xref: /linux/drivers/acpi/osl.c (revision 13abf8130139c2ccd4962a7e5a8902be5e6cb5a7)
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 
49 #define _COMPONENT		ACPI_OS_SERVICES
50 ACPI_MODULE_NAME	("osl")
51 
52 #define PREFIX		"ACPI: "
53 
54 struct acpi_os_dpc
55 {
56     acpi_osd_exec_callback  function;
57     void		    *context;
58 };
59 
60 #ifdef CONFIG_ACPI_CUSTOM_DSDT
61 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
62 #endif
63 
64 #ifdef ENABLE_DEBUGGER
65 #include <linux/kdb.h>
66 
67 /* stuff for debugger support */
68 int acpi_in_debugger;
69 EXPORT_SYMBOL(acpi_in_debugger);
70 
71 extern char line_buf[80];
72 #endif /*ENABLE_DEBUGGER*/
73 
74 int acpi_specific_hotkey_enabled = TRUE;
75 EXPORT_SYMBOL(acpi_specific_hotkey_enabled);
76 
77 static unsigned int acpi_irq_irq;
78 static acpi_osd_handler acpi_irq_handler;
79 static void *acpi_irq_context;
80 static struct workqueue_struct *kacpid_wq;
81 
82 acpi_status
83 acpi_os_initialize(void)
84 {
85 	return AE_OK;
86 }
87 
88 acpi_status
89 acpi_os_initialize1(void)
90 {
91 	/*
92 	 * Initialize PCI configuration space access, as we'll need to access
93 	 * it while walking the namespace (bus 0 and root bridges w/ _BBNs).
94 	 */
95 #ifdef CONFIG_ACPI_PCI
96 	if (!raw_pci_ops) {
97 		printk(KERN_ERR PREFIX "Access to PCI configuration space unavailable\n");
98 		return AE_NULL_ENTRY;
99 	}
100 #endif
101 	kacpid_wq = create_singlethread_workqueue("kacpid");
102 	BUG_ON(!kacpid_wq);
103 
104 	return AE_OK;
105 }
106 
107 acpi_status
108 acpi_os_terminate(void)
109 {
110 	if (acpi_irq_handler) {
111 		acpi_os_remove_interrupt_handler(acpi_irq_irq,
112 						 acpi_irq_handler);
113 	}
114 
115 	destroy_workqueue(kacpid_wq);
116 
117 	return AE_OK;
118 }
119 
120 void
121 acpi_os_printf(const char *fmt,...)
122 {
123 	va_list args;
124 	va_start(args, fmt);
125 	acpi_os_vprintf(fmt, args);
126 	va_end(args);
127 }
128 EXPORT_SYMBOL(acpi_os_printf);
129 
130 void
131 acpi_os_vprintf(const char *fmt, va_list args)
132 {
133 	static char buffer[512];
134 
135 	vsprintf(buffer, fmt, args);
136 
137 #ifdef ENABLE_DEBUGGER
138 	if (acpi_in_debugger) {
139 		kdb_printf("%s", buffer);
140 	} else {
141 		printk("%s", buffer);
142 	}
143 #else
144 	printk("%s", buffer);
145 #endif
146 }
147 
148 extern int acpi_in_resume;
149 void *
150 acpi_os_allocate(acpi_size size)
151 {
152 	if (acpi_in_resume)
153 		return kmalloc(size, GFP_ATOMIC);
154 	else
155 		return kmalloc(size, GFP_KERNEL);
156 }
157 
158 void
159 acpi_os_free(void *ptr)
160 {
161 	kfree(ptr);
162 }
163 EXPORT_SYMBOL(acpi_os_free);
164 
165 acpi_status
166 acpi_os_get_root_pointer(u32 flags, struct acpi_pointer *addr)
167 {
168 	if (efi_enabled) {
169 		addr->pointer_type = ACPI_PHYSICAL_POINTER;
170 		if (efi.acpi20)
171 			addr->pointer.physical =
172 				(acpi_physical_address) virt_to_phys(efi.acpi20);
173 		else if (efi.acpi)
174 			addr->pointer.physical =
