1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
4  *
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 #define pr_fmt(fmt) "ACPI: utils: " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/hardirq.h>
17 #include <linux/acpi.h>
18 #include <linux/dynamic_debug.h>
19 
20 #include "internal.h"
21 #include "sleep.h"
22 
23 /* --------------------------------------------------------------------------
24                             Object Evaluation Helpers
25    -------------------------------------------------------------------------- */
acpi_util_eval_error(acpi_handle h,acpi_string p,acpi_status s)26 static void acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
27 {
28 	acpi_handle_debug(h, "Evaluate [%s]: %s\n", p, acpi_format_exception(s));
29 }
30 
31 acpi_status
acpi_extract_package(union acpi_object * package,struct acpi_buffer * format,struct acpi_buffer * buffer)32 acpi_extract_package(union acpi_object *package,
33 		     struct acpi_buffer *format, struct acpi_buffer *buffer)
34 {
35 	u32 size_required = 0;
36 	u32 tail_offset = 0;
37 	char *format_string = NULL;
38 	u32 format_count = 0;
39 	u32 i = 0;
40 	u8 *head = NULL;
41 	u8 *tail = NULL;
42 
43 
44 	if (!package || (package->type != ACPI_TYPE_PACKAGE)
45 	    || (package->package.count < 1)) {
46 		pr_debug("Invalid package argument\n");
47 		return AE_BAD_PARAMETER;
48 	}
49 
50 	if (!format || !format->pointer || (format->length < 1)) {
51 		pr_debug("Invalid format argument\n");
52 		return AE_BAD_PARAMETER;
53 	}
54 
55 	if (!buffer) {
56 		pr_debug("Invalid buffer argument\n");
57 		return AE_BAD_PARAMETER;
58 	}
59 
60 	format_count = (format->length / sizeof(char)) - 1;
61 	if (format_count > package->package.count) {
62 		pr_debug("Format specifies more objects [%d] than present [%d]\n",
63 			 format_count, package->package.count);
64 		return AE_BAD_DATA;
65 	}
66 
67 	format_string = format->pointer;
68 
69 	/*
70 	 * Calculate size_required.
71 	 */
72 	for (i = 0; i < format_count; i++) {
73 
74 		union acpi_object *element = &(package->package.elements[i]);
75 
76 		switch (element->type) {
77 
78 		case ACPI_TYPE_INTEGER:
79 			switch (format_string[i]) {
80 			case 'N':
81 				size_required += sizeof(u64);
82 				tail_offset += sizeof(u64);
83 				break;
84 			case 'S':
85 				size_required +=
86 				    sizeof(char *) + sizeof(u64) +
87 				    sizeof(char);
88 				tail_offset += sizeof(char *);
89 				break;
90 			default:
91 				pr_debug("Invalid package element [%d]: got number, expected [%c]\n",
92 					 i, format_string[i]);
93 				return AE_BAD_DATA;
94 			}
95 			break;
96 
97 		case ACPI_TYPE_STRING:
98 		case ACPI_TYPE_BUFFER:
99 			switch (format_string[i]) {
100 			case 'S':
101 				size_required +=
102 				    sizeof(char *) +
103 				    (element->string.length * sizeof(char)) +
104 				    sizeof(char);
105 				tail_offset += sizeof(char *);
106 				break;
107 			case 'B':
108 				size_required +=
109 				    sizeof(u8 *) + element->buffer.length;
110 				tail_offset += sizeof(u8 *);
111 				break;
112 			default:
113 				pr_debug("Invalid package element [%d] got string/buffer, expected [%c]\n",
114 					 i, format_string[i]);
115 				return AE_BAD_DATA;
116 			}
117 			break;
118 		case ACPI_TYPE_LOCAL_REFERENCE:
119 			switch (format_string[i]) {
120 			case 'R':
121 				size_required += sizeof(void *);
122 				tail_offset += sizeof(void *);
123 				break;
124 			default:
125 				pr_debug("Invalid package element [%d] got reference, expected [%c]\n",
126 					 i, format_string[i]);
127 				return AE_BAD_DATA;
128 			}
129 			break;
130 
131 		case ACPI_TYPE_PACKAGE:
132 		default:
133 			pr_debug("Unsupported element at index=%d\n", i);
134 			/* TBD: handle nested packages... */
135 			return AE_SUPPORT;
136 		}
137 	}
138 
139 	/*
140 	 * Validate output buffer.
