Merge branch 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak...
[linux-2.6] / drivers / acpi / pci_link.c
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  *  You should have received a copy of the GNU General Public License along
21  *  with this program; if not, write to the Free Software Foundation, Inc.,
22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23  *
24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25  *
26  * TBD: 
27  *      1. Support more than one IRQ resource entry per link device (index).
28  *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
29  *         for IRQ management (e.g. start()->_SRS).
30  */
31
32 #include <linux/sysdev.h>
33 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/init.h>
36 #include <linux/types.h>
37 #include <linux/proc_fs.h>
38 #include <linux/spinlock.h>
39 #include <linux/pm.h>
40 #include <linux/pci.h>
41 #include <linux/mutex.h>
42
43 #include <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
45
46 #define _COMPONENT              ACPI_PCI_COMPONENT
47 ACPI_MODULE_NAME("pci_link");
48 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
49 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
50 #define ACPI_PCI_LINK_FILE_INFO         "info"
51 #define ACPI_PCI_LINK_FILE_STATUS       "state"
52 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
53 static int acpi_pci_link_add(struct acpi_device *device);
54 static int acpi_pci_link_remove(struct acpi_device *device, int type);
55
56 static struct acpi_device_id link_device_ids[] = {
57         {"PNP0C0F", 0},
58         {"", 0},
59 };
60 MODULE_DEVICE_TABLE(acpi, link_device_ids);
61
62 static struct acpi_driver acpi_pci_link_driver = {
63         .name = "pci_link",
64         .class = ACPI_PCI_LINK_CLASS,
65         .ids = link_device_ids,
66         .ops = {
67                 .add = acpi_pci_link_add,
68                 .remove = acpi_pci_link_remove,
69                 },
70 };
71
72 /*
73  * If a link is initialized, we never change its active and initialized
74  * later even the link is disable. Instead, we just repick the active irq
75  */
76 struct acpi_pci_link_irq {
77         u8 active;              /* Current IRQ */
78         u8 triggering;          /* All IRQs */
79         u8 polarity;    /* All IRQs */
80         u8 resource_type;
81         u8 possible_count;
82         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
83         u8 initialized:1;
84         u8 reserved:7;
85 };
86
87 struct acpi_pci_link {
88         struct list_head node;
89         struct acpi_device *device;
90         struct acpi_pci_link_irq irq;
91         int refcnt;
92 };
93
94 static struct {
95         int count;
96         struct list_head entries;
97 } acpi_link;
98 static DEFINE_MUTEX(acpi_link_lock);
99
100 /* --------------------------------------------------------------------------
101                             PCI Link Device Management
102    -------------------------------------------------------------------------- */
103
104 /*
105  * set context (link) possible list from resource list
106  */
107 static acpi_status
108 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
109 {
110         struct acpi_pci_link *link = context;
111         u32 i = 0;
112
113
114         switch (resource->type) {
115         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
116         case ACPI_RESOURCE_TYPE_END_TAG:
117                 return AE_OK;
118         case ACPI_RESOURCE_TYPE_IRQ:
119                 {
120                         struct acpi_resource_irq *p = &resource->data.irq;
121                         if (!p || !p->interrupt_count) {
122                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
123                                                   "Blank _PRS IRQ resource\n"));
124                                 return AE_OK;
125                         }
126                         for (i = 0;
127                              (i < p->interrupt_count
128                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
129                                 if (!p->interrupts[i]) {
130                                         printk(KERN_WARNING PREFIX
131                                                "Invalid _PRS IRQ %d\n",
132                                                p->interrupts[i]);
133                                         continue;
134                                 }
135                                 link->irq.possible[i] = p->interrupts[i];
136                                 link->irq.possible_count++;
137                         }
138                         link->irq.triggering = p->triggering;
139                         link->irq.polarity = p->polarity;
140                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
141                         break;
142                 }
143         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
144                 {
145                         struct acpi_resource_extended_irq *p =
146                             &resource->data.extended_irq;
147                         if (!p || !p->interrupt_count) {
148                                 printk(KERN_WARNING PREFIX
149                                               "Blank _PRS EXT IRQ resource\n");
