xref: /linux/drivers/acpi/osl.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 != EFI_INVALID_TABLE_ADDR)
160 			addr->pointer.physical = efi.acpi20;
161 		else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
162 			addr->pointer.physical = efi.acpi;
163 		else {
164 			printk(KERN_ERR PREFIX
165 			       "System description tables not found\n");
166 			return AE_NOT_FOUND;
167 		}
168 	} else {
169 		if (ACPI_FAILURE(acpi_find_root_pointer(flags, addr))) {
170 			printk(KERN_ERR PREFIX
171 			       "System description tables not found\n");
172 			return AE_NOT_FOUND;
173 		}
174 	}
175 
176 	return AE_OK;
177 }
178 
179 acpi_status
180 acpi_os_map_memory(acpi_physical_address phys, acpi_size size,
181 		   void __iomem ** virt)
182 {
183 	if (phys > ULONG_MAX) {
184 		printk(KERN_ERR PREFIX "Cannot map memory that high\n");
185 		return AE_BAD_PARAMETER;
186 	}
187 	/*
188 	 * ioremap checks to ensure this is in reserved space
189 	 */
190 	*virt = ioremap((unsigned long)phys, size);
191 
192 	if (!*virt)
193 		return AE_NO_MEMORY;
194 
195 	return AE_OK;
196 }
197 EXPORT_SYMBOL_GPL(acpi_os_map_memory);
198 
199 void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
200 {
201 	iounmap(virt);
202 }
203 EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
204 
205 #ifdef ACPI_FUTURE_USAGE
206 acpi_status
207 acpi_os_get_physical_address(void *virt, acpi_physical_address * phys)
208 {
209 	if (!phys || !virt)
210 		return AE_BAD_PARAMETER;
211 
212 	*phys = virt_to_phys(virt);
213 
214 	return AE_OK;
215 }
216 #endif
217 
218 #define ACPI_MAX_OVERRIDE_LEN 100
219 
220 static char acpi_os_name[ACPI_MAX_OVERRIDE_LEN];
221 
222 acpi_status
223 acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
224 			    acpi_string * new_val)
225 {
226 	if (!init_val || !new_val)
227 		return AE_BAD_PARAMETER;
228 
229 	*new_val = NULL;
230 	if (!memcmp(init_val->name, "_OS_", 4) && strlen(acpi_os_name)) {
231 		printk(KERN_INFO PREFIX "Overriding _OS definition to '%s'\n",
232 		       acpi_os_name);
233 		*new_val = acpi_os_name;
234 	}
235 
236 	return AE_OK;
237 }
238 
239 acpi_status
240 acpi_os_table_override(struct acpi_table_header * existing_table,
241 		       struct acpi_table_header ** new_table)
242 {
243 	if (!existing_table || !new_table)
244 		return AE_BAD_PARAMETER;
245 
246 #ifdef CONFIG_ACPI_CUSTOM_DSDT
247 	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
248 		*new_table = (struct acpi_table_header *)AmlCode;
249 	else
250 		*new_table = NULL;
251 #else
252 	*new_table = NULL;
253 #endif
254 	return AE_OK;
255 }
256 
257 static irqreturn_t acpi_irq(int irq, void *dev_id, struct pt_regs *regs)
258 {
259 	return (*acpi_irq_handler) (acpi_irq_context) ? IRQ_HANDLED : IRQ_NONE;
260 }
261 
262 acpi_status
263 acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler,
264 				  void *context)
265 {
266 	unsigned int irq;
267 
268 	/*
269 	 * Ignore the GSI from the core, and use the value in our copy of the
270 	 * FADT. It may not be the same if an interrupt source override exists
271 	 * for the SCI.