175 				(acpi_physical_address) virt_to_phys(efi.acpi);
176 		else {
177 			printk(KERN_ERR PREFIX "System description tables not found\n");
178 			return AE_NOT_FOUND;
179 		}
180 	} else {
181 		if (ACPI_FAILURE(acpi_find_root_pointer(flags, addr))) {
182 			printk(KERN_ERR PREFIX "System description tables not found\n");
183 			return AE_NOT_FOUND;
184 		}
185 	}
186 
187 	return AE_OK;
188 }
189 
190 acpi_status
191 acpi_os_map_memory(acpi_physical_address phys, acpi_size size, void __iomem **virt)
192 {
193 	if (efi_enabled) {
194 		if (EFI_MEMORY_WB & efi_mem_attributes(phys)) {
195 			*virt = (void __iomem *) phys_to_virt(phys);
196 		} else {
197 			*virt = ioremap(phys, size);
198 		}
199 	} else {
200 		if (phys > ULONG_MAX) {
201 			printk(KERN_ERR PREFIX "Cannot map memory that high\n");
202 			return AE_BAD_PARAMETER;
203 		}
204 		/*
205 	 	 * ioremap checks to ensure this is in reserved space
206 	 	 */
207 		*virt = ioremap((unsigned long) phys, size);
208 	}
209 
210 	if (!*virt)
211 		return AE_NO_MEMORY;
212 
213 	return AE_OK;
214 }
215 
216 void
217 acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
218 {
219 	iounmap(virt);
220 }
221 
222 #ifdef ACPI_FUTURE_USAGE
223 acpi_status
224 acpi_os_get_physical_address(void *virt, acpi_physical_address *phys)
225 {
226 	if(!phys || !virt)
227 		return AE_BAD_PARAMETER;
228 
229 	*phys = virt_to_phys(virt);
230 
231 	return AE_OK;
232 }
233 #endif
234 
235 #define ACPI_MAX_OVERRIDE_LEN 100
236 
237 static char acpi_os_name[ACPI_MAX_OVERRIDE_LEN];
238 
239 acpi_status
240 acpi_os_predefined_override (const struct acpi_predefined_names *init_val,
241 		             acpi_string *new_val)
242 {
243 	if (!init_val || !new_val)
244 		return AE_BAD_PARAMETER;
245 
246 	*new_val = NULL;
247 	if (!memcmp (init_val->name, "_OS_", 4) && strlen(acpi_os_name)) {
248 		printk(KERN_INFO PREFIX "Overriding _OS definition to '%s'\n",
249 			acpi_os_name);
250 		*new_val = acpi_os_name;
251 	}
252 
253 	return AE_OK;
254 }
255 
256 acpi_status
257 acpi_os_table_override (struct acpi_table_header *existing_table,
258 			struct acpi_table_header **new_table)
259 {
260 	if (!existing_table || !new_table)
261 		return AE_BAD_PARAMETER;
262 
263 #ifdef CONFIG_ACPI_CUSTOM_DSDT
264 	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
265 		*new_table = (struct acpi_table_header*)AmlCode;
266 	else
267 		*new_table = NULL;
268 #else
269 	*new_table = NULL;
270 #endif
271 	return AE_OK;
272 }
273 
274 static irqreturn_t
275 acpi_irq(int irq, void *dev_id, struct pt_regs *regs)
276 {
277 	return (*acpi_irq_handler)(acpi_irq_context) ? IRQ_HANDLED : IRQ_NONE;
278 }
279 
280 acpi_status
281 acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler, void *context)
282 {
283 	unsigned int irq;
284 
285 	/*
286 	 * Ignore the GSI from the core, and use the value in our copy of the
287 	 * FADT. It may not be the same if an interrupt source override exists
288 	 * for the SCI.
