xref: /linux/drivers/acpi/acpica/nsnames.c (revision ead5d1f4d877e92c051e1a1ade623d0d30e71619)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
3  *
4  * Module Name: nsnames - Name manipulation and search
5  *
6  ******************************************************************************/
7 
8 #include <acpi/acpi.h>
9 #include "accommon.h"
10 #include "amlcode.h"
11 #include "acnamesp.h"
12 
13 #define _COMPONENT          ACPI_NAMESPACE
14 ACPI_MODULE_NAME("nsnames")
15 
16 /*******************************************************************************
17  *
18  * FUNCTION:    acpi_ns_get_external_pathname
19  *
20  * PARAMETERS:  node            - Namespace node whose pathname is needed
21  *
22  * RETURN:      Pointer to storage containing the fully qualified name of
23  *              the node, In external format (name segments separated by path
24  *              separators.)
25  *
26  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
27  *              for error and debug statements.
28  *
29  ******************************************************************************/
acpi_ns_get_external_pathname(struct acpi_namespace_node * node)30 char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
31 {
32 	char *name_buffer;
33 
34 	ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
35 
36 	name_buffer = acpi_ns_get_normalized_pathname(node, FALSE);
37 	return_PTR(name_buffer);
38 }
39 
40 /*******************************************************************************
41  *
42  * FUNCTION:    acpi_ns_get_pathname_length
43  *
44  * PARAMETERS:  node        - Namespace node
45  *
46  * RETURN:      Length of path, including prefix
47  *
48  * DESCRIPTION: Get the length of the pathname string for this node
49  *
50  ******************************************************************************/
51 
acpi_ns_get_pathname_length(struct acpi_namespace_node * node)52 acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
53 {
54 	acpi_size size;
55 
56 	/* Validate the Node */
57 
58 	if (ACPI_GET_DESCRIPTOR_TYPE(node) != ACPI_DESC_TYPE_NAMED) {
59 		ACPI_ERROR((AE_INFO,
60 			    "Invalid/cached reference target node: %p, descriptor type %d",
61 			    node, ACPI_GET_DESCRIPTOR_TYPE(node)));
62 		return (0);
63 	}
64 
65 	size = acpi_ns_build_normalized_path(node, NULL, 0, FALSE);
66 	return (size);
67 }
68 
69 /*******************************************************************************
70  *
71  * FUNCTION:    acpi_ns_handle_to_name
72  *
73  * PARAMETERS:  target_handle           - Handle of named object whose name is
74  *                                        to be found
75  *              buffer                  - Where the name is returned
76  *
77  * RETURN:      Status, Buffer is filled with name if status is AE_OK
78  *
79  * DESCRIPTION: Build and return a full namespace name
80  *
81  ******************************************************************************/
82 
83 acpi_status
acpi_ns_handle_to_name(acpi_handle target_handle,struct acpi_buffer * buffer)84 acpi_ns_handle_to_name(acpi_handle target_handle, struct acpi_buffer *buffer)
85 {
86 	acpi_status status;
87 	struct acpi_namespace_node *node;
88 	const char *node_name;
89 
90 	ACPI_FUNCTION_TRACE_PTR(ns_handle_to_name, target_handle);
91 
92 	node = acpi_ns_validate_handle(target_handle);
93 	if (!node) {
94 		return_ACPI_STATUS(AE_BAD_PARAMETER);
95 	}
96 
97 	/* Validate/Allocate/Clear caller buffer */
98 
99 	status = acpi_ut_initialize_buffer(buffer, ACPI_PATH_SEGMENT_LENGTH);
100 	if (ACPI_FAILURE(status)) {
101 		return_ACPI_STATUS(status);
102 	}
103 
104 	/* Just copy the ACPI name from the Node and zero terminate it */
105 
106 	node_name = acpi_ut_get_node_name(node);
107 	ACPI_COPY_NAMESEG(buffer->pointer, node_name);
108 	((char *)buffer->pointer)[ACPI_NAMESEG_SIZE] = 0;
109 
110 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%4.4s\n", (char *)buffer->pointer));
111 	return_ACPI_STATUS(AE_OK);
112 }
113 
114 /*******************************************************************************