272 	 */
273 	gsi = acpi_fadt.sci_int;
274 	if (acpi_gsi_to_irq(gsi, &irq) < 0) {
275 		printk(KERN_ERR PREFIX "SCI (ACPI GSI %d) not registered\n",
276 		       gsi);
277 		return AE_OK;
278 	}
279 
280 	acpi_irq_handler = handler;
281 	acpi_irq_context = context;
282 	if (request_irq(irq, acpi_irq, SA_SHIRQ, "acpi", acpi_irq)) {
283 		printk(KERN_ERR PREFIX "SCI (IRQ%d) allocation failed\n", irq);
284 		return AE_NOT_ACQUIRED;
285 	}
286 	acpi_irq_irq = irq;
287 
288 	return AE_OK;
289 }
290 
291 acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
292 {
293 	if (irq) {
294 		free_irq(irq, acpi_irq);
295 		acpi_irq_handler = NULL;
296 		acpi_irq_irq = 0;
297 	}
298 
299 	return AE_OK;
300 }
301 
302 /*
303  * Running in interpreter thread context, safe to sleep
304  */
305 
306 void acpi_os_sleep(acpi_integer ms)
307 {
308 	schedule_timeout_interruptible(msecs_to_jiffies(ms));
309 }
310 
311 EXPORT_SYMBOL(acpi_os_sleep);
312 
313 void acpi_os_stall(u32 us)
314 {
315 	while (us) {
316 		u32 delay = 1000;
317 
318 		if (delay > us)
319 			delay = us;
320 		udelay(delay);
321 		touch_nmi_watchdog();
322 		us -= delay;
323 	}
324 }
325 
326 EXPORT_SYMBOL(acpi_os_stall);
327 
328 /*
329  * Support ACPI 3.0 AML Timer operand
330  * Returns 64-bit free-running, monotonically increasing timer
331  * with 100ns granularity
332  */
333 u64 acpi_os_get_timer(void)
334 {
335 	static u64 t;
336 
337 #ifdef	CONFIG_HPET
338 	/* TBD: use HPET if available */
339 #endif
340 
341 #ifdef	CONFIG_X86_PM_TIMER
342 	/* TBD: default to PM timer if HPET was not available */
343 #endif
344 	if (!t)
345 		printk(KERN_ERR PREFIX "acpi_os_get_timer() TBD\n");
346 
347 	return ++t;
348 }
349 
350 acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width)
351 {
352 	u32 dummy;
353 
354 	if (!value)
355 		value = &dummy;
356 
357 	switch (width) {
358 	case 8:
359 		*(u8 *) value = inb(port);
360 		break;
361 	case 16:
362 		*(u16 *) value = inw(port);
363 		break;
364 	case 32:
365 		*(u32 *) value = inl(port);
366 		break;
367 	default:
368 		BUG();
369 	}
370 
371 	return AE_OK;
372 }
373 
374 EXPORT_SYMBOL(acpi_os_read_port);
375 
376 acpi_status acpi_os_write_port(acpi_io_address port, u32 value, u32 width)
377 {
378 	switch (width) {
379 	case 8:
380 		outb(value, port);
381 		break;
382 	case 16:
383 		outw(value, port);
384 		break;
385 	case 32:
386 		outl(value, port);
387 		break;
388 	default:
389 		BUG();
390 	}
391 
392 	return AE_OK;
393 }
394 
395 EXPORT_SYMBOL(acpi_os_write_port);
396 
397 acpi_status
398 acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width)
399 {
400 	u32 dummy;
401 	void __iomem *virt_addr;
402 
403 	virt_addr = ioremap(phys_addr, width);
404 	if (!value)
405 		value = &dummy;
406 
407 	switch (width) {
408 	case 8:
409 		*(u8 *) value = readb(virt_addr);
410 		break;
411 	case 16:
412 		*(u16 *) value = readw(virt_addr);
413 		break;
414 	case 32:
415 		*(u32 *) value = readl(virt_addr);
416 		break;
417 	default:
418 		BUG();
419 	}
420 
421 	iounmap(virt_addr);
422 
423 	return AE_OK;
424 }
425 
