xref: /openbmc/linux/drivers/acpi/acpica/evgpeinit.c (revision 9ffc93f2)
1 /******************************************************************************
2  *
3  * Module Name: evgpeinit - System GPE initialization and update
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2012, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acevents.h"
47 #include "acnamesp.h"
48 
49 #define _COMPONENT          ACPI_EVENTS
50 ACPI_MODULE_NAME("evgpeinit")
51 
52 /*
53  * Note: History of _PRW support in ACPICA
54  *
55  * Originally (2000 - 2010), the GPE initialization code performed a walk of
56  * the entire namespace to execute the _PRW methods and detect all GPEs
57  * capable of waking the system.
58  *
59  * As of 10/2010, the _PRW method execution has been removed since it is
60  * actually unnecessary. The host OS must in fact execute all _PRW methods
61  * in order to identify the device/power-resource dependencies. We now put
62  * the onus on the host OS to identify the wake GPEs as part of this process
63  * and to inform ACPICA of these GPEs via the acpi_setup_gpe_for_wake interface. This
64  * not only reduces the complexity of the ACPICA initialization code, but in
65  * some cases (on systems with very large namespaces) it should reduce the
66  * kernel boot time as well.
67  */
68 
69 /*******************************************************************************
70  *
71  * FUNCTION:    acpi_ev_gpe_initialize
72  *
73  * PARAMETERS:  None
74  *
75  * RETURN:      Status
76  *
77  * DESCRIPTION: Initialize the GPE data structures and the FADT GPE 0/1 blocks
78  *
79  ******************************************************************************/
80 acpi_status acpi_ev_gpe_initialize(void)
81 {
82 	u32 register_count0 = 0;
83 	u32 register_count1 = 0;
84 	u32 gpe_number_max = 0;
85 	acpi_status status;
86 
87 	ACPI_FUNCTION_TRACE(ev_gpe_initialize);
88 
89 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
90 	if (ACPI_FAILURE(status)) {
91 		return_ACPI_STATUS(status);
92 	}
93 
94 	/*
95 	 * Initialize the GPE Block(s) defined in the FADT
96 	 *
97 	 * Why the GPE register block lengths are divided by 2:  From the ACPI
98 	 * Spec, section "General-Purpose Event Registers", we have:
99 	 *
100 	 * "Each register block contains two registers of equal length
101 	 *  GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the
102 	 *  GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN
103 	 *  The length of the GPE1_STS and GPE1_EN registers is equal to
104 	 *  half the GPE1_LEN. If a generic register block is not supported
105 	 *  then its respective block pointer and block length values in the
106 	 *  FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need
107 	 *  to be the same size."
108 	 */
109 
110 	/*
111 	 * Determine the maximum GPE number for this machine.
112 	 *
113 	 * Note: both GPE0 and GPE1 are optional, and either can exist without
114 	 * the other.
115 	 *
116 	 * If EITHER the register length OR the block address are zero, then that
117 	 * particular block is not supported.
118 	 */
119 	if (acpi_gbl_FADT.gpe0_block_length &&
120 	    acpi_gbl_FADT.xgpe0_block.address) {
121 
122 		/* GPE block 0 exists (has both length and address > 0) */
123 
124 		register_count0 = (u16)(acpi_gbl_FADT.gpe0_block_length / 2);
125 
126 		gpe_number_max =
127 		    (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;
128 
129 		/* Install GPE Block 0 */
130 
131 		status = acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
132 						  &acpi_gbl_FADT.xgpe0_block,
133 						  register_count0, 0,
134 						  acpi_gbl_FADT.sci_interrupt,
135 						  &acpi_gbl_gpe_fadt_blocks[0]);
136 
137 		if (ACPI_FAILURE(status)) {
138 			ACPI_EXCEPTION((AE_INFO, status,
139 					"Could not create GPE Block 0"));
140 		}
141 	}
142 
143 	if (acpi_gbl_FADT.gpe1_block_length &&
144 	    acpi_gbl_FADT.xgpe1_block.address) {
145 
146 		/* GPE block 1 exists (has both length and address > 0) */
147 
148 		register_count1 = (u16)(acpi_gbl_FADT.gpe1_block_length / 2);
149 
150 		/* Check for GPE0/GPE1 overlap (if both banks exist) */
151 
152 		if ((register_count0) &&
153 		    (gpe_number_max >= acpi_gbl_FADT.gpe1_base)) {
154 			ACPI_ERROR((AE_INFO,
155 				    "GPE0 block (GPE 0 to %u) overlaps the GPE1 block "
156 				    "(GPE %u to %u) - Ignoring GPE1",
157 				    gpe_number_max, acpi_gbl_FADT.gpe1_base,
158 				    acpi_gbl_FADT.gpe1_base +
159 				    ((register_count1 *
160 				      ACPI_GPE_REGISTER_WIDTH) - 1)));
161 
162 			/* Ignore GPE1 block by setting the register count to zero */
163 
164 			register_count1 = 0;
165 		} else {
166 			/* Install GPE Block 1 */
167 
168 			status =
169 			    acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
170 						     &acpi_gbl_FADT.xgpe1_block,
171 						     register_count1,
172 						     acpi_gbl_FADT.gpe1_base,
173 						     acpi_gbl_FADT.