150                                 return AE_OK;
151                         }
152                         for (i = 0;
153                              (i < p->interrupt_count
154                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
155                                 if (!p->interrupts[i]) {
156                                         printk(KERN_WARNING PREFIX
157                                                "Invalid _PRS IRQ %d\n",
158                                                p->interrupts[i]);
159                                         continue;
160                                 }
161                                 link->irq.possible[i] = p->interrupts[i];
162                                 link->irq.possible_count++;
163                         }
164                         link->irq.triggering = p->triggering;
165                         link->irq.polarity = p->polarity;
166                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
167                         break;
168                 }
169         default:
170                 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
171                        resource->type);
172                 return AE_OK;
173         }
174
175         return AE_CTRL_TERMINATE;
176 }
177
178 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
179 {
180         acpi_status status;
181
182
183         if (!link)
184                 return -EINVAL;
185
186         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
187                                      acpi_pci_link_check_possible, link);
188         if (ACPI_FAILURE(status)) {
189                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
190                 return -ENODEV;
191         }
192
193         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
194                           "Found %d possible IRQs\n",
195                           link->irq.possible_count));
196
197         return 0;
198 }
199
200 static acpi_status
201 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
202 {
203         int *irq = (int *)context;
204
205
206         switch (resource->type) {
207         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
208         case ACPI_RESOURCE_TYPE_END_TAG:
209                 return AE_OK;
210         case ACPI_RESOURCE_TYPE_IRQ:
211                 {
212                         struct acpi_resource_irq *p = &resource->data.irq;
213                         if (!p || !p->interrupt_count) {
214                                 /*
215                                  * IRQ descriptors may have no IRQ# bits set,
216                                  * particularly those those w/ _STA disabled
217                                  */
218                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
219                                                   "Blank _CRS IRQ resource\n"));
220                                 return AE_OK;
221                         }
222                         *irq = p->interrupts[0];
223                         break;
224                 }
225         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
226                 {
227                         struct acpi_resource_extended_irq *p =
228                             &resource->data.extended_irq;
229                         if (!p || !p->interrupt_count) {
230                                 /*
231                                  * extended IRQ descriptors must
232                                  * return at least 1 IRQ
233                                  */
234                                 printk(KERN_WARNING PREFIX
235                                               "Blank _CRS EXT IRQ resource\n");
236                                 return AE_OK;
237                         }
238                         *irq = p->interrupts[0];
239                         break;
240                 }
241                 break;
242         default:
243                 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
244                        resource->type);
245                 return AE_OK;
246         }
247
248         return AE_CTRL_TERMINATE;
249 }
250
251 /*
252  * Run _CRS and set link->irq.active
253  *
254  * return value:
255  * 0 - success
256  * !0 - failure
257  */
258 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
259 {
260         int result = 0;
261         acpi_status status = AE_OK;
262         int irq = 0;
263
264         if (!link)
265                 return -EINVAL;
266
267         link->irq.active = 0;
268
269         /* in practice, status disabled is meaningless, ignore it */
270         if (acpi_strict) {
271                 /* Query _STA, set link->device->status */
272                 result = acpi_bus_get_status(link->device);
273                 if (result) {
274                         printk(KERN_ERR PREFIX "Unable to read status\n");
275                         goto end;
276                 }
277
278                 if (!link->device->status.enabled) {
279                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
280                         return 0;
281                 }
282         }
283
284         /* 
285          * Query and parse _CRS to get the current IRQ assignment. 