426 acpi_status
427 acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)
428 {
429 	void __iomem *virt_addr;
430 
431 	virt_addr = ioremap(phys_addr, width);
432 
433 	switch (width) {
434 	case 8:
435 		writeb(value, virt_addr);
436 		break;
437 	case 16:
438 		writew(value, virt_addr);
439 		break;
440 	case 32:
441 		writel(value, virt_addr);
442 		break;
443 	default:
444 		BUG();
445 	}
446 
447 	iounmap(virt_addr);
448 
449 	return AE_OK;
450 }
451 
452 acpi_status
453 acpi_os_read_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
454 			       void *value, u32 width)
455 {
456 	int result, size;
457 
458 	if (!value)
459 		return AE_BAD_PARAMETER;
460 
461 	switch (width) {
462 	case 8:
463 		size = 1;
464 		break;
465 	case 16:
466 		size = 2;
467 		break;
468 	case 32:
469 		size = 4;
470 		break;
471 	default:
472 		return AE_ERROR;
473 	}
474 
475 	BUG_ON(!raw_pci_ops);
476 
477 	result = raw_pci_ops->read(pci_id->segment, pci_id->bus,
478 				   PCI_DEVFN(pci_id->device, pci_id->function),
479 				   reg, size, value);
480 
481 	return (result ? AE_ERROR : AE_OK);
482 }
483 
484 EXPORT_SYMBOL(acpi_os_read_pci_configuration);
485 
486 acpi_status
487 acpi_os_write_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
488 				acpi_integer value, u32 width)
489 {
490 	int result, size;
491 
492 	switch (width) {
493 	case 8:
494 		size = 1;
495 		break;
496 	case 16:
497 		size = 2;
498 		break;
499 	case 32:
500 		size = 4;
501 		break;
502 	default:
503 		return AE_ERROR;
504 	}
505 
506 	BUG_ON(!raw_pci_ops);
507 
508 	result = raw_pci_ops->write(pci_id->segment, pci_id->bus,
509 				    PCI_DEVFN(pci_id->device, pci_id->function),
510 				    reg, size, value);
511 
512 	return (result ? AE_ERROR : AE_OK);
513 }
514 
515 /* TODO: Change code to take advantage of driver model more */
516 static void acpi_os_derive_pci_id_2(acpi_handle rhandle,	/* upper bound  */
517 				    acpi_handle chandle,	/* current node */
518 				    struct acpi_pci_id **id,
519 				    int *is_bridge, u8 * bus_number)
520 {
521 	acpi_handle handle;
522 	struct acpi_pci_id *pci_id = *id;
523 	acpi_status status;
524 	unsigned long temp;
525 	acpi_object_type type;
526 	u8 tu8;
527 
528 	acpi_get_parent(chandle, &handle);
529 	if (handle != rhandle) {
530 		acpi_os_derive_pci_id_2(rhandle, handle, &pci_id, is_bridge,
531 					bus_number);
532 
533 		status = acpi_get_type(handle, &type);
534 		if ((ACPI_FAILURE(status)) || (type != ACPI_TYPE_DEVICE))
535 			return;
536 
537 		status =
538 		    acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL,
539 					  &temp);
540 		if (ACPI_SUCCESS(status)) {
541 			pci_id->device = ACPI_HIWORD(ACPI_LODWORD(temp));
542 			pci_id->function = ACPI_LOWORD(ACPI_LODWORD(temp));
543 
544 			if (*is_bridge)
545 				pci_id->bus = *bus_number;
546 
547 			/* any nicer way to get bus number of bridge ? */
548 			status =
549 			    acpi_os_read_pci_configuration(pci_id, 0x0e, &tu8,
550 							   8);
551 			if (ACPI_SUCCESS(status)
552 			    && ((tu8 & 0x7f) == 1 || (tu8 & 0x7f) == 2)) {
553 				status =