174 						     sci_interrupt,
175 						     &acpi_gbl_gpe_fadt_blocks
176 						     [1]);
177 
178 			if (ACPI_FAILURE(status)) {
179 				ACPI_EXCEPTION((AE_INFO, status,
180 						"Could not create GPE Block 1"));
181 			}
182 
183 			/*
184 			 * GPE0 and GPE1 do not have to be contiguous in the GPE number
185 			 * space. However, GPE0 always starts at GPE number zero.
186 			 */
187 			gpe_number_max = acpi_gbl_FADT.gpe1_base +
188 			    ((register_count1 * ACPI_GPE_REGISTER_WIDTH) - 1);
189 		}
190 	}
191 
192 	/* Exit if there are no GPE registers */
193 
194 	if ((register_count0 + register_count1) == 0) {
195 
196 		/* GPEs are not required by ACPI, this is OK */
197 
198 		ACPI_DEBUG_PRINT((ACPI_DB_INIT,
199 				  "There are no GPE blocks defined in the FADT\n"));
200 		status = AE_OK;
201 		goto cleanup;
202 	}
203 
204 	/* Check for Max GPE number out-of-range */
205 
206 	if (gpe_number_max > ACPI_GPE_MAX) {
207 		ACPI_ERROR((AE_INFO,
208 			    "Maximum GPE number from FADT is too large: 0x%X",
209 			    gpe_number_max));
210 		status = AE_BAD_VALUE;
211 		goto cleanup;
212 	}
213 
214       cleanup:
215 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
216 	return_ACPI_STATUS(AE_OK);
217 }
218 
219 /*******************************************************************************
220  *
221  * FUNCTION:    acpi_ev_update_gpes
222  *
223  * PARAMETERS:  table_owner_id      - ID of the newly-loaded ACPI table
224  *
225  * RETURN:      None
226  *
227  * DESCRIPTION: Check for new GPE methods (_Lxx/_Exx) made available as a
228  *              result of a Load() or load_table() operation. If new GPE
229  *              methods have been installed, register the new methods.
230  *
231  ******************************************************************************/
232 
233 void acpi_ev_update_gpes(acpi_owner_id table_owner_id)
234 {
235 	struct acpi_gpe_xrupt_info *gpe_xrupt_info;
236 	struct acpi_gpe_block_info *gpe_block;
237 	struct acpi_gpe_walk_info walk_info;
238 	acpi_status status = AE_OK;
239 
240 	/*
241 	 * Find any _Lxx/_Exx GPE methods that have just been loaded.
242 	 *
243 	 * Any GPEs that correspond to new _Lxx/_Exx methods are immediately
244 	 * enabled.
245 	 *
246 	 * Examine the namespace underneath each gpe_device within the
247 	 * gpe_block lists.
248 	 */
249 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
250 	if (ACPI_FAILURE(status)) {
251 		return;
252 	}
253 
254 	walk_info.count = 0;
255 	walk_info.owner_id = table_owner_id;
256 	walk_info.execute_by_owner_id = TRUE;
257 
258 	/* Walk the interrupt level descriptor list */
259 
260 	gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
261 	while (gpe_xrupt_info) {
262 
263 		/* Walk all Gpe Blocks attached to this interrupt level */
264 
265 		gpe_block = gpe_xrupt_info->gpe_block_list_head;
266 		while (gpe_block) {
267 			walk_info.gpe_block = gpe_block;
268 			walk_info.gpe_device = gpe_block->node;
269 
270 			status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD,
271 							walk_info.gpe_device,
272 							ACPI_UINT32_MAX,
273 							ACPI_NS_WALK_NO_UNLOCK,
274 							acpi_ev_match_gpe_method,
275 							NULL, &walk_info, NULL);
276 			if (ACPI_FAILURE(status)) {
277 				ACPI_EXCEPTION((AE_INFO, status,
278 						"While decoding _Lxx/_Exx methods"));
279 			}
280 
281 			gpe_block = gpe_block->next;
282 		}
283 
284 		gpe_xrupt_info = gpe_xrupt_info->next;
285 	}
286 
287 	if (walk_info.count) {
288 		ACPI_INFO((AE_INFO, "Enabled %u new GPEs", walk_info.count));
289 	}
290 
291 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
292 	return;
293 }
294 
295 /*******************************************************************************
296  *
297  * FUNCTION:    acpi_ev_match_gpe_method
298  *
299  * PARAMETERS:  Callback from walk_namespace
300  *
301  * RETURN:      Status
302  *
303  * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
304  *              control method under the _GPE portion of the namespace.
305  *              Extract the name and GPE type from the object, saving this
306  *              information for quick lookup during GPE dispatch. Allows a
307  *              per-owner_id evaluation if execute_by_owner_id is TRUE in the
308  *              walk_info parameter block.
