V4L/DVB (4110): Small bug in saa7127.c
[linux-2.6] / drivers / acpi / osl.c
1 /*
2  *  acpi_osl.c - OS-dependent functions ($Revision: 83 $)
3  *
4  *  Copyright (C) 2000       Andrew Henroid
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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
13  *  (at your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful,
16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *  GNU General Public License for more details.
19  *
20  *  You should have received a copy of the GNU General Public License
21  *  along with this program; if not, write to the Free Software
22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23  *
24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25  *
26  */
27
28 #include <linux/config.h>
29 #include <linux/module.h>
30 #include <linux/kernel.h>
31 #include <linux/slab.h>
32 #include <linux/mm.h>
33 #include <linux/pci.h>
34 #include <linux/smp_lock.h>
35 #include <linux/interrupt.h>
36 #include <linux/kmod.h>
37 #include <linux/delay.h>
38 #include <linux/workqueue.h>
39 #include <linux/nmi.h>
40 #include <linux/kthread.h>
41 #include <acpi/acpi.h>
42 #include <asm/io.h>
43 #include <acpi/acpi_bus.h>
44 #include <acpi/processor.h>
45 #include <asm/uaccess.h>
46
47 #include <linux/efi.h>
48
49 #define _COMPONENT              ACPI_OS_SERVICES
50 ACPI_MODULE_NAME("osl")
51 #define PREFIX          "ACPI: "
52 struct acpi_os_dpc {
53         acpi_osd_exec_callback function;
54         void *context;
55 };
56
57 #ifdef CONFIG_ACPI_CUSTOM_DSDT
58 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
59 #endif
60
61 #ifdef ENABLE_DEBUGGER
62 #include <linux/kdb.h>
63
64 /* stuff for debugger support */
65 int acpi_in_debugger;
66 EXPORT_SYMBOL(acpi_in_debugger);
67
68 extern char line_buf[80];
69 #endif                          /*ENABLE_DEBUGGER */
70
71 int acpi_specific_hotkey_enabled = TRUE;
72 EXPORT_SYMBOL(acpi_specific_hotkey_enabled);
73
74 static unsigned int acpi_irq_irq;
75 static acpi_osd_handler acpi_irq_handler;
76 static void *acpi_irq_context;
77 static struct workqueue_struct *kacpid_wq;
78
79 acpi_status acpi_os_initialize(void)
80 {
81         return AE_OK;
82 }
83
84 acpi_status acpi_os_initialize1(void)
85 {
86         /*
87          * Initialize PCI configuration space access, as we'll need to access
88          * it while walking the namespace (bus 0 and root bridges w/ _BBNs).
89          */
90         if (!raw_pci_ops) {
91                 printk(KERN_ERR PREFIX
92                        "Access to PCI configuration space unavailable\n");
93                 return AE_NULL_ENTRY;
94         }
95         kacpid_wq = create_singlethread_workqueue("kacpid");
96         BUG_ON(!kacpid_wq);
97
98         return AE_OK;
99 }
100
101 acpi_status acpi_os_terminate(void)
102 {
103         if (acpi_irq_handler) {
104                 acpi_os_remove_interrupt_handler(acpi_irq_irq,
105                                                  acpi_irq_handler);
106         }
107
108         destroy_workqueue(kacpid_wq);
109
110         return AE_OK;
111 }
112
113 void acpi_os_printf(const char *fmt, ...)