554 				    acpi_os_read_pci_configuration(pci_id, 0x18,
555 								   &tu8, 8);
556 				if (!ACPI_SUCCESS(status)) {
557 					/* Certainly broken...  FIX ME */
558 					return;
559 				}
560 				*is_bridge = 1;
561 				pci_id->bus = tu8;
562 				status =
563 				    acpi_os_read_pci_configuration(pci_id, 0x19,
564 								   &tu8, 8);
565 				if (ACPI_SUCCESS(status)) {
566 					*bus_number = tu8;
567 				}
568 			} else
569 				*is_bridge = 0;
570 		}
571 	}
572 }
573 
574 void acpi_os_derive_pci_id(acpi_handle rhandle,	/* upper bound  */
575 			   acpi_handle chandle,	/* current node */
576 			   struct acpi_pci_id **id)
577 {
578 	int is_bridge = 1;
579 	u8 bus_number = (*id)->bus;
580 
581 	acpi_os_derive_pci_id_2(rhandle, chandle, id, &is_bridge, &bus_number);
582 }
583 
584 static void acpi_os_execute_deferred(void *context)
585 {
586 	struct acpi_os_dpc *dpc = NULL;
587 
588 	ACPI_FUNCTION_TRACE("os_execute_deferred");
589 
590 	dpc = (struct acpi_os_dpc *)context;
591 	if (!dpc) {
592 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) context.\n"));
593 		return_VOID;
594 	}
595 
596 	dpc->function(dpc->context);
597 
598 	kfree(dpc);
599 
600 	return_VOID;
601 }
602 
603 acpi_status
604 acpi_os_queue_for_execution(u32 priority,
605 			    acpi_osd_exec_callback function, void *context)
606 {
607 	acpi_status status = AE_OK;
608 	struct acpi_os_dpc *dpc;
609 	struct work_struct *task;
610 
611 	ACPI_FUNCTION_TRACE("os_queue_for_execution");
612 
613 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
614 			  "Scheduling function [%p(%p)] for deferred execution.\n",
615 			  function, context));
616 
617 	if (!function)
618 		return_ACPI_STATUS(AE_BAD_PARAMETER);
619 
620 	/*
621 	 * Allocate/initialize DPC structure.  Note that this memory will be
622 	 * freed by the callee.  The kernel handles the tq_struct list  in a
623 	 * way that allows us to also free its memory inside the callee.
624 	 * Because we may want to schedule several tasks with different
625 	 * parameters we can't use the approach some kernel code uses of
626 	 * having a static tq_struct.
627 	 * We can save time and code by allocating the DPC and tq_structs
628 	 * from the same memory.
629 	 */
630 
631 	dpc =
632 	    kmalloc(sizeof(struct acpi_os_dpc) + sizeof(struct work_struct),
633 		    GFP_ATOMIC);
634 	if (!dpc)
635 		return_ACPI_STATUS(AE_NO_MEMORY);
636 
637 	dpc->function = function;
638 	dpc->context = context;
639 
640 	task = (void *)(dpc + 1);
641 	INIT_WORK(task, acpi_os_execute_deferred, (void *)dpc);
642 
643 	if (!queue_work(kacpid_wq, task)) {
644 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
645 				  "Call to queue_work() failed.\n"));
646 		kfree(dpc);
647 		status = AE_ERROR;
648 	}
649 
650 	return_ACPI_STATUS(status);
651 }
652 
653 EXPORT_SYMBOL(acpi_os_queue_for_execution);
654 
655 void acpi_os_wait_events_complete(void *context)
656 {
657 	flush_workqueue(kacpid_wq);
658 }
659 
660 EXPORT_SYMBOL(acpi_os_wait_events_complete);
661 
662 /*
663  * Allocate the memory for a spinlock and initialize it.
