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