114 {
115         va_list args;
116         va_start(args, fmt);
117         acpi_os_vprintf(fmt, args);
118         va_end(args);
119 }
120
121 EXPORT_SYMBOL(acpi_os_printf);
122
123 void acpi_os_vprintf(const char *fmt, va_list args)
124 {
125         static char buffer[512];
126
127         vsprintf(buffer, fmt, args);
128
129 #ifdef ENABLE_DEBUGGER
130         if (acpi_in_debugger) {
131                 kdb_printf("%s", buffer);
132         } else {
133                 printk("%s", buffer);
134         }
135 #else
136         printk("%s", buffer);
137 #endif
138 }
139
140 extern int acpi_in_resume;
141 void *acpi_os_allocate(acpi_size size)
142 {
143         if (acpi_in_resume)
144                 return kmalloc(size, GFP_ATOMIC);
145         else
146                 return kmalloc(size, GFP_KERNEL);
147 }
148
149 void acpi_os_free(void *ptr)
150 {
151         kfree(ptr);
152 }
153
154 EXPORT_SYMBOL(acpi_os_free);
155
156 acpi_status acpi_os_get_root_pointer(u32 flags, struct acpi_pointer *addr)
157 {
158         if (efi_enabled) {
159                 addr->pointer_type = ACPI_PHYSICAL_POINTER;
160                 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
161                         addr->pointer.physical = efi.acpi20;
162                 else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
163                         addr->pointer.physical = efi.acpi;
164                 else {
165                         printk(KERN_ERR PREFIX
166                                "System description tables not found\n");
167                         return AE_NOT_FOUND;
168                 }
169         } else {
170                 if (ACPI_FAILURE(acpi_find_root_pointer(flags, addr))) {
171                         printk(KERN_ERR PREFIX
172                                "System description tables not found\n");
173                         return AE_NOT_FOUND;
174                 }
175         }
176
177         return AE_OK;
178 }
179
180 acpi_status
181 acpi_os_map_memory(acpi_physical_address phys, acpi_size size,
182                    void __iomem ** virt)
183 {
184         if (phys > ULONG_MAX) {
185                 printk(KERN_ERR PREFIX "Cannot map memory that high\n");
186                 return AE_BAD_PARAMETER;
187         }
188         /*
189          * ioremap checks to ensure this is in reserved space
190          */
191         *virt = ioremap((unsigned long)phys, size);
192
193         if (!*virt)
194                 return AE_NO_MEMORY;
195
196         return AE_OK;
197 }
198 EXPORT_SYMBOL_GPL(acpi_os_map_memory);
199
200 void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
201 {
202         iounmap(virt);
203 }
204 EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
205
206 #ifdef ACPI_FUTURE_USAGE
207 acpi_status
208 acpi_os_get_physical_address(void *virt, acpi_physical_address * phys)
209 {
210         if (!phys || !virt)
211                 return AE_BAD_PARAMETER;
212
213         *phys = virt_to_phys(virt);
214
215         return AE_OK;
216 }
217 #endif
218
219 #define ACPI_MAX_OVERRIDE_LEN 100
220
221 static char acpi_os_name[ACPI_MAX_OVERRIDE_LEN];
222
223 acpi_status
224 acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
225                             acpi_string * new_val)
226 {
227         if (!init_val || !new_val)
228                 return AE_BAD_PARAMETER;
229
230         *new_val = NULL;
231         if (!memcmp(init_val->name, "_OS_", 4) && strlen(acpi_os_name)) {
232                 printk(KERN_INFO PREFIX "Overriding _OS definition to '%s'\n",
233                        acpi_os_name);
234                 *new_val = acpi_os_name;
235         }
236
237         return AE_OK;
238 }
239
240 acpi_status
241 acpi_os_table_override(struct acpi_table_header * existing_table,
242                        struct acpi_table_header ** new_table)
243 {
244         if (!existing_table || !new_table)
245                 return AE_BAD_PARAMETER;
246
247 #ifdef CONFIG_ACPI_CUSTOM_DSDT
248         if (strncmp(existing_table->signature, "DSDT", 4) == 0)
249                 *new_table = (struct acpi_table_header *)AmlCode;
250         else
251                 *new_table = NULL;
252 #else
253         *new_table = NULL;
254 #endif
255         return AE_OK;
256 }
257
258 static irqreturn_t acpi_irq(int irq, void *dev_id, struct pt_regs *regs)
259 {
260         return (*acpi_irq_handler) (acpi_irq_context) ? IRQ_HANDLED : IRQ_NONE;
261 }
262
263 acpi_status
264 acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler,
265                                   void *context)
266 {
267         unsigned int irq;
268
269         /*
270          * Ignore the GSI from the core, and use the value in our copy of the
271          * FADT. It may not be the same if an interrupt source override exists
272          * for the SCI.