289 	 */
290 	gsi = acpi_fadt.sci_int;
291 	if (acpi_gsi_to_irq(gsi, &irq) < 0) {
292 		printk(KERN_ERR PREFIX "SCI (ACPI GSI %d) not registered\n",
293 		       gsi);
294 		return AE_OK;
295 	}
296 
297 	acpi_irq_handler = handler;
298 	acpi_irq_context = context;
299 	if (request_irq(irq, acpi_irq, SA_SHIRQ, "acpi", acpi_irq)) {
300 		printk(KERN_ERR PREFIX "SCI (IRQ%d) allocation failed\n", irq);
301 		return AE_NOT_ACQUIRED;
302 	}
303 	acpi_irq_irq = irq;
304 
305 	return AE_OK;
306 }
307 
308 acpi_status
309 acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
310 {
311 	if (irq) {
312 		free_irq(irq, acpi_irq);
313 		acpi_irq_handler = NULL;
314 		acpi_irq_irq = 0;
315 	}
316 
317 	return AE_OK;
318 }
319 
320 /*
321  * Running in interpreter thread context, safe to sleep
322  */
323 
324 void
325 acpi_os_sleep(acpi_integer ms)
326 {
327 	current->state = TASK_INTERRUPTIBLE;
328 	schedule_timeout(((signed long) ms * HZ) / 1000);
329 }
330 EXPORT_SYMBOL(acpi_os_sleep);
331 
332 void
333 acpi_os_stall(u32 us)
334 {
335 	while (us) {
336 		u32 delay = 1000;
337 
338 		if (delay > us)
339 			delay = us;
340 		udelay(delay);
341 		touch_nmi_watchdog();
342 		us -= delay;
343 	}
344 }
345 EXPORT_SYMBOL(acpi_os_stall);
346 
347 /*
348  * Support ACPI 3.0 AML Timer operand
349  * Returns 64-bit free-running, monotonically increasing timer
350  * with 100ns granularity
351  */
352 u64
353 acpi_os_get_timer (void)
354 {
355 	static u64 t;
356 
357 #ifdef	CONFIG_HPET
358 	/* TBD: use HPET if available */
359 #endif
360 
361 #ifdef	CONFIG_X86_PM_TIMER
362 	/* TBD: default to PM timer if HPET was not available */
363 #endif
364 	if (!t)
365 		printk(KERN_ERR PREFIX "acpi_os_get_timer() TBD\n");
366 
367 	return ++t;
368 }
369 
370 acpi_status
371 acpi_os_read_port(
372 	acpi_io_address	port,
373 	u32		*value,
374 	u32		width)
375 {
376 	u32 dummy;
377 
378 	if (!value)
379 		value = &dummy;
380 
381 	switch (width)
382 	{
383 	case 8:
384 		*(u8*)  value = inb(port);
385 		break;
386 	case 16:
387 		*(u16*) value = inw(port);
388 		break;
389 	case 32:
390 		*(u32*) value = inl(port);
391 		break;
392 	default:
393 		BUG();
394 	}
395 
396 	return AE_OK;
397 }
398 EXPORT_SYMBOL(acpi_os_read_port);
399 
400 acpi_status
401 acpi_os_write_port(
402 	acpi_io_address	port,
403 	u32		value,
404 	u32		width)
405 {
406 	switch (width)
407 	{
408 	case 8:
409 		outb(value, port);
410 		break;
411 	case 16:
412 		outw(value, port);
413 		break;
414 	case 32:
415 		outl(value, port);
416 		break;
417 	default:
418 		BUG();
419 	}
420 
421 	return AE_OK;
422 }
423 EXPORT_SYMBOL(acpi_os_write_port);
424 
425 acpi_status
426 acpi_os_read_memory(
427 	acpi_physical_address	phys_addr,
428 	u32			*value,
429 	u32			width)
430 {
431 	u32			dummy;
432 	void __iomem		*virt_addr;
433 	int			iomem = 0;
434 
435 	if (efi_enabled) {
436 		if (EFI_MEMORY_WB & efi_mem_attributes(phys_addr)) {
437 			/* HACK ALERT! We can use readb/w/l on real memory too.. */
438 			virt_addr = (void __iomem *) phys_to_virt(phys_addr);
439 		} else {
440 			iomem = 1;
441 			virt_addr = ioremap(phys_addr, width);
442 		}
443 	} else
444 		virt_addr = (void __iomem *) phys_to_virt(phys_addr);
445 	if (!value)
446 		value = &dummy;
447 
448 	switch (width) {
449 	case 8:
450 		*(u8*) value = readb(virt_addr);
451 		break;
452 	case 16:
453 		*(u16*) value = readw(virt_addr);
454 		break;
455 	case 32:
456 		*(u32*) value = readl(virt_addr);
457 		break;
458 	default:
459 		BUG();
460 	}
461 
462 	if (efi_enabled) {
463 		if (iomem)
464 			iounmap(virt_addr);
465 	}
466 
467 	return AE_OK;
468 }
469 
470 acpi_status
471 acpi_os_write_memory(
472 	acpi_physical_address	phys_addr,
473 	u32			value,
474 	u32			width)
475 {