664  */
665 acpi_status acpi_os_create_lock(acpi_handle * out_handle)
666 {
667 	spinlock_t *lock_ptr;
668 
669 	ACPI_FUNCTION_TRACE("os_create_lock");
670 
671 	lock_ptr = acpi_os_allocate(sizeof(spinlock_t));
672 
673 	spin_lock_init(lock_ptr);
674 
675 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating spinlock[%p].\n", lock_ptr));
676 
677 	*out_handle = lock_ptr;
678 
679 	return_ACPI_STATUS(AE_OK);
680 }
681 
682 /*
683  * Deallocate the memory for a spinlock.
684  */
685 void acpi_os_delete_lock(acpi_handle handle)
686 {
687 	ACPI_FUNCTION_TRACE("os_create_lock");
688 
689 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting spinlock[%p].\n", handle));
690 
691 	acpi_os_free(handle);
692 
693 	return_VOID;
694 }
695 
696 acpi_status
697 acpi_os_create_semaphore(u32 max_units, u32 initial_units, acpi_handle * handle)
698 {
699 	struct semaphore *sem = NULL;
700 
701 	ACPI_FUNCTION_TRACE("os_create_semaphore");
702 
703 	sem = acpi_os_allocate(sizeof(struct semaphore));
704 	if (!sem)
705 		return_ACPI_STATUS(AE_NO_MEMORY);
706 	memset(sem, 0, sizeof(struct semaphore));
707 
708 	sema_init(sem, initial_units);
709 
710 	*handle = (acpi_handle *) sem;
711 
712 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating semaphore[%p|%d].\n",
713 			  *handle, initial_units));
714 
715 	return_ACPI_STATUS(AE_OK);
716 }
717 
718 EXPORT_SYMBOL(acpi_os_create_semaphore);
719 
720 /*
721  * TODO: A better way to delete semaphores?  Linux doesn't have a
722  * 'delete_semaphore()' function -- may result in an invalid
723  * pointer dereference for non-synchronized consumers.	Should
724  * we at least check for blocked threads and signal/cancel them?
725  */
726 
727 acpi_status acpi_os_delete_semaphore(acpi_handle handle)
728 {
729 	struct semaphore *sem = (struct semaphore *)handle;
730 
731 	ACPI_FUNCTION_TRACE("os_delete_semaphore");
732 
733 	if (!sem)
734 		return_ACPI_STATUS(AE_BAD_PARAMETER);
735 
736 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting semaphore[%p].\n", handle));
737 
738 	acpi_os_free(sem);
739 	sem = NULL;
740 
741 	return_ACPI_STATUS(AE_OK);
742 }
743 
744 EXPORT_SYMBOL(acpi_os_delete_semaphore);
745 
746 /*
747  * TODO: The kernel doesn't have a 'down_timeout' function -- had to
748  * improvise.  The process is to sleep for one scheduler quantum
749  * until the semaphore becomes available.  Downside is that this
750  * may result in starvation for timeout-based waits when there's
751  * lots of semaphore activity.
752  *
753  * TODO: Support for units > 1?
754  */
755 acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
756 {
757 	acpi_status status = AE_OK;
758 	struct semaphore *sem = (struct semaphore *)handle;
759 	int ret = 0;
760 
761 	ACPI_FUNCTION_TRACE("os_wait_semaphore");
762 
763 	if (!sem || (units < 1))
764 		return_ACPI_STATUS(AE_BAD_PARAMETER);
765 
766 	if (units > 1)
767 		return_ACPI_STATUS(AE_SUPPORT);
768 
769 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Waiting for semaphore[%p|%d|%d]\n",
770 			  handle, units, timeout));
771 
772 	if (in_atomic())
773 		timeout = 0;
774 
775 	switch (timeout) {
776 		/*
777 		 * No Wait:
778 		 * --------
779 		 * A zero timeout value indicates that we shouldn't wait - just
780 		 * acquire the semaphore if available otherwise return AE_TIME
781 		 * (a.k.a. 'would block').