273          */
274         gsi = acpi_fadt.sci_int;
275         if (acpi_gsi_to_irq(gsi, &irq) < 0) {
276                 printk(KERN_ERR PREFIX "SCI (ACPI GSI %d) not registered\n",
277                        gsi);
278                 return AE_OK;
279         }
280
281         acpi_irq_handler = handler;
282         acpi_irq_context = context;
283         if (request_irq(irq, acpi_irq, SA_SHIRQ, "acpi", acpi_irq)) {
284                 printk(KERN_ERR PREFIX "SCI (IRQ%d) allocation failed\n", irq);
285                 return AE_NOT_ACQUIRED;
286         }
287         acpi_irq_irq = irq;
288
289         return AE_OK;
290 }
291
292 acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
293 {
294         if (irq) {
295                 free_irq(irq, acpi_irq);
296                 acpi_irq_handler = NULL;
297                 acpi_irq_irq = 0;
298         }
299
300         return AE_OK;
301 }
302
303 /*
304  * Running in interpreter thread context, safe to sleep
305  */
306
307 void acpi_os_sleep(acpi_integer ms)
308 {
309         schedule_timeout_interruptible(msecs_to_jiffies(ms));
310 }
311
312 EXPORT_SYMBOL(acpi_os_sleep);
313
314 void acpi_os_stall(u32 us)
315 {
316         while (us) {
317                 u32 delay = 1000;
318
319                 if (delay > us)
320                         delay = us;
321                 udelay(delay);
322                 touch_nmi_watchdog();
323                 us -= delay;
324         }
325 }
326
327 EXPORT_SYMBOL(acpi_os_stall);
328
329 /*
330  * Support ACPI 3.0 AML Timer operand
331  * Returns 64-bit free-running, monotonically increasing timer
332  * with 100ns granularity
333  */
334 u64 acpi_os_get_timer(void)
335 {
336         static u64 t;
337
338 #ifdef  CONFIG_HPET
339         /* TBD: use HPET if available */
340 #endif
341
342 #ifdef  CONFIG_X86_PM_TIMER
343         /* TBD: default to PM timer if HPET was not available */
344 #endif
345         if (!t)
346                 printk(KERN_ERR PREFIX "acpi_os_get_timer() TBD\n");
347
348         return ++t;
349 }
350
351 acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width)
352 {
353         u32 dummy;
354
355         if (!value)
356                 value = &dummy;
357
358         switch (width) {
359         case 8:
360                 *(u8 *) value = inb(port);
361                 break;
362         case 16:
363                 *(u16 *) value = inw(port);
364                 break;
365         case 32:
366                 *(u32 *) value = inl(port);
367                 break;
368         default:
369                 BUG();
370         }
371
372         return AE_OK;
373 }
374
375 EXPORT_SYMBOL(acpi_os_read_port);
376
377 acpi_status acpi_os_write_port(acpi_io_address port, u32 value, u32 width)
378 {
379         switch (width) {
380         case 8:
381                 outb(value, port);
382                 break;
383         case 16:
384                 outw(value, port);
385                 break;
386         case 32:
387                 outl(value, port);
388                 break;
389         default:
390                 BUG();
391         }
392
393         return AE_OK;
394 }
395
396 EXPORT_SYMBOL(acpi_os_write_port);
397
398 acpi_status
399 acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width)
400 {
401         u32 dummy;
402         void __iomem *virt_addr;
403
404         virt_addr = ioremap(phys_addr, width);
405         if (!value)
406                 value = &dummy;
407
408         switch (width) {
409         case 8:
410                 *(u8 *) value = readb(virt_addr);
411                 break;
412         case 16:
413                 *(u16 *) value = readw(virt_addr);
414                 break;
415         case 32:
416                 *(u32 *) value = readl(virt_addr);
417                 break;
418         default:
419                 BUG();
420         }
421
422         iounmap(virt_addr);
423
424         return AE_OK;
425 }
426
427 acpi_status
428 acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)
429 {
430         void __iomem *virt_addr;
431
432         virt_addr = ioremap(phys_addr, width);
433
434         switch (width) {
435         case 8:
436                 writeb(value, virt_addr);
437                 break;
438         case 16:
439                 writew(value, virt_addr);
440                 break;
441         case 32:
442                 writel(value, virt_addr);
443                 break;
444         default:
445                 BUG();
446         }
447
448         iounmap(virt_addr);
449
450         return AE_OK;
451 }
452
453 acpi_status
454 acpi_os_read_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
455                                void *value, u32 width)
456 {
457         int result, size;
458
459         if (!value)
460                 return AE_BAD_PARAMETER;
461
462         switch (width) {
463         case 8:
464                 size = 1;
465                 break;
466         case 16:
467                 size = 2;
468                 break;
469         case 32:
470                 size = 4;
471                 break;
472         default:
473                 return AE_ERROR;
474         }
475
476         BUG_ON(!raw_pci_ops);
477
478         result = raw_pci_ops->read(pci_id->segment, pci_id->bus,
479                                    PCI_DEVFN(pci_id->device, pci_id->function),
480                                    reg, size, value);
481
482         return (result ? AE_ERROR : AE_OK);
483 }
484
485 EXPORT_SYMBOL(acpi_os_read_pci_configuration);
486
487 acpi_status
488 acpi_os_write_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
489                                 acpi_integer value, u32 width)
490 {
491         int result, size;
492
493         switch (width) {
494         case 8:
495                 size = 1;
496                 break;
497         case 16:
