Pull sem2mutex into release branch
[linux-2.6.git] / 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_HID               "PNP0C0F"
50 #define ACPI_PCI_LINK_DRIVER_NAME       "ACPI PCI Interrupt Link Driver"
51 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
52 #define ACPI_PCI_LINK_FILE_INFO         "info"
53 #define ACPI_PCI_LINK_FILE_STATUS       "state"
54 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
55 static int acpi_pci_link_add(struct acpi_device *device);
56 static int acpi_pci_link_remove(struct acpi_device *device, int type);
57
58 static struct acpi_driver acpi_pci_link_driver = {
59         .name = ACPI_PCI_LINK_DRIVER_NAME,
60         .class = ACPI_PCI_LINK_CLASS,
61         .ids = ACPI_PCI_LINK_HID,
62         .ops = {
63                 .add = acpi_pci_link_add,
64                 .remove = acpi_pci_link_remove,
65                 },
66 };
67
68 /*
69  * If a link is initialized, we never change its active and initialized
70  * later even the link is disable. Instead, we just repick the active irq
71  */
72 struct acpi_pci_link_irq {
73         u8 active;              /* Current IRQ */
74         u8 triggering;          /* All IRQs */
75         u8 polarity;    /* All IRQs */
76         u8 resource_type;
77         u8 possible_count;
78         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
79         u8 initialized:1;
80         u8 reserved:7;
81 };
82
83 struct acpi_pci_link {
84         struct list_head node;
85         struct acpi_device *device;
86         acpi_handle handle;
87         struct acpi_pci_link_irq irq;
88         int refcnt;
89 };
90
91 static struct {
92         int count;
93         struct list_head entries;
94 } acpi_link;
95 DEFINE_MUTEX(acpi_link_lock);
96
97 /* --------------------------------------------------------------------------
98                             PCI Link Device Management
99    -------------------------------------------------------------------------- */
100
101 /*
102  * set context (link) possible list from resource list
103  */
104 static acpi_status
105 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
106 {
107         struct acpi_pci_link *link = (struct acpi_pci_link *)context;
108         u32 i = 0;
109
110         ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
111
112         switch (resource->type) {
113         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
114                 return_ACPI_STATUS(AE_OK);
115         case ACPI_RESOURCE_TYPE_IRQ:
116                 {
117                         struct acpi_resource_irq *p = &resource->data.irq;
118                         if (!p || !p->interrupt_count) {
119                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
120                                                   "Blank IRQ resource\n"));
121                                 return_ACPI_STATUS(AE_OK);
122                         }
123                         for (i = 0;
124                              (i < p->interrupt_count
125                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
126                                 if (!p->interrupts[i]) {
127                                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
128                                                           "Invalid IRQ %d\n",
129                                                           p->interrupts[i]));
130                                         continue;
131                                 }
132                                 link->irq.possible[i] = p->interrupts[i];
133                                 link->irq.possible_count++;
134                         }
135                         link->irq.triggering = p->triggering;
136                         link->irq.polarity = p->polarity;
137                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
138                         break;
139                 }
140         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
141                 {
142                         struct acpi_resource_extended_irq *p =
143                             &resource->data.extended_irq;
144                         if (!p || !p->interrupt_count) {
145                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
146                                                   "Blank EXT IRQ resource\n"));
147                                 return_ACPI_STATUS(AE_OK);
148                         }
149                         for (i = 0;
150                              (i < p->interrupt_count
151                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
152                                 if (!p->interrupts[i]) {
153                                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
154                                                           "Invalid IRQ %d\n",
155                                                           p->interrupts[i]));
156                                         continue;
157                                 }
158                                 link->irq.possible[i] = p->interrupts[i];
159                                 link->irq.possible_count++;
160                         }
161                         link->irq.triggering = p->triggering;
162                         link->irq.polarity = p->polarity;
163                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
164                         break;
165                 }
166         default:
167                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
168                                   "Resource is not an IRQ entry\n"));
169                 return_ACPI_STATUS(AE_OK);
170         }
171
172         return_ACPI_STATUS(AE_CTRL_TERMINATE);
173 }
174
175 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
176 {
177         acpi_status status;
178
179         ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
180
181         if (!link)
182                 return_VALUE(-EINVAL);
183
184         status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
185                                      acpi_pci_link_check_possible, link);
186         if (ACPI_FAILURE(status)) {
187                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
188                 return_VALUE(-ENODEV);
189         }
190
191         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
192                           "Found %d possible IRQs\n",
193                           link->irq.possible_count));
194
195         return_VALUE(0);
196 }
197
