ACPI: Remove unnecessary from/to-void* and to-void casts in drivers/acpi
[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         struct acpi_pci_link_irq irq;
87         int refcnt;
88 };
89
90 static struct {
91         int count;
92         struct list_head entries;
93 } acpi_link;
94 DEFINE_MUTEX(acpi_link_lock);
95
96 /* --------------------------------------------------------------------------
97                             PCI Link Device Management
98    -------------------------------------------------------------------------- */
99
100 /*
101  * set context (link) possible list from resource list
102  */
103 static acpi_status
104 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
105 {
106         struct acpi_pci_link *link = context;
107         u32 i = 0;
108
109
110         switch (resource->type) {
111         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
112                 return AE_OK;
113         case ACPI_RESOURCE_TYPE_IRQ:
114                 {
115                         struct acpi_resource_irq *p = &resource->data.irq;
116                         if (!p || !p->interrupt_count) {
117                                 printk(KERN_WARNING PREFIX "Blank IRQ resource\n");
118                                 return AE_OK;
119                         }
120                         for (i = 0;
121                              (i < p->interrupt_count
122                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
123                                 if (!p->interrupts[i]) {
124                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
125                                                       p->interrupts[i]);
126                                         continue;
127                                 }
128                                 link->irq.possible[i] = p->interrupts[i];
129                                 link->irq.possible_count++;
130                         }
131                         link->irq.triggering = p->triggering;
132                         link->irq.polarity = p->polarity;
133                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
134                         break;
135                 }
136         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
137                 {
138                         struct acpi_resource_extended_irq *p =
139                             &resource->data.extended_irq;
140                         if (!p || !p->interrupt_count) {
141                                 printk(KERN_WARNING PREFIX
142                                               "Blank EXT IRQ resource\n");
143                                 return AE_OK;
144                         }
145                         for (i = 0;
146                              (i < p->interrupt_count
147                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
148                                 if (!p->interrupts[i]) {
149                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
150                                                       p->interrupts[i]);
151                                         continue;
152                                 }
153                                 link->irq.possible[i] = p->interrupts[i];
154                                 link->irq.possible_count++;
155                         }
156                         link->irq.triggering = p->triggering;
157                         link->irq.polarity = p->polarity;
158                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
159                         break;
160                 }
161         default:
162                 printk(KERN_ERR PREFIX "Resource is not an IRQ entry\n");
163                 return AE_OK;
164         }
165
166         return AE_CTRL_TERMINATE;
167 }
168
169 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
170 {
171         acpi_status status;
172
173
174         if (!link)
175                 return -EINVAL;
176
177         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
178                                      acpi_pci_link_check_possible, link);
179         if (ACPI_FAILURE(status)) {
180                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
181                 return -ENODEV;
182         }
183
184         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
185                           "Found %d possible IRQs\n",
186                           link->irq.possible_count));
187
188         return 0;
189 }
190
191 static acpi_status
192 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
193 {
194         int *irq = (int *)context;
195
196
197         switch (resource->type) {
198         case ACPI_RESOURCE_TYPE_IRQ:
199                 {
200                         struct acpi_resource_irq *p = &resource->data.irq;
201                         if (!p || !p->interrupt_count) {
202                                 /*
203                                  * IRQ descriptors may have no IRQ# bits set,
204                                  * particularly those those w/ _STA disabled
205                                  */
206                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
207                                                   "Blank IRQ resource\n"));
208                                 return AE_OK;
209                         }
210                         *irq = p->interrupts[0];
211                         break;
212                 }
213         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
214                 {
215                         struct acpi_resource_extended_irq *p =
216                             &resource->data.extended_irq;
217                         if (!p || !p->interrupt_count) {
218                                 /*
219                                  * extended IRQ descriptors must
220                                  * return at least 1 IRQ
221                                  */
222                                 printk(KERN_WARNING PREFIX
223                                               "Blank EXT IRQ resource\n");
224                                 return AE_OK;
225                         }
226                         *irq = p->interrupts[0];
227                         break;
228                 }
229                 break;
230         default:
231                 printk(KERN_ERR PREFIX "Resource %d isn't an IRQ\n", resource->type);
232         case ACPI_RESOURCE_TYPE_END_TAG:
233                 return AE_OK;
234         }
235         return AE_CTRL_TERMINATE;
236 }
237
238 /*
239  * Run _CRS and set link->irq.active
240  *
241  * return value:
242  * 0 - success
243  * !0 - failure
244  */
245 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
246 {
247         int result = 0;
248         acpi_status status = AE_OK;
249         int irq = 0;
250
251         if (!link)
252                 return -EINVAL;
253
254         link->irq.active = 0;
255
256         /* in practice, status disabled is meaningless, ignore it */
257         if (acpi_strict) {
258                 /* Query _STA, set link->device->status */
259                 result = acpi_bus_get_status(link->device);
260                 if (result) {
261                         printk(KERN_ERR PREFIX "Unable to read status\n");
262                         goto end;
263                 }
264
265                 if (!link->device->status.enabled) {
266                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
267                         return 0;
268                 }
269         }
270
271         /* 
272          * Query and parse _CRS to get the current IRQ assignment. 
