xref: /linux/drivers/acpi/osl.c (revision 5e8d780d745c1619aba81fe7166c5a4b5cad2b84)
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
1215