198 static acpi_status
199 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
200 {
201         int *irq = (int *)context;
202
203         ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
204
205         switch (resource->type) {
206         case ACPI_RESOURCE_TYPE_IRQ:
207                 {
208                         struct acpi_resource_irq *p = &resource->data.irq;
209                         if (!p || !p->interrupt_count) {
210                                 /*
211                                  * IRQ descriptors may have no IRQ# bits set,
212                                  * particularly those those w/ _STA disabled
213                                  */
214                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
215                                                   "Blank IRQ resource\n"));
216                                 return_ACPI_STATUS(AE_OK);
217                         }
218                         *irq = p->interrupts[0];
219                         break;
220                 }
221         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
222                 {
223                         struct acpi_resource_extended_irq *p =
224                             &resource->data.extended_irq;
225                         if (!p || !p->interrupt_count) {
226                                 /*
227                                  * extended IRQ descriptors must
228                                  * return at least 1 IRQ
229                                  */
230                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
231                                                   "Blank EXT IRQ resource\n"));
232                                 return_ACPI_STATUS(AE_OK);
233                         }
234                         *irq = p->interrupts[0];
235                         break;
236                 }
237                 break;
238         default:
239                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Resource %d isn't an IRQ\n", resource->type));
240         case ACPI_RESOURCE_TYPE_END_TAG:
241                 return_ACPI_STATUS(AE_OK);
242         }
243         return_ACPI_STATUS(AE_CTRL_TERMINATE);
244 }
245
246 /*
247  * Run _CRS and set link->irq.active
248  *
249  * return value:
250  * 0 - success
251  * !0 - failure
252  */
253 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
254 {
255         int result = 0;
256         acpi_status status = AE_OK;
257         int irq = 0;
258
259         ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
260
261         if (!link || !link->handle)
262                 return_VALUE(-EINVAL);
263
264         link->irq.active = 0;
265
266         /* in practice, status disabled is meaningless, ignore it */
267         if (acpi_strict) {
268                 /* Query _STA, set link->device->status */
269                 result = acpi_bus_get_status(link->device);
270                 if (result) {
271                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
272                                           "Unable to read status\n"));
273                         goto end;
274                 }
275
276                 if (!link->device->status.enabled) {
277                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
278                         return_VALUE(0);
279                 }
280         }
281
282         /* 
283          * Query and parse _CRS to get the current IRQ assignment. 
284          */
285
286         status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
287                                      acpi_pci_link_check_current, &irq);
288         if (ACPI_FAILURE(status)) {
289                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
290                 result = -ENODEV;
291                 goto end;
292         }
293
294         if (acpi_strict && !irq) {
295                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
296                 result = -ENODEV;
297         }
298
299         link->irq.active = irq;
300
301         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
302
303       end:
304         return_VALUE(result);
305 }
306
307 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
308 {
309         int result = 0;
310         acpi_status status = AE_OK;
311         struct {
312                 struct acpi_resource res;
313                 struct acpi_resource end;
314         } *resource;
315         struct acpi_buffer buffer = { 0, NULL };
316
317         ACPI_FUNCTION_TRACE("acpi_pci_link_set");
318
319         if (!link || !irq)
320                 return_VALUE(-EINVAL);
321
322         resource = kmalloc(sizeof(*resource) + 1, GFP_ATOMIC);
323         if (!resource)
324                 return_VALUE(-ENOMEM);
325
326         memset(resource, 0, sizeof(*resource) + 1);
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("ACPI BUG: 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->handle, &buffer);
374
375         /* check for total failure */
376         if (ACPI_FAILURE(status)) {
377                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
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                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "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_VALUE(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         ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");
496
497         /*
498          * Update penalties to facilitate IRQ balancing.
499          */
500         list_for_each(node, &acpi_link.entries) {
501
502                 link = list_entry(node, struct acpi_pci_link, node);
503                 if (!link) {
504                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
505                                           "Invalid link context\n"));
506                         continue;
507                 }
508
509                 /*
510                  * reflect the possible and active irqs in the penalty table --
511                  * useful for breaking ties.
512                  */
513                 if (link->irq.possible_count) {
514                         int penalty =
515                             PIRQ_PENALTY_PCI_POSSIBLE /
516                             link->irq.possible_count;
517
518                         for (i = 0; i < link->irq.possible_count; i++) {
519                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
520                                         acpi_irq_penalty[link->irq.