141 	 */
142 	if (buffer->length == ACPI_ALLOCATE_BUFFER) {
143 		buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
144 		if (!buffer->pointer)
145 			return AE_NO_MEMORY;
146 		buffer->length = size_required;
147 	} else {
148 		if (buffer->length < size_required) {
149 			buffer->length = size_required;
150 			return AE_BUFFER_OVERFLOW;
151 		} else if (buffer->length != size_required ||
152 			   !buffer->pointer) {
153 			return AE_BAD_PARAMETER;
154 		}
155 	}
156 
157 	head = buffer->pointer;
158 	tail = buffer->pointer + tail_offset;
159 
160 	/*
161 	 * Extract package data.
162 	 */
163 	for (i = 0; i < format_count; i++) {
164 
165 		u8 **pointer = NULL;
166 		union acpi_object *element = &(package->package.elements[i]);
167 
168 		switch (element->type) {
169 
170 		case ACPI_TYPE_INTEGER:
171 			switch (format_string[i]) {
172 			case 'N':
173 				*((u64 *) head) =
174 				    element->integer.value;
175 				head += sizeof(u64);
176 				break;
177 			case 'S':
178 				pointer = (u8 **) head;
179 				*pointer = tail;
180 				*((u64 *) tail) =
181 				    element->integer.value;
182 				head += sizeof(u64 *);
183 				tail += sizeof(u64);
184 				/* NULL terminate string */
185 				*tail = (char)0;
186 				tail += sizeof(char);
187 				break;
188 			default:
189 				/* Should never get here */
190 				break;
191 			}
192 			break;
193 
194 		case ACPI_TYPE_STRING:
195 		case ACPI_TYPE_BUFFER:
196 			switch (format_string[i]) {
197 			case 'S':
198 				pointer = (u8 **) head;
199 				*pointer = tail;
200 				memcpy(tail, element->string.pointer,
201 				       element->string.length);
202 				head += sizeof(char *);
203 				tail += element->string.length * sizeof(char);
204 				/* NULL terminate string */
205 				*tail = (char)0;
206 				tail += sizeof(char);
207 				break;
208 			case 'B':
209 				pointer = (u8 **) head;
210 				*pointer = tail;
211 				memcpy(tail, element->buffer.pointer,
212 				       element->buffer.length);
213 				head += sizeof(u8 *);
214 				tail += element->buffer.length;
215 				break;
216 			default:
217 				/* Should never get here */
218 				break;
219 			}
220 			break;
221 		case ACPI_TYPE_LOCAL_REFERENCE:
222 			switch (format_string[i]) {
223 			case 'R':
224 				*(void **)head =
225 				    (void *)element->reference.handle;
226 				head += sizeof(void *);
227 				break;
228 			default:
229 				/* Should never get here */
230 				break;
231 			}
232 			break;
233 		case ACPI_TYPE_PACKAGE:
234 			/* TBD: handle nested packages... */
235 		default:
236 			/* Should never get here */
237 			break;
238 		}
239 	}
240 
241 	return AE_OK;
242 }
243 
244 EXPORT_SYMBOL(acpi_extract_package);
245 
246 acpi_status
acpi_evaluate_integer(acpi_handle handle,acpi_string pathname,struct acpi_object_list * arguments,unsigned long long * data)247 acpi_evaluate_integer(acpi_handle handle,
248 		      acpi_string pathname,
249 		      struct acpi_object_list *arguments, unsigned long long *data)
250 {
251 	acpi_status status = AE_OK;
252 	union acpi_object element;
253 	struct acpi_buffer buffer = { 0, NULL };
254 
255 	if (!data)
256 		return AE_BAD_PARAMETER;
257 
258 	buffer.length = sizeof(union acpi_object);
259 	buffer.pointer = &element;
260 	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
261 	if (ACPI_FAILURE(status)) {
262 		acpi_util_eval_error(handle, pathname, status);
263 		return status;
264 	}
265 
266 	if (element.type != ACPI_TYPE_INTEGER) {
267 		acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
268 		return AE_BAD_DATA;
269 	}
270 
271 	*data = element.integer.value;
272 
273 	acpi_handle_debug(handle, "Return value [%llu]\n", *data);
274 
275 	return AE_OK;
276 }
277 
278 EXPORT_SYMBOL(acpi_evaluate_integer);
279 
acpi_get_local_address(acpi_handle handle,u32 * addr)280 int acpi_get_local_address(acpi_handle handle, u32 *addr)
281 {
282 	unsigned long long adr;
283 	acpi_status status;
284 