782 		 */
783 	case 0:
784 		if (down_trylock(sem))
785 			status = AE_TIME;
786 		break;
787 
788 		/*
789 		 * Wait Indefinitely:
790 		 * ------------------
791 		 */
792 	case ACPI_WAIT_FOREVER:
793 		down(sem);
794 		break;
795 
796 		/*
797 		 * Wait w/ Timeout:
798 		 * ----------------
799 		 */
800 	default:
801 		// TODO: A better timeout algorithm?
802 		{
803 			int i = 0;
804 			static const int quantum_ms = 1000 / HZ;
805 
806 			ret = down_trylock(sem);
807 			for (i = timeout; (i > 0 && ret != 0); i -= quantum_ms) {
808 				schedule_timeout_interruptible(1);
809 				ret = down_trylock(sem);
810 			}
811 
812 			if (ret != 0)
813 				status = AE_TIME;
814 		}
815 		break;
816 	}
817 
818 	if (ACPI_FAILURE(status)) {
819 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
820 				  "Failed to acquire semaphore[%p|%d|%d], %s\n",
821 				  handle, units, timeout,
822 				  acpi_format_exception(status)));
823 	} else {
824 		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
825 				  "Acquired semaphore[%p|%d|%d]\n", handle,
826 				  units, timeout));
827 	}
828 
829 	return_ACPI_STATUS(status);
830 }
831 
832 EXPORT_SYMBOL(acpi_os_wait_semaphore);
833 
834 /*
835  * TODO: Support for units > 1?
836  */
837 acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
838 {
839 	struct semaphore *sem = (struct semaphore *)handle;
840 
841 	ACPI_FUNCTION_TRACE("os_signal_semaphore");
842 
843 	if (!sem || (units < 1))
844 		return_ACPI_STATUS(AE_BAD_PARAMETER);
845 
846 	if (units > 1)
847 		return_ACPI_STATUS(AE_SUPPORT);
848 
849 	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Signaling semaphore[%p|%d]\n", handle,
850 			  units));
851 
852 	up(sem);
853 
854 	return_ACPI_STATUS(AE_OK);
855 }
856 
857 EXPORT_SYMBOL(acpi_os_signal_semaphore);
858 
859 #ifdef ACPI_FUTURE_USAGE
860 u32 acpi_os_get_line(char *buffer)
861 {
862 
863 #ifdef ENABLE_DEBUGGER
864 	if (acpi_in_debugger) {
865 		u32 chars;
866 
867 		kdb_read(buffer, sizeof(line_buf));
868 
869 		/* remove the CR kdb includes */
870 		chars = strlen(buffer) - 1;
871 		buffer[chars] = '\0';
872 	}
873 #endif
874 
875 	return 0;
876 }
877 #endif				/*  ACPI_FUTURE_USAGE  */
878 
879 /* Assumes no unreadable holes inbetween */
880 u8 acpi_os_readable(void *ptr, acpi_size len)
881 {
882 #if defined(__i386__) || defined(__x86_64__)
883 	char tmp;
884 	return !__get_user(tmp, (char __user *)ptr)
885 	    && !__get_user(tmp, (char __user *)ptr + len - 1);
886 #endif
887 	return 1;
888 }
889 
890 #ifdef ACPI_FUTURE_USAGE
891 u8 acpi_os_writable(void *ptr, acpi_size len)
892 {
893 	/* could do dummy write (racy) or a kernel page table lookup.
894 	   The later may be difficult at early boot when kmap doesn't work yet. */
895 	return 1;
896 }
897 #endif
898 
899 u32 acpi_os_get_thread_id(void)
900 {
901 	if (!in_atomic())
902 		return current->pid;
903 
904 	return 0;
905 }
906 
907 acpi_status acpi_os_signal(u32 function, void *info)
908 {
909 	switch (function) {
910 	case ACPI_SIGNAL_FATAL:
911 		printk(KERN_ERR PREFIX "Fatal opcode executed\n");
912 		break;
913 	case ACPI_SIGNAL_BREAKPOINT:
914 		/*
915 		 * AML Breakpoint
916 		 * ACPI spec. says to treat it as a NOP unless
917 		 * you are debugging.  So if/when we integrate
918 		 * AML debugger into the kernel debugger its
919 		 * hook will go here.  But until then it is
920 		 * not useful to print anything on breakpoints.