286          */
287
288         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
289                                      acpi_pci_link_check_current, &irq);
290         if (ACPI_FAILURE(status)) {
291                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
292                 result = -ENODEV;
293                 goto end;
294         }
295
296         if (acpi_strict && !irq) {
297                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
298                 result = -ENODEV;
299         }
300
301         link->irq.active = irq;
302
303         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
304
305       end:
306         return result;
307 }
308
309 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
310 {
311         int result = 0;
312         acpi_status status = AE_OK;
313         struct {
314                 struct acpi_resource res;
315                 struct acpi_resource end;
316         } *resource;
317         struct acpi_buffer buffer = { 0, NULL };
318
319
320         if (!link || !irq)
321                 return -EINVAL;
322
323         resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
324         if (!resource)
325                 return -ENOMEM;
326
327         buffer.length = sizeof(*resource) + 1;
328         buffer.pointer = resource;
329
330         switch (link->irq.resource_type) {
331         case ACPI_RESOURCE_TYPE_IRQ:
332                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
333                 resource->res.length = sizeof(struct acpi_resource);
334                 resource->res.data.irq.triggering = link->irq.triggering;
335                 resource->res.data.irq.polarity =
336                     link->irq.polarity;
337                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
338                         resource->res.data.irq.sharable =
339                             ACPI_EXCLUSIVE;
340                 else
341                         resource->res.data.irq.sharable = ACPI_SHARED;
342                 resource->res.data.irq.interrupt_count = 1;
343                 resource->res.data.irq.interrupts[0] = irq;
344                 break;
345
346         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
347                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
348                 resource->res.length = sizeof(struct acpi_resource);
349                 resource->res.data.extended_irq.producer_consumer =
350                     ACPI_CONSUMER;
351                 resource->res.data.extended_irq.triggering =
352                     link->irq.triggering;
353                 resource->res.data.extended_irq.polarity =
354                     link->irq.polarity;
355                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
356                         resource->res.data.irq.sharable =
357                             ACPI_EXCLUSIVE;
358                 else
359                         resource->res.data.irq.sharable = ACPI_SHARED;
360                 resource->res.data.extended_irq.interrupt_count = 1;
361                 resource->res.data.extended_irq.interrupts[0] = irq;
362                 /* ignore resource_source, it's optional */
363                 break;
364         default:
365                 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
366                 result = -EINVAL;
367                 goto end;
368
369         }
370         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
371
372         /* Attempt to set the resource */
373         status = acpi_set_current_resources(link->device->handle, &buffer);
374
375         /* check for total failure */
376         if (ACPI_FAILURE(status)) {
377                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
378                 result = -ENODEV;
379                 goto end;
380         }
381
382         /* Query _STA, set device->status */
383         result = acpi_bus_get_status(link->device);
384         if (result) {
385                 printk(KERN_ERR PREFIX "Unable to read status\n");
386                 goto end;
387         }
388         if (!link->device->status.enabled) {
389                 printk(KERN_WARNING PREFIX
390                               "%s [%s] disabled and referenced, BIOS bug\n",
391                               acpi_device_name(link->device),
392                               acpi_device_bid(link->device));
393         }
394
395         /* Query _CRS, set link->irq.active */
396         result = acpi_pci_link_get_current(link);
397         if (result) {
398                 goto end;
399         }
400
401         /*
402          * Is current setting not what we set?
403          * set link->irq.active
404          */
405         if (link->irq.active != irq) {
406                 /*
407                  * policy: when _CRS doesn't return what we just _SRS
408                  * assume _SRS worked and override _CRS value.
409                  */
410                 printk(KERN_WARNING PREFIX
411                               "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
412                               acpi_device_name(link->device),
413                               acpi_device_bid(link->device), link->irq.active, irq);
414                 link->irq.active = irq;
415         }
416
417         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
418
419       end:
420         kfree(resource);
421         return result;
422 }
423
424 /* --------------------------------------------------------------------------
425                             PCI Link IRQ Management
426    -------------------------------------------------------------------------- */
427
428 /*
429  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
430  * Link Devices to move the PIRQs around to minimize sharing.
431  * 
432  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
433  * that the BIOS has already set to active.  This is necessary because
434  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
435  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
436  * even if acpi_irq_nobalance is set.
437  *
438  * A tables of penalties avoids directing PCI interrupts to well known
439  * ISA IRQs. Boot params are available to over-ride the default table:
440  *
441  * List interrupts that are free for PCI use.
442  * acpi_irq_pci=n[,m]
443  *
444  * List interrupts that should not be used for PCI:
445  * acpi_irq_isa=n[,m]
446  *
447  * Note that PCI IRQ routers have a list of possible IRQs,
448  * which may not include the IRQs this table says are available.
449  * 
450  * Since this heuristic can't tell the difference between a link
451  * that no device will attach to, vs. a link which may be shared
452  * by multiple active devices -- it is not optimal.
453  *
454  * If interrupt performance is that important, get an IO-APIC system
455  * with a pin dedicated to each device.  Or for that matter, an MSI
456  * enabled system.
457  */
458
459 #define ACPI_MAX_IRQS           256
460 #define ACPI_MAX_ISA_IRQ        16
461
462 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
463 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
464 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
465 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
466 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
467 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
468
469 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
470         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
471         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
472         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
473         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
474         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
475         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
476         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
477         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
478         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
479         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
480         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
481         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
482         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
483         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
484         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
485         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
486         /* >IRQ15 */
487 };
488
489 int __init acpi_irq_penalty_init(void)
490 {
491         struct list_head *node = NULL;
492         struct acpi_pci_link *link = NULL;
493         int i = 0;
494
495
496         /*
497          * Update penalties to facilitate IRQ balancing.