498                 size = 2;
499                 break;
500         case 32:
501                 size = 4;
502                 break;
503         default:
504                 return AE_ERROR;
505         }
506
507         BUG_ON(!raw_pci_ops);
508
509         result = raw_pci_ops->write(pci_id->segment, pci_id->bus,
510                                     PCI_DEVFN(pci_id->device, pci_id->function),
511                                     reg, size, value);
512
513         return (result ? AE_ERROR : AE_OK);
514 }
515
516 /* TODO: Change code to take advantage of driver model more */
517 static void acpi_os_derive_pci_id_2(acpi_handle rhandle,        /* upper bound  */
518                                     acpi_handle chandle,        /* current node */
519                                     struct acpi_pci_id **id,
520                                     int *is_bridge, u8 * bus_number)
521 {
522         acpi_handle handle;
523         struct acpi_pci_id *pci_id = *id;
524         acpi_status status;
525         unsigned long temp;
526         acpi_object_type type;
527         u8 tu8;
528
529         acpi_get_parent(chandle, &handle);
530         if (handle != rhandle) {
531                 acpi_os_derive_pci_id_2(rhandle, handle, &pci_id, is_bridge,
532                                         bus_number);
533
534                 status = acpi_get_type(handle, &type);
535                 if ((ACPI_FAILURE(status)) || (type != ACPI_TYPE_DEVICE))
536                         return;
537
538                 status =
539                     acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL,
540                                           &temp);
541                 if (ACPI_SUCCESS(status)) {
542                         pci_id->device = ACPI_HIWORD(ACPI_LODWORD(temp));
543                         pci_id->function = ACPI_LOWORD(ACPI_LODWORD(temp));
544
545                         if (*is_bridge)
546                                 pci_id->bus = *bus_number;
547
548                         /* any nicer way to get bus number of bridge ? */
549                         status =
550                             acpi_os_read_pci_configuration(pci_id, 0x0e, &tu8,
551                                                            8);
552                         if (ACPI_SUCCESS(status)
553                             && ((tu8 & 0x7f) == 1 || (tu8 & 0x7f) == 2)) {
554                                 status =
555                                     acpi_os_read_pci_configuration(pci_id, 0x18,
556                                                                    &tu8, 8);
557                                 if (!ACPI_SUCCESS(status)) {
558                                         /* Certainly broken...  FIX ME */
559                                         return;
560                                 }
561                                 *is_bridge = 1;
562                                 pci_id->bus = tu8;
563                                 status =
564                                     acpi_os_read_pci_configuration(pci_id, 0x19,
565                                                                    &tu8, 8);
566                                 if (ACPI_SUCCESS(status)) {
567                                         *bus_number = tu8;
568                                 }
569                         } else
570                                 *is_bridge = 0;
571                 }
572         }
573 }
574
575 void acpi_os_derive_pci_id(acpi_handle rhandle, /* upper bound  */
576                            acpi_handle chandle, /* current node */
577                            struct acpi_pci_id **id)
578 {
579         int is_bridge = 1;
580         u8 bus_number = (*id)->bus;
581
582         acpi_os_derive_pci_id_2(rhandle, chandle, id, &is_bridge, &bus_number);
583 }
584
585 static void acpi_os_execute_deferred(void *context)
586 {
587         struct acpi_os_dpc *dpc = NULL;
588
589         ACPI_FUNCTION_TRACE("os_execute_deferred");
590
591         dpc = (struct acpi_os_dpc *)context;
592         if (!dpc) {
593                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) context.\n"));
594                 return_VOID;
595         }
596
597         dpc->function(dpc->context);
598
599         kfree(dpc);
600
601         return_VOID;
602 }
603
604 static int acpi_os_execute_thread(void *context)
605 {
606         struct acpi_os_dpc *dpc = (struct acpi_os_dpc *)context;
607         if (dpc) {
608                 dpc->function(dpc->context);
609                 kfree(dpc);
610         }
611         do_exit(0);
612 }
613
614 /*******************************************************************************
615  *
616  * FUNCTION:    acpi_os_execute
617  *
618  * PARAMETERS:  Type               - Type of the callback
619  *              Function           - Function to be executed
620  *              Context            - Function parameters
621  *
622  * RETURN:      Status
623  *
624  * DESCRIPTION: Depending on type, either queues function for deferred execution or
625  *              immediately executes function on a separate thread.
626  *
627  ******************************************************************************/
628
629 acpi_status acpi_os_execute(acpi_execute_type type,
630                             acpi_osd_exec_callback function, void *context)
631 {
632         acpi_status status = AE_OK;
633         struct acpi_os_dpc *dpc;
634         struct work_struct *task;
635         struct task_struct *p;
636
637         if (!function)
638                 return AE_BAD_PARAMETER;
639         /*
640          * Allocate/initialize DPC structure.  Note that this memory will be
641          * freed by the callee.  The kernel handles the tq_struct list  in a
642          * way that allows us to also free its memory inside the callee.
