xref: /linux/drivers/acpi/utils.c (revision 47902f3611b392209e2a412bf7ec02dca95e666d)
1 /*
2  *  acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *
7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; either version 2 of the License, or (at
12  *  your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful, but
15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  *  General Public License for more details.
18  *
19  *  You should have received a copy of the GNU General Public License along
20  *  with this program; if not, write to the Free Software Foundation, Inc.,
21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22  *
23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24  */
25 
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <acpi/acpi_bus.h>
32 #include <acpi/acpi_drivers.h>
33 
34 #include "internal.h"
35 
36 #define _COMPONENT		ACPI_BUS_COMPONENT
37 ACPI_MODULE_NAME("utils");
38 
39 /* --------------------------------------------------------------------------
40                             Object Evaluation Helpers
41    -------------------------------------------------------------------------- */
42 static void
43 acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
44 {
45 #ifdef ACPI_DEBUG_OUTPUT
46 	char prefix[80] = {'\0'};
47 	struct acpi_buffer buffer = {sizeof(prefix), prefix};
48 	acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
49 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n",
50 		(char *) prefix, p, acpi_format_exception(s)));
51 #else
52 	return;
53 #endif
54 }
55 
56 acpi_status
57 acpi_extract_package(union acpi_object *package,
58 		     struct acpi_buffer *format, struct acpi_buffer *buffer)
59 {
60 	u32 size_required = 0;
61 	u32 tail_offset = 0;
62 	char *format_string = NULL;
63 	u32 format_count = 0;
64 	u32 i = 0;
65 	u8 *head = NULL;
66 	u8 *tail = NULL;
67 
68 
69 	if (!package || (package->type != ACPI_TYPE_PACKAGE)
70 	    || (package->package.count < 1)) {
71 		printk(KERN_WARNING PREFIX "Invalid package argument\n");
72 		return AE_BAD_PARAMETER;
73 	}
74 
75 	if (!format || !format->pointer || (format->length < 1)) {
76 		printk(KERN_WARNING PREFIX "Invalid format argument\n");
77 		return AE_BAD_PARAMETER;
78 	}
79 
80 	if (!buffer) {
81 		printk(KERN_WARNING PREFIX "Invalid buffer argument\n");
82 		return AE_BAD_PARAMETER;
83 	}
84 
85 	format_count = (format->length / sizeof(char)) - 1;
86 	if (format_count > package->package.count) {
87 		printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
88 			      " than exist in package [%d].\n",
89 			      format_count, package->package.count);
90 		return AE_BAD_DATA;
91 	}
92 
93 	format_string = format->pointer;
94 
95 	/*
96 	 * Calculate size_required.
97 	 */
98 	for (i = 0; i < format_count; i++) {
99 
100 		union acpi_object *element = &(package->package.elements[i]);
101 
102 		if (!element) {
103 			return AE_BAD_DATA;
104 		}
105 
106 		switch (element->type) {
107 
108 		case ACPI_TYPE_INTEGER:
109 			switch (format_string[i]) {
110 			case 'N':
111 				size_required += sizeof(u64);
112 				tail_offset += sizeof(u64);
113 				break;
114 			case 'S':
115 				size_required +=
116 				    sizeof(char *) + sizeof(u64) +
117 				    sizeof(char);
118 				tail_offset += sizeof(char *);
119 				break;
120 			default:
121 				printk(KERN_WARNING PREFIX "Invalid package element"
122 					      " [%d]: got number, expecing"
123 					      " [%c]\n",
124 					      i, format_string[i]);
125 				return AE_BAD_DATA;
126 				break;
127 			}
128 			break;
129 
130 		case ACPI_TYPE_STRING:
131 		case ACPI_TYPE_BUFFER:
132 			switch (format_string[i]) {
133 			case 'S':
134 				size_required +=
135 				    sizeof(char *) +
136 				    (element->string.length * sizeof(char)) +
137 				    sizeof(char);
138 				tail_offset += sizeof(char *);
139 				break;
140 			case 'B':
141 				size_required +=
142 				    sizeof(u8 *) +
143 				    (element->buffer.length * sizeof(u8));
144 				tail_offset += sizeof(u8 *);
145 				break;
146 			default:
147 				printk(KERN_WARNING PREFIX "Invalid package element"
148 					      " [%d] got string/buffer,"
149 					      " expecing [%c]\n",
150 					      i, format_string[i]);
151 				return AE_BAD_DATA;
152 				break;
153 			}
154 			break;
155 
156 		case ACPI_TYPE_PACKAGE:
157 		default:
158 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
159 					  "Found unsupported element at index=%d\n",
160 					  i));
161 			/* TBD: handle nested packages... */
162 			return AE_SUPPORT;
163 			break;
164 		}
165 	}
166 
167 	/*
168 	 * Validate output buffer.
169 	 */
170 	if (buffer->length < size_required) {
171 		buffer->length = size_required;
172 		return AE_BUFFER_OVERFLOW;
173 	} else if (buffer->length != size_required || !buffer->pointer) {
174 		return AE_BAD_PARAMETER;
175 	}
176 
177 	head = buffer->pointer;
178 	tail = buffer->pointer + tail_offset;
179 
180 	/*
181 	 * Extract package data.