498          */
499         list_for_each(node, &acpi_link.entries) {
500
501                 link = list_entry(node, struct acpi_pci_link, node);
502                 if (!link) {
503                         printk(KERN_ERR PREFIX "Invalid link context\n");
504                         continue;
505                 }
506
507                 /*
508                  * reflect the possible and active irqs in the penalty table --
509                  * useful for breaking ties.
510                  */
511                 if (link->irq.possible_count) {
512                         int penalty =
513                             PIRQ_PENALTY_PCI_POSSIBLE /
514                             link->irq.possible_count;
515
516                         for (i = 0; i < link->irq.possible_count; i++) {
517                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
518                                         acpi_irq_penalty[link->irq.
519                                                          possible[i]] +=
520                                             penalty;
521                         }
522
523                 } else if (link->irq.active) {
524                         acpi_irq_penalty[link->irq.active] +=
525                             PIRQ_PENALTY_PCI_POSSIBLE;
526                 }
527         }
528         /* Add a penalty for the SCI */
529         acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
530
531         return 0;
532 }
533
534 static int acpi_irq_balance;    /* 0: static, 1: balance */
535
536 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
537 {
538         int irq;
539         int i;
540
541
542         if (link->irq.initialized) {
543                 if (link->refcnt == 0)
544                         /* This means the link is disabled but initialized */
545                         acpi_pci_link_set(link, link->irq.active);
546                 return 0;
547         }
548
549         /*
550          * search for active IRQ in list of possible IRQs.
551          */
552         for (i = 0; i < link->irq.possible_count; ++i) {
553                 if (link->irq.active == link->irq.possible[i])
554                         break;
555         }
556         /*
557          * forget active IRQ that is not in possible list
558          */
559         if (i == link->irq.possible_count) {
560                 if (acpi_strict)
561                         printk(KERN_WARNING PREFIX "_CRS %d not found"
562                                       " in _PRS\n", link->irq.active);
563                 link->irq.active = 0;
564         }
565
566         /*
567          * if active found, use it; else pick entry from end of possible list.
568          */
569         if (link->irq.active) {
570                 irq = link->irq.active;
571         } else {
572                 irq = link->irq.possible[link->irq.possible_count - 1];
573         }
574
575         if (acpi_irq_balance || !link->irq.active) {
576                 /*
577                  * Select the best IRQ.  This is done in reverse to promote
578                  * the use of IRQs 9, 10, 11, and >15.
579                  */
580                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
581                         if (acpi_irq_penalty[irq] >
582                             acpi_irq_penalty[link->irq.possible[i]])
583                                 irq = link->irq.possible[i];
584                 }
585         }
586
587         /* Attempt to enable the link device at this IRQ. */
588         if (acpi_pci_link_set(link, irq)) {
589                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
590                             "Try pci=noacpi or acpi=off\n",
591                             acpi_device_name(link->device),
592                             acpi_device_bid(link->device));
593                 return -ENODEV;
594         } else {
595                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
596                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
597                        acpi_device_name(link->device),
598                        acpi_device_bid(link->device), link->irq.active);
599         }
600
601         link->irq.initialized = 1;
602
603         return 0;
604 }
605
606 /*
607  * acpi_pci_link_allocate_irq
608  * success: return IRQ >= 0
609  * failure: return -1
610  */
611
612 int
613 acpi_pci_link_allocate_irq(acpi_handle handle,
614                            int index,
615                            int *triggering, int *polarity, char **name)
616 {
617         int result = 0;
618         struct acpi_device *device = NULL;
619         struct acpi_pci_link *link = NULL;
620
621
622         result = acpi_bus_get_device(handle, &device);
623         if (result) {
624                 printk(KERN_ERR PREFIX "Invalid link device\n");
625                 return -1;
626         }
627
628         link = acpi_driver_data(device);
629         if (!link) {
630                 printk(KERN_ERR PREFIX "Invalid link context\n");
631                 return -1;
632         }
633
634         /* TBD: Support multiple index (IRQ) entries per Link Device */
635         if (index) {