643          * Because we may want to schedule several tasks with different
644          * parameters we can't use the approach some kernel code uses of
645          * having a static tq_struct.
646          * We can save time and code by allocating the DPC and tq_structs
647          * from the same memory.
648          */
649         if (type == OSL_NOTIFY_HANDLER) {
650                 dpc = kmalloc(sizeof(struct acpi_os_dpc), GFP_KERNEL);
651         } else {
652                 dpc = kmalloc(sizeof(struct acpi_os_dpc) +
653                                 sizeof(struct work_struct), GFP_ATOMIC);
654         }
655         if (!dpc)
656                 return AE_NO_MEMORY;
657         dpc->function = function;
658         dpc->context = context;
659
660         if (type == OSL_NOTIFY_HANDLER) {
661                 p = kthread_create(acpi_os_execute_thread, dpc, "kacpid_notify");
662                 if (!IS_ERR(p)) {
663                         wake_up_process(p);
664                 } else {
665                         status = AE_NO_MEMORY;
666                         kfree(dpc);
667                 }
668         } else {
669                 task = (void *)(dpc + 1);
670                 INIT_WORK(task, acpi_os_execute_deferred, (void *)dpc);
671                 if (!queue_work(kacpid_wq, task)) {
672                         status = AE_ERROR;
673                         kfree(dpc);
674                 }
675         }
676         return status;
677 }
678
679 EXPORT_SYMBOL(acpi_os_execute);
680
681 void acpi_os_wait_events_complete(void *context)
682 {
683         flush_workqueue(kacpid_wq);
684 }
685
686 EXPORT_SYMBOL(acpi_os_wait_events_complete);
687
688 /*
689  * Allocate the memory for a spinlock and initialize it.
690  */
691 acpi_status acpi_os_create_lock(acpi_handle * out_handle)
692 {
693         spinlock_t *lock_ptr;
694
695         ACPI_FUNCTION_TRACE("os_create_lock");
696
697         lock_ptr = acpi_os_allocate(sizeof(spinlock_t));
698
699         spin_lock_init(lock_ptr);
700
701         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating spinlock[%p].\n", lock_ptr));
702
703         *out_handle = lock_ptr;
704
705         return_ACPI_STATUS(AE_OK);
706 }
707
708 /*
709  * Deallocate the memory for a spinlock.
710  */
711 void acpi_os_delete_lock(acpi_handle handle)
712 {
713         ACPI_FUNCTION_TRACE("os_create_lock");
714
715         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting spinlock[%p].\n", handle));
716
717         acpi_os_free(handle);
718
719         return_VOID;
720 }
721
722 acpi_status
723 acpi_os_create_semaphore(u32 max_units, u32 initial_units, acpi_handle * handle)
724 {
725         struct semaphore *sem = NULL;
726
727         ACPI_FUNCTION_TRACE("os_create_semaphore");
728
729         sem = acpi_os_allocate(sizeof(struct semaphore));
730         if (!sem)
731                 return_ACPI_STATUS(AE_NO_MEMORY);
732         memset(sem, 0, sizeof(struct semaphore));
733
734         sema_init(sem, initial_units);
735
736         *handle = (acpi_handle *) sem;
737
738         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating semaphore[%p|%d].\n",
739                           *handle, initial_units));
740
741         return_ACPI_STATUS(AE_OK);
742 }
743
744 EXPORT_SYMBOL(acpi_os_create_semaphore);
745
746 /*
747  * TODO: A better way to delete semaphores?  Linux doesn't have a
748  * 'delete_semaphore()' function -- may result in an invalid
749  * pointer dereference for non-synchronized consumers.  Should
750  * we at least check for blocked threads and signal/cancel them?
751  */
752
753 acpi_status acpi_os_delete_semaphore(acpi_handle handle)
754 {
755         struct semaphore *sem = (struct semaphore *)handle;
756
757         ACPI_FUNCTION_TRACE("os_delete_semaphore");
758
759         if (!sem)
760                 return_ACPI_STATUS(AE_BAD_PARAMETER);
761
762         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting semaphore[%p].\n", handle));
763
764         acpi_os_free(sem);
765         sem = NULL;
766
767         return_ACPI_STATUS(AE_OK);
768 }
769
770 EXPORT_SYMBOL(acpi_os_delete_semaphore);
771
772 /*
773  * TODO: The kernel doesn't have a 'down_timeout' function -- had to
774  * improvise.  The process is to sleep for one scheduler quantum
775  * until the semaphore becomes available.  Downside is that this
776  * may result in starvation for timeout-based waits when there's
777  * lots of semaphore activity.