521                                                          possible[i]] +=
522                                             penalty;
523                         }
524
525                 } else if (link->irq.active) {
526                         acpi_irq_penalty[link->irq.active] +=
527                             PIRQ_PENALTY_PCI_POSSIBLE;
528                 }
529         }
530         /* Add a penalty for the SCI */
531         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
532
533         return_VALUE(0);
534 }
535
536 static int acpi_irq_balance;    /* 0: static, 1: balance */
537
538 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
539 {
540         int irq;
541         int i;
542
543         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
544
545         if (link->irq.initialized) {
546                 if (link->refcnt == 0)
547                         /* This means the link is disabled but initialized */
548                         acpi_pci_link_set(link, link->irq.active);
549                 return_VALUE(0);
550         }
551
552         /*
553          * search for active IRQ in list of possible IRQs.
554          */
555         for (i = 0; i < link->irq.possible_count; ++i) {
556                 if (link->irq.active == link->irq.possible[i])
557                         break;
558         }
559         /*
560          * forget active IRQ that is not in possible list
561          */
562         if (i == link->irq.possible_count) {
563                 if (acpi_strict)
564                         printk(KERN_WARNING PREFIX "_CRS %d not found"
565                                " in _PRS\n", link->irq.active);
566                 link->irq.active = 0;
567         }
568
569         /*
570          * if active found, use it; else pick entry from end of possible list.
571          */
572         if (link->irq.active) {
573                 irq = link->irq.active;
574         } else {
575                 irq = link->irq.possible[link->irq.possible_count - 1];
576         }
577
578         if (acpi_irq_balance || !link->irq.active) {
579                 /*
580                  * Select the best IRQ.  This is done in reverse to promote
581                  * the use of IRQs 9, 10, 11, and >15.
582                  */
583                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
584                         if (acpi_irq_penalty[irq] >
585                             acpi_irq_penalty[link->irq.possible[i]])
586                                 irq = link->irq.possible[i];
587                 }
588         }
589
590         /* Attempt to enable the link device at this IRQ. */
591         if (acpi_pci_link_set(link, irq)) {
592                 printk(PREFIX
593                        "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
594                        "Try pci=noacpi or acpi=off\n",
595                        acpi_device_name(link->device),
596                        acpi_device_bid(link->device));
597                 return_VALUE(-ENODEV);
598         } else {
599                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
600                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
601                        acpi_device_name(link->device),
602                        acpi_device_bid(link->device), link->irq.active);
603         }
604
605         link->irq.initialized = 1;
606
607         return_VALUE(0);
608 }
609
610 /*
611  * acpi_pci_link_allocate_irq
612  * success: return IRQ >= 0
613  * failure: return -1
614  */
615
616 int
617 acpi_pci_link_allocate_irq(acpi_handle handle,
618                            int index,
619                            int *triggering, int *polarity, char **name)
620 {
621         int result = 0;
622         struct acpi_device *device = NULL;
623         struct acpi_pci_link *link = NULL;
624
625         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate_irq");
626
627         result = acpi_bus_get_device(handle, &device);
628         if (result) {
629                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
630                 return_VALUE(-1);
631         }
632
633         link = (struct acpi_pci_link *)acpi_driver_data(device);
634         if (!link) {
635                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
636                 return_VALUE(-1);
637         }
638
639         /* TBD: Support multiple index (IRQ) entries per Link Device */
640         if (index) {
641                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
642                 return_VALUE(-1);
643         }
644
645         mutex_lock(&acpi_link_lock);
646         if (acpi_pci_link_allocate(link)) {
647                 mutex_unlock(&acpi_link_lock);
648                 return_VALUE(-1);
649         }
650
651         if (!link->irq.active) {
652                 mutex_unlock(&acpi_link_lock);
653                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
654                 return_VALUE(-1);
655         }
656         link->refcnt++;
657         mutex_unlock(&acpi_link_lock);
658
659         if (triggering)
660                 *triggering = link->irq.triggering;
661         if (polarity)
662                 *polarity = link->irq.polarity;
663         if (name)
664                 *name = acpi_device_bid(link->device);
665         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
666                           "Link %s is referenced\n",
667                           acpi_device_bid(link->device)));
668         return_VALUE(link->irq.active);
669 }
670
671 /*
672  * We don't change link's irq information here.  After it is reenabled, we
673  * continue use the info
674  */
675 int acpi_pci_link_free_irq(acpi_handle handle)
676 {
677         struct acpi_device *device = NULL;
678         struct acpi_pci_link *link = NULL;
679         acpi_status result;
680
681         ACPI_FUNCTION_TRACE("acpi_pci_link_free_irq");
682
683         result = acpi_bus_get_device(handle, &device);
684         if (result) {
685                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
686                 return_VALUE(-1);
687         }
688
689         link = (struct acpi_pci_link *)acpi_driver_data(device);
690         if (!link) {
691                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
692                 return_VALUE(-1);
693         }
694
695         mutex_lock(&acpi_link_lock);
696         if (!link->irq.initialized) {
697                 mutex_unlock(&acpi_link_lock);
698                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link isn't initialized\n"));
699                 return_VALUE(-1);
700         }
701 #ifdef  FUTURE_USE
702         /*
703          * The Link reference count allows us to _DISable an unused link
704          * and suspend time, and set it again  on resume.
