xref: /linux/drivers/acpi/osl.c (revision 2624f124b3b5d550ab2fbef7ee3bc0e1fed09722)
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 <acpi/acpi.h>
41 #include <asm/io.h>
42 #include <acpi/acpi_bus.h>
43 #include <acpi/processor.h>
44 #include <asm/uaccess.h>
45 
46 #include <linux/efi.h>
47 
48 #define _COMPONENT		ACPI_OS_SERVICES
49 ACPI_MODULE_NAME("osl")
50 #define PREFIX		"ACPI: "
51 struct acpi_os_dpc {
52 	acpi_osd_exec_callback function;
53 	void *context;
54 };
55 
56 #ifdef CONFIG_ACPI_CUSTOM_DSDT
57 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
58 #endif
59 
60 #ifdef ENABLE_DEBUGGER
61 #include <linux/kdb.h>
62 
63 /* stuff for debugger support */
64 int acpi_in_debugger;
65 EXPORT_SYMBOL(acpi_in_debugger);
66 
67 extern char line_buf[80];
68 #endif				/*ENABLE_DEBUGGER */
69 
70 int acpi_specific_hotkey_enabled = TRUE;
71 EXPORT_SYMBOL(acpi_specific_hotkey_enabled);
72 
73 static unsigned int acpi_irq_irq;
74 static acpi_osd_handler acpi_irq_handler;
75 static void *acpi_irq_context;
76 static struct workqueue_struct *kacpid_wq;
77 
78 acpi_status acpi_os_initialize(void)
79 {
80 	return AE_OK;
81 }
82 
83 acpi_status acpi_os_initialize1(void)
84 {
85 	/*
86 	 * Initialize PCI configuration space access, as we'll need to access
87 	 * it while walking the namespace (bus 0 and root bridges w/ _BBNs).
88 	 */
89 	if (!raw_pci_ops) {
90 		printk(KERN_ERR PREFIX
91 		       "Access to PCI configuration space unavailable\n");
92 		return AE_NULL_ENTRY;
93 	}
94 	kacpid_wq = create_singlethread_workqueue("kacpid");
95 	BUG_ON(!kacpid_wq);
96 
97 	return AE_OK;
98 }
99 
100 acpi_status acpi_os_terminate(void)
101 {
102 	if (acpi_irq_handler) {
103 		acpi_os_remove_interrupt_handler(acpi_irq_irq,
104 						 acpi_irq_handler);
105 	}
106 
107 	destroy_workqueue(kacpid_wq);
108 
109 	return AE_OK;
110 }
111 
112 void acpi_os_printf(const char *fmt, ...)
113 {
114 	va_list args;
115 	va_start(args, fmt);
116 	acpi_os_vprintf(fmt, args);
117 	va_end(args);
118 }
119 
120 EXPORT_SYMBOL(acpi_os_printf);
121 
122 void acpi_os_vprintf(const char *fmt, va_list args)
123 {
124 	static char buffer[512];
125 
126 	vsprintf(buffer, fmt, args);
127 
128 #ifdef ENABLE_DEBUGGER
129 	if (acpi_in_debugger) {
130 		kdb_printf("%s", buffer);
131 	} else {
132 		printk("%s", buffer);
133 	}
134 #else
135 	printk("%s", buffer);
136 #endif
137 }
138 
139 extern int acpi_in_resume;
140 void *acpi_os_allocate(acpi_size size)
141 {
142 	if (acpi_in_resume)
143 		return kmalloc(size, GFP_ATOMIC);
144 	else
145 		return kmalloc(size, GFP_KERNEL);
146 }
147 
148 void acpi_os_free(void *ptr)
149 {
150 	kfree(ptr);
151 }
152 
153 EXPORT_SYMBOL(acpi_os_free);
154 
155 acpi_status acpi_os_get_root_pointer(u32 flags, struct acpi_pointer *addr)
156 {
157 	if (efi_enabled) {
158 		addr->pointer_type = ACPI_PHYSICAL_POINTER;
159 		if (efi.acpi20)
160 			addr->pointer.physical =
161 			    (acpi_physical_address) virt_to_phys(efi.acpi20);
162 		else if (efi.acpi)