636                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
637                 return -1;
638         }
639
640         mutex_lock(&acpi_link_lock);
641         if (acpi_pci_link_allocate(link)) {
642                 mutex_unlock(&acpi_link_lock);
643                 return -1;
644         }
645
646         if (!link->irq.active) {
647                 mutex_unlock(&acpi_link_lock);
648                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
649                 return -1;
650         }
651         link->refcnt++;
652         mutex_unlock(&acpi_link_lock);
653
654         if (triggering)
655                 *triggering = link->irq.triggering;
656         if (polarity)
657                 *polarity = link->irq.polarity;
658         if (name)
659                 *name = acpi_device_bid(link->device);
660         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
661                           "Link %s is referenced\n",
662                           acpi_device_bid(link->device)));
663         return (link->irq.active);
664 }
665
666 /*
667  * We don't change link's irq information here.  After it is reenabled, we
668  * continue use the info
669  */
670 int acpi_pci_link_free_irq(acpi_handle handle)
671 {
672         struct acpi_device *device = NULL;
673         struct acpi_pci_link *link = NULL;
674         acpi_status result;
675
676
677         result = acpi_bus_get_device(handle, &device);
678         if (result) {
679                 printk(KERN_ERR PREFIX "Invalid link device\n");
680                 return -1;
681         }
682
683         link = acpi_driver_data(device);
684         if (!link) {
685                 printk(KERN_ERR PREFIX "Invalid link context\n");
686                 return -1;
687         }
688
689         mutex_lock(&acpi_link_lock);
690         if (!link->irq.initialized) {
691                 mutex_unlock(&acpi_link_lock);
692                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
693                 return -1;
694         }
695 #ifdef  FUTURE_USE
696         /*
697          * The Link reference count allows us to _DISable an unused link
698          * and suspend time, and set it again  on resume.
699          * However, 2.6.12 still has irq_router.resume
700          * which blindly restores the link state.
701          * So we disable the reference count method
702          * to prevent duplicate acpi_pci_link_set()
703          * which would harm some systems
704          */
705         link->refcnt--;
706 #endif
707         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
708                           "Link %s is dereferenced\n",
709                           acpi_device_bid(link->device)));
710
711         if (link->refcnt == 0) {
712                 acpi_ut_evaluate_object(link->device->handle, "_DIS", 0, NULL);
713         }
714         mutex_unlock(&acpi_link_lock);
715         return (link->irq.active);
716 }
717
718 /* --------------------------------------------------------------------------
719                                  Driver Interface
720    -------------------------------------------------------------------------- */
721
722 static int acpi_pci_link_add(struct acpi_device *device)
723 {
724         int result = 0;
725         struct acpi_pci_link *link = NULL;
726         int i = 0;
727         int found = 0;
728
729
730         if (!device)
731                 return -EINVAL;
732
733         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
734         if (!link)
735                 return -ENOMEM;
736
737         link->device = device;
738         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
739         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
740         acpi_driver_data(device) = link;
741
742         mutex_lock(&acpi_link_lock);
743         result = acpi_pci_link_get_possible(link);
744         if (result)
745                 goto end;
746
747         /* query and set link->irq.active */
748         acpi_pci_link_get_current(link);
749
750         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
751                acpi_device_bid(device));
752         for (i = 0; i < link->irq.possible_count; i++) {
753                 if (link->irq.active == link->irq.possible[i]) {
754                         printk(" *%d", link->irq.possible[i]);
755                         found = 1;
756                 } else
757                         printk(" %d", link->irq.possible[i]);
758         }
759
760         printk(")");
761
762         if (!found)
763                 printk(" *%d", link->irq.active);
764
765         if (!link->device->status.enabled)
766                 printk(", disabled.");
767
768         printk("\n");
769
770         /* TBD: Acquire/release lock */
771         list_add_tail(&link->node, &acpi_link.entries);
772         acpi_link.count++;
773
774       end:
775         /* disable all links -- to be activated on use */
776         acpi_ut_evaluate_object(device->handle, "_DIS", 0, NULL);
777         mutex_unlock(&acpi_link_lock);
778
779         if (result)
780                 kfree(link);
781
782         return result;
783 }
784
