xref: /openbmc/linux/drivers/acpi/acpica/evgpeinit.c (revision b830f94f)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: evgpeinit - System GPE initialization and update
5  *
6  * Copyright (C) 2000 - 2019, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acevents.h"
13 #include "acnamesp.h"
14 
15 #define _COMPONENT          ACPI_EVENTS
16 ACPI_MODULE_NAME("evgpeinit")
17 #if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
18 /*
19  * Note: History of _PRW support in ACPICA
20  *
21  * Originally (2000 - 2010), the GPE initialization code performed a walk of
22  * the entire namespace to execute the _PRW methods and detect all GPEs
23  * capable of waking the system.
24  *
25  * As of 10/2010, the _PRW method execution has been removed since it is
26  * actually unnecessary. The host OS must in fact execute all _PRW methods
27  * in order to identify the device/power-resource dependencies. We now put
28  * the onus on the host OS to identify the wake GPEs as part of this process
29  * and to inform ACPICA of these GPEs via the acpi_setup_gpe_for_wake interface. This
30  * not only reduces the complexity of the ACPICA initialization code, but in
31  * some cases (on systems with very large namespaces) it should reduce the
32  * kernel boot time as well.
33  */
34 
35 /*******************************************************************************
36  *
37  * FUNCTION:    acpi_ev_gpe_initialize
38  *
39  * PARAMETERS:  None
40  *
41  * RETURN:      Status
42  *
43  * DESCRIPTION: Initialize the GPE data structures and the FADT GPE 0/1 blocks
44  *
45  ******************************************************************************/
46 acpi_status acpi_ev_gpe_initialize(void)
47 {
48 	u32 register_count0 = 0;
49 	u32 register_count1 = 0;
50 	u32 gpe_number_max = 0;
51 	acpi_status status;
52 
53 	ACPI_FUNCTION_TRACE(ev_gpe_initialize);
54 
55 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT,
56 			      "Initializing General Purpose Events (GPEs):\n"));
57 
58 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
59 	if (ACPI_FAILURE(status)) {
60 		return_ACPI_STATUS(status);
61 	}
62 
63 	/*
64 	 * Initialize the GPE Block(s) defined in the FADT
65 	 *
66 	 * Why the GPE register block lengths are divided by 2:  From the ACPI
67 	 * Spec, section "General-Purpose Event Registers", we have:
68 	 *
69 	 * "Each register block contains two registers of equal length
70 	 *  GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the
71 	 *  GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN
72 	 *  The length of the GPE1_STS and GPE1_EN registers is equal to
73 	 *  half the GPE1_LEN. If a generic register block is not supported
74 	 *  then its respective block pointer and block length values in the
75 	 *  FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need
76 	 *  to be the same size."
77 	 */
78 
79 	/*
80 	 * Determine the maximum GPE number for this machine.
81 	 *
82 	 * Note: both GPE0 and GPE1 are optional, and either can exist without
83 	 * the other.
84 	 *
85 	 * If EITHER the register length OR the block address are zero, then that
86 	 * particular block is not supported.
87 	 */
88 	if (acpi_gbl_FADT.gpe0_block_length &&
89 	    acpi_gbl_FADT.xgpe0_block.address) {
90 
91 		/* GPE block 0 exists (has both length and address > 0) */
92 
93 		register_count0 = (u16)(acpi_gbl_FADT.gpe0_block_length / 2);
94 		gpe_number_max =
95 		    (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;
96 
97 		/* Install GPE Block 0 */
98 
99 		status = acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
100 						  acpi_gbl_FADT.xgpe0_block.
101 						  address,
102 						  acpi_gbl_FADT.xgpe0_block.
