link->irq.active);
584 link->irq.active = 0;
585 }
586
587 /*
588 * if active found, use it; else pick entry from end of possible list.
589 */
590 if (link->irq.active)
591 irq = link->irq.active;
592 else
593 irq = link->irq.possible[link->irq.possible_count - 1];
594
595 if (acpi_irq_balance || !link->irq.active) {
596 /*
597 * Select the best IRQ. This is done in reverse to promote
598 * the use of IRQs 9, 10, 11, and >15.
599 */
600 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
601 if (acpi_irq_get_penalty(irq) >
602 acpi_irq_get_penalty(link->irq.possible[i]))
603 irq = link->irq.possible[i];
604 }
605 }
606 if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
607 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
608 "Try pci=noacpi or acpi=off\n",
609 acpi_device_name(link->device),
610 acpi_device_bid(link->device));
611 return -ENODEV;
612 }
613
614 /* Attempt to enable the link device at this IRQ. */
615 if (acpi_pci_link_set(link, irq)) {
616 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
617 "Try pci=noacpi or acpi=off\n",
618 acpi_device_name(link->device),
619 acpi_device_bid(link->device));
620 return -ENODEV;
621 } else {
622 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
623 acpi_device_name(link->device),
624 acpi_device_bid(link->device), link->irq.active);
625 }
626
627 link->irq.initialized = 1;
628 return 0;
629 }
630
631 /*
632 * acpi_pci_link_allocate_irq
633 * success: return IRQ >= 0
634 * failure: return -1
635 */
636 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
637 int *polarity, char **name)
638 {
639 int result;
640 struct acpi_device *device;
641 struct acpi_pci_link *link;
642
643 result = acpi_bus_get_device(handle, &device);
644 if (result) {
645 printk(KERN_ERR PREFIX "Invalid link device\n");
646 return -1;
647 }
648
649 link = acpi_driver_data(device);
650 if (!link) {
651 printk(KERN_ERR PREFIX "Invalid link context\n");
652 return -1;
653 }
654
655 /* TBD: Support multiple index (IRQ) entries per Link Device */
656 if (index) {
657 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
658 return -1;
659 }
660
661 mutex_lock(&acpi_link_lock);
662 if (acpi_pci_link_allocate(link)) {
663 mutex_unlock(&acpi_link_lock);
664 return -1;
665 }
666
667 if (!link->irq.active) {
668 mutex_unlock(&acpi_link_lock);
669 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
670 return -1;
671 }
672 link->refcnt++;
673 mutex_unlock(&acpi_link_lock);
674
675 if (triggering)
676 *triggering = link->irq.triggering;
677 if (polarity)
678 *polarity = link->irq.polarity;
679 if (name)
680 *name = acpi_device_bid(link->device);
681 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
682 "Link %s is referenced\n",
683 acpi_device_bid(link->device)));
684 return (link->irq.active);
685 }
686
687 /*
688 * We don't change link's irq information here. After it is reenabled, we
689 * continue use the info
690 */
691 int acpi_pci_link_free_irq(acpi_handle handle)
692 {
693 struct acpi_device *device;
694 struct acpi_pci_link *link;
695 acpi_status result;
696
697 result = acpi_bus_get_device(handle, &device);
698 if (result) {
699 printk(KERN_ERR PREFIX "Invalid link device\n");
700 return -1;
701 }
702
703 link = acpi_driver_data(device);
704 if (!link) {
705 printk(KERN_ERR PREFIX "Invalid link context\n");
706 return -1;
707 }
708
709 mutex_lock(&acpi_link_lock);
710 if (!link->irq.initialized) {
711 mutex_unlock(&acpi_link_lock);
712 printk(KERN_ERR PREFIX "Link isn't initialized\n");
713 return -1;
714 }
715 #ifdef FUTURE_USE
716 /*
717 * The Link reference count allows us to _DISable an unused link
718 * and suspend time, and set it again on resume.
719 * However, 2.6.12 still has irq_router.resume
720 * which blindly restores the link state.