785 static int acpi_pci_link_resume(struct acpi_pci_link *link)
786 {
787
788         if (link->refcnt && link->irq.active && link->irq.initialized)
789                 return (acpi_pci_link_set(link, link->irq.active));
790         else
791                 return 0;
792 }
793
794 static int irqrouter_resume(struct sys_device *dev)
795 {
796         struct list_head *node = NULL;
797         struct acpi_pci_link *link = NULL;
798
799
800         /* Make sure SCI is enabled again (Apple firmware bug?) */
801         acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
802
803         list_for_each(node, &acpi_link.entries) {
804                 link = list_entry(node, struct acpi_pci_link, node);
805                 if (!link) {
806                         printk(KERN_ERR PREFIX "Invalid link context\n");
807                         continue;
808                 }
809                 acpi_pci_link_resume(link);
810         }
811         return 0;
812 }
813
814 static int acpi_pci_link_remove(struct acpi_device *device, int type)
815 {
816         struct acpi_pci_link *link = NULL;
817
818
819         if (!device || !acpi_driver_data(device))
820                 return -EINVAL;
821
822         link = acpi_driver_data(device);
823
824         mutex_lock(&acpi_link_lock);
825         list_del(&link->node);
826         mutex_unlock(&acpi_link_lock);
827
828         kfree(link);
829
830         return 0;
831 }
832
833 /*
834  * modify acpi_irq_penalty[] from cmdline
835  */
836 static int __init acpi_irq_penalty_update(char *str, int used)
837 {
838         int i;
839
840         for (i = 0; i < 16; i++) {
841                 int retval;
842                 int irq;
843
844                 retval = get_option(&str, &irq);
845
846                 if (!retval)
847                         break;  /* no number found */
848
849                 if (irq < 0)
850                         continue;
851
852                 if (irq >= ARRAY_SIZE(acpi_irq_penalty))
853                         continue;
854
855                 if (used)
856                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
857                 else
858                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
859
860                 if (retval != 2)        /* no next number */
861                         break;
862         }
863         return 1;
864 }
865
866 /*
867  * We'd like PNP to call this routine for the
868  * single ISA_USED value for each legacy device.
869  * But instead it calls us with each POSSIBLE setting.
870  * There is no ISA_POSSIBLE weight, so we simply use
871  * the (small) PCI_USING penalty.
872  */
873 void acpi_penalize_isa_irq(int irq, int active)
874 {
875         if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
876                 if (active)
877                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
878                 else
879                         acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
880         }
881 }
882
883 /*
884  * Over-ride default table to reserve additional IRQs for use by ISA
885  * e.g. acpi_irq_isa=5
886  * Useful for telling ACPI how not to interfere with your ISA sound card.
887  */
888 static int __init acpi_irq_isa(char *str)
889 {
890         return acpi_irq_penalty_update(str, 1);
891 }
892
893 __setup("acpi_irq_isa=", acpi_irq_isa);
894
895 /*
896  * Over-ride default table to free additional IRQs for use by PCI
897  * e.g. acpi_irq_pci=7,15
898  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
899  */
900 static int __init acpi_irq_pci(char *str)
901 {
902         return acpi_irq_penalty_update(str, 0);
903 }
904
905 __setup("acpi_irq_pci=", acpi_irq_pci);
906
907 static int __init acpi_irq_nobalance_set(char *str)
908 {
909         acpi_irq_balance = 0;
910         return 1;
911 }
912
913 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
914
915 int __init acpi_irq_balance_set(char *str)
916 {
917         acpi_irq_balance = 1;
918         return 1;
919 }
920
921 __setup("acpi_irq_balance", acpi_irq_balance_set);
922
923 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
924 static struct sysdev_class irqrouter_sysdev_class = {
925         .name = "irqrouter",
926         .resume = irqrouter_resume,
927 };
928
929 static struct sys_device device_irqrouter = {
930         .id = 0,
931         .cls = &irqrouter_sysdev_class,
932 };
933
934 static int __init irqrouter_init_sysfs(void)
935 {
936         int error;
937
938
939         if (acpi_disabled || acpi_noirq)
940                 return 0;
941
942         error = sysdev_class_register(&irqrouter_sysdev_class);
943         if (!error)
944                 error = sysdev_register(&device_irqrouter);
945
946         return error;
947 }
948
949 device_initcall(irqrouter_init_sysfs);
950
951 static int __init acpi_pci_link_init(void)
952 {
953
954         if (acpi_noirq)
955                 return 0;
956
957         acpi_link.count = 0;
958         INIT_LIST_HEAD(&acpi_link.entries);
959
960         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
961                 return -ENODEV;
962
963         return 0;
964 }
965
966 subsys_initcall(acpi_pci_link_init);