115  *
116  * FUNCTION:    acpi_ns_handle_to_pathname
117  *
118  * PARAMETERS:  target_handle           - Handle of named object whose name is
119  *                                        to be found
120  *              buffer                  - Where the pathname is returned
121  *              no_trailing             - Remove trailing '_' for each name
122  *                                        segment
123  *
124  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
125  *
126  * DESCRIPTION: Build and return a full namespace pathname
127  *
128  ******************************************************************************/
129 
130 acpi_status
acpi_ns_handle_to_pathname(acpi_handle target_handle,struct acpi_buffer * buffer,u8 no_trailing)131 acpi_ns_handle_to_pathname(acpi_handle target_handle,
132 			   struct acpi_buffer *buffer, u8 no_trailing)
133 {
134 	acpi_status status;
135 	struct acpi_namespace_node *node;
136 	acpi_size required_size;
137 
138 	ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
139 
140 	node = acpi_ns_validate_handle(target_handle);
141 	if (!node) {
142 		return_ACPI_STATUS(AE_BAD_PARAMETER);
143 	}
144 
145 	/* Determine size required for the caller buffer */
146 
147 	required_size =
148 	    acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
149 	if (!required_size) {
150 		return_ACPI_STATUS(AE_BAD_PARAMETER);
151 	}
152 
153 	/* Validate/Allocate/Clear caller buffer */
154 
155 	status = acpi_ut_initialize_buffer(buffer, required_size);
156 	if (ACPI_FAILURE(status)) {
157 		return_ACPI_STATUS(status);
158 	}
159 
160 	/* Build the path in the caller buffer */
161 
162 	(void)acpi_ns_build_normalized_path(node, buffer->pointer,
163 					    (u32)required_size, no_trailing);
164 
165 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
166 			  (char *)buffer->pointer, (u32) required_size));
167 	return_ACPI_STATUS(AE_OK);
168 }
169 
170 /*******************************************************************************
171  *
172  * FUNCTION:    acpi_ns_build_normalized_path
173  *
174  * PARAMETERS:  node        - Namespace node
175  *              full_path   - Where the path name is returned
176  *              path_size   - Size of returned path name buffer
177  *              no_trailing - Remove trailing '_' from each name segment
178  *
179  * RETURN:      Return 1 if the AML path is empty, otherwise returning (length
180  *              of pathname + 1) which means the 'FullPath' contains a trailing
181  *              null.
182  *
183  * DESCRIPTION: Build and return a full namespace pathname.
184  *              Note that if the size of 'FullPath' isn't large enough to
185  *              contain the namespace node's path name, the actual required
186  *              buffer length is returned, and it should be greater than
187  *              'PathSize'. So callers are able to check the returning value
188  *              to determine the buffer size of 'FullPath'.
189  *
190  ******************************************************************************/
191 
192 u32
acpi_ns_build_normalized_path(struct acpi_namespace_node * node,char * full_path,u32 path_size,u8 no_trailing)193 acpi_ns_build_normalized_path(struct acpi_namespace_node *node,
194 			      char *full_path, u32 path_size, u8 no_trailing)
195 {
196 	u32 length = 0, i;
197 	char name[ACPI_NAMESEG_SIZE];
198 	u8 do_no_trailing;
199 	char c, *left, *right;
200 	struct acpi_namespace_node *next_node;
201 
202 	ACPI_FUNCTION_TRACE_PTR(ns_build_normalized_path, node);
203 
204 #define ACPI_PATH_PUT8(path, size, byte, length)    \
205 	do {                                            \
206 		if ((length) < (size))                      \
207 		{                                           \
208 			(path)[(length)] = (byte);              \
209 		}                                           \
210 		(length)++;                                 \
211 	} while (0)
212 
213 	/*
214 	 * Make sure the path_size is correct, so that we don't need to
215 	 * validate both full_path and path_size.