778  *
779  * TODO: Support for units > 1?
780  */
781 acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
782 {
783         acpi_status status = AE_OK;
784         struct semaphore *sem = (struct semaphore *)handle;
785         int ret = 0;
786
787         ACPI_FUNCTION_TRACE("os_wait_semaphore");
788
789         if (!sem || (units < 1))
790                 return_ACPI_STATUS(AE_BAD_PARAMETER);
791
792         if (units > 1)
793                 return_ACPI_STATUS(AE_SUPPORT);
794
795         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Waiting for semaphore[%p|%d|%d]\n",
796                           handle, units, timeout));
797
798         switch (timeout) {
799                 /*
800                  * No Wait:
801                  * --------
802                  * A zero timeout value indicates that we shouldn't wait - just
803                  * acquire the semaphore if available otherwise return AE_TIME
804                  * (a.k.a. 'would block').
805                  */
806         case 0:
807                 if (down_trylock(sem))
808                         status = AE_TIME;
809                 break;
810
811                 /*
812                  * Wait Indefinitely:
813                  * ------------------
814                  */
815         case ACPI_WAIT_FOREVER:
816                 down(sem);
817                 break;
818
819                 /*
820                  * Wait w/ Timeout:
821                  * ----------------
822                  */
823         default:
824                 // TODO: A better timeout algorithm?
825                 {
826                         int i = 0;
827                         static const int quantum_ms = 1000 / HZ;
828
829                         ret = down_trylock(sem);
830                         for (i = timeout; (i > 0 && ret != 0); i -= quantum_ms) {
831                                 schedule_timeout_interruptible(1);
832                                 ret = down_trylock(sem);
833                         }
834
835                         if (ret != 0)
836                                 status = AE_TIME;
837                 }
838                 break;
839         }
840
841         if (ACPI_FAILURE(status)) {
842                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
843                                   "Failed to acquire semaphore[%p|%d|%d], %s\n",
844                                   handle, units, timeout,
845                                   acpi_format_exception(status)));
846         } else {
847                 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
848                                   "Acquired semaphore[%p|%d|%d]\n", handle,
849                                   units, timeout));
850         }
851
852         return_ACPI_STATUS(status);
853 }
854
855 EXPORT_SYMBOL(acpi_os_wait_semaphore);
856
857 /*
858  * TODO: Support for units > 1?
859  */
860 acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
861 {
862         struct semaphore *sem = (struct semaphore *)handle;
863
864         ACPI_FUNCTION_TRACE("os_signal_semaphore");
865
866         if (!sem || (units < 1))
867                 return_ACPI_STATUS(AE_BAD_PARAMETER);
868
869         if (units > 1)
870                 return_ACPI_STATUS(AE_SUPPORT);
871
872         ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Signaling semaphore[%p|%d]\n", handle,
873                           units));
874
875         up(sem);
876
877         return_ACPI_STATUS(AE_OK);
878 }
879
880 EXPORT_SYMBOL(acpi_os_signal_semaphore);
881
882 #ifdef ACPI_FUTURE_USAGE
883 u32 acpi_os_get_line(char *buffer)
884 {
885
886 #ifdef ENABLE_DEBUGGER
887         if (acpi_in_debugger) {
888                 u32 chars;
889
890                 kdb_read(buffer, sizeof(line_buf));
891
892                 /* remove the CR kdb includes */
893                 chars = strlen(buffer) - 1;
894                 buffer[chars] = '\0';
895         }
896 #endif
897
898         return 0;
899 }
900 #endif                          /*  ACPI_FUTURE_USAGE  */
901
902 /* Assumes no unreadable holes inbetween */
903 u8 acpi_os_readable(void *ptr, acpi_size len)
904 {
905 #if defined(__i386__) || defined(__x86_64__)
906         char tmp;
907         return !__get_user(tmp, (char __user *)ptr)
908             && !__get_user(tmp, (char __user *)ptr + len - 1);
909 #endif
910         return 1;
911 }
912
913 #ifdef ACPI_FUTURE_USAGE
914 u8 acpi_os_writable(void *ptr, acpi_size len)
915 {
916         /* could do dummy write (racy) or a kernel page table lookup.