285 	status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
286 	if (ACPI_FAILURE(status))
287 		return -ENODATA;
288 
289 	*addr = (u32)adr;
290 	return 0;
291 }
292 EXPORT_SYMBOL(acpi_get_local_address);
293 
294 #define ACPI_MAX_SUB_BUF_SIZE	9
295 
acpi_get_subsystem_id(acpi_handle handle)296 const char *acpi_get_subsystem_id(acpi_handle handle)
297 {
298 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
299 	union acpi_object *obj;
300 	acpi_status status;
301 	const char *sub;
302 	size_t len;
303 
304 	status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
305 	if (ACPI_FAILURE(status)) {
306 		acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
307 		return ERR_PTR(-ENODATA);
308 	}
309 
310 	obj = buffer.pointer;
311 	if (obj->type == ACPI_TYPE_STRING) {
312 		len = strlen(obj->string.pointer);
313 		if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {
314 			sub = kstrdup(obj->string.pointer, GFP_KERNEL);
315 			if (!sub)
316 				sub = ERR_PTR(-ENOMEM);
317 		} else {
318 			acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);
319 			sub = ERR_PTR(-ENODATA);
320 		}
321 	} else {
322 		acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
323 		sub = ERR_PTR(-ENODATA);
324 	}
325 
326 	acpi_os_free(buffer.pointer);
327 
328 	return sub;
329 }
330 EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
331 
332 acpi_status
acpi_evaluate_reference(acpi_handle handle,acpi_string pathname,struct acpi_object_list * arguments,struct acpi_handle_list * list)333 acpi_evaluate_reference(acpi_handle handle,
334 			acpi_string pathname,
335 			struct acpi_object_list *arguments,
336 			struct acpi_handle_list *list)
337 {
338 	acpi_status status = AE_OK;
339 	union acpi_object *package = NULL;
340 	union acpi_object *element = NULL;
341 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
342 	u32 i = 0;
343 
344 
345 	if (!list) {
346 		return AE_BAD_PARAMETER;
347 	}
348 
349 	/* Evaluate object. */
350 
351 	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
352 	if (ACPI_FAILURE(status))
353 		goto end;
354 
355 	package = buffer.pointer;
356 
357 	if ((buffer.length == 0) || !package) {
358 		status = AE_BAD_DATA;
359 		acpi_util_eval_error(handle, pathname, status);
360 		goto end;
361 	}
362 	if (package->type != ACPI_TYPE_PACKAGE) {
363 		status = AE_BAD_DATA;
364 		acpi_util_eval_error(handle, pathname, status);
365 		goto end;
366 	}
367 	if (!package->package.count) {
368 		status = AE_BAD_DATA;
369 		acpi_util_eval_error(handle, pathname, status);
370 		goto end;
371 	}
372 
373 	if (package->package.count > ACPI_MAX_HANDLES) {
374 		kfree(package);
375 		return AE_NO_MEMORY;
376 	}
377 	list->count = package->package.count;
378 
379 	/* Extract package data. */
380 
381 	for (i = 0; i < list->count; i++) {
382 
383 		element = &(package->package.elements[i]);
384 
385 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
386 			status = AE_BAD_DATA;
387 			acpi_util_eval_error(handle, pathname, status);
388 			break;
389 		}
390 
391 		if (!element->reference.handle) {
392 			status = AE_NULL_ENTRY;
393 			acpi_util_eval_error(handle, pathname, status);
394 			break;
395 		}
396 		/* Get the  acpi_handle. */
397 
398 		list->handles[i] = element->reference.handle;
399 		acpi_handle_debug(list->handles[i], "Found in reference list\n");
400 	}
401 
402       end:
403 	if (ACPI_FAILURE(status)) {
404 		list->count = 0;
405 		//kfree(list->handles);
406 	}
407 
408 	kfree(buffer.pointer);
409 
410 	return status;
411 }
412 
413 EXPORT_SYMBOL(acpi_evaluate_reference);
414 
415 acpi_status
acpi_get_physical_device_location(acpi_handle handle,struct acpi_pld_info ** pld)416 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
417 {
418 	acpi_status status;
419 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
420 	union acpi_object *output;
421 
422 	status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
423 
424 	if (ACPI_FAILURE(status))