216 	 */
217 	if (!full_path) {
218 		path_size = 0;
219 	}
220 
221 	if (!node) {
222 		goto build_trailing_null;
223 	}
224 
225 	next_node = node;
226 	while (next_node && next_node != acpi_gbl_root_node) {
227 		if (next_node != node) {
228 			ACPI_PATH_PUT8(full_path, path_size,
229 				       AML_DUAL_NAME_PREFIX, length);
230 		}
231 
232 		ACPI_MOVE_32_TO_32(name, &next_node->name);
233 		do_no_trailing = no_trailing;
234 		for (i = 0; i < 4; i++) {
235 			c = name[4 - i - 1];
236 			if (do_no_trailing && c != '_') {
237 				do_no_trailing = FALSE;
238 			}
239 			if (!do_no_trailing) {
240 				ACPI_PATH_PUT8(full_path, path_size, c, length);
241 			}
242 		}
243 
244 		next_node = next_node->parent;
245 	}
246 
247 	ACPI_PATH_PUT8(full_path, path_size, AML_ROOT_PREFIX, length);
248 
249 	/* Reverse the path string */
250 
251 	if (length <= path_size) {
252 		left = full_path;
253 		right = full_path + length - 1;
254 
255 		while (left < right) {
256 			c = *left;
257 			*left++ = *right;
258 			*right-- = c;
259 		}
260 	}
261 
262 	/* Append the trailing null */
263 
264 build_trailing_null:
265 	ACPI_PATH_PUT8(full_path, path_size, '\0', length);
266 
267 #undef ACPI_PATH_PUT8
268 
269 	return_UINT32(length);
270 }
271 
272 /*******************************************************************************
273  *
274  * FUNCTION:    acpi_ns_get_normalized_pathname
275  *
276  * PARAMETERS:  node            - Namespace node whose pathname is needed
277  *              no_trailing     - Remove trailing '_' from each name segment
278  *
279  * RETURN:      Pointer to storage containing the fully qualified name of
280  *              the node, In external format (name segments separated by path
281  *              separators.)
282  *
283  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
284  *              for error and debug statements. All trailing '_' will be
285  *              removed from the full pathname if 'NoTrailing' is specified..
286  *
287  ******************************************************************************/
288 
acpi_ns_get_normalized_pathname(struct acpi_namespace_node * node,u8 no_trailing)289 char *acpi_ns_get_normalized_pathname(struct acpi_namespace_node *node,
290 				      u8 no_trailing)
291 {
292 	char *name_buffer;
293 	acpi_size size;
294 
295 	ACPI_FUNCTION_TRACE_PTR(ns_get_normalized_pathname, node);
296 
297 	/* Calculate required buffer size based on depth below root */
298 
299 	size = acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
300 	if (!size) {
301 		return_PTR(NULL);
302 	}
303 
304 	/* Allocate a buffer to be returned to caller */
305 
306 	name_buffer = ACPI_ALLOCATE_ZEROED(size);
307 	if (!name_buffer) {
308 		ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
309 		return_PTR(NULL);
310 	}
311 
312 	/* Build the path in the allocated buffer */
313 
314 	(void)acpi_ns_build_normalized_path(node, name_buffer, (u32)size,
315 					    no_trailing);
316 
317 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES, "%s: Path \"%s\"\n",
318 			      ACPI_GET_FUNCTION_NAME, name_buffer));
319 
320 	return_PTR(name_buffer);
321 }
322 
323 /*******************************************************************************
324  *
325  * FUNCTION:    acpi_ns_build_prefixed_pathname
326  *
327  * PARAMETERS:  prefix_scope        - Scope/Path that prefixes the internal path
328  *              internal_path       - Name or path of the namespace node
329  *
330  * RETURN:      None
331  *
332  * DESCRIPTION: Construct a fully qualified pathname from a concatenation of:
333  *              1) Path associated with the prefix_scope namespace node
334  *              2) External path representation of the Internal path