163 			addr->pointer.physical =
164 			    (acpi_physical_address) virt_to_phys(efi.acpi);
165 		else {
166 			printk(KERN_ERR PREFIX
167 			       "System description tables not found\n");
168 			return AE_NOT_FOUND;
169 		}
170 	} else {
171 		if (ACPI_FAILURE(acpi_find_root_pointer(flags, addr))) {
172 			printk(KERN_ERR PREFIX
173 			       "System description tables not found\n");
174 			return AE_NOT_FOUND;
175 		}
176 	}
177 
178 	return AE_OK;
179 }
180 
181 acpi_status
182 acpi_os_map_memory(acpi_physical_address phys, acpi_size size,
183 		   void __iomem ** virt)
184 {
185 	if (efi_enabled) {
186 		if (EFI_MEMORY_WB & efi_mem_attributes(phys)) {
187 			*virt = (void __iomem *)phys_to_virt(phys);
188 		} else {
189 			*virt = ioremap(phys, size);
190 		}
191 	} else {
192 		if (phys > ULONG_MAX) {
193 			printk(KERN_ERR PREFIX "Cannot map memory that high\n");
194 			return AE_BAD_PARAMETER;
195 		}
196 		/*
197 		 * ioremap checks to ensure this is in reserved space
198 		 */
199 		*virt = ioremap((unsigned long)phys, size);
200 	}
201 
202 	if (!*virt)
203 		return AE_NO_MEMORY;
204 
205 	return AE_OK;
206 }
207 
208 void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
209 {
210 	iounmap(virt);
211 }
212 
213 #ifdef ACPI_FUTURE_USAGE
214 acpi_status
215 acpi_os_get_physical_address(void *virt, acpi_physical_address * phys)
216 {
217 	if (!phys || !virt)
218 		return AE_BAD_PARAMETER;
219 
220 	*phys = virt_to_phys(virt);
221 
222 	return AE_OK;
223 }
224 #endif
225 
226 #define ACPI_MAX_OVERRIDE_LEN 100
227 
228 static char acpi_os_name[ACPI_MAX_OVERRIDE_LEN];
229 
230 acpi_status
231 acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
232 			    acpi_string * new_val)
233 {
234 	if (!init_val || !new_val)
235 		return AE_BAD_PARAMETER;
236 
237 	*new_val = NULL;
238 	if (!memcmp(init_val->name, "_OS_", 4) && strlen(acpi_os_name)) {
239 		printk(KERN_INFO PREFIX "Overriding _OS definition to '%s'\n",
240 		       acpi_os_name);
241 		*new_val = acpi_os_name;
242 	}
243 
244 	return AE_OK;
245 }
246 
247 acpi_status
248 acpi_os_table_override(struct acpi_table_header * existing_table,
249 		       struct acpi_table_header ** new_table)
250 {
251 	if (!existing_table || !new_table)
252 		return AE_BAD_PARAMETER;
253 
254 #ifdef CONFIG_ACPI_CUSTOM_DSDT
255 	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
256 		*new_table = (struct acpi_table_header *)AmlCode;
257 	else
258 		*new_table = NULL;
259 #else
260 	*new_table = NULL;
261 #endif
262 	return AE_OK;
263 }
264 
265 static irqreturn_t acpi_irq(int irq, void *dev_id, struct pt_regs *regs)
266 {
267 	return (*acpi_irq_handler) (acpi_irq_context) ? IRQ_HANDLED : IRQ_NONE;
268 }
269 
270 acpi_status
271 acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler,
272 				  void *context)
273 {
274 	unsigned int irq;
275 
276 	/*
277 	 * Ignore the GSI from the core, and use the value in our copy of the
278 	 * FADT. It may not be the same if an interrupt source override exists
279 	 * for the SCI.