917            The later may be difficult at early boot when kmap doesn't work yet. */
918         return 1;
919 }
920 #endif
921
922 acpi_status acpi_os_signal(u32 function, void *info)
923 {
924         switch (function) {
925         case ACPI_SIGNAL_FATAL:
926                 printk(KERN_ERR PREFIX "Fatal opcode executed\n");
927                 break;
928         case ACPI_SIGNAL_BREAKPOINT:
929                 /*
930                  * AML Breakpoint
931                  * ACPI spec. says to treat it as a NOP unless
932                  * you are debugging.  So if/when we integrate
933                  * AML debugger into the kernel debugger its
934                  * hook will go here.  But until then it is
935                  * not useful to print anything on breakpoints.
936                  */
937                 break;
938         default:
939                 break;
940         }
941
942         return AE_OK;
943 }
944
945 EXPORT_SYMBOL(acpi_os_signal);
946
947 static int __init acpi_os_name_setup(char *str)
948 {
949         char *p = acpi_os_name;
950         int count = ACPI_MAX_OVERRIDE_LEN - 1;
951
952         if (!str || !*str)
953                 return 0;
954
955         for (; count-- && str && *str; str++) {
956                 if (isalnum(*str) || *str == ' ' || *str == ':')
957                         *p++ = *str;
958                 else if (*str == '\'' || *str == '"')
959                         continue;
960                 else
961                         break;
962         }
963         *p = 0;
964
965         return 1;
966
967 }
968
969 __setup("acpi_os_name=", acpi_os_name_setup);
970
971 /*
972  * _OSI control
973  * empty string disables _OSI
974  * TBD additional string adds to _OSI
975  */
976 static int __init acpi_osi_setup(char *str)
977 {
978         if (str == NULL || *str == '\0') {
979                 printk(KERN_INFO PREFIX "_OSI method disabled\n");
980                 acpi_gbl_create_osi_method = FALSE;
981         } else {
982                 /* TBD */
983                 printk(KERN_ERR PREFIX "_OSI additional string ignored -- %s\n",
984                        str);
985         }
986
987         return 1;
988 }
989
990 __setup("acpi_osi=", acpi_osi_setup);
991
992 /* enable serialization to combat AE_ALREADY_EXISTS errors */
993 static int __init acpi_serialize_setup(char *str)
994 {
995         printk(KERN_INFO PREFIX "serialize enabled\n");
996
997         acpi_gbl_all_methods_serialized = TRUE;
998
999         return 1;
1000 }
1001
1002 __setup("acpi_serialize", acpi_serialize_setup);
1003
1004 /*
1005  * Wake and Run-Time GPES are expected to be separate.
1006  * We disable wake-GPEs at run-time to prevent spurious
1007  * interrupts.
1008  *
1009  * However, if a system exists that shares Wake and
1010  * Run-time events on the same GPE this flag is available
1011  * to tell Linux to keep the wake-time GPEs enabled at run-time.
1012  */
1013 static int __init acpi_wake_gpes_always_on_setup(char *str)
1014 {
1015         printk(KERN_INFO PREFIX "wake GPEs not disabled\n");
1016
1017         acpi_gbl_leave_wake_gpes_disabled = FALSE;
1018
1019         return 1;
1020 }
1021
1022 __setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
1023
1024 static int __init acpi_hotkey_setup(char *str)
1025 {
1026         acpi_specific_hotkey_enabled = FALSE;
1027         return 1;
1028 }
1029
1030 __setup("acpi_generic_hotkey", acpi_hotkey_setup);
1031
1032 /*
1033  * max_cstate is defined in the base kernel so modules can
1034  * change it w/o depending on the state of the processor module.
1035  */
1036 unsigned int max_cstate = ACPI_PROCESSOR_MAX_POWER;
1037
1038 EXPORT_SYMBOL(max_cstate);
1039
1040 /*
1041  * Acquire a spinlock.
1042  *
1043  * handle is a pointer to the spinlock_t.
1044  */
1045
1046 acpi_cpu_flags acpi_os_acquire_lock(acpi_handle handle)
1047 {
1048         acpi_cpu_flags flags;
1049         spin_lock_irqsave((spinlock_t *) handle, flags);
1050         return flags;
1051 }
1052
1053 /*
1054  * Release a spinlock. See above.