309  *
310  *              The name of each GPE control method is of the form:
311  *              "_Lxx" or "_Exx", where:
312  *                  L      - means that the GPE is level triggered
313  *                  E      - means that the GPE is edge triggered
314  *                  xx     - is the GPE number [in HEX]
315  *
316  * If walk_info->execute_by_owner_id is TRUE, we only execute examine GPE methods
317  * with that owner.
318  *
319  ******************************************************************************/
320 
321 acpi_status
322 acpi_ev_match_gpe_method(acpi_handle obj_handle,
323 			 u32 level, void *context, void **return_value)
324 {
325 	struct acpi_namespace_node *method_node =
326 	    ACPI_CAST_PTR(struct acpi_namespace_node, obj_handle);
327 	struct acpi_gpe_walk_info *walk_info =
328 	    ACPI_CAST_PTR(struct acpi_gpe_walk_info, context);
329 	struct acpi_gpe_event_info *gpe_event_info;
330 	u32 gpe_number;
331 	char name[ACPI_NAME_SIZE + 1];
332 	u8 type;
333 
334 	ACPI_FUNCTION_TRACE(ev_match_gpe_method);
335 
336 	/* Check if requested owner_id matches this owner_id */
337 
338 	if ((walk_info->execute_by_owner_id) &&
339 	    (method_node->owner_id != walk_info->owner_id)) {
340 		return_ACPI_STATUS(AE_OK);
341 	}
342 
343 	/*
344 	 * Match and decode the _Lxx and _Exx GPE method names
345 	 *
346 	 * 1) Extract the method name and null terminate it
347 	 */
348 	ACPI_MOVE_32_TO_32(name, &method_node->name.integer);
349 	name[ACPI_NAME_SIZE] = 0;
350 
351 	/* 2) Name must begin with an underscore */
352 
353 	if (name[0] != '_') {
354 		return_ACPI_STATUS(AE_OK);	/* Ignore this method */
355 	}
356 
357 	/*
358 	 * 3) Edge/Level determination is based on the 2nd character
359 	 *    of the method name
360 	 */
361 	switch (name[1]) {
362 	case 'L':
363 		type = ACPI_GPE_LEVEL_TRIGGERED;
364 		break;
365 
366 	case 'E':
367 		type = ACPI_GPE_EDGE_TRIGGERED;
368 		break;
369 
370 	default:
371 		/* Unknown method type, just ignore it */
372 
373 		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
374 				  "Ignoring unknown GPE method type: %s "
375 				  "(name not of form _Lxx or _Exx)", name));
376 		return_ACPI_STATUS(AE_OK);
377 	}
378 
379 	/* 4) The last two characters of the name are the hex GPE Number */
380 
381 	gpe_number = ACPI_STRTOUL(&name[2], NULL, 16);
382 	if (gpe_number == ACPI_UINT32_MAX) {
383 
384 		/* Conversion failed; invalid method, just ignore it */
385 
386 		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
387 				  "Could not extract GPE number from name: %s "
388 				  "(name is not of form _Lxx or _Exx)", name));
389 		return_ACPI_STATUS(AE_OK);
390 	}
391 
392 	/* Ensure that we have a valid GPE number for this GPE block */
393 
394 	gpe_event_info =
395 	    acpi_ev_low_get_gpe_info(gpe_number, walk_info->gpe_block);
396 	if (!gpe_event_info) {
397 		/*
398 		 * This gpe_number is not valid for this GPE block, just ignore it.
399 		 * However, it may be valid for a different GPE block, since GPE0
400 		 * and GPE1 methods both appear under \_GPE.
401 		 */
402 		return_ACPI_STATUS(AE_OK);
403 	}
404 
405 	if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
406 	    ACPI_GPE_DISPATCH_HANDLER) {
407 
408 		/* If there is already a handler, ignore this GPE method */
409 
410 		return_ACPI_STATUS(AE_OK);
411 	}
412 
413 	if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
414 	    ACPI_GPE_DISPATCH_METHOD) {
415 		/*
416 		 * If there is already a method, ignore this method. But check
417 		 * for a type mismatch (if both the _Lxx AND _Exx exist)
418 		 */
419 		if (type != (gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK)) {
420 			ACPI_ERROR((AE_INFO,
421 				    "For GPE 0x%.2X, found both _L%2.2X and _E%2.2X methods",
422 				    gpe_number, gpe_number, gpe_number));
423 		}
424 		return_ACPI_STATUS(AE_OK);
425 	}
426 
427 	/* Disable the GPE in case it's been enabled already. */
428 	(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
429 
430 	/*
431 	 * Add the GPE information from above to the gpe_event_info block for
432 	 * use during dispatch of this GPE.
433 	 */
434 	gpe_event_info->flags &= ~(ACPI_GPE_DISPATCH_MASK);
435 	gpe_event_info->flags |= (u8)(type | ACPI_GPE_DISPATCH_METHOD);
436 	gpe_event_info->dispatch.method_node = method_node;
437 
438 	ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
439 			  "Registered GPE method %s as GPE number 0x%.2X\n",
440 			  name, gpe_number));
441 	return_ACPI_STATUS(AE_OK);
442 }
443