280 	 */
281 	gsi = acpi_fadt.sci_int;
282 	if (acpi_gsi_to_irq(gsi, &irq) < 0) {
283 		printk(KERN_ERR PREFIX "SCI (ACPI GSI %d) not registered\n",
284 		       gsi);
285 		return AE_OK;
286 	}
287 
288 	acpi_irq_handler = handler;
289 	acpi_irq_context = context;
290 	if (request_irq(irq, acpi_irq, SA_SHIRQ, "acpi", acpi_irq)) {
291 		printk(KERN_ERR PREFIX "SCI (IRQ%d) allocation failed\n", irq);
292 		return AE_NOT_ACQUIRED;
293 	}
294 	acpi_irq_irq = irq;
295 
296 	return AE_OK;
297 }
298 
299 acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
300 {
301 	if (irq) {
302 		free_irq(irq, acpi_irq);
303 		acpi_irq_handler = NULL;
304 		acpi_irq_irq = 0;
305 	}
306 
307 	return AE_OK;
308 }
309 
310 /*
311  * Running in interpreter thread context, safe to sleep
312  */
313 
314 void acpi_os_sleep(acpi_integer ms)
315 {
316 	current->state = TASK_INTERRUPTIBLE;
317 	schedule_timeout(((signed long)ms * HZ) / 1000);
318 }
319 
320 EXPORT_SYMBOL(acpi_os_sleep);
321 
322 void acpi_os_stall(u32 us)
323 {
324 	while (us) {
325 		u32 delay = 1000;
326 
327 		if (delay > us)
328 			delay = us;
329 		udelay(delay);
330 		touch_nmi_watchdog();
331 		us -= delay;
332 	}
333 }
334 
335 EXPORT_SYMBOL(acpi_os_stall);
336 
337 /*
338  * Support ACPI 3.0 AML Timer operand
339  * Returns 64-bit free-running, monotonically increasing timer
340  * with 100ns granularity
341  */
342 u64 acpi_os_get_timer(void)
343 {
344 	static u64 t;
345 
346 #ifdef	CONFIG_HPET
347 	/* TBD: use HPET if available */
348 #endif
349 
350 #ifdef	CONFIG_X86_PM_TIMER
351 	/* TBD: default to PM timer if HPET was not available */
352 #endif
353 	if (!t)
354 		printk(KERN_ERR PREFIX "acpi_os_get_timer() TBD\n");
355 
356 	return ++t;
357 }
358 
359 acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width)
360 {
361 	u32 dummy;
362 
363 	if (!value)
364 		value = &dummy;
365 
366 	switch (width) {
367 	case 8:
368 		*(u8 *) value = inb(port);
369 		break;
370 	case 16:
371 		*(u16 *) value = inw(port);
372 		break;
373 	case 32:
374 		*(u32 *) value = inl(port);
375 		break;
376 	default:
377 		BUG();
378 	}
379 
380 	return AE_OK;
381 }
382 
383 EXPORT_SYMBOL(acpi_os_read_port);
384 
385 acpi_status acpi_os_write_port(acpi_io_address port, u32 value, u32 width)
386 {
387 	switch (width) {
388 	case 8:
389 		outb(value, port);
390 		break;
391 	case 16:
392 		outw(value, port);
393 		break;
394 	case 32:
395 		outl(value, port);
396 		break;
397 	default:
398 		BUG();
399 	}
400 
401 	return AE_OK;
402 }
403 
404 EXPORT_SYMBOL(acpi_os_write_port);
405 
406 acpi_status
407 acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width)
408 {
409 	u32 dummy;
410 	void __iomem *virt_addr;
411 	int iomem = 0;
412 
413 	if (efi_enabled) {
414 		if (EFI_MEMORY_WB & efi_mem_attributes(phys_addr)) {
415 			/* HACK ALERT! We can use readb/w/l on real memory too.. */
416 			virt_addr = (void __iomem *)phys_to_virt(phys_addr);
417 		} else {
418 			iomem = 1;
419 			virt_addr = ioremap(phys_addr, width);
420 		}
421 	} else
422 		virt_addr = (void __iomem *)phys_to_virt(phys_addr);
423 	if (!value)
424 		value = &dummy;
425 
426 	switch (width) {
427 	case 8:
428 		*(u8 *) value = readb(virt_addr);
429 		break;
430 	case 16:
431 		*(u16 *) value = readw(virt_addr);
432 		break;
433 	case 32:
434 		*(u32 *) value = readl(virt_addr);
435 		break;
436 	default:
437 		BUG();
438 	}
439 
440 	if (efi_enabled) {
441 		if (iomem)
442 			iounmap(virt_addr);
443 	}
444 
445 	return AE_OK;
446 }
447 
448 acpi_status
449 acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)
450 {
451 	void __iomem *virt_addr;
452 	int iomem = 0;
453 
454 	if (efi_enabled) {
455 		if (EFI_MEMORY_WB & efi_mem_attributes(phys_addr)) {
456 			/* HACK ALERT! We can use writeb/w/l on real memory too */
457 			virt_addr = (void __iomem *)phys_to_virt(phys_addr);
458 		} else {
459 			iomem = 1;
460 			virt_addr = ioremap(phys_addr, width);
461 		}
462 	} else
463 		virt_addr = (void __iomem *)phys_to_virt(phys_addr);
464 
465 	switch (width) {
466 	case 8:
467 		writeb(value, virt_addr);
468 		break;
469 	case 16:
470 		writew(value, virt_addr);
471 		break;
472 	case 32:
473 		writel(value, virt_addr);
474 		break;
475 	default:
476 		BUG();
477 	}
478 
479 	if (iomem)
480 		iounmap(virt_addr);
481 
482 	return AE_OK;
483 }
484 
485 acpi_status
486 acpi_os_read_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
487 			       void *value, u32 width)