1055  */
1056
1057 void acpi_os_release_lock(acpi_handle handle, acpi_cpu_flags flags)
1058 {
1059         spin_unlock_irqrestore((spinlock_t *) handle, flags);
1060 }
1061
1062 #ifndef ACPI_USE_LOCAL_CACHE
1063
1064 /*******************************************************************************
1065  *
1066  * FUNCTION:    acpi_os_create_cache
1067  *
1068  * PARAMETERS:  name      - Ascii name for the cache
1069  *              size      - Size of each cached object
1070  *              depth     - Maximum depth of the cache (in objects) <ignored>
1071  *              cache     - Where the new cache object is returned
1072  *
1073  * RETURN:      status
1074  *
1075  * DESCRIPTION: Create a cache object
1076  *
1077  ******************************************************************************/
1078
1079 acpi_status
1080 acpi_os_create_cache(char *name, u16 size, u16 depth, acpi_cache_t ** cache)
1081 {
1082         *cache = kmem_cache_create(name, size, 0, 0, NULL, NULL);
1083         if (cache == NULL)
1084                 return AE_ERROR;
1085         else
1086                 return AE_OK;
1087 }
1088
1089 /*******************************************************************************
1090  *
1091  * FUNCTION:    acpi_os_purge_cache
1092  *
1093  * PARAMETERS:  Cache           - Handle to cache object
1094  *
1095  * RETURN:      Status
1096  *
1097  * DESCRIPTION: Free all objects within the requested cache.
1098  *
1099  ******************************************************************************/
1100
1101 acpi_status acpi_os_purge_cache(acpi_cache_t * cache)
1102 {
1103         (void)kmem_cache_shrink(cache);
1104         return (AE_OK);
1105 }
1106
1107 /*******************************************************************************
1108  *
1109  * FUNCTION:    acpi_os_delete_cache
1110  *
1111  * PARAMETERS:  Cache           - Handle to cache object
1112  *
1113  * RETURN:      Status
1114  *
1115  * DESCRIPTION: Free all objects within the requested cache and delete the
1116  *              cache object.
1117  *
1118  ******************************************************************************/
1119
1120 acpi_status acpi_os_delete_cache(acpi_cache_t * cache)
1121 {
1122         (void)kmem_cache_destroy(cache);
1123         return (AE_OK);
1124 }
1125
1126 /*******************************************************************************
1127  *
1128  * FUNCTION:    acpi_os_release_object
1129  *
1130  * PARAMETERS:  Cache       - Handle to cache object
1131  *              Object      - The object to be released
1132  *
1133  * RETURN:      None
1134  *
1135  * DESCRIPTION: Release an object to the specified cache.  If cache is full,
1136  *              the object is deleted.
1137  *
1138  ******************************************************************************/
1139
1140 acpi_status acpi_os_release_object(acpi_cache_t * cache, void *object)
1141 {
1142         kmem_cache_free(cache, object);
1143         return (AE_OK);
1144 }
1145
1146 /*******************************************************************************
1147  *
1148  * FUNCTION:    acpi_os_acquire_object
1149  *
1150  * PARAMETERS:  Cache           - Handle to cache object
1151  *              ReturnObject    - Where the object is returned
1152  *
1153  * RETURN:      Status
1154  *
1155  * DESCRIPTION: Return a zero-filled object.
1156  *
1157  ******************************************************************************/
1158
1159 void *acpi_os_acquire_object(acpi_cache_t * cache)
1160 {
1161         void *object = kmem_cache_zalloc(cache, GFP_KERNEL);
1162         WARN_ON(!object);
1163         return object;
1164 }
1165
1166 /******************************************************************************
1167  *
1168  * FUNCTION:    acpi_os_validate_interface
1169  *
1170  * PARAMETERS:  interface           - Requested interface to be validated
1171  *
1172  * RETURN:      AE_OK if interface is supported, AE_SUPPORT otherwise
1173  *
1174  * DESCRIPTION: Match an interface string to the interfaces supported by the
1175  *              host. Strings originate from an AML call to the _OSI method.
1176  *
1177  *****************************************************************************/
1178
1179 acpi_status
1180 acpi_os_validate_interface (char *interface)
1181 {
1182
1183     return AE_SUPPORT;
1184 }
1185
1186
1187 /******************************************************************************
1188  *
1189  * FUNCTION:    acpi_os_validate_address
1190  *
1191  * PARAMETERS:  space_id             - ACPI space ID
1192  *              address             - Physical address
1193  *              length              - Address length
1194  *
1195  * RETURN:      AE_OK if address/length is valid for the space_id. Otherwise,
1196  *              should return AE_AML_ILLEGAL_ADDRESS.
1197  *
1198  * DESCRIPTION: Validate a system address via the host OS. Used to validate
1199  *              the addresses accessed by AML operation regions.
1200  *
1201  *****************************************************************************/
1202
1203 acpi_status
1204 acpi_os_validate_address (
1205     u8                   space_id,
1206     acpi_physical_address   address,
1207     acpi_size               length)
1208 {
1209
1210     return AE_OK;
1211 }
1212
1213
1214 #endif