273          */
274
275         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
276                                      acpi_pci_link_check_current, &irq);
277         if (ACPI_FAILURE(status)) {
278                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
279                 result = -ENODEV;
280                 goto end;
281         }
282
283         if (acpi_strict && !irq) {
284                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
285                 result = -ENODEV;
286         }
287
288         link->irq.active = irq;
289
290         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
291
292       end:
293         return result;
294 }
295
296 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
297 {
298         int result = 0;
299         acpi_status status = AE_OK;
300         struct {
301                 struct acpi_resource res;
302                 struct acpi_resource end;
303         } *resource;
304         struct acpi_buffer buffer = { 0, NULL };
305
306
307         if (!link || !irq)
308                 return -EINVAL;
309
310         resource = kmalloc(sizeof(*resource) + 1, GFP_ATOMIC);
311         if (!resource)
312                 return -ENOMEM;
313
314         memset(resource, 0, sizeof(*resource) + 1);
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 list_head *node = NULL;
480         struct acpi_pci_link *link = NULL;
481         int i = 0;
482
483
484         /*
485          * Update penalties to facilitate IRQ balancing.
486          */
487         list_for_each(node, &acpi_link.entries) {
488
489                 link = list_entry(node, struct acpi_pci_link, node);
490                 if (!link) {
491                         printk(KERN_ERR PREFIX "Invalid link context\n");
492                         continue;
493                 }
494
495                 /*
496                  * reflect the possible and active irqs in the penalty table --
497                  * useful for breaking ties.
498                  */
499                 if (link->irq.possible_count) {
500                         int penalty =
501                             PIRQ_PENALTY_PCI_POSSIBLE /
502                             link->irq.possible_count;
503
504                         for (i = 0; i < link->irq.possible_count; i++) {
505                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
506                                         acpi_irq_penalty[link->irq.
507                                                          possible[i]] +=
508                                             penalty;
509                         }
510
511                 } else if (link->irq.active) {
512                         acpi_irq_penalty[link->irq.active] +=
513                             PIRQ_PENALTY_PCI_POSSIBLE;
514                 }
515         }
516         /* Add a penalty for the SCI */
517         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
518
519         return 0;
520 }
521
522 static int acpi_irq_balance;    /* 0: static, 1: balance */
523
524 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
525 {
526         int irq;
527         int i;
528
529
530         if (link->irq.initialized) {
531                 if (link->refcnt == 0)
532                         /* This means the link is disabled but initialized */
533                         acpi_pci_link_set(link, link->irq.active);
534                 return 0;
535         }
536
537         /*
538          * search for active IRQ in list of possible IRQs.
539          */
540         for (i = 0; i < link->irq.possible_count; ++i) {
541                 if (link->irq.active == link->irq.possible[i])
542                         break;
543         }
544         /*
545          * forget active IRQ that is not in possible list
546          */
547         if (i == link->irq.possible_count) {
548                 if (acpi_strict)
549                         printk(KERN_WARNING PREFIX "_CRS %d not found"
550                                       " in _PRS\n", link->irq.active);
551                 link->irq.active = 0;
552         }
553
554         /*
555          * if active found, use it; else pick entry from end of possible list.
556          */
557         if (link->irq.active) {
558                 irq = link->irq.active;
559         } else {
560                 irq = link->irq.possible[link->irq.possible_count - 1];
561         }
562
563         if (acpi_irq_balance || !link->irq.active) {
564                 /*
565                  * Select the best IRQ.  This is done in reverse to promote
566                  * the use of IRQs 9, 10, 11, and >15.