425 		return status;
426 
427 	output = buffer.pointer;
428 
429 	if (!output || output->type != ACPI_TYPE_PACKAGE
430 	    || !output->package.count
431 	    || output->package.elements[0].type != ACPI_TYPE_BUFFER
432 	    || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
433 		status = AE_TYPE;
434 		goto out;
435 	}
436 
437 	status = acpi_decode_pld_buffer(
438 			output->package.elements[0].buffer.pointer,
439 			output->package.elements[0].buffer.length,
440 			pld);
441 
442 out:
443 	kfree(buffer.pointer);
444 	return status;
445 }
446 EXPORT_SYMBOL(acpi_get_physical_device_location);
447 
448 /**
449  * acpi_evaluate_ost: Evaluate _OST for hotplug operations
450  * @handle: ACPI device handle
451  * @source_event: source event code
452  * @status_code: status code
453  * @status_buf: optional detailed information (NULL if none)
454  *
455  * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
456  * must call this function when evaluating _OST for hotplug operations.
457  * When the platform does not support _OST, this function has no effect.
458  */
459 acpi_status
acpi_evaluate_ost(acpi_handle handle,u32 source_event,u32 status_code,struct acpi_buffer * status_buf)460 acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
461 		  struct acpi_buffer *status_buf)
462 {
463 	union acpi_object params[3] = {
464 		{.type = ACPI_TYPE_INTEGER,},
465 		{.type = ACPI_TYPE_INTEGER,},
466 		{.type = ACPI_TYPE_BUFFER,}
467 	};
468 	struct acpi_object_list arg_list = {3, params};
469 
470 	params[0].integer.value = source_event;
471 	params[1].integer.value = status_code;
472 	if (status_buf != NULL) {
473 		params[2].buffer.pointer = status_buf->pointer;
474 		params[2].buffer.length = status_buf->length;
475 	} else {
476 		params[2].buffer.pointer = NULL;
477 		params[2].buffer.length = 0;
478 	}
479 
480 	return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
481 }
482 EXPORT_SYMBOL(acpi_evaluate_ost);
483 
484 /**
485  * acpi_handle_path: Return the object path of handle
486  * @handle: ACPI device handle
487  *
488  * Caller must free the returned buffer
489  */
acpi_handle_path(acpi_handle handle)490 static char *acpi_handle_path(acpi_handle handle)
491 {
492 	struct acpi_buffer buffer = {
493 		.length = ACPI_ALLOCATE_BUFFER,
494 		.pointer = NULL
495 	};
496 
497 	if (in_interrupt() ||
498 	    acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
499 		return NULL;
500 	return buffer.pointer;
501 }
502 
503 /**
504  * acpi_handle_printk: Print message with ACPI prefix and object path
505  * @level: log level
506  * @handle: ACPI device handle
507  * @fmt: format string
508  *
509  * This function is called through acpi_handle_<level> macros and prints
510  * a message with ACPI prefix and object path.  This function acquires
511  * the global namespace mutex to obtain an object path.  In interrupt
512  * context, it shows the object path as <n/a>.
513  */
514 void
acpi_handle_printk(const char * level,acpi_handle handle,const char * fmt,...)515 acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
516 {
517 	struct va_format vaf;
518 	va_list args;
519 	const char *path;
520 
521 	va_start(args, fmt);
522 	vaf.fmt = fmt;
523 	vaf.va = &args;
524 
525 	path = acpi_handle_path(handle);
526 	printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
527 
528 	va_end(args);
529 	kfree(path);
530 }
531 EXPORT_SYMBOL(acpi_handle_printk);
532 
533 #if defined(CONFIG_DYNAMIC_DEBUG)
534 /**
535  * __acpi_handle_debug: pr_debug with ACPI prefix and object path
536  * @descriptor: Dynamic Debug descriptor
537  * @handle: ACPI device handle
538  * @fmt: format string
539  *
540  * This function is called through acpi_handle_debug macro and debug
541  * prints a message with ACPI prefix and object path. This function
542  * acquires the global namespace mutex to obtain an object path.  In
543  * interrupt context, it shows the object path as <n/a>.