721 * So we disable the reference count method
722 * to prevent duplicate acpi_pci_link_set()
723 * which would harm some systems
724 */
725 link->refcnt--;
726 #endif
727 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
728 "Link %s is dereferenced\n",
729 acpi_device_bid(link->device)));
730
731 if (link->refcnt == 0)
732 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
733
734 mutex_unlock(&acpi_link_lock);
735 return (link->irq.active);
736 }
737
738 /* --------------------------------------------------------------------------
739 Driver Interface
740 -------------------------------------------------------------------------- */
741
742 static int acpi_pci_link_add(struct acpi_device *device,
743 const struct acpi_device_id *not_used)
744 {
745 int result;
746 struct acpi_pci_link *link;
747 int i;
748 int found = 0;
749
750 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
751 if (!link)
752 return -ENOMEM;
753
754 link->device = device;
755 strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
756 strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
757 device->driver_data = link;
758
759 mutex_lock(&acpi_link_lock);
760 result = acpi_pci_link_get_possible(link);
761 if (result)
762 goto end;
763
764 /* query and set link->irq.active */
765 acpi_pci_link_get_current(link);
766
767 printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
768 acpi_device_bid(device));
769 for (i = 0; i < link->irq.possible_count; i++) {
770 if (link->irq.active == link->irq.possible[i]) {
771 printk(KERN_CONT " *%d", link->irq.possible[i]);
772 found = 1;
773 } else
774 printk(KERN_CONT " %d", link->irq.possible[i]);
775 }
776
777 printk(KERN_CONT ")");
778
779 if (!found)
780 printk(KERN_CONT " *%d", link->irq.active);
781
782 if (!link->device->status.enabled)
783 printk(KERN_CONT ", disabled.");
784
785 printk(KERN_CONT "\n");
786
787 list_add_tail(&link->list, &acpi_link_list);
788
789 end:
790 /* disable all links -- to be activated on use */
791 acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
792 mutex_unlock(&acpi_link_lock);
793
794 if (result)
795 kfree(link);
796
797 return result < 0 ? result : 1;
798 }
799
800 static int acpi_pci_link_resume(struct acpi_pci_link *link)
801 {
802 if (link->refcnt && link->irq.active && link->irq.initialized)
803 return (acpi_pci_link_set(link, link->irq.active));
804
805 return 0;
806 }
807
808 static void irqrouter_resume(void)
809 {
810 struct acpi_pci_link *link;
811
812 list_for_each_entry(link, &acpi_link_list, list) {
813 acpi_pci_link_resume(link);
814 }
815 }
816
817 static void acpi_pci_link_remove(struct acpi_device *device)
818 {
819 struct acpi_pci_link *link;
820
821 link = acpi_driver_data(device);
822
823 mutex_lock(&acpi_link_lock);
824 list_del(&link->list);
825 mutex_unlock(&acpi_link_lock);
826
827 kfree(link);
828 }
829
830 /*
831 * modify acpi_isa_irq_penalty[] from cmdline
832 */
833 static int __init acpi_irq_penalty_update(char *str, int used)
834 {
835 int i;
836
837 for (i = 0; i < 16; i++) {
838 int retval;
839 int irq;
840 int new_penalty;
841
842 retval = get_option(&str, &irq);
843
844 if (!retval)
845 break; /* no number found */
846
847 /* see if this is a ISA IRQ */
848 if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
849 continue;
850
851 if (used)
852 new_penalty = acpi_irq_get_penalty(irq) +
853 PIRQ_PENALTY_ISA_USED;
854 else
855 new_penalty = 0;
856
857 acpi_isa_irq_penalty[irq] = new_penalty;
858 if (retval != 2) /* no next number */
859 break;
860 }
861 return 1;
862 }
863
864 /*
865 * We'd like PNP to call this routine for the
866 * single ISA_USED value for each legacy device.
867 * But instead it calls us with each POSSIBLE setting.
868 * There is no ISA_POSSIBLE weight, so we simply use
869 * the (small) PCI_USING penalty.
870 */
871 void acpi_penalize_isa_irq(int irq, int active)
872 {
873 if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
874 acpi_isa_irq_penalty[irq] = acpi_irq_get_penalty(irq) +
875 (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
876 }
877
878 bool acpi_isa_irq_available(int irq)
879 {
880 return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
881 acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
882 }
883
884 /*
885 * Over-ride default table to reserve additional IRQs for use by ISA
886 * e.g. acpi_irq_isa=5
887 * Useful for telling ACPI how not to interfere with your ISA sound card.
888 */
889 static int __init acpi_irq_isa(char *str)
890 {
891 return acpi_irq_penalty_update(str, 1);
892 }
893
894 __setup("acpi_irq_isa=", acpi_irq_isa);
895
896 /*
897 * Over-ride default table to free additional IRQs for use by PCI
898 * e.g. acpi_irq_pci=7,15
899 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
900 */
901 static int __init acpi_irq_pci(char *str)
902 {
903 return acpi_irq_penalty_update(str, 0);
904 }
905
906 __setup("acpi_irq_pci=", acpi_irq_pci);
907
908 static int __init acpi_irq_nobalance_set(char *str)
909 {
910 acpi_irq_balance = 0;
911 return 1;
912 }
913
914 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
915
916 static int __init acpi_irq_balance_set(char *str)
917 {
918 acpi_irq_balance = 1;
919 return 1;
920 }
921
922 __setup("acpi_irq_balance", acpi_irq_balance_set);
923
924 static struct syscore_ops irqrouter_syscore_ops = {
925 .resume = irqrouter_resume,
926 };
927
928 void __init acpi_pci_link_init(void)
929 {
930 if (acpi_noirq)
931 return;
932
933 if (acpi_irq_balance == -1) {
934 /* no command line switch: enable balancing in IOAPIC mode */
935 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
936 acpi_irq_balance = 1;
937 else
938 acpi_irq_balance = 0;
939 }
940 register_syscore_ops(&irqrouter_syscore_ops);
941 acpi_scan_add_handler(&pci_link_handler);
942 }
Linux with added FPC-III support