103 						  space_id, register_count0, 0,
104 						  acpi_gbl_FADT.sci_interrupt,
105 						  &acpi_gbl_gpe_fadt_blocks[0]);
106 
107 		if (ACPI_FAILURE(status)) {
108 			ACPI_EXCEPTION((AE_INFO, status,
109 					"Could not create GPE Block 0"));
110 		}
111 	}
112 
113 	if (acpi_gbl_FADT.gpe1_block_length &&
114 	    acpi_gbl_FADT.xgpe1_block.address) {
115 
116 		/* GPE block 1 exists (has both length and address > 0) */
117 
118 		register_count1 = (u16)(acpi_gbl_FADT.gpe1_block_length / 2);
119 
120 		/* Check for GPE0/GPE1 overlap (if both banks exist) */
121 
122 		if ((register_count0) &&
123 		    (gpe_number_max >= acpi_gbl_FADT.gpe1_base)) {
124 			ACPI_ERROR((AE_INFO,
125 				    "GPE0 block (GPE 0 to %u) overlaps the GPE1 block "
126 				    "(GPE %u to %u) - Ignoring GPE1",
127 				    gpe_number_max, acpi_gbl_FADT.gpe1_base,
128 				    acpi_gbl_FADT.gpe1_base +
129 				    ((register_count1 *
130 				      ACPI_GPE_REGISTER_WIDTH) - 1)));
131 
132 			/* Ignore GPE1 block by setting the register count to zero */
133 
134 			register_count1 = 0;
135 		} else {
136 			/* Install GPE Block 1 */
137 
138 			status =
139 			    acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
140 						     acpi_gbl_FADT.xgpe1_block.
141 						     address,
142 						     acpi_gbl_FADT.xgpe1_block.
143 						     space_id, register_count1,
144 						     acpi_gbl_FADT.gpe1_base,
145 						     acpi_gbl_FADT.
146 						     sci_interrupt,
147 						     &acpi_gbl_gpe_fadt_blocks
148 						     [1]);
149 
150 			if (ACPI_FAILURE(status)) {
151 				ACPI_EXCEPTION((AE_INFO, status,
152 						"Could not create GPE Block 1"));
153 			}
154 
155 			/*
156 			 * GPE0 and GPE1 do not have to be contiguous in the GPE number
157 			 * space. However, GPE0 always starts at GPE number zero.
158 			 */
159 			gpe_number_max = acpi_gbl_FADT.gpe1_base +
160 			    ((register_count1 * ACPI_GPE_REGISTER_WIDTH) - 1);
161 		}
162 	}
163 
164 	/* Exit if there are no GPE registers */
165 
166 	if ((register_count0 + register_count1) == 0) {
167 
168 		/* GPEs are not required by ACPI, this is OK */
169 
170 		ACPI_DEBUG_PRINT((ACPI_DB_INIT,
171 				  "There are no GPE blocks defined in the FADT\n"));
172 		status = AE_OK;
173 		goto cleanup;
174 	}
175 
176 cleanup:
177 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
178 	return_ACPI_STATUS(AE_OK);
179 }
180 
181 /*******************************************************************************
182  *
183  * FUNCTION:    acpi_ev_update_gpes
184  *
185  * PARAMETERS:  table_owner_id      - ID of the newly-loaded ACPI table
186  *
187  * RETURN:      None
188  *
189  * DESCRIPTION: Check for new GPE methods (_Lxx/_Exx) made available as a
190  *              result of a Load() or load_table() operation. If new GPE
191  *              methods have been installed, register the new methods.
192  *
193  ******************************************************************************/
194 
195 void acpi_ev_update_gpes(acpi_owner_id table_owner_id)
196 {
197 	struct acpi_gpe_xrupt_info *gpe_xrupt_info;
198 	struct acpi_gpe_block_info *gpe_block;
199 	struct acpi_gpe_walk_info walk_info;
200 	acpi_status status = AE_OK;
201 
202 	/*
203 	 * Find any _Lxx/_Exx GPE methods that have just been loaded.