544  */
545 void
__acpi_handle_debug(struct _ddebug * descriptor,acpi_handle handle,const char * fmt,...)546 __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
547 		    const char *fmt, ...)
548 {
549 	struct va_format vaf;
550 	va_list args;
551 	const char *path;
552 
553 	va_start(args, fmt);
554 	vaf.fmt = fmt;
555 	vaf.va = &args;
556 
557 	path = acpi_handle_path(handle);
558 	__dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
559 
560 	va_end(args);
561 	kfree(path);
562 }
563 EXPORT_SYMBOL(__acpi_handle_debug);
564 #endif
565 
566 /**
567  * acpi_evaluation_failure_warn - Log evaluation failure warning.
568  * @handle: Parent object handle.
569  * @name: Name of the object whose evaluation has failed.
570  * @status: Status value returned by the failing object evaluation.
571  */
acpi_evaluation_failure_warn(acpi_handle handle,const char * name,acpi_status status)572 void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,
573 				  acpi_status status)
574 {
575 	acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,
576 			 acpi_format_exception(status));
577 }
578 EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);
579 
580 /**
581  * acpi_has_method: Check whether @handle has a method named @name
582  * @handle: ACPI device handle
583  * @name: name of object or method
584  *
585  * Check whether @handle has a method named @name.
586  */
acpi_has_method(acpi_handle handle,char * name)587 bool acpi_has_method(acpi_handle handle, char *name)
588 {
589 	acpi_handle tmp;
590 
591 	return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
592 }
593 EXPORT_SYMBOL(acpi_has_method);
594 
acpi_execute_simple_method(acpi_handle handle,char * method,u64 arg)595 acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
596 				       u64 arg)
597 {
598 	union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
599 	struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
600 
601 	obj.integer.value = arg;
602 
603 	return acpi_evaluate_object(handle, method, &arg_list, NULL);
604 }
605 EXPORT_SYMBOL(acpi_execute_simple_method);
606 
607 /**
608  * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
609  * @handle: ACPI device handle
610  *
611  * Evaluate device's _EJ0 method for hotplug operations.
612  */
acpi_evaluate_ej0(acpi_handle handle)613 acpi_status acpi_evaluate_ej0(acpi_handle handle)
614 {
615 	acpi_status status;
616 
617 	status = acpi_execute_simple_method(handle, "_EJ0", 1);
618 	if (status == AE_NOT_FOUND)
619 		acpi_handle_warn(handle, "No _EJ0 support for device\n");
620 	else if (ACPI_FAILURE(status))
621 		acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
622 
623 	return status;
624 }
625 
626 /**
627  * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
628  * @handle: ACPI device handle
629  * @lock: lock device if non-zero, otherwise unlock device
630  *
631  * Evaluate device's _LCK method if present to lock/unlock device
632  */
acpi_evaluate_lck(acpi_handle handle,int lock)633 acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
634 {
635 	acpi_status status;
636 
637 	status = acpi_execute_simple_method(handle, "_LCK", !!lock);
638 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
639 		if (lock)
640 			acpi_handle_warn(handle,
641 				"Locking device failed (0x%x)\n", status);
642 		else
643 			acpi_handle_warn(handle,
644 				"Unlocking device failed (0x%x)\n", status);
645 	}
646 
647 	return status;
648 }
649 
650 /**
651  * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
652  * @handle: ACPI device handle
653  * @space_id: ACPI address space id to register OpRegion presence for
654  * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
655  *            ACPI_REG_DISCONNECT
656  *
657  * Evaluate device's _REG method to register OpRegion presence.