567                  */
568                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
569                         if (acpi_irq_penalty[irq] >
570                             acpi_irq_penalty[link->irq.possible[i]])
571                                 irq = link->irq.possible[i];
572                 }
573         }
574
575         /* Attempt to enable the link device at this IRQ. */
576         if (acpi_pci_link_set(link, irq)) {
577                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
578                             "Try pci=noacpi or acpi=off\n",
579                             acpi_device_name(link->device),
580                             acpi_device_bid(link->device));
581                 return -ENODEV;
582         } else {
583                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
584                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
585                        acpi_device_name(link->device),
586                        acpi_device_bid(link->device), link->irq.active);
587         }
588
589         link->irq.initialized = 1;
590
591         return 0;
592 }
593
594 /*
595  * acpi_pci_link_allocate_irq
596  * success: return IRQ >= 0
597  * failure: return -1
598  */
599
600 int
601 acpi_pci_link_allocate_irq(acpi_handle handle,
602                            int index,
603                            int *triggering, int *polarity, char **name)
604 {
605         int result = 0;
606         struct acpi_device *device = NULL;
607         struct acpi_pci_link *link = NULL;
608
609
610         result = acpi_bus_get_device(handle, &device);
611         if (result) {
612                 printk(KERN_ERR PREFIX "Invalid link device\n");
613                 return -1;
614         }
615
616         link = acpi_driver_data(device);
617         if (!link) {
618                 printk(KERN_ERR PREFIX "Invalid link context\n");
619                 return -1;
620         }
621
622         /* TBD: Support multiple index (IRQ) entries per Link Device */
623         if (index) {
624                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
625                 return -1;
626         }
627
628         mutex_lock(&acpi_link_lock);
629         if (acpi_pci_link_allocate(link)) {
630                 mutex_unlock(&acpi_link_lock);
631                 return -1;
632         }
633
634         if (!link->irq.active) {
635                 mutex_unlock(&acpi_link_lock);
636                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
637                 return -1;
638         }
639         link->refcnt++;
640         mutex_unlock(&acpi_link_lock);
641
642         if (triggering)
643                 *triggering = link->irq.triggering;
644         if (polarity)
645                 *polarity = link->irq.polarity;
646         if (name)
647                 *name = acpi_device_bid(link->device);
648         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
649                           "Link %s is referenced\n",
650                           acpi_device_bid(link->device)));
651         return (link->irq.active);
652 }
653
654 /*
655  * We don't change link's irq information here.  After it is reenabled, we
656  * continue use the info
657  */
658 int acpi_pci_link_free_irq(acpi_handle handle)
659 {
660         struct acpi_device *device = NULL;
661         struct acpi_pci_link *link = NULL;
662         acpi_status result;
663
664
665         result = acpi_bus_get_device(handle, &device);
666         if (result) {
667                 printk(KERN_ERR PREFIX "Invalid link device\n");
668                 return -1;
669         }
670
671         link = acpi_driver_data(device);
672         if (!link) {
673                 printk(KERN_ERR PREFIX "Invalid link context\n");
674                 return -1;
675         }
676
677         mutex_lock(&acpi_link_lock);
678         if (!link->irq.initialized) {
679                 mutex_unlock(&acpi_link_lock);
680                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
681                 return -1;
682         }
683 #ifdef  FUTURE_USE
684         /*
685          * The Link reference count allows us to _DISable an unused link
686          * and suspend time, and set it again  on resume.
687          * However, 2.6.12 still has irq_router.resume
688          * which blindly restores the link state.
689          * So we disable the reference count method
690          * to prevent duplicate acpi_pci_link_set()
691          * which would harm some systems
692          */
693         link->refcnt--;
694 #endif
695         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
696                           "Link %s is dereferenced\n",
697                           acpi_device_bid(link->device)));
698
699         if (link->refcnt == 0) {
700                 acpi_ut_evaluate_object(link->device->handle, "_DIS", 0, NULL);
701         }
702         mutex_unlock(&acpi_link_lock);
703         return (link->irq.active);
704 }
705
706 /* --------------------------------------------------------------------------
707                                  Driver Interface
708    -------------------------------------------------------------------------- */
709
710 static int acpi_pci_link_add(struct acpi_device *device)
711 {
712         int result = 0;
713         struct acpi_pci_link *link = NULL;
714         int i = 0;
715         int found = 0;
716
717
718         if (!device)
719                 return -EINVAL;
720
721         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
722         if (!link)
723                 return -ENOMEM;
724         memset(link, 0, sizeof(struct acpi_pci_link));
725
726         link->device = device;
727         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
728         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
729         acpi_driver_data(device) = link;
730
731         mutex_lock(&acpi_link_lock);
732         result = acpi_pci_link_get_possible(link);
733         if (result)
734                 goto end;
735
736         /* query and set link->irq.active */
737         acpi_pci_link_get_current(link);
738
739         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