204 	 *
205 	 * Any GPEs that correspond to new _Lxx/_Exx methods are immediately
206 	 * enabled.
207 	 *
208 	 * Examine the namespace underneath each gpe_device within the
209 	 * gpe_block lists.
210 	 */
211 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
212 	if (ACPI_FAILURE(status)) {
213 		return;
214 	}
215 
216 	walk_info.count = 0;
217 	walk_info.owner_id = table_owner_id;
218 	walk_info.execute_by_owner_id = TRUE;
219 
220 	/* Walk the interrupt level descriptor list */
221 
222 	gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
223 	while (gpe_xrupt_info) {
224 
225 		/* Walk all Gpe Blocks attached to this interrupt level */
226 
227 		gpe_block = gpe_xrupt_info->gpe_block_list_head;
228 		while (gpe_block) {
229 			walk_info.gpe_block = gpe_block;
230 			walk_info.gpe_device = gpe_block->node;
231 
232 			status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD,
233 							walk_info.gpe_device,
234 							ACPI_UINT32_MAX,
235 							ACPI_NS_WALK_NO_UNLOCK,
236 							acpi_ev_match_gpe_method,
237 							NULL, &walk_info, NULL);
238 			if (ACPI_FAILURE(status)) {
239 				ACPI_EXCEPTION((AE_INFO, status,
240 						"While decoding _Lxx/_Exx methods"));
241 			}
242 
243 			gpe_block = gpe_block->next;
244 		}
245 
246 		gpe_xrupt_info = gpe_xrupt_info->next;
247 	}
248 
249 	if (walk_info.count) {
250 		ACPI_INFO(("Enabled %u new GPEs", walk_info.count));
251 	}
252 
253 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
254 	return;
255 }
256 
257 /*******************************************************************************
258  *
259  * FUNCTION:    acpi_ev_match_gpe_method
260  *
261  * PARAMETERS:  Callback from walk_namespace
262  *
263  * RETURN:      Status
264  *
265  * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
266  *              control method under the _GPE portion of the namespace.
267  *              Extract the name and GPE type from the object, saving this
268  *              information for quick lookup during GPE dispatch. Allows a
269  *              per-owner_id evaluation if execute_by_owner_id is TRUE in the
270  *              walk_info parameter block.
271  *
272  *              The name of each GPE control method is of the form:
273  *              "_Lxx" or "_Exx", where:
274  *                  L      - means that the GPE is level triggered
275  *                  E      - means that the GPE is edge triggered
276  *                  xx     - is the GPE number [in HEX]
277  *
278  * If walk_info->execute_by_owner_id is TRUE, we only execute examine GPE methods
279  * with that owner.
280  *
281  ******************************************************************************/
282 
283 acpi_status
284 acpi_ev_match_gpe_method(acpi_handle obj_handle,
285 			 u32 level, void *context, void **return_value)
286 {
287 	struct acpi_namespace_node *method_node =
288 	    ACPI_CAST_PTR(struct acpi_namespace_node, obj_handle);
289 	struct acpi_gpe_walk_info *walk_info =
290 	    ACPI_CAST_PTR(struct acpi_gpe_walk_info, context);
291 	struct acpi_gpe_event_info *gpe_event_info;
292 	acpi_status status;
293 	u32 gpe_number;
294 	u8 temp_gpe_number;
295 	char name[ACPI_NAMESEG_SIZE + 1];
296 	u8 type;
297 
298 	ACPI_FUNCTION_TRACE(ev_match_gpe_method);
299 
300 	/* Check if requested owner_id matches this owner_id */
301 
302 	if ((walk_info->execute_by_owner_id) &&
303 	    (method_node->owner_id != walk_info->owner_id)) {
304 		return_ACPI_STATUS(AE_OK);
305 	}