658  */
acpi_evaluate_reg(acpi_handle handle,u8 space_id,u32 function)659 acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
660 {
661 	struct acpi_object_list arg_list;
662 	union acpi_object params[2];
663 
664 	params[0].type = ACPI_TYPE_INTEGER;
665 	params[0].integer.value = space_id;
666 	params[1].type = ACPI_TYPE_INTEGER;
667 	params[1].integer.value = function;
668 	arg_list.count = 2;
669 	arg_list.pointer = params;
670 
671 	return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
672 }
673 EXPORT_SYMBOL(acpi_evaluate_reg);
674 
675 /**
676  * acpi_evaluate_dsm - evaluate device's _DSM method
677  * @handle: ACPI device handle
678  * @guid: GUID of requested functions, should be 16 bytes
679  * @rev: revision number of requested function
680  * @func: requested function number
681  * @argv4: the function specific parameter
682  *
683  * Evaluate device's _DSM method with specified GUID, revision id and
684  * function number. Caller needs to free the returned object.
685  *
686  * Though ACPI defines the fourth parameter for _DSM should be a package,
687  * some old BIOSes do expect a buffer or an integer etc.
688  */
689 union acpi_object *
acpi_evaluate_dsm(acpi_handle handle,const guid_t * guid,u64 rev,u64 func,union acpi_object * argv4)690 acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
691 		  union acpi_object *argv4)
692 {
693 	acpi_status ret;
694 	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
695 	union acpi_object params[4];
696 	struct acpi_object_list input = {
697 		.count = 4,
698 		.pointer = params,
699 	};
700 
701 	params[0].type = ACPI_TYPE_BUFFER;
702 	params[0].buffer.length = 16;
703 	params[0].buffer.pointer = (u8 *)guid;
704 	params[1].type = ACPI_TYPE_INTEGER;
705 	params[1].integer.value = rev;
706 	params[2].type = ACPI_TYPE_INTEGER;
707 	params[2].integer.value = func;
708 	if (argv4) {
709 		params[3] = *argv4;
710 	} else {
711 		params[3].type = ACPI_TYPE_PACKAGE;
712 		params[3].package.count = 0;
713 		params[3].package.elements = NULL;
714 	}
715 
716 	ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
717 	if (ACPI_SUCCESS(ret))
718 		return (union acpi_object *)buf.pointer;
719 
720 	if (ret != AE_NOT_FOUND)
721 		acpi_handle_warn(handle,
722 				 "failed to evaluate _DSM %pUb (0x%x)\n", guid, ret);
723 
724 	return NULL;
725 }
726 EXPORT_SYMBOL(acpi_evaluate_dsm);
727 
728 /**
729  * acpi_check_dsm - check if _DSM method supports requested functions.
730  * @handle: ACPI device handle
731  * @guid: GUID of requested functions, should be 16 bytes at least
732  * @rev: revision number of requested functions
733  * @funcs: bitmap of requested functions
734  *
735  * Evaluate device's _DSM method to check whether it supports requested
736  * functions. Currently only support 64 functions at maximum, should be
737  * enough for now.
738  */
acpi_check_dsm(acpi_handle handle,const guid_t * guid,u64 rev,u64 funcs)739 bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
740 {
741 	int i;
742 	u64 mask = 0;
743 	union acpi_object *obj;
744 
745 	if (funcs == 0)
746 		return false;
747 
748 	obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
749 	if (!obj)
750 		return false;
751 
752 	/* For compatibility, old BIOSes may return an integer */
753 	if (obj->type == ACPI_TYPE_INTEGER)
754 		mask = obj->integer.value;
755 	else if (obj->type == ACPI_TYPE_BUFFER)
756 		for (i = 0; i < obj->buffer.length && i < 8; i++)
757 			mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
758 	ACPI_FREE(obj);
759 
760 	/*
761 	 * Bit 0 indicates whether there's support for any functions other than
762 	 * function 0 for the specified GUID and revision.
763 	 */
764 	if ((mask & 0x1) && (mask & funcs) == funcs)
765 		return true;
766 
767 	return false;
768 }
769 EXPORT_SYMBOL(acpi_check_dsm);
770 
771 /**
772  * acpi_dev_hid_uid_match - Match device by supplied HID and UID
773  * @adev: ACPI device to match.
774  * @hid2: Hardware ID of the device.
775  * @uid2: Unique ID of the device, pass NULL to not check _UID.
776  *
777  * Matches HID and UID in @adev with given @hid2 and @uid2.
778  * Returns true if matches.