705          * However, 2.6.12 still has irq_router.resume
706          * which blindly restores the link state.
707          * So we disable the reference count method
708          * to prevent duplicate acpi_pci_link_set()
709          * which would harm some systems
710          */
711         link->refcnt--;
712 #endif
713         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
714                           "Link %s is dereferenced\n",
715                           acpi_device_bid(link->device)));
716
717         if (link->refcnt == 0) {
718                 acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
719         }
720         mutex_unlock(&acpi_link_lock);
721         return_VALUE(link->irq.active);
722 }
723
724 /* --------------------------------------------------------------------------
725                                  Driver Interface
726    -------------------------------------------------------------------------- */
727
728 static int acpi_pci_link_add(struct acpi_device *device)
729 {
730         int result = 0;
731         struct acpi_pci_link *link = NULL;
732         int i = 0;
733         int found = 0;
734
735         ACPI_FUNCTION_TRACE("acpi_pci_link_add");
736
737         if (!device)
738                 return_VALUE(-EINVAL);
739
740         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
741         if (!link)
742                 return_VALUE(-ENOMEM);
743         memset(link, 0, sizeof(struct acpi_pci_link));
744
745         link->device = device;
746         link->handle = device->handle;
747         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
748         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
749         acpi_driver_data(device) = link;
750
751         mutex_lock(&acpi_link_lock);
752         result = acpi_pci_link_get_possible(link);
753         if (result)
754                 goto end;
755
756         /* query and set link->irq.active */
757         acpi_pci_link_get_current(link);
758
759         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
760                acpi_device_bid(device));
761         for (i = 0; i < link->irq.possible_count; i++) {
762                 if (link->irq.active == link->irq.possible[i]) {
763                         printk(" *%d", link->irq.possible[i]);
764                         found = 1;
765                 } else
766                         printk(" %d", link->irq.possible[i]);
767         }
768
769         printk(")");
770
771         if (!found)
772                 printk(" *%d", link->irq.active);
773
774         if (!link->device->status.enabled)
775                 printk(", disabled.");
776
777         printk("\n");
778
779         /* TBD: Acquire/release lock */
780         list_add_tail(&link->node, &acpi_link.entries);
781         acpi_link.count++;
782
783       end:
784         /* disable all links -- to be activated on use */
785         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
786         mutex_unlock(&acpi_link_lock);
787
788         if (result)
789                 kfree(link);
790
791         return_VALUE(result);
792 }
793
794 static int acpi_pci_link_resume(struct acpi_pci_link *link)
795 {
796         ACPI_FUNCTION_TRACE("acpi_pci_link_resume");
797
798         if (link->refcnt && link->irq.active && link->irq.initialized)
799                 return_VALUE(acpi_pci_link_set(link, link->irq.active));
800         else
801                 return_VALUE(0);
802 }
803
804 /*
805  * FIXME: this is a workaround to avoid nasty warning.  It will be removed
806  * after every device calls pci_disable_device in .resume.