488 {
489 	int result, size;
490 
491 	if (!value)
492 		return AE_BAD_PARAMETER;
493 
494 	switch (width) {
495 	case 8:
496 		size = 1;
497 		break;
498 	case 16:
499 		size = 2;
500 		break;
501 	case 32:
502 		size = 4;
503 		break;
504 	default:
505 		return AE_ERROR;
506 	}
507 
508 	BUG_ON(!raw_pci_ops);
509 
510 	result = raw_pci_ops->read(pci_id->segment, pci_id->bus,
511 				   PCI_DEVFN(pci_id->device, pci_id->function),
512 				   reg, size, value);
513 
514 	return (result ? AE_ERROR : AE_OK);
515 }
516 
517 EXPORT_SYMBOL(acpi_os_read_pci_configuration);
518 
519 acpi_status
520 acpi_os_write_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
521 				acpi_integer value, u32 width)
522 {
523 	int result, size;
524 
525 	switch (width) {
526 	case 8:
527 		size = 1;
528 		break;
529 	case 16:
530 		size = 2;
531 		break;
532 	case 32:
533 		size = 4;
534 		break;
535 	default:
536 		return AE_ERROR;
537 	}
538 
539 	BUG_ON(!raw_pci_ops);
540 
541 	result = raw_pci_ops->write(pci_id->segment, pci_id->bus,
542 				    PCI_DEVFN(pci_id->device, pci_id->function),
543 				    reg, size, value);
544 
545 	return (result ? AE_ERROR : AE_OK);
546 }
547 
548 /* TODO: Change code to take advantage of driver model more */
549 static void acpi_os_derive_pci_id_2(acpi_handle rhandle,	/* upper bound  */
550 				    acpi_handle chandle,	/* current node */
551 				    struct acpi_pci_id **id,
552 				    int *is_bridge, u8 * bus_number)
553 {
554 	acpi_handle handle;
555 	struct acpi_pci_id *pci_id = *id;
556 	acpi_status status;
557 	unsigned long temp;
558 	acpi_object_type type;
559 	u8 tu8;
560 
561 	acpi_get_parent(chandle, &handle);
562 	if (handle != rhandle) {
563 		acpi_os_derive_pci_id_2(rhandle, handle, &pci_id, is_bridge,
564 					bus_number);
565 
566 		status = acpi_get_type(handle, &type);
567 		if ((ACPI_FAILURE(status)) || (type != ACPI_TYPE_DEVICE))
568 			return;
569 
570 		status =
571 		    acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL,
572 					  &temp);
573 		if (ACPI_SUCCESS(status)) {
574 			pci_id->device = ACPI_HIWORD(ACPI_LODWORD(temp));
575 			pci_id->function = ACPI_LOWORD(ACPI_LODWORD(temp));
576 
577 			if (*is_bridge)
578 				pci_id->bus = *bus_number;
579 
580 			/* any nicer way to get bus number of bridge ? */
581 			status =
582 			    acpi_os_read_pci_configuration(pci_id, 0x0e, &tu8,
583 							   8);
584 			if (ACPI_SUCCESS(status)
585 			    && ((tu8 & 0x7f) == 1 || (tu8 & 0x7f) == 2)) {
586 				status =
587 				    acpi_os_read_pci_configuration(pci_id, 0x18,
588 								   &tu8, 8);
589 				if (!ACPI_SUCCESS(status)) {
590 					/* Certainly broken...  FIX ME */
591 					return;
592 				}
593 				*is_bridge = 1;
594 				pci_id->bus = tu8;
595 				status =
596 				    acpi_os_read_pci_configuration(pci_id, 0x19,
597 								   &tu8, 8);
598 				if (ACPI_SUCCESS(status)) {
599 					*bus_number = tu8;
600 				}
601 			} else
602 				*is_bridge = 0;
603 		}
604 	}
605 }
606 
607 void acpi_os_derive_pci_id(acpi_handle rhandle,	/* upper bound  */
608 			   acpi_handle chandle,	/* current node */
609 			   struct acpi_pci_id **id)
610 {
611 	int is_bridge = 1;
612 	u8 bus_number = (*id)->bus;
613 
614 	acpi_os_derive_pci_id_2(rhandle, chandle, id, &is_bridge, &bus_number);
615 }
616 
617 static void acpi_os_execute_deferred(void *context)
618 {
619 	struct acpi_os_dpc *dpc = NULL;
620 
621 	ACPI_FUNCTION_TRACE("os_execute_deferred");
622 
623 	dpc = (struct acpi_os_dpc *)context;
624 	if (!dpc) {
625 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) context.\n"));
626 		return_VOID;
627 	}
628 
629 	dpc->function(dpc->context);
630 
631 	kfree(dpc);
632 
633 	return_VOID;
634 }
635 
636 acpi_status
637 acpi_os_queue_for_execution(u32 priority,
638 			    acpi_osd_exec_callback function, void *context)
639 {
640 	acpi_status status = AE_OK;
641 	struct acpi_os_dpc *dpc;
642 	struct work_struct *task;
643 
644 	ACPI_FUNCTION_TRACE("os_queue_for_execution");
645 
646 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
647 			  "Scheduling function [%p(%p)] for deferred execution.\n",
648 			  function, context));
649 
650 	if (!function)
651 		return_ACPI_STATUS(AE_BAD_PARAMETER);
652 
653 	/*
654 	 * Allocate/initialize DPC structure.  Note that this memory will be
655 	 * freed by the callee.  The kernel handles the tq_struct list  in a
656 	 * way that allows us to also free its memory inside the callee.
