xref: /openbmc/linux/drivers/acpi/acpica/evgpeinit.c (revision 4f3db074)
1 /******************************************************************************
2  *
3  * Module Name: evgpeinit - System GPE initialization and update
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, 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 #if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
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 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT,
90 			      "Initializing General Purpose Events (GPEs):\n"));
91 
92 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
93 	if (ACPI_FAILURE(status)) {
94 		return_ACPI_STATUS(status);
95 	}
96 
97 	/*
98 	 * Initialize the GPE Block(s) defined in the FADT
99 	 *
100 	 * Why the GPE register block lengths are divided by 2:  From the ACPI
101 	 * Spec, section "General-Purpose Event Registers", we have:
102 	 *
103 	 * "Each register block contains two registers of equal length
104 	 *  GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the
105 	 *  GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN
106 	 *  The length of the GPE1_STS and GPE1_EN registers is equal to
107 	 *  half the GPE1_LEN. If a generic register block is not supported
108 	 *  then its respective block pointer and block length values in the
109 	 *  FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need
110 	 *  to be the same size."
111 	 */
112 
113 	/*
114 	 * Determine the maximum GPE number for this machine.
115 	 *
116 	 * Note: both GPE0 and GPE1 are optional, and either can exist without
117 	 * the other.
118 	 *
119 	 * If EITHER the register length OR the block address are zero, then that
120 	 * particular block is not supported.
121 	 */
122 	if (acpi_gbl_FADT.gpe0_block_length &&
123 	    acpi_gbl_FADT.xgpe0_block.address) {
124 
125 		/* GPE block 0 exists (has both length and address > 0) */
126 
127 		register_count0 = (u16)(acpi_gbl_FADT.gpe0_block_length / 2);
128 		gpe_number_max =
129 		    (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;
130 
131 		/* Install GPE Block 0 */
132 
133 		status = acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
134 						  acpi_gbl_FADT.xgpe0_block.
135 						  address,
136 						  acpi_gbl_FADT.xgpe0_block.
137 						  space_id, register_count0, 0,
138 						  acpi_gbl_FADT.sci_interrupt,
139 						  &acpi_gbl_gpe_fadt_blocks[0]);
140 
141 		if (ACPI_FAILURE(status)) {
142 			ACPI_EXCEPTION((AE_INFO, status,
143 					"Could not create GPE Block 0"));
144 		}
145 	}
146 
147 	if (acpi_gbl_FADT.gpe1_block_length &&
148 	    acpi_gbl_FADT.xgpe1_block.address) {
149 
150 		/* GPE block 1 exists (has both length and address > 0) */
151 
152 		register_count1 = (u16)(acpi_gbl_FADT.gpe1_block_length / 2);
153 
154 		/* Check for GPE0/GPE1 overlap (if both banks exist) */
155 
156 		if ((register_count0) &&
157 		    (gpe_number_max >= acpi_gbl_FADT.gpe1_base)) {
158 			ACPI_ERROR((AE_INFO,
159 				    "GPE0 block (GPE 0 to %u) overlaps the GPE1 block "
160 				    "(GPE %u to %u) - Ignoring GPE1",
161 				    gpe_number_max, acpi_gbl_FADT.gpe1_base,
162 				    acpi_gbl_FADT.gpe1_base +
163 				    ((register_count1 *
164 				      ACPI_GPE_REGISTER_WIDTH) - 1)));
165 
166 			/* Ignore GPE1 block by setting the register count to zero */
167 
168 			register_count1 = 0;
169 		} else {
170 			/* Install GPE Block 1 */
171 
172 			status =
173 			    acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
174 						     acpi_gbl_FADT.xgpe1_block.
175 						     address,
176 						     acpi_gbl_FADT.xgpe1_block.
177 						     space_id, register_count1,
178 						     acpi_gbl_FADT.gpe1_base,
179 						     acpi_gbl_FADT.
180 						     sci_interrupt,
181 						     &acpi_gbl_gpe_fadt_blocks
182 						     [1]);
183 
184 			if (ACPI_FAILURE(status)) {
185 				ACPI_EXCEPTION((AE_INFO, status,
186 						"Could not create GPE Block 1"));
187 			}
188 
189 			/*
190 			 * GPE0 and GPE1 do not have to be contiguous in the GPE number
191 			 * space. However, GPE0 always starts at GPE number zero.