476 	void __iomem		*virt_addr;
477 	int			iomem = 0;
478 
479 	if (efi_enabled) {
480 		if (EFI_MEMORY_WB & efi_mem_attributes(phys_addr)) {
481 			/* HACK ALERT! We can use writeb/w/l on real memory too */
482 			virt_addr = (void __iomem *) phys_to_virt(phys_addr);
483 		} else {
484 			iomem = 1;
485 			virt_addr = ioremap(phys_addr, width);
486 		}
487 	} else
488 		virt_addr = (void __iomem *) phys_to_virt(phys_addr);
489 
490 	switch (width) {
491 	case 8:
492 		writeb(value, virt_addr);
493 		break;
494 	case 16:
495 		writew(value, virt_addr);
496 		break;
497 	case 32:
498 		writel(value, virt_addr);
499 		break;
500 	default:
501 		BUG();
502 	}
503 
504 	if (iomem)
505 		iounmap(virt_addr);
506 
507 	return AE_OK;
508 }
509 
510 #ifdef CONFIG_ACPI_PCI
511 
512 acpi_status
513 acpi_os_read_pci_configuration (struct acpi_pci_id *pci_id, u32 reg, void *value, u32 width)
514 {
515 	int result, size;
516 
517 	if (!value)
518 		return AE_BAD_PARAMETER;
519 
520 	switch (width) {
521 	case 8:
522 		size = 1;
523 		break;
524 	case 16:
525 		size = 2;
526 		break;
527 	case 32:
528 		size = 4;
529 		break;
530 	default:
531 		return AE_ERROR;
532 	}
533 
534 	BUG_ON(!raw_pci_ops);
535 
536 	result = raw_pci_ops->read(pci_id->segment, pci_id->bus,
537 				PCI_DEVFN(pci_id->device, pci_id->function),
538 				reg, size, value);
539 
540 	return (result ? AE_ERROR : AE_OK);
541 }
542 EXPORT_SYMBOL(acpi_os_read_pci_configuration);
543 
544 acpi_status
545 acpi_os_write_pci_configuration (struct acpi_pci_id *pci_id, u32 reg, acpi_integer value, u32 width)
546 {
547 	int result, size;
548 
549 	switch (width) {
550 	case 8:
551 		size = 1;
552 		break;
553 	case 16:
554 		size = 2;
555 		break;
556 	case 32:
557 		size = 4;
558 		break;
559 	default:
560 		return AE_ERROR;
561 	}
562 
563 	BUG_ON(!raw_pci_ops);
564 
565 	result = raw_pci_ops->write(pci_id->segment, pci_id->bus,
566 				PCI_DEVFN(pci_id->device, pci_id->function),
567 				reg, size, value);
568 
569 	return (result ? AE_ERROR : AE_OK);
570 }
571 
572 /* TODO: Change code to take advantage of driver model more */
573 static void
574 acpi_os_derive_pci_id_2 (
575 	acpi_handle		rhandle,        /* upper bound  */
576 	acpi_handle		chandle,        /* current node */
577 	struct acpi_pci_id	**id,
578 	int			*is_bridge,
579 	u8			*bus_number)
580 {
581 	acpi_handle		handle;
582 	struct acpi_pci_id	*pci_id = *id;
583 	acpi_status		status;
584 	unsigned long		temp;
585 	acpi_object_type	type;
586 	u8			tu8;
587 
588 	acpi_get_parent(chandle, &handle);
589 	if (handle != rhandle) {
590 		acpi_os_derive_pci_id_2(rhandle, handle, &pci_id, is_bridge, bus_number);
591 
592 		status = acpi_get_type(handle, &type);
593 		if ( (ACPI_FAILURE(status)) || (type != ACPI_TYPE_DEVICE) )
594 			return;
595 
596 		status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &temp);
597 		if (ACPI_SUCCESS(status)) {
598 			pci_id->device  = ACPI_HIWORD (ACPI_LODWORD (temp));
599 			pci_id->function = ACPI_LOWORD (ACPI_LODWORD (temp));
600 
601 			if (*is_bridge)
602 				pci_id->bus = *bus_number;
603 
604 			/* any nicer way to get bus number of bridge ? */
605 			status = acpi_os_read_pci_configuration(pci_id, 0x0e, &tu8, 8);
606 			if (ACPI_SUCCESS(status) &&
607 			    ((tu8 & 0x7f) == 1 || (tu8 & 0x7f) == 2)) {
608 				status = acpi_os_read_pci_configuration(pci_id, 0x18, &tu8, 8);
609 				if (!ACPI_SUCCESS(status)) {
610 					/* Certainly broken...  FIX ME */
611 					return;
612 				}
613 				*is_bridge = 1;
614 				pci_id->bus = tu8;
615 				status = acpi_os_read_pci_configuration(pci_id, 0x19, &tu8, 8);
616 				if (ACPI_SUCCESS(status)) {
617 					*bus_number = tu8;
618 				}
619 			} else
620 				*is_bridge = 0;
621 		}
622 	}
623 }