807  */
808 int acpi_in_resume;
809 static int irqrouter_resume(struct sys_device *dev)
810 {
811         struct list_head *node = NULL;
812         struct acpi_pci_link *link = NULL;
813
814         ACPI_FUNCTION_TRACE("irqrouter_resume");
815
816         acpi_in_resume = 1;
817         list_for_each(node, &acpi_link.entries) {
818                 link = list_entry(node, struct acpi_pci_link, node);
819                 if (!link) {
820                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
821                                           "Invalid link context\n"));
822                         continue;
823                 }
824                 acpi_pci_link_resume(link);
825         }
826         acpi_in_resume = 0;
827         return_VALUE(0);
828 }
829
830 static int acpi_pci_link_remove(struct acpi_device *device, int type)
831 {
832         struct acpi_pci_link *link = NULL;
833
834         ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
835
836         if (!device || !acpi_driver_data(device))
837                 return_VALUE(-EINVAL);
838
839         link = (struct acpi_pci_link *)acpi_driver_data(device);
840
841         mutex_lock(&acpi_link_lock);
842         list_del(&link->node);
843         mutex_unlock(&acpi_link_lock);
844
845         kfree(link);
846
847         return_VALUE(0);
848 }
849
850 /*
851  * modify acpi_irq_penalty[] from cmdline
852  */
853 static int __init acpi_irq_penalty_update(char *str, int used)
854 {
855         int i;
856
857         for (i = 0; i < 16; i++) {
858                 int retval;
859                 int irq;
860
861                 retval = get_option(&str, &irq);
862
863                 if (!retval)
864                         break;  /* no number found */
865
866                 if (irq < 0)
867                         continue;
868
869                 if (irq >= ACPI_MAX_IRQS)
870                         continue;
871
872                 if (used)
873                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
874                 else
875                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
876
877                 if (retval != 2)        /* no next number */
878                         break;
879         }
880         return 1;
881 }
882
883 /*
884  * We'd like PNP to call this routine for the
885  * single ISA_USED value for each legacy device.
886  * But instead it calls us with each POSSIBLE setting.
887  * There is no ISA_POSSIBLE weight, so we simply use
888  * the (small) PCI_USING penalty.
889  */
890 void acpi_penalize_isa_irq(int irq, int active)
891 {
892         if (active)
893                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
894         else
895                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
896 }
897
898 /*
899  * Over-ride default table to reserve additional IRQs for use by ISA
900  * e.g. acpi_irq_isa=5
901  * Useful for telling ACPI how not to interfere with your ISA sound card.
902  */
903 static int __init acpi_irq_isa(char *str)
904 {
905         return acpi_irq_penalty_update(str, 1);
906 }
907
908 __setup("acpi_irq_isa=", acpi_irq_isa);
909
910 /*
911  * Over-ride default table to free additional IRQs for use by PCI
912  * e.g. acpi_irq_pci=7,15
913  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
914  */
915 static int __init acpi_irq_pci(char *str)
916 {
917         return acpi_irq_penalty_update(str, 0);
918 }
919
920 __setup("acpi_irq_pci=", acpi_irq_pci);
921
922 static int __init acpi_irq_nobalance_set(char *str)
923 {
924         acpi_irq_balance = 0;
925         return 1;
926 }
927
928 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
929
930 int __init acpi_irq_balance_set(char *str)
931 {
932         acpi_irq_balance = 1;
933         return 1;
934 }
935
936 __setup("acpi_irq_balance", acpi_irq_balance_set);
937
938 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
939 static struct sysdev_class irqrouter_sysdev_class = {
940         set_kset_name("irqrouter"),
941         .resume = irqrouter_resume,
942 };
943
944 static struct sys_device device_irqrouter = {
945         .id = 0,
946         .cls = &irqrouter_sysdev_class,
947 };
948
949 static int __init irqrouter_init_sysfs(void)
950 {
951         int error;
952
953         ACPI_FUNCTION_TRACE("irqrouter_init_sysfs");
954
955         if (acpi_disabled || acpi_noirq)
956                 return_VALUE(0);
957
958         error = sysdev_class_register(&irqrouter_sysdev_class);
959         if (!error)
960                 error = sysdev_register(&device_irqrouter);
961
962         return_VALUE(error);
963 }
964
965 device_initcall(irqrouter_init_sysfs);
966
967 static int __init acpi_pci_link_init(void)
968 {
969         ACPI_FUNCTION_TRACE("acpi_pci_link_init");
970
971         if (acpi_noirq)
972                 return_VALUE(0);
973
974         acpi_link.count = 0;
975         INIT_LIST_HEAD(&acpi_link.entries);
976
977         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
978                 return_VALUE(-ENODEV);
979
980         return_VALUE(0);
981 }
982
983 subsys_initcall(acpi_pci_link_init);