921 		 */
922 		break;
923 	default:
924 		break;
925 	}
926 
927 	return AE_OK;
928 }
929 
930 EXPORT_SYMBOL(acpi_os_signal);
931 
932 static int __init acpi_os_name_setup(char *str)
933 {
934 	char *p = acpi_os_name;
935 	int count = ACPI_MAX_OVERRIDE_LEN - 1;
936 
937 	if (!str || !*str)
938 		return 0;
939 
940 	for (; count-- && str && *str; str++) {
941 		if (isalnum(*str) || *str == ' ' || *str == ':')
942 			*p++ = *str;
943 		else if (*str == '\'' || *str == '"')
944 			continue;
945 		else
946 			break;
947 	}
948 	*p = 0;
949 
950 	return 1;
951 
952 }
953 
954 __setup("acpi_os_name=", acpi_os_name_setup);
955 
956 /*
957  * _OSI control
958  * empty string disables _OSI
959  * TBD additional string adds to _OSI
960  */
961 static int __init acpi_osi_setup(char *str)
962 {
963 	if (str == NULL || *str == '\0') {
964 		printk(KERN_INFO PREFIX "_OSI method disabled\n");
965 		acpi_gbl_create_osi_method = FALSE;
966 	} else {
967 		/* TBD */
968 		printk(KERN_ERR PREFIX "_OSI additional string ignored -- %s\n",
969 		       str);
970 	}
971 
972 	return 1;
973 }
974 
975 __setup("acpi_osi=", acpi_osi_setup);
976 
977 /* enable serialization to combat AE_ALREADY_EXISTS errors */
978 static int __init acpi_serialize_setup(char *str)
979 {
980 	printk(KERN_INFO PREFIX "serialize enabled\n");
981 
982 	acpi_gbl_all_methods_serialized = TRUE;
983 
984 	return 1;
985 }
986 
987 __setup("acpi_serialize", acpi_serialize_setup);
988 
989 /*
990  * Wake and Run-Time GPES are expected to be separate.
991  * We disable wake-GPEs at run-time to prevent spurious
992  * interrupts.
993  *
994  * However, if a system exists that shares Wake and
995  * Run-time events on the same GPE this flag is available
996  * to tell Linux to keep the wake-time GPEs enabled at run-time.
997  */
998 static int __init acpi_wake_gpes_always_on_setup(char *str)
999 {
1000 	printk(KERN_INFO PREFIX "wake GPEs not disabled\n");
1001 
1002 	acpi_gbl_leave_wake_gpes_disabled = FALSE;
1003 
1004 	return 1;
1005 }
1006 
1007 __setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
1008 
1009 static int __init acpi_hotkey_setup(char *str)
1010 {
1011 	acpi_specific_hotkey_enabled = FALSE;
1012 	return 1;
1013 }
1014 
1015 __setup("acpi_generic_hotkey", acpi_hotkey_setup);
1016 
1017 /*
1018  * max_cstate is defined in the base kernel so modules can
1019  * change it w/o depending on the state of the processor module.
1020  */
1021 unsigned int max_cstate = ACPI_PROCESSOR_MAX_POWER;
1022 
1023 EXPORT_SYMBOL(max_cstate);
1024 
1025 /*
1026  * Acquire a spinlock.
1027  *
1028  * handle is a pointer to the spinlock_t.