624 
625 void
626 acpi_os_derive_pci_id (
627 	acpi_handle		rhandle,        /* upper bound  */
628 	acpi_handle		chandle,        /* current node */
629 	struct acpi_pci_id	**id)
630 {
631 	int is_bridge = 1;
632 	u8 bus_number = (*id)->bus;
633 
634 	acpi_os_derive_pci_id_2(rhandle, chandle, id, &is_bridge, &bus_number);
635 }
636 
637 #else /*!CONFIG_ACPI_PCI*/
638 
639 acpi_status
640 acpi_os_write_pci_configuration (
641 	struct acpi_pci_id	*pci_id,
642 	u32			reg,
643 	acpi_integer		value,
644 	u32			width)
645 {
646 	return AE_SUPPORT;
647 }
648 
649 acpi_status
650 acpi_os_read_pci_configuration (
651 	struct acpi_pci_id	*pci_id,
652 	u32			reg,
653 	void			*value,
654 	u32			width)
655 {
656 	return AE_SUPPORT;
657 }
658 
659 void
660 acpi_os_derive_pci_id (
661 	acpi_handle		rhandle,        /* upper bound  */
662 	acpi_handle		chandle,        /* current node */
663 	struct acpi_pci_id	**id)
664 {
665 }
666 
667 #endif /*CONFIG_ACPI_PCI*/
668 
669 static void
670 acpi_os_execute_deferred (
671 	void *context)
672 {
673 	struct acpi_os_dpc	*dpc = NULL;
674 
675 	ACPI_FUNCTION_TRACE ("os_execute_deferred");
676 
677 	dpc = (struct acpi_os_dpc *) context;
678 	if (!dpc) {
679 		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Invalid (NULL) context.\n"));
680 		return_VOID;
681 	}
682 
683 	dpc->function(dpc->context);
684 
685 	kfree(dpc);
686 
687 	return_VOID;
688 }
689 
690 acpi_status
691 acpi_os_queue_for_execution(
692 	u32			priority,
693 	acpi_osd_exec_callback	function,
694 	void			*context)
695 {
696 	acpi_status 		status = AE_OK;
697 	struct acpi_os_dpc	*dpc;
698 	struct work_struct	*task;
699 
700 	ACPI_FUNCTION_TRACE ("os_queue_for_execution");
701 
702 	ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Scheduling function [%p(%p)] for deferred execution.\n", function, context));
703 
704 	if (!function)
705 		return_ACPI_STATUS (AE_BAD_PARAMETER);
706 
707 	/*
708 	 * Allocate/initialize DPC structure.  Note that this memory will be
709 	 * freed by the callee.  The kernel handles the tq_struct list  in a
710 	 * way that allows us to also free its memory inside the callee.
711 	 * Because we may want to schedule several tasks with different
712 	 * parameters we can't use the approach some kernel code uses of
713 	 * having a static tq_struct.
714 	 * We can save time and code by allocating the DPC and tq_structs
715 	 * from the same memory.
716 	 */
717 
718 	dpc = kmalloc(sizeof(struct acpi_os_dpc)+sizeof(struct work_struct), GFP_ATOMIC);
719 	if (!dpc)
720 		return_ACPI_STATUS (AE_NO_MEMORY);
721 
722 	dpc->function = function;
723 	dpc->context = context;
724 
725 	task = (void *)(dpc+1);
726 	INIT_WORK(task, acpi_os_execute_deferred, (void*)dpc);
727 
728 	if (!queue_work(kacpid_wq, task)) {
729 		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Call to queue_work() failed.\n"));
730 		kfree(dpc);
731 		status = AE_ERROR;
732 	}
733 
734 	return_ACPI_STATUS (status);
735 }
736 EXPORT_SYMBOL(acpi_os_queue_for_execution);
737 
738 void
739 acpi_os_wait_events_complete(
740 	void *context)
741 {
742 	flush_workqueue(kacpid_wq);
743 }
744 EXPORT_SYMBOL(acpi_os_wait_events_complete);
745 
746 /*
747  * Allocate the memory for a spinlock and initialize it.
748  */
749 acpi_status
750 acpi_os_create_lock (
751 	acpi_handle	*out_handle)
752 {
753 	spinlock_t *lock_ptr;
754 
755 	ACPI_FUNCTION_TRACE ("os_create_lock");
756 
757 	lock_ptr = acpi_os_allocate(sizeof(spinlock_t));
758 
759 	spin_lock_init(lock_ptr);
760 
761 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Creating spinlock[%p].\n", lock_ptr));
762 
763 	*out_handle = lock_ptr;
764 
765 	return_ACPI_STATUS (AE_OK);
766 }
767 
768 
769 /*
770  * Deallocate the memory for a spinlock.