192 			 */
193 			gpe_number_max = acpi_gbl_FADT.gpe1_base +
194 			    ((register_count1 * ACPI_GPE_REGISTER_WIDTH) - 1);
195 		}
196 	}
197 
198 	/* Exit if there are no GPE registers */
199 
200 	if ((register_count0 + register_count1) == 0) {
201 
202 		/* GPEs are not required by ACPI, this is OK */
203 
204 		ACPI_DEBUG_PRINT((ACPI_DB_INIT,
205 				  "There are no GPE blocks defined in the FADT\n"));
206 		status = AE_OK;
207 		goto cleanup;
208 	}
209 
210 cleanup:
211 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
212 	return_ACPI_STATUS(AE_OK);
213 }
214 
215 /*******************************************************************************
216  *
217  * FUNCTION:    acpi_ev_update_gpes
218  *
219  * PARAMETERS:  table_owner_id      - ID of the newly-loaded ACPI table
220  *
221  * RETURN:      None
222  *
223  * DESCRIPTION: Check for new GPE methods (_Lxx/_Exx) made available as a
224  *              result of a Load() or load_table() operation. If new GPE
225  *              methods have been installed, register the new methods.
226  *
227  ******************************************************************************/
228 
229 void acpi_ev_update_gpes(acpi_owner_id table_owner_id)
230 {
231 	struct acpi_gpe_xrupt_info *gpe_xrupt_info;
232 	struct acpi_gpe_block_info *gpe_block;
233 	struct acpi_gpe_walk_info walk_info;
234 	acpi_status status = AE_OK;
235 
236 	/*
237 	 * Find any _Lxx/_Exx GPE methods that have just been loaded.
238 	 *
239 	 * Any GPEs that correspond to new _Lxx/_Exx methods are immediately
240 	 * enabled.
241 	 *
242 	 * Examine the namespace underneath each gpe_device within the
243 	 * gpe_block lists.
244 	 */
245 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
246 	if (ACPI_FAILURE(status)) {
247 		return;
248 	}
249 
250 	walk_info.count = 0;
251 	walk_info.owner_id = table_owner_id;
252 	walk_info.execute_by_owner_id = TRUE;
253 
254 	/* Walk the interrupt level descriptor list */
255 
256 	gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
257 	while (gpe_xrupt_info) {
258 
259 		/* Walk all Gpe Blocks attached to this interrupt level */
260 
261 		gpe_block = gpe_xrupt_info->gpe_block_list_head;
262 		while (gpe_block) {
263 			walk_info.gpe_block = gpe_block;
264 			walk_info.gpe_device = gpe_block->node;
265 
266 			status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD,
267 							walk_info.gpe_device,
268 							ACPI_UINT32_MAX,
269 							ACPI_NS_WALK_NO_UNLOCK,
270 							acpi_ev_match_gpe_method,
271 							NULL, &walk_info, NULL);
272 			if (ACPI_FAILURE(status)) {
273 				ACPI_EXCEPTION((AE_INFO, status,
274 						"While decoding _Lxx/_Exx methods"));
275 			}
276 
277 			gpe_block = gpe_block->next;
278 		}
279 
280 		gpe_xrupt_info = gpe_xrupt_info->next;
281 	}
282 
283 	if (walk_info.count) {
284 		ACPI_INFO((AE_INFO, "Enabled %u new GPEs", walk_info.count));
285 	}
286 
287 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
288 	return;
289 }
290 
291 /*******************************************************************************
292  *
293  * FUNCTION:    acpi_ev_match_gpe_method
294  *
295  * PARAMETERS:  Callback from walk_namespace
296  *
297  * RETURN:      Status
298  *
299  * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
300  *              control method under the _GPE portion of the namespace.
301  *              Extract the name and GPE type from the object, saving this
302  *              information for quick lookup during GPE dispatch. Allows a
303  *              per-owner_id evaluation if execute_by_owner_id is TRUE in the
304  *              walk_info parameter block.
305  *
306  *              The name of each GPE control method is of the form:
307  *              "_Lxx" or "_Exx", where:
308  *                  L      - means that the GPE is level triggered
309  *                  E      - means that the GPE is edge triggered
310  *                  xx     - is the GPE number [in HEX]
311  *
312  * If walk_info->execute_by_owner_id is TRUE, we only execute examine GPE methods
313  * with that owner.