657 	 * Because we may want to schedule several tasks with different
658 	 * parameters we can't use the approach some kernel code uses of
659 	 * having a static tq_struct.
660 	 * We can save time and code by allocating the DPC and tq_structs
661 	 * from the same memory.
662 	 */
663 
664 	dpc =
665 	    kmalloc(sizeof(struct acpi_os_dpc) + sizeof(struct work_struct),
666 		    GFP_ATOMIC);
667 	if (!dpc)
668 		return_ACPI_STATUS(AE_NO_MEMORY);
669 
670 	dpc->function = function;
671 	dpc->context = context;
672 
673 	task = (void *)(dpc + 1);
674 	INIT_WORK(task, acpi_os_execute_deferred, (void *)dpc);
675 
676 	if (!queue_work(kacpid_wq, task)) {
677 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
678 				  "Call to queue_work() failed.\n"));
679 		kfree(dpc);
680 		status = AE_ERROR;
681 	}
682 
683 	return_ACPI_STATUS(status);
684 }
685 
686 EXPORT_SYMBOL(acpi_os_queue_for_execution);
687 
688 void acpi_os_wait_events_complete(void *context)
689 {
690 	flush_workqueue(kacpid_wq);
691 }
692 
693 EXPORT_SYMBOL(acpi_os_wait_events_complete);
694 
695 /*
696  * Allocate the memory for a spinlock and initialize it.
697  */
698 acpi_status acpi_os_create_lock(acpi_handle * out_handle)
699 {
700 	spinlock_t *lock_ptr;
701 
702 	ACPI_FUNCTION_TRACE("os_create_lock");
703 
704 	lock_ptr = acpi_os_allocate(sizeof(spinlock_t));
705 
706 	spin_lock_init(lock_ptr);
707 
708 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating spinlock[%p].\n", lock_ptr));
709 
710 	*out_handle = lock_ptr;
711 
712 	return_ACPI_STATUS(AE_OK);
713 }
714 
715 /*
716  * Deallocate the memory for a spinlock.
717  */
718 void acpi_os_delete_lock(acpi_handle handle)
719 {
720 	ACPI_FUNCTION_TRACE("os_create_lock");
721 
722 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting spinlock[%p].\n", handle));
723 
724 	acpi_os_free(handle);
725 
726 	return_VOID;
727 }
728 
729 acpi_status
730 acpi_os_create_semaphore(u32 max_units, u32 initial_units, acpi_handle * handle)
731 {
732 	struct semaphore *sem = NULL;
733 
734 	ACPI_FUNCTION_TRACE("os_create_semaphore");
735 
736 	sem = acpi_os_allocate(sizeof(struct semaphore));
737 	if (!sem)
738 		return_ACPI_STATUS(AE_NO_MEMORY);
739 	memset(sem, 0, sizeof(struct semaphore));
740 
741 	sema_init(sem, initial_units);
742 
743 	*handle = (acpi_handle *) sem;
744 
745 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating semaphore[%p|%d].\n",
746 			  *handle, initial_units));
747 
748 	return_ACPI_STATUS(AE_OK);
749 }
750 
751 EXPORT_SYMBOL(acpi_os_create_semaphore);
752 
753 /*
754  * TODO: A better way to delete semaphores?  Linux doesn't have a
755  * 'delete_semaphore()' function -- may result in an invalid
756  * pointer dereference for non-synchronized consumers.	Should
757  * we at least check for blocked threads and signal/cancel them?