771  */
772 void
773 acpi_os_delete_lock (
774 	acpi_handle	handle)
775 {
776 	ACPI_FUNCTION_TRACE ("os_create_lock");
777 
778 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Deleting spinlock[%p].\n", handle));
779 
780 	acpi_os_free(handle);
781 
782 	return_VOID;
783 }
784 
785 /*
786  * Acquire a spinlock.
787  *
788  * handle is a pointer to the spinlock_t.
789  * flags is *not* the result of save_flags - it is an ACPI-specific flag variable
790  *   that indicates whether we are at interrupt level.
791  */
792 void
793 acpi_os_acquire_lock (
794 	acpi_handle	handle,
795 	u32		flags)
796 {
797 	ACPI_FUNCTION_TRACE ("os_acquire_lock");
798 
799 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Acquiring spinlock[%p] from %s level\n", handle,
800 		((flags & ACPI_NOT_ISR) ? "non-interrupt" : "interrupt")));
801 
802 	if (flags & ACPI_NOT_ISR)
803 		ACPI_DISABLE_IRQS();
804 
805 	spin_lock((spinlock_t *)handle);
806 
807 	return_VOID;
808 }
809 
810 
811 /*
812  * Release a spinlock. See above.
813  */
814 void
815 acpi_os_release_lock (
816 	acpi_handle	handle,
817 	u32		flags)
818 {
819 	ACPI_FUNCTION_TRACE ("os_release_lock");
820 
821 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Releasing spinlock[%p] from %s level\n", handle,
822 		((flags & ACPI_NOT_ISR) ? "non-interrupt" : "interrupt")));
823 
824 	spin_unlock((spinlock_t *)handle);
825 
826 	if (flags & ACPI_NOT_ISR)
827 		ACPI_ENABLE_IRQS();
828 
829 	return_VOID;
830 }
831 
832 
833 acpi_status
834 acpi_os_create_semaphore(
835 	u32		max_units,
836 	u32		initial_units,
837 	acpi_handle	*handle)
838 {
839 	struct semaphore	*sem = NULL;
840 
841 	ACPI_FUNCTION_TRACE ("os_create_semaphore");
842 
843 	sem = acpi_os_allocate(sizeof(struct semaphore));
844 	if (!sem)
845 		return_ACPI_STATUS (AE_NO_MEMORY);
846 	memset(sem, 0, sizeof(struct semaphore));
847 
848 	sema_init(sem, initial_units);
849 
850 	*handle = (acpi_handle*)sem;
851 
852 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Creating semaphore[%p|%d].\n", *handle, initial_units));
853 
854 	return_ACPI_STATUS (AE_OK);
855 }
856 EXPORT_SYMBOL(acpi_os_create_semaphore);
857 
858 
859 /*
860  * TODO: A better way to delete semaphores?  Linux doesn't have a
861  * 'delete_semaphore()' function -- may result in an invalid
862  * pointer dereference for non-synchronized consumers.	Should
863  * we at least check for blocked threads and signal/cancel them?
864  */
865 
866 acpi_status
867 acpi_os_delete_semaphore(
868 	acpi_handle	handle)
869 {
870 	struct semaphore *sem = (struct semaphore*) handle;
871 
872 	ACPI_FUNCTION_TRACE ("os_delete_semaphore");
873 
874 	if (!sem)
875 		return_ACPI_STATUS (AE_BAD_PARAMETER);
876 
877 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Deleting semaphore[%p].\n", handle));
878 
879 	acpi_os_free(sem); sem =  NULL;
880 
881 	return_ACPI_STATUS (AE_OK);
882 }
883 EXPORT_SYMBOL(acpi_os_delete_semaphore);
884 
885 
886 /*
887  * TODO: The kernel doesn't have a 'down_timeout' function -- had to
888  * improvise.  The process is to sleep for one scheduler quantum
889  * until the semaphore becomes available.  Downside is that this
890  * may result in starvation for timeout-based waits when there's
891  * lots of semaphore activity.
892  *
893  * TODO: Support for units > 1?
