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