758  */
759 
760 acpi_status acpi_os_delete_semaphore(acpi_handle handle)
761 {
762 	struct semaphore *sem = (struct semaphore *)handle;
763 
764 	ACPI_FUNCTION_TRACE("os_delete_semaphore");
765 
766 	if (!sem)
767 		return_ACPI_STATUS(AE_BAD_PARAMETER);
768 
769 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting semaphore[%p].\n", handle));
770 
771 	acpi_os_free(sem);
772 	sem = NULL;
773 
774 	return_ACPI_STATUS(AE_OK);
775 }
776 
777 EXPORT_SYMBOL(acpi_os_delete_semaphore);
778 
779 /*
780  * TODO: The kernel doesn't have a 'down_timeout' function -- had to
781  * improvise.  The process is to sleep for one scheduler quantum
782  * until the semaphore becomes available.  Downside is that this
783  * may result in starvation for timeout-based waits when there's
784  * lots of semaphore activity.
785  *
786  * TODO: Support for units > 1?
787  */
788 acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
789 {
790 	acpi_status status = AE_OK;
791 	struct semaphore *sem = (struct semaphore *)handle;
792 	int ret = 0;
793 
794 	ACPI_FUNCTION_TRACE("os_wait_semaphore");
795 
796 	if (!sem || (units < 1))
797 		return_ACPI_STATUS(AE_BAD_PARAMETER);
798 
799 	if (units > 1)
800 		return_ACPI_STATUS(AE_SUPPORT);
801 
802 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Waiting for semaphore[%p|%d|%d]\n",
803 			  handle, units, timeout));
804 
805 	if (in_atomic())
806 		timeout = 0;
807 
808 	switch (timeout) {
809 		/*
810 		 * No Wait:
811 		 * --------
812 		 * A zero timeout value indicates that we shouldn't wait - just
813 		 * acquire the semaphore if available otherwise return AE_TIME
814 		 * (a.k.a. 'would block').
815 		 */
816 	case 0:
817 		if (down_trylock(sem))
818 			status = AE_TIME;
819 		break;
820 
821 		/*
822 		 * Wait Indefinitely:
823 		 * ------------------
824 		 */
825 	case ACPI_WAIT_FOREVER:
826 		down(sem);
827 		break;
828 
829 		/*
830 		 * Wait w/ Timeout:
831 		 * ----------------
832 		 */
833 	default:
834 		// TODO: A better timeout algorithm?
835 		{
836 			int i = 0;
837 			static const int quantum_ms = 1000 / HZ;
838 
839 			ret = down_trylock(sem);
840 			for (i = timeout; (i > 0 && ret < 0); i -= quantum_ms) {
841 				current->state = TASK_INTERRUPTIBLE;
842 				schedule_timeout(1);
843 				ret = down_trylock(sem);
844 			}
845 
846 			if (ret != 0)
847 				status = AE_TIME;
848 		}
849 		break;
850 	}
851 
852 	if (ACPI_FAILURE(status)) {
853 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
854 				  "Failed to acquire semaphore[%p|%d|%d], %s\n",
855 				  handle, units, timeout,
856 				  acpi_format_exception(status)));
857 	} else {
858 		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
859 				  "Acquired semaphore[%p|%d|%d]\n", handle,
860 				  units, timeout));
861 	}
862 
863 	return_ACPI_STATUS(status);
864 }
865 
866 EXPORT_SYMBOL(acpi_os_wait_semaphore);
867 
868 /*
869  * TODO: Support for units > 1?
870  */
871 acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
872 {
873 	struct semaphore *sem = (struct semaphore *)handle;
874 
875 	ACPI_FUNCTION_TRACE("os_signal_semaphore");
876 
877 	if (!sem || (units < 1))
878 		return_ACPI_STATUS(AE_BAD_PARAMETER);
879 
880 	if (units > 1)
881 		return_ACPI_STATUS(AE_SUPPORT);
882 
883 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Signaling semaphore[%p|%d]\n", handle,
884 			  units));
885 
886 	up(sem);
887 
888 	return_ACPI_STATUS(AE_OK);
889 }
890 
891 EXPORT_SYMBOL(acpi_os_signal_semaphore);
892 
893 #ifdef ACPI_FUTURE_USAGE
894 u32 acpi_os_get_line(char *buffer)
895 {
896 
897 #ifdef ENABLE_DEBUGGER
898 	if (acpi_in_debugger) {
899 		u32 chars;
900 
901 		kdb_read(buffer, sizeof(line_buf));
902 
903 		/* remove the CR kdb includes */
904 		chars = strlen(buffer) - 1;
905 		buffer[chars] = '\0';
906 	}
907 #endif
908 
909 	return 0;
910 }
911 #endif				/*  ACPI_FUTURE_USAGE  */
912 
913 /* Assumes no unreadable holes inbetween */
914 u8 acpi_os_readable(void *ptr, acpi_size len)
915 {
916 #if defined(__i386__) || defined(__x86_64__)
917 	char tmp;
918 	return !__get_user(tmp, (char __user *)ptr)
919 	    && !__get_user(tmp, (char __user *)ptr + len - 1);
920 #endif
921 	return 1;
922 }
923 
924 #ifdef ACPI_FUTURE_USAGE
925 u8 acpi_os_writable(void *ptr, acpi_size len)
926 {
927 	/* could do dummy write (racy) or a kernel page table lookup.