894  */
895 acpi_status
896 acpi_os_wait_semaphore(
897 	acpi_handle		handle,
898 	u32			units,
899 	u16			timeout)
900 {
901 	acpi_status		status = AE_OK;
902 	struct semaphore	*sem = (struct semaphore*)handle;
903 	int			ret = 0;
904 
905 	ACPI_FUNCTION_TRACE ("os_wait_semaphore");
906 
907 	if (!sem || (units < 1))
908 		return_ACPI_STATUS (AE_BAD_PARAMETER);
909 
910 	if (units > 1)
911 		return_ACPI_STATUS (AE_SUPPORT);
912 
913 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Waiting for semaphore[%p|%d|%d]\n", handle, units, timeout));
914 
915 	if (in_atomic())
916 		timeout = 0;
917 
918 	switch (timeout)
919 	{
920 		/*
921 		 * No Wait:
922 		 * --------
923 		 * A zero timeout value indicates that we shouldn't wait - just
924 		 * acquire the semaphore if available otherwise return AE_TIME
925 		 * (a.k.a. 'would block').
926 		 */
927 		case 0:
928 		if(down_trylock(sem))
929 			status = AE_TIME;
930 		break;
931 
932 		/*
933 		 * Wait Indefinitely:
934 		 * ------------------
935 		 */
936 		case ACPI_WAIT_FOREVER:
937 		down(sem);
938 		break;
939 
940 		/*
941 		 * Wait w/ Timeout:
942 		 * ----------------
943 		 */
944 		default:
945 		// TODO: A better timeout algorithm?
946 		{
947 			int i = 0;
948 			static const int quantum_ms = 1000/HZ;
949 
950 			ret = down_trylock(sem);
951 			for (i = timeout; (i > 0 && ret < 0); i -= quantum_ms) {
952 				current->state = TASK_INTERRUPTIBLE;
953 				schedule_timeout(1);
954 				ret = down_trylock(sem);
955 			}
956 
957 			if (ret != 0)
958 				status = AE_TIME;
959 		}
960 		break;
961 	}
962 
963 	if (ACPI_FAILURE(status)) {
964 		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Failed to acquire semaphore[%p|%d|%d], %s\n",
965 			handle, units, timeout, acpi_format_exception(status)));
966 	}
967 	else {
968 		ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Acquired semaphore[%p|%d|%d]\n", handle, units, timeout));
969 	}
970 
971 	return_ACPI_STATUS (status);
972 }
973 EXPORT_SYMBOL(acpi_os_wait_semaphore);
974 
975 
976 /*
977  * TODO: Support for units > 1?
978  */
979 acpi_status
980 acpi_os_signal_semaphore(
981     acpi_handle 	    handle,
982     u32 		    units)
983 {
984 	struct semaphore *sem = (struct semaphore *) handle;
985 
986 	ACPI_FUNCTION_TRACE ("os_signal_semaphore");
987 
988 	if (!sem || (units < 1))
989 		return_ACPI_STATUS (AE_BAD_PARAMETER);
990 
991 	if (units > 1)
992 		return_ACPI_STATUS (AE_SUPPORT);
993 
994 	ACPI_DEBUG_PRINT ((ACPI_DB_MUTEX, "Signaling semaphore[%p|%d]\n", handle, units));
995 
996 	up(sem);
997 
998 	return_ACPI_STATUS (AE_OK);
999 }
1000 EXPORT_SYMBOL(acpi_os_signal_semaphore);
1001 
1002 #ifdef ACPI_FUTURE_USAGE
1003 u32
1004 acpi_os_get_line(char *buffer)
1005 {
1006 
1007 #ifdef ENABLE_DEBUGGER
1008 	if (acpi_in_debugger) {
1009 		u32 chars;
1010 
1011 		kdb_read(buffer, sizeof(line_buf));
1012 
1013 		/* remove the CR kdb includes */
1014 		chars = strlen(buffer) - 1;
1015 		buffer[chars] = '\0';
1016 	}
1017 #endif
1018 
1019 	return 0;
1020 }
1021 #endif  /*  ACPI_FUTURE_USAGE  */
1022 
1023 /* Assumes no unreadable holes inbetween */
1024 u8
1025 acpi_os_readable(void *ptr, acpi_size len)
1026 {
1027 #if defined(__i386__) || defined(__x86_64__)
1028 	char tmp;
1029 	return !__get_user(tmp, (char __user *)ptr) && !__get_user(tmp, (char __user *)ptr + len - 1);
1030 #endif
1031 	return 1;
1032 }
1033 
1034 #ifdef ACPI_FUTURE_USAGE
1035 u8
1036 acpi_os_writable(void *ptr, acpi_size len)
1037 {
1038 	/* could do dummy write (racy) or a kernel page table lookup.