779  */
acpi_dev_hid_uid_match(struct acpi_device * adev,const char * hid2,const char * uid2)780 bool acpi_dev_hid_uid_match(struct acpi_device *adev,
781 			    const char *hid2, const char *uid2)
782 {
783 	const char *hid1 = acpi_device_hid(adev);
784 	const char *uid1 = acpi_device_uid(adev);
785 
786 	if (strcmp(hid1, hid2))
787 		return false;
788 
789 	if (!uid2)
790 		return true;
791 
792 	return uid1 && !strcmp(uid1, uid2);
793 }
794 EXPORT_SYMBOL(acpi_dev_hid_uid_match);
795 
796 /**
797  * acpi_dev_uid_to_integer - treat ACPI device _UID as integer
798  * @adev: ACPI device to get _UID from
799  * @integer: output buffer for integer
800  *
801  * Considers _UID as integer and converts it to @integer.
802  *
803  * Returns 0 on success, or negative error code otherwise.
804  */
acpi_dev_uid_to_integer(struct acpi_device * adev,u64 * integer)805 int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)
806 {
807 	const char *uid;
808 
809 	if (!adev)
810 		return -ENODEV;
811 
812 	uid = acpi_device_uid(adev);
813 	if (!uid)
814 		return -ENODATA;
815 
816 	return kstrtou64(uid, 0, integer);
817 }
818 EXPORT_SYMBOL(acpi_dev_uid_to_integer);
819 
820 /**
821  * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
822  * @hid: Hardware ID of the device.
823  *
824  * Return %true if the device was present at the moment of invocation.
825  * Note that if the device is pluggable, it may since have disappeared.
826  *
827  * For this function to work, acpi_bus_scan() must have been executed
828  * which happens in the subsys_initcall() subsection. Hence, do not
829  * call from a subsys_initcall() or earlier (use acpi_get_devices()
830  * instead). Calling from module_init() is fine (which is synonymous
831  * with device_initcall()).
832  */
acpi_dev_found(const char * hid)833 bool acpi_dev_found(const char *hid)
834 {
835 	struct acpi_device_bus_id *acpi_device_bus_id;
836 	bool found = false;
837 
838 	mutex_lock(&acpi_device_lock);
839 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
840 		if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
841 			found = true;
842 			break;
843 		}
844 	mutex_unlock(&acpi_device_lock);
845 
846 	return found;
847 }
848 EXPORT_SYMBOL(acpi_dev_found);
849 
850 struct acpi_dev_match_info {
851 	struct acpi_device_id hid[2];
852 	const char *uid;
853 	s64 hrv;
854 };
855 
acpi_dev_match_cb(struct device * dev,const void * data)856 static int acpi_dev_match_cb(struct device *dev, const void *data)
857 {
858 	struct acpi_device *adev = to_acpi_device(dev);
859 	const struct acpi_dev_match_info *match = data;
860 	unsigned long long hrv;
861 	acpi_status status;
862 
863 	if (acpi_match_device_ids(adev, match->hid))
864 		return 0;
865 
866 	if (match->uid && (!adev->pnp.unique_id ||
867 	    strcmp(adev->pnp.unique_id, match->uid)))
868 		return 0;
869 
870 	if (match->hrv == -1)
871 		return 1;
872 
873 	status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
874 	if (ACPI_FAILURE(status))
875 		return 0;
876 
877 	return hrv == match->hrv;
878 }
879 
880 /**
881  * acpi_dev_present - Detect that a given ACPI device is present
882  * @hid: Hardware ID of the device.
883  * @uid: Unique ID of the device, pass NULL to not check _UID
884  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
885  *
886  * Return %true if a matching device was present at the moment of invocation.
887  * Note that if the device is pluggable, it may since have disappeared.
888  *
889  * Note that unlike acpi_dev_found() this function checks the status
890  * of the device. So for devices which are present in the DSDT, but
891  * which are disabled (their _STA callback returns 0) this function
892  * will return false.
893  *
894  * For this function to work, acpi_bus_scan() must have been executed
895  * which happens in the subsys_initcall() subsection. Hence, do not
896  * call from a subsys_initcall() or earlier (use acpi_get_devices()
897  * instead). Calling from module_init() is fine (which is synonymous
898  * with device_initcall()).