928 	   The later may be difficult at early boot when kmap doesn't work yet. */
929 	return 1;
930 }
931 #endif
932 
933 u32 acpi_os_get_thread_id(void)
934 {
935 	if (!in_atomic())
936 		return current->pid;
937 
938 	return 0;
939 }
940 
941 acpi_status acpi_os_signal(u32 function, void *info)
942 {
943 	switch (function) {
944 	case ACPI_SIGNAL_FATAL:
945 		printk(KERN_ERR PREFIX "Fatal opcode executed\n");
946 		break;
947 	case ACPI_SIGNAL_BREAKPOINT:
948 		/*
949 		 * AML Breakpoint
950 		 * ACPI spec. says to treat it as a NOP unless
951 		 * you are debugging.  So if/when we integrate
952 		 * AML debugger into the kernel debugger its
953 		 * hook will go here.  But until then it is
954 		 * not useful to print anything on breakpoints.
955 		 */
956 		break;
957 	default:
958 		break;
959 	}
960 
961 	return AE_OK;
962 }
963 
964 EXPORT_SYMBOL(acpi_os_signal);
965 
966 static int __init acpi_os_name_setup(char *str)
967 {
968 	char *p = acpi_os_name;
969 	int count = ACPI_MAX_OVERRIDE_LEN - 1;
970 
971 	if (!str || !*str)
972 		return 0;
973 
974 	for (; count-- && str && *str; str++) {
975 		if (isalnum(*str) || *str == ' ' || *str == ':')
976 			*p++ = *str;
977 		else if (*str == '\'' || *str == '"')
978 			continue;
979 		else
980 			break;
981 	}
982 	*p = 0;
983 
984 	return 1;
985 
986 }
987 
988 __setup("acpi_os_name=", acpi_os_name_setup);
989 
990 /*
991  * _OSI control
992  * empty string disables _OSI
993  * TBD additional string adds to _OSI
994  */
995 static int __init acpi_osi_setup(char *str)
996 {
997 	if (str == NULL || *str == '\0') {
998 		printk(KERN_INFO PREFIX "_OSI method disabled\n");
999 		acpi_gbl_create_osi_method = FALSE;
1000 	} else {
1001 		/* TBD */
1002 		printk(KERN_ERR PREFIX "_OSI additional string ignored -- %s\n",
1003 		       str);
1004 	}
1005 
1006 	return 1;
1007 }
1008 
1009 __setup("acpi_osi=", acpi_osi_setup);
1010 
1011 /* enable serialization to combat AE_ALREADY_EXISTS errors */
1012 static int __init acpi_serialize_setup(char *str)
1013 {
1014 	printk(KERN_INFO PREFIX "serialize enabled\n");
1015 
1016 	acpi_gbl_all_methods_serialized = TRUE;
1017 
1018 	return 1;
1019 }
1020 
1021 __setup("acpi_serialize", acpi_serialize_setup);
1022 
1023 /*
1024  * Wake and Run-Time GPES are expected to be separate.
1025  * We disable wake-GPEs at run-time to prevent spurious
1026  * interrupts.
1027  *
1028  * However, if a system exists that shares Wake and
1029  * Run-time events on the same GPE this flag is available
1030  * to tell Linux to keep the wake-time GPEs enabled at run-time.
1031  */
1032 static int __init acpi_wake_gpes_always_on_setup(char *str)
1033 {
1034 	printk(KERN_INFO PREFIX "wake GPEs not disabled\n");
1035 
1036 	acpi_gbl_leave_wake_gpes_disabled = FALSE;
1037 
1038 	return 1;
1039 }
1040 
1041 __setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
1042 
1043 static int __init acpi_hotkey_setup(char *str)
1044 {
1045 	acpi_specific_hotkey_enabled = FALSE;
1046 	return 1;
1047 }
1048 
1049 __setup("acpi_generic_hotkey", acpi_hotkey_setup);
1050 
1051 /*
1052  * max_cstate is defined in the base kernel so modules can
1053  * change it w/o depending on the state of the processor module.