335  *
336  ******************************************************************************/
337 
acpi_ns_build_prefixed_pathname(union acpi_generic_state * prefix_scope,const char * internal_path)338 char *acpi_ns_build_prefixed_pathname(union acpi_generic_state *prefix_scope,
339 				      const char *internal_path)
340 {
341 	acpi_status status;
342 	char *full_path = NULL;
343 	char *external_path = NULL;
344 	char *prefix_path = NULL;
345 	acpi_size prefix_path_length = 0;
346 
347 	/* If there is a prefix, get the pathname to it */
348 
349 	if (prefix_scope && prefix_scope->scope.node) {
350 		prefix_path =
351 		    acpi_ns_get_normalized_pathname(prefix_scope->scope.node,
352 						    TRUE);
353 		if (prefix_path) {
354 			prefix_path_length = strlen(prefix_path);
355 		}
356 	}
357 
358 	status = acpi_ns_externalize_name(ACPI_UINT32_MAX, internal_path,
359 					  NULL, &external_path);
360 	if (ACPI_FAILURE(status)) {
361 		goto cleanup;
362 	}
363 
364 	/* Merge the prefix path and the path. 2 is for one dot and trailing null */
365 
366 	full_path =
367 	    ACPI_ALLOCATE_ZEROED(prefix_path_length + strlen(external_path) +
368 				 2);
369 	if (!full_path) {
370 		goto cleanup;
371 	}
372 
373 	/* Don't merge if the External path is already fully qualified */
374 
375 	if (prefix_path && (*external_path != '\\') && (*external_path != '^')) {
376 		strcat(full_path, prefix_path);
377 		if (prefix_path[1]) {
378 			strcat(full_path, ".");
379 		}
380 	}
381 
382 	acpi_ns_normalize_pathname(external_path);
383 	strcat(full_path, external_path);
384 
385 cleanup:
386 	if (prefix_path) {
387 		ACPI_FREE(prefix_path);
388 	}
389 	if (external_path) {
390 		ACPI_FREE(external_path);
391 	}
392 
393 	return (full_path);
394 }
395 
396 /*******************************************************************************
397  *
398  * FUNCTION:    acpi_ns_normalize_pathname
399  *
400  * PARAMETERS:  original_path       - Path to be normalized, in External format
401  *
402  * RETURN:      The original path is processed in-place
403  *
404  * DESCRIPTION: Remove trailing underscores from each element of a path.
405  *
406  *              For example:  \A___.B___.C___ becomes \A.B.C
407  *
408  ******************************************************************************/
409 
acpi_ns_normalize_pathname(char * original_path)410 void acpi_ns_normalize_pathname(char *original_path)
411 {
412 	char *input_path = original_path;
413 	char *new_path_buffer;
414 	char *new_path;
415 	u32 i;
416 
417 	/* Allocate a temp buffer in which to construct the new path */
418 
419 	new_path_buffer = ACPI_ALLOCATE_ZEROED(strlen(input_path) + 1);
420 	new_path = new_path_buffer;
421 	if (!new_path_buffer) {
422 		return;
423 	}
424 
425 	/* Special characters may appear at the beginning of the path */
426 
427 	if (*input_path == '\\') {
428 		*new_path = *input_path;
429 		new_path++;
430 		input_path++;
431 	}
432 
433 	while (*input_path == '^') {
434 		*new_path = *input_path;
435 		new_path++;
436 		input_path++;
437 	}
438 
439 	/* Remainder of the path */
440 
441 	while (*input_path) {
442 
443 		/* Do one nameseg at a time */
444 
445 		for (i = 0; (i < ACPI_NAMESEG_SIZE) && *input_path; i++) {
446 			if ((i == 0) || (*input_path != '_')) {	/* First char is allowed to be underscore */
447 				*new_path = *input_path;
448 				new_path++;
449 			}
450 
451 			input_path++;
452 		}
453 
454 		/* Dot means that there are more namesegs to come */
455 
456 		if (*input_path == '.') {
457 			*new_path = *input_path;
458 			new_path++;
459 			input_path++;
460 		}
461 	}
462 
463 	*new_path = 0;
464 	strcpy(original_path, new_path_buffer);
465 	ACPI_FREE(new_path_buffer);
466 }
467