314  *
315  ******************************************************************************/
316 
317 acpi_status
318 acpi_ev_match_gpe_method(acpi_handle obj_handle,
319 			 u32 level, void *context, void **return_value)
320 {
321 	struct acpi_namespace_node *method_node =
322 	    ACPI_CAST_PTR(struct acpi_namespace_node, obj_handle);
323 	struct acpi_gpe_walk_info *walk_info =
324 	    ACPI_CAST_PTR(struct acpi_gpe_walk_info, context);
325 	struct acpi_gpe_event_info *gpe_event_info;
326 	u32 gpe_number;
327 	char name[ACPI_NAME_SIZE + 1];
328 	u8 type;
329 
330 	ACPI_FUNCTION_TRACE(ev_match_gpe_method);
331 
332 	/* Check if requested owner_id matches this owner_id */
333 
334 	if ((walk_info->execute_by_owner_id) &&
335 	    (method_node->owner_id != walk_info->owner_id)) {
336 		return_ACPI_STATUS(AE_OK);
337 	}
338 
339 	/*
340 	 * Match and decode the _Lxx and _Exx GPE method names
341 	 *
342 	 * 1) Extract the method name and null terminate it
343 	 */
344 	ACPI_MOVE_32_TO_32(name, &method_node->name.integer);
345 	name[ACPI_NAME_SIZE] = 0;
346 
347 	/* 2) Name must begin with an underscore */
348 
349 	if (name[0] != '_') {
350 		return_ACPI_STATUS(AE_OK);	/* Ignore this method */
351 	}
352 
353 	/*
354 	 * 3) Edge/Level determination is based on the 2nd character
355 	 *    of the method name
356 	 */
357 	switch (name[1]) {
358 	case 'L':
359 
360 		type = ACPI_GPE_LEVEL_TRIGGERED;
361 		break;
362 
363 	case 'E':
364 
365 		type = ACPI_GPE_EDGE_TRIGGERED;
366 		break;
367 
368 	default:
369 
370 		/* Unknown method type, just ignore it */
371 
372 		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
373 				  "Ignoring unknown GPE method type: %s "
374 				  "(name not of form _Lxx or _Exx)", name));
375 		return_ACPI_STATUS(AE_OK);
376 	}
377 
378 	/* 4) The last two characters of the name are the hex GPE Number */
379 
380 	gpe_number = ACPI_STRTOUL(&name[2], NULL, 16);
381 	if (gpe_number == ACPI_UINT32_MAX) {
382 
383 		/* Conversion failed; invalid method, just ignore it */
384 
385 		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
386 				  "Could not extract GPE number from name: %s "
387 				  "(name is not of form _Lxx or _Exx)", name));
388 		return_ACPI_STATUS(AE_OK);
389 	}
390 
391 	/* Ensure that we have a valid GPE number for this GPE block */
392 
393 	gpe_event_info =
394 	    acpi_ev_low_get_gpe_info(gpe_number, walk_info->gpe_block);
395 	if (!gpe_event_info) {
396 		/*
397 		 * This gpe_number is not valid for this GPE block, just ignore it.
398 		 * However, it may be valid for a different GPE block, since GPE0
399 		 * and GPE1 methods both appear under \_GPE.
400 		 */
401 		return_ACPI_STATUS(AE_OK);
402 	}
403 
404 	if ((ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
405 	     ACPI_GPE_DISPATCH_HANDLER) ||
406 	    (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
407 	     ACPI_GPE_DISPATCH_RAW_HANDLER)) {
408 
409 		/* If there is already a handler, ignore this GPE method */
410 
411 		return_ACPI_STATUS(AE_OK);
412 	}
413 
414 	if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
415 	    ACPI_GPE_DISPATCH_METHOD) {
416 		/*
417 		 * If there is already a method, ignore this method. But check
418 		 * for a type mismatch (if both the _Lxx AND _Exx exist)
419 		 */
420 		if (type != (gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK)) {
421 			ACPI_ERROR((AE_INFO,
422 				    "For GPE 0x%.2X, found both _L%2.2X and _E%2.2X methods",
423 				    gpe_number, gpe_number, gpe_number));
424 		}
425 		return_ACPI_STATUS(AE_OK);
426 	}
427 
428 	/* Disable the GPE in case it's been enabled already. */
429 
430 	(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
431 
432 	/*
433 	 * Add the GPE information from above to the gpe_event_info block for
434 	 * use during dispatch of this GPE.
435 	 */
436 	gpe_event_info->flags &= ~(ACPI_GPE_DISPATCH_MASK);
437 	gpe_event_info->flags |= (u8)(type | ACPI_GPE_DISPATCH_METHOD);
438 	gpe_event_info->dispatch.method_node = method_node;
439 
440 	ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
441 			  "Registered GPE method %s as GPE number 0x%.2X\n",
442 			  name, gpe_number));
443 	return_ACPI_STATUS(AE_OK);
444 }
445 
446 #endif				/* !ACPI_REDUCED_HARDWARE */
447