182 	 */
183 	for (i = 0; i < format_count; i++) {
184 
185 		u8 **pointer = NULL;
186 		union acpi_object *element = &(package->package.elements[i]);
187 
188 		if (!element) {
189 			return AE_BAD_DATA;
190 		}
191 
192 		switch (element->type) {
193 
194 		case ACPI_TYPE_INTEGER:
195 			switch (format_string[i]) {
196 			case 'N':
197 				*((u64 *) head) =
198 				    element->integer.value;
199 				head += sizeof(u64);
200 				break;
201 			case 'S':
202 				pointer = (u8 **) head;
203 				*pointer = tail;
204 				*((u64 *) tail) =
205 				    element->integer.value;
206 				head += sizeof(u64 *);
207 				tail += sizeof(u64);
208 				/* NULL terminate string */
209 				*tail = (char)0;
210 				tail += sizeof(char);
211 				break;
212 			default:
213 				/* Should never get here */
214 				break;
215 			}
216 			break;
217 
218 		case ACPI_TYPE_STRING:
219 		case ACPI_TYPE_BUFFER:
220 			switch (format_string[i]) {
221 			case 'S':
222 				pointer = (u8 **) head;
223 				*pointer = tail;
224 				memcpy(tail, element->string.pointer,
225 				       element->string.length);
226 				head += sizeof(char *);
227 				tail += element->string.length * sizeof(char);
228 				/* NULL terminate string */
229 				*tail = (char)0;
230 				tail += sizeof(char);
231 				break;
232 			case 'B':
233 				pointer = (u8 **) head;
234 				*pointer = tail;
235 				memcpy(tail, element->buffer.pointer,
236 				       element->buffer.length);
237 				head += sizeof(u8 *);
238 				tail += element->buffer.length * sizeof(u8);
239 				break;
240 			default:
241 				/* Should never get here */
242 				break;
243 			}
244 			break;
245 
246 		case ACPI_TYPE_PACKAGE:
247 			/* TBD: handle nested packages... */
248 		default:
249 			/* Should never get here */
250 			break;
251 		}
252 	}
253 
254 	return AE_OK;
255 }
256 
257 EXPORT_SYMBOL(acpi_extract_package);
258 
259 acpi_status
260 acpi_evaluate_integer(acpi_handle handle,
261 		      acpi_string pathname,
262 		      struct acpi_object_list *arguments, unsigned long long *data)
263 {
264 	acpi_status status = AE_OK;
265 	union acpi_object element;
266 	struct acpi_buffer buffer = { 0, NULL };
267 
268 	if (!data)
269 		return AE_BAD_PARAMETER;
270 
271 	buffer.length = sizeof(union acpi_object);
272 	buffer.pointer = &element;
273 	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
274 	if (ACPI_FAILURE(status)) {
275 		acpi_util_eval_error(handle, pathname, status);
276 		return status;
277 	}
278 
279 	if (element.type != ACPI_TYPE_INTEGER) {
280 		acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
281 		return AE_BAD_DATA;
282 	}
283 
284 	*data = element.integer.value;
285 
286 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));
287 
288 	return AE_OK;
289 }
290 
291 EXPORT_SYMBOL(acpi_evaluate_integer);
292 
293 acpi_status
294 acpi_evaluate_reference(acpi_handle handle,
295 			acpi_string pathname,
296 			struct acpi_object_list *arguments,
297 			struct acpi_handle_list *list)
298 {
299 	acpi_status status = AE_OK;
300 	union acpi_object *package = NULL;
301 	union acpi_object *element = NULL;
302 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
303 	u32 i = 0;
304 
305 
306 	if (!list) {
307 		return AE_BAD_PARAMETER;
308 	}
309 
310 	/* Evaluate object. */
311 
312 	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
313 	if (ACPI_FAILURE(status))
314 		goto end;
315 
316 	package = buffer.pointer;
317 
318 	if ((buffer.length == 0) || !package) {
319 		printk(KERN_ERR PREFIX "No return object (len %X ptr %p)\n",
320 			    (unsigned)buffer.length, package);
321 		status = AE_BAD_DATA;
322 		acpi_util_eval_error(handle, pathname, status);
323 		goto end;
324 	}
325 	if (package->type != ACPI_TYPE_PACKAGE) {
326 		printk(KERN_ERR PREFIX "Expecting a [Package], found type %X\n",
327 			    package->type);
328 		status = AE_BAD_DATA;
329 		acpi_util_eval_error(handle, pathname, status);
330 		goto end;
331 	}
332 	if (!package->package.count) {
333 		printk(KERN_ERR PREFIX "[Package] has zero elements (%p)\n",
334 			    package);
335 		status = AE_BAD_DATA;
336 		acpi_util_eval_error(handle, pathname, status);
337 		goto end;
338 	}
339 
340 	if (package->package.count > ACPI_MAX_HANDLES) {
341 		return AE_NO_MEMORY;
342 	}
343 	list->count = package->package.count;
344 
345 	/* Extract package data. */
346 
347 	for (i = 0; i < list->count; i++) {
348 
349 		element = &(package->package.elements[i]);
350 
351 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
352 			status = AE_BAD_DATA;
353 			printk(KERN_ERR PREFIX
354 				    "Expecting a [Reference] package element, found type %X\n",
355 				    element->type);
356 			acpi_util_eval_error(handle, pathname, status);
357 			break;
358 		}
359 
360 		if (!element->reference.handle) {
361 			printk(KERN_WARNING PREFIX "Invalid reference in"
362 			       " package %s\n", pathname);
363 			status = AE_NULL_ENTRY;
364 			break;
365 		}
366 		/* Get the  acpi_handle. */
367 
368 		list->handles[i] = element->reference.handle;
369 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n",
370 				  list->handles[i]));
371 	}
372 
373       end:
374 	if (ACPI_FAILURE(status)) {
375 		list->count = 0;
376 		//kfree(list->handles);
377 	}
378 
379 	kfree(buffer.pointer);
380 
381 	return status;
382 }
383 
384 EXPORT_SYMBOL(acpi_evaluate_reference);
385