306 
307 	/*
308 	 * Match and decode the _Lxx and _Exx GPE method names
309 	 *
310 	 * 1) Extract the method name and null terminate it
311 	 */
312 	ACPI_MOVE_32_TO_32(name, &method_node->name.integer);
313 	name[ACPI_NAMESEG_SIZE] = 0;
314 
315 	/* 2) Name must begin with an underscore */
316 
317 	if (name[0] != '_') {
318 		return_ACPI_STATUS(AE_OK);	/* Ignore this method */
319 	}
320 
321 	/*
322 	 * 3) Edge/Level determination is based on the 2nd character
323 	 *    of the method name
324 	 */
325 	switch (name[1]) {
326 	case 'L':
327 
328 		type = ACPI_GPE_LEVEL_TRIGGERED;
329 		break;
330 
331 	case 'E':
332 
333 		type = ACPI_GPE_EDGE_TRIGGERED;
334 		break;
335 
336 	default:
337 
338 		/* Unknown method type, just ignore it */
339 
340 		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
341 				  "Ignoring unknown GPE method type: %s "
342 				  "(name not of form _Lxx or _Exx)", name));
343 		return_ACPI_STATUS(AE_OK);
344 	}
345 
346 	/* 4) The last two characters of the name are the hex GPE Number */
347 
348 	status = acpi_ut_ascii_to_hex_byte(&name[2], &temp_gpe_number);
349 	if (ACPI_FAILURE(status)) {
350 
351 		/* Conversion failed; invalid method, just ignore it */
352 
353 		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
354 				  "Could not extract GPE number from name: %s "
355 				  "(name is not of form _Lxx or _Exx)", name));
356 		return_ACPI_STATUS(AE_OK);
357 	}
358 
359 	/* Ensure that we have a valid GPE number for this GPE block */
360 
361 	gpe_number = (u32)temp_gpe_number;
362 	gpe_event_info =
363 	    acpi_ev_low_get_gpe_info(gpe_number, walk_info->gpe_block);
364 	if (!gpe_event_info) {
365 		/*
366 		 * This gpe_number is not valid for this GPE block, just ignore it.
367 		 * However, it may be valid for a different GPE block, since GPE0
368 		 * and GPE1 methods both appear under \_GPE.
369 		 */
370 		return_ACPI_STATUS(AE_OK);
371 	}
372 
373 	if ((ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
374 	     ACPI_GPE_DISPATCH_HANDLER) ||
375 	    (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
376 	     ACPI_GPE_DISPATCH_RAW_HANDLER)) {
377 
378 		/* If there is already a handler, ignore this GPE method */
379 
380 		return_ACPI_STATUS(AE_OK);
381 	}
382 
383 	if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
384 	    ACPI_GPE_DISPATCH_METHOD) {
385 		/*
386 		 * If there is already a method, ignore this method. But check
387 		 * for a type mismatch (if both the _Lxx AND _Exx exist)
388 		 */
389 		if (type != (gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK)) {
390 			ACPI_ERROR((AE_INFO,
391 				    "For GPE 0x%.2X, found both _L%2.2X and _E%2.2X methods",
392 				    gpe_number, gpe_number, gpe_number));
393 		}
394 		return_ACPI_STATUS(AE_OK);
395 	}
396 
397 	/* Disable the GPE in case it's been enabled already. */
398 
399 	(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
400 
401 	/*
402 	 * Add the GPE information from above to the gpe_event_info block for
403 	 * use during dispatch of this GPE.
404 	 */
405 	gpe_event_info->flags &= ~(ACPI_GPE_DISPATCH_MASK);
406 	gpe_event_info->flags |= (u8)(type | ACPI_GPE_DISPATCH_METHOD);
407 	gpe_event_info->dispatch.method_node = method_node;
408 
409 	ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
410 			  "Registered GPE method %s as GPE number 0x%.2X\n",
411 			  name, gpe_number));
412 	return_ACPI_STATUS(AE_OK);
413 }
414 
415 #endif				/* !ACPI_REDUCED_HARDWARE */
416