1029  */
1030 
1031 acpi_cpu_flags acpi_os_acquire_lock(acpi_handle handle)
1032 {
1033 	acpi_cpu_flags flags;
1034 	spin_lock_irqsave((spinlock_t *) handle, flags);
1035 	return flags;
1036 }
1037 
1038 /*
1039  * Release a spinlock. See above.
1040  */
1041 
1042 void acpi_os_release_lock(acpi_handle handle, acpi_cpu_flags flags)
1043 {
1044 	spin_unlock_irqrestore((spinlock_t *) handle, flags);
1045 }
1046 
1047 #ifndef ACPI_USE_LOCAL_CACHE
1048 
1049 /*******************************************************************************
1050  *
1051  * FUNCTION:    acpi_os_create_cache
1052  *
1053  * PARAMETERS:  CacheName       - Ascii name for the cache
1054  *              ObjectSize      - Size of each cached object
1055  *              MaxDepth        - Maximum depth of the cache (in objects)
1056  *              ReturnCache     - Where the new cache object is returned
1057  *
1058  * RETURN:      Status
1059  *
1060  * DESCRIPTION: Create a cache object
1061  *
1062  ******************************************************************************/
1063 
1064 acpi_status
1065 acpi_os_create_cache(char *name, u16 size, u16 depth, acpi_cache_t ** cache)
1066 {
1067 	*cache = kmem_cache_create(name, size, 0, 0, NULL, NULL);
1068 	return AE_OK;
1069 }
1070 
1071 /*******************************************************************************
1072  *
1073  * FUNCTION:    acpi_os_purge_cache
1074  *
1075  * PARAMETERS:  Cache           - Handle to cache object
1076  *
1077  * RETURN:      Status
1078  *
1079  * DESCRIPTION: Free all objects within the requested cache.
1080  *
1081  ******************************************************************************/
1082 
1083 acpi_status acpi_os_purge_cache(acpi_cache_t * cache)
1084 {
1085 	(void)kmem_cache_shrink(cache);
1086 	return (AE_OK);
1087 }
1088 
1089 /*******************************************************************************
1090  *
1091  * FUNCTION:    acpi_os_delete_cache
1092  *
1093  * PARAMETERS:  Cache           - Handle to cache object
1094  *
1095  * RETURN:      Status
1096  *
1097  * DESCRIPTION: Free all objects within the requested cache and delete the
1098  *              cache object.
1099  *
1100  ******************************************************************************/
1101 
1102 acpi_status acpi_os_delete_cache(acpi_cache_t * cache)
1103 {
1104 	(void)kmem_cache_destroy(cache);
1105 	return (AE_OK);
1106 }
1107 
1108 /*******************************************************************************
1109  *
1110  * FUNCTION:    acpi_os_release_object
1111  *
1112  * PARAMETERS:  Cache       - Handle to cache object
1113  *              Object      - The object to be released
1114  *
1115  * RETURN:      None
1116  *
1117  * DESCRIPTION: Release an object to the specified cache.  If cache is full,
1118  *              the object is deleted.
1119  *
1120  ******************************************************************************/
1121 
1122 acpi_status acpi_os_release_object(acpi_cache_t * cache, void *object)
1123 {
1124 	kmem_cache_free(cache, object);
1125 	return (AE_OK);
1126 }
1127 
1128 /*******************************************************************************
1129  *
1130  * FUNCTION:    acpi_os_acquire_object
1131  *
1132  * PARAMETERS:  Cache           - Handle to cache object
1133  *              ReturnObject    - Where the object is returned
1134  *
1135  * RETURN:      Status
1136  *
1137  * DESCRIPTION: Get an object from the specified cache.  If cache is empty,
1138  *              the object is allocated.
1139  *
1140  ******************************************************************************/
1141 
1142 void *acpi_os_acquire_object(acpi_cache_t * cache)
1143 {
1144 	void *object = kmem_cache_alloc(cache, GFP_KERNEL);
1145 	WARN_ON(!object);
1146 	return object;
1147 }
1148 
1149 #endif
1150