1054  */
1055 unsigned int max_cstate = ACPI_PROCESSOR_MAX_POWER;
1056 
1057 EXPORT_SYMBOL(max_cstate);
1058 
1059 /*
1060  * Acquire a spinlock.
1061  *
1062  * handle is a pointer to the spinlock_t.
1063  * flags is *not* the result of save_flags - it is an ACPI-specific flag variable
1064  *   that indicates whether we are at interrupt level.
1065  */
1066 
1067 unsigned long acpi_os_acquire_lock(acpi_handle handle)
1068 {
1069 	unsigned long flags;
1070 	spin_lock_irqsave((spinlock_t *) handle, flags);
1071 	return flags;
1072 }
1073 
1074 /*
1075  * Release a spinlock. See above.
1076  */
1077 
1078 void acpi_os_release_lock(acpi_handle handle, unsigned long flags)
1079 {
1080 	spin_unlock_irqrestore((spinlock_t *) handle, flags);
1081 }
1082 
1083 #ifndef ACPI_USE_LOCAL_CACHE
1084 
1085 /*******************************************************************************
1086  *
1087  * FUNCTION:    acpi_os_create_cache
1088  *
1089  * PARAMETERS:  CacheName       - Ascii name for the cache
1090  *              ObjectSize      - Size of each cached object
1091  *              MaxDepth        - Maximum depth of the cache (in objects)
1092  *              ReturnCache     - Where the new cache object is returned
1093  *
1094  * RETURN:      Status
1095  *
1096  * DESCRIPTION: Create a cache object
1097  *
1098  ******************************************************************************/
1099 
1100 acpi_status
1101 acpi_os_create_cache(char *name, u16 size, u16 depth, acpi_cache_t ** cache)
1102 {
1103 	*cache = kmem_cache_create(name, size, 0, 0, NULL, NULL);
1104 	return AE_OK;
1105 }
1106 
1107 /*******************************************************************************
1108  *
1109  * FUNCTION:    acpi_os_purge_cache
1110  *
1111  * PARAMETERS:  Cache           - Handle to cache object
1112  *
1113  * RETURN:      Status
1114  *
1115  * DESCRIPTION: Free all objects within the requested cache.
1116  *
1117  ******************************************************************************/
1118 
1119 acpi_status acpi_os_purge_cache(acpi_cache_t * cache)
1120 {
1121 	(void)kmem_cache_shrink(cache);
1122 	return (AE_OK);
1123 }
1124 
1125 /*******************************************************************************
1126  *
1127  * FUNCTION:    acpi_os_delete_cache
1128  *
1129  * PARAMETERS:  Cache           - Handle to cache object
1130  *
1131  * RETURN:      Status
1132  *
1133  * DESCRIPTION: Free all objects within the requested cache and delete the
1134  *              cache object.
1135  *
1136  ******************************************************************************/
1137 
1138 acpi_status acpi_os_delete_cache(acpi_cache_t * cache)
1139 {
1140 	(void)kmem_cache_destroy(cache);
1141 	return (AE_OK);
1142 }
1143 
1144 /*******************************************************************************
1145  *
1146  * FUNCTION:    acpi_os_release_object
1147  *
1148  * PARAMETERS:  Cache       - Handle to cache object
1149  *              Object      - The object to be released
1150  *
1151  * RETURN:      None
1152  *
1153  * DESCRIPTION: Release an object to the specified cache.  If cache is full,
1154  *              the object is deleted.
1155  *
1156  ******************************************************************************/
1157 
1158 acpi_status acpi_os_release_object(acpi_cache_t * cache, void *object)
1159 {
1160 	kmem_cache_free(cache, object);
1161 	return (AE_OK);
1162 }
1163 
1164 /*******************************************************************************
1165  *
1166  * FUNCTION:    acpi_os_acquire_object
1167  *
1168  * PARAMETERS:  Cache           - Handle to cache object
1169  *              ReturnObject    - Where the object is returned
1170  *
1171  * RETURN:      Status
1172  *
1173  * DESCRIPTION: Get an object from the specified cache.  If cache is empty,
1174  *              the object is allocated.
1175  *
1176  ******************************************************************************/
1177 
1178 void *acpi_os_acquire_object(acpi_cache_t * cache)
1179 {
1180 	void *object = kmem_cache_alloc(cache, GFP_KERNEL);
1181 	WARN_ON(!object);
1182 	return object;
1183 }
1184 
1185 #endif
1186