899  */
acpi_dev_present(const char * hid,const char * uid,s64 hrv)900 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
901 {
902 	struct acpi_dev_match_info match = {};
903 	struct device *dev;
904 
905 	strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
906 	match.uid = uid;
907 	match.hrv = hrv;
908 
909 	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
910 	put_device(dev);
911 	return !!dev;
912 }
913 EXPORT_SYMBOL(acpi_dev_present);
914 
915 /**
916  * acpi_dev_get_next_match_dev - Return the next match of ACPI device
917  * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv
918  * @hid: Hardware ID of the device.
919  * @uid: Unique ID of the device, pass NULL to not check _UID
920  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
921  *
922  * Return the next match of ACPI device if another matching device was present
923  * at the moment of invocation, or NULL otherwise.
924  *
925  * The caller is responsible for invoking acpi_dev_put() on the returned device.
926  * On the other hand the function invokes  acpi_dev_put() on the given @adev
927  * assuming that its reference counter had been increased beforehand.
928  *
929  * See additional information in acpi_dev_present() as well.
930  */
931 struct acpi_device *
acpi_dev_get_next_match_dev(struct acpi_device * adev,const char * hid,const char * uid,s64 hrv)932 acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)
933 {
934 	struct device *start = adev ? &adev->dev : NULL;
935 	struct acpi_dev_match_info match = {};
936 	struct device *dev;
937 
938 	strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
939 	match.uid = uid;
940 	match.hrv = hrv;
941 
942 	dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
943 	acpi_dev_put(adev);
944 	return dev ? to_acpi_device(dev) : NULL;
945 }
946 EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
947 
948 /**
949  * acpi_dev_get_first_match_dev - Return the first match of ACPI device
950  * @hid: Hardware ID of the device.
951  * @uid: Unique ID of the device, pass NULL to not check _UID
952  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
953  *
954  * Return the first match of ACPI device if a matching device was present
955  * at the moment of invocation, or NULL otherwise.
956  *
957  * The caller is responsible for invoking acpi_dev_put() on the returned device.
958  *
959  * See additional information in acpi_dev_present() as well.
960  */
961 struct acpi_device *
acpi_dev_get_first_match_dev(const char * hid,const char * uid,s64 hrv)962 acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
963 {
964 	return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);
965 }
966 EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
967 
968 /**
969  * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
970  *
971  * Return true when running on an ACPI-reduced-hw machine, false otherwise.
972  */
acpi_reduced_hardware(void)973 bool acpi_reduced_hardware(void)
974 {
975 	return acpi_gbl_reduced_hardware;
976 }
977 EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
978 
979 /*
980  * acpi_backlight= handling, this is done here rather then in video_detect.c
981  * because __setup cannot be used in modules.
982  */
983 char acpi_video_backlight_string[16];
984 EXPORT_SYMBOL(acpi_video_backlight_string);
985 
acpi_backlight(char * str)986 static int __init acpi_backlight(char *str)
987 {
988 	strscpy(acpi_video_backlight_string, str,
989 		sizeof(acpi_video_backlight_string));
990 	return 1;
991 }
992 __setup("acpi_backlight=", acpi_backlight);
993 
994 /**
995  * acpi_match_platform_list - Check if the system matches with a given list
996  * @plat: pointer to acpi_platform_list table terminated by a NULL entry
997  *
998  * Return the matched index if the system is found in the platform list.
999  * Otherwise, return a negative error code.
1000  */
acpi_match_platform_list(const struct acpi_platform_list * plat)1001 int acpi_match_platform_list(const struct acpi_platform_list *plat)
1002 {
1003 	struct acpi_table_header hdr;
1004 	int idx = 0;
1005 
1006 	if (acpi_disabled)
1007 		return -ENODEV;
1008 
1009 	for (; plat->oem_id[0]; plat++, idx++) {
1010 		if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
1011 			continue;
1012 
1013 		if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
1014 			continue;
1015 
1016 		if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
1017 			continue;
1018 
1019 		if ((plat->pred == all_versions) ||
1020 		    (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
1021 		    (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
1022 		    (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
1023 			return idx;
1024 	}
1025 
1026 	return -ENODEV;
1027 }
1028 EXPORT_SYMBOL(acpi_match_platform_list);
1029