1039 	   The later may be difficult at early boot when kmap doesn't work yet. */
1040 	return 1;
1041 }
1042 #endif
1043 
1044 u32
1045 acpi_os_get_thread_id (void)
1046 {
1047 	if (!in_atomic())
1048 		return current->pid;
1049 
1050 	return 0;
1051 }
1052 
1053 acpi_status
1054 acpi_os_signal (
1055     u32		function,
1056     void	*info)
1057 {
1058 	switch (function)
1059 	{
1060 	case ACPI_SIGNAL_FATAL:
1061 		printk(KERN_ERR PREFIX "Fatal opcode executed\n");
1062 		break;
1063 	case ACPI_SIGNAL_BREAKPOINT:
1064 		/*
1065 		 * AML Breakpoint
1066 		 * ACPI spec. says to treat it as a NOP unless
1067 		 * you are debugging.  So if/when we integrate
1068 		 * AML debugger into the kernel debugger its
1069 		 * hook will go here.  But until then it is
1070 		 * not useful to print anything on breakpoints.
1071 		 */
1072 		break;
1073 	default:
1074 		break;
1075 	}
1076 
1077 	return AE_OK;
1078 }
1079 EXPORT_SYMBOL(acpi_os_signal);
1080 
1081 static int __init
1082 acpi_os_name_setup(char *str)
1083 {
1084 	char *p = acpi_os_name;
1085 	int count = ACPI_MAX_OVERRIDE_LEN-1;
1086 
1087 	if (!str || !*str)
1088 		return 0;
1089 
1090 	for (; count-- && str && *str; str++) {
1091 		if (isalnum(*str) || *str == ' ' || *str == ':')
1092 			*p++ = *str;
1093 		else if (*str == '\'' || *str == '"')
1094 			continue;
1095 		else
1096 			break;
1097 	}
1098 	*p = 0;
1099 
1100 	return 1;
1101 
1102 }
1103 
1104 __setup("acpi_os_name=", acpi_os_name_setup);
1105 
1106 /*
1107  * _OSI control
1108  * empty string disables _OSI
1109  * TBD additional string adds to _OSI
1110  */
1111 static int __init
1112 acpi_osi_setup(char *str)
1113 {
1114 	if (str == NULL || *str == '\0') {
1115 		printk(KERN_INFO PREFIX "_OSI method disabled\n");
1116 		acpi_gbl_create_osi_method = FALSE;
1117 	} else
1118 	{
1119 		/* TBD */
1120 		printk(KERN_ERR PREFIX "_OSI additional string ignored -- %s\n", str);
1121 	}
1122 
1123 	return 1;
1124 }
1125 
1126 __setup("acpi_osi=", acpi_osi_setup);
1127 
1128 /* enable serialization to combat AE_ALREADY_EXISTS errors */
1129 static int __init
1130 acpi_serialize_setup(char *str)
1131 {
1132 	printk(KERN_INFO PREFIX "serialize enabled\n");
1133 
1134 	acpi_gbl_all_methods_serialized = TRUE;
1135 
1136 	return 1;
1137 }
1138 
1139 __setup("acpi_serialize", acpi_serialize_setup);
1140 
1141 /*
1142  * Wake and Run-Time GPES are expected to be separate.
1143  * We disable wake-GPEs at run-time to prevent spurious
1144  * interrupts.
1145  *
1146  * However, if a system exists that shares Wake and
1147  * Run-time events on the same GPE this flag is available
1148  * to tell Linux to keep the wake-time GPEs enabled at run-time.
1149  */
1150 static int __init
1151 acpi_wake_gpes_always_on_setup(char *str)
1152 {
1153 	printk(KERN_INFO PREFIX "wake GPEs not disabled\n");
1154 
1155 	acpi_gbl_leave_wake_gpes_disabled = FALSE;
1156 
1157 	return 1;
1158 }
1159 
1160 __setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
1161 
1162 int __init
1163 acpi_hotkey_setup(char *str)
1164 {
1165 	acpi_specific_hotkey_enabled = FALSE;
1166 	return 1;
1167 }
1168 
1169 __setup("acpi_generic_hotkey", acpi_hotkey_setup);
1170 
1171 /*
1172  * max_cstate is defined in the base kernel so modules can
1173  * change it w/o depending on the state of the processor module.
1174  */
1175 unsigned int max_cstate = ACPI_PROCESSOR_MAX_POWER;
1176 
1177 
1178 EXPORT_SYMBOL(max_cstate);
1179