740                acpi_device_bid(device));
741         for (i = 0; i < link->irq.possible_count; i++) {
742                 if (link->irq.active == link->irq.possible[i]) {
743                         printk(" *%d", link->irq.possible[i]);
744                         found = 1;
745                 } else
746                         printk(" %d", link->irq.possible[i]);
747         }
748
749         printk(")");
750
751         if (!found)
752                 printk(" *%d", link->irq.active);
753
754         if (!link->device->status.enabled)
755                 printk(", disabled.");
756
757         printk("\n");
758
759         /* TBD: Acquire/release lock */
760         list_add_tail(&link->node, &acpi_link.entries);
761         acpi_link.count++;
762
763       end:
764         /* disable all links -- to be activated on use */
765         acpi_ut_evaluate_object(device->handle, "_DIS", 0, NULL);
766         mutex_unlock(&acpi_link_lock);
767
768         if (result)
769                 kfree(link);
770
771         return result;
772 }
773
774 static int acpi_pci_link_resume(struct acpi_pci_link *link)
775 {
776
777         if (link->refcnt && link->irq.active && link->irq.initialized)
778                 return (acpi_pci_link_set(link, link->irq.active));
779         else
780                 return 0;
781 }
782
783 static int irqrouter_resume(struct sys_device *dev)
784 {
785         struct list_head *node = NULL;
786         struct acpi_pci_link *link = NULL;
787
788
789         /* Make sure SCI is enabled again (Apple firmware bug?) */
790         acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1, ACPI_MTX_DO_NOT_LOCK);
791
792         list_for_each(node, &acpi_link.entries) {
793                 link = list_entry(node, struct acpi_pci_link, node);
794                 if (!link) {
795                         printk(KERN_ERR PREFIX "Invalid link context\n");
796                         continue;
797                 }
798                 acpi_pci_link_resume(link);
799         }
800         return 0;
801 }
802
803 static int acpi_pci_link_remove(struct acpi_device *device, int type)
804 {
805         struct acpi_pci_link *link = NULL;
806
807
808         if (!device || !acpi_driver_data(device))
809                 return -EINVAL;
810
811         link = acpi_driver_data(device);
812
813         mutex_lock(&acpi_link_lock);
814         list_del(&link->node);
815         mutex_unlock(&acpi_link_lock);
816
817         kfree(link);
818
819         return 0;
820 }
821
822 /*
823  * modify acpi_irq_penalty[] from cmdline
824  */
825 static int __init acpi_irq_penalty_update(char *str, int used)
826 {
827         int i;
828
829         for (i = 0; i < 16; i++) {
830                 int retval;
831                 int irq;
832
833                 retval = get_option(&str, &irq);
834
835                 if (!retval)
836                         break;  /* no number found */
837
838                 if (irq < 0)
839                         continue;
840
841                 if (irq >= ACPI_MAX_IRQS)
842                         continue;
843
844                 if (used)
845                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
846                 else
847                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
848
849                 if (retval != 2)        /* no next number */
850                         break;
851         }
852         return 1;
853 }
854
855 /*
856  * We'd like PNP to call this routine for the
857  * single ISA_USED value for each legacy device.
858  * But instead it calls us with each POSSIBLE setting.
859  * There is no ISA_POSSIBLE weight, so we simply use
860  * the (small) PCI_USING penalty.
861  */
862 void acpi_penalize_isa_irq(int irq, int active)
863 {
864         if (active)
865                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
866         else
867                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
868 }
869
870 /*
871  * Over-ride default table to reserve additional IRQs for use by ISA
872  * e.g. acpi_irq_isa=5
873  * Useful for telling ACPI how not to interfere with your ISA sound card.
874  */
875 static int __init acpi_irq_isa(char *str)
876 {
877         return acpi_irq_penalty_update(str, 1);
878 }
879
880 __setup("acpi_irq_isa=", acpi_irq_isa);
881
882 /*
883  * Over-ride default table to free additional IRQs for use by PCI
884  * e.g. acpi_irq_pci=7,15
885  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
886  */
887 static int __init acpi_irq_pci(char *str)
888 {
889         return acpi_irq_penalty_update(str, 0);
890 }
891
892 __setup("acpi_irq_pci=", acpi_irq_pci);
893
894 static int __init acpi_irq_nobalance_set(char *str)
895 {
896         acpi_irq_balance = 0;
897         return 1;
898 }
899
900 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
901
902 int __init acpi_irq_balance_set(char *str)
903 {
904         acpi_irq_balance = 1;
905         return 1;
906 }
907
908 __setup("acpi_irq_balance", acpi_irq_balance_set);
909
910 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
911 static struct sysdev_class irqrouter_sysdev_class = {
912         set_kset_name("irqrouter"),
913         .resume = irqrouter_resume,
914 };
915
916 static struct sys_device device_irqrouter = {
917         .id = 0,
918         .cls = &irqrouter_sysdev_class,
919 };
920
921 static int __init irqrouter_init_sysfs(void)
922 {
923         int error;
924
925
926         if (acpi_disabled || acpi_noirq)
927                 return 0;
928
929         error = sysdev_class_register(&irqrouter_sysdev_class);
930         if (!error)
931                 error = sysdev_register(&device_irqrouter);
932
933         return error;
934 }
935
936 device_initcall(irqrouter_init_sysfs);
937
938 static int __init acpi_pci_link_init(void)
939 {
940
941         if (acpi_noirq)
942                 return 0;
943
944         acpi_link.count = 0;
945         INIT_LIST_HEAD(&acpi_link.entries);
946
947         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
948                 return -ENODEV;
949
950         return 0;
951 }
952
953 subsys_initcall(acpi_pci_link_init);