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 - 2025, 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
16ACPI_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#ifdef ACPI_GPE_USE_LOGICAL_ADDRESSES
36#define ACPI_FADT_GPE_BLOCK_ADDRESS(N) \
37 acpi_gbl_FADT.xgpe##N##_block.space_id == \
38 ACPI_ADR_SPACE_SYSTEM_MEMORY ? \
39 (u64)acpi_gbl_xgpe##N##_block_logical_address : \
40 acpi_gbl_FADT.xgpe##N##_block.address
41#else
42#define ACPI_FADT_GPE_BLOCK_ADDRESS(N) acpi_gbl_FADT.xgpe##N##_block.address
43#endif /* ACPI_GPE_USE_LOGICAL_ADDRESSES */
44
45/*******************************************************************************
46 *
47 * FUNCTION: acpi_ev_gpe_initialize
48 *
49 * PARAMETERS: None
50 *
51 * RETURN: Status
52 *
53 * DESCRIPTION: Initialize the GPE data structures and the FADT GPE 0/1 blocks
54 *
55 ******************************************************************************/
56acpi_status acpi_ev_gpe_initialize(void)
57{
58 u32 register_count0 = 0;
59 u32 register_count1 = 0;
60 u32 gpe_number_max = 0;
61 acpi_status status;
62 u64 address;
63
64 ACPI_FUNCTION_TRACE(ev_gpe_initialize);
65
66 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT,
67 "Initializing General Purpose Events (GPEs):\n"));
68
69 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
70 if (ACPI_FAILURE(status)) {
71 return_ACPI_STATUS(status);
72 }
73
74 /*
75 * Initialize the GPE Block(s) defined in the FADT
76 *
77 * Why the GPE register block lengths are divided by 2: From the ACPI
78 * Spec, section "General-Purpose Event Registers", we have:
79 *
80 * "Each register block contains two registers of equal length
81 * GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the
82 * GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN
83 * The length of the GPE1_STS and GPE1_EN registers is equal to
84 * half the GPE1_LEN. If a generic register block is not supported
85 * then its respective block pointer and block length values in the
86 * FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need
87 * to be the same size."
88 */
89
90 /*
91 * Determine the maximum GPE number for this machine.
92 *
93 * Note: both GPE0 and GPE1 are optional, and either can exist without
94 * the other.
95 *
96 * If EITHER the register length OR the block address are zero, then that
97 * particular block is not supported.
98 */
99 address = ACPI_FADT_GPE_BLOCK_ADDRESS(0);
100
101 if (acpi_gbl_FADT.gpe0_block_length && address) {
102
103 /* GPE block 0 exists (has both length and address > 0) */
104
105 register_count0 = (u16)(acpi_gbl_FADT.gpe0_block_length / 2);
106 gpe_number_max =
107 (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;
108
109 /* Install GPE Block 0 */
110
111 status = acpi_ev_create_gpe_block(gpe_device: acpi_gbl_fadt_gpe_device,
112 address,
113 space_id: acpi_gbl_FADT.xgpe0_block.
114 space_id, register_count: register_count0, gpe_block_base_number: 0,
115 interrupt_number: acpi_gbl_FADT.sci_interrupt,
116 return_gpe_block: &acpi_gbl_gpe_fadt_blocks[0]);
117
118 if (ACPI_FAILURE(status)) {
119 ACPI_EXCEPTION((AE_INFO, status,
120 "Could not create GPE Block 0"));
121 }
122 }
123
124 address = ACPI_FADT_GPE_BLOCK_ADDRESS(1);
125
126 if (acpi_gbl_FADT.gpe1_block_length && address) {
127
128 /* GPE block 1 exists (has both length and address > 0) */
129
130 register_count1 = (u16)(acpi_gbl_FADT.gpe1_block_length / 2);
131
132 /* Check for GPE0/GPE1 overlap (if both banks exist) */
133
134 if ((register_count0) &&
135 (gpe_number_max >= acpi_gbl_FADT.gpe1_base)) {
136 ACPI_ERROR((AE_INFO,
137 "GPE0 block (GPE 0 to %u) overlaps the GPE1 block "
138 "(GPE %u to %u) - Ignoring GPE1",
139 gpe_number_max, acpi_gbl_FADT.gpe1_base,
140 acpi_gbl_FADT.gpe1_base +
141 ((register_count1 *
142 ACPI_GPE_REGISTER_WIDTH) - 1)));
143
144 /* Ignore GPE1 block by setting the register count to zero */
145
146 register_count1 = 0;
147 } else {
148 /* Install GPE Block 1 */
149
150 status =
151 acpi_ev_create_gpe_block(gpe_device: acpi_gbl_fadt_gpe_device,
152 address,
153 space_id: acpi_gbl_FADT.xgpe1_block.
154 space_id, register_count: register_count1,
155 gpe_block_base_number: acpi_gbl_FADT.gpe1_base,
156 interrupt_number: acpi_gbl_FADT.
157 sci_interrupt,
158 return_gpe_block: &acpi_gbl_gpe_fadt_blocks
159 [1]);
160
161 if (ACPI_FAILURE(status)) {
162 ACPI_EXCEPTION((AE_INFO, status,
163 "Could not create GPE Block 1"));
164 }
165
166 /*
167 * GPE0 and GPE1 do not have to be contiguous in the GPE number
168 * space. However, GPE0 always starts at GPE number zero.
169 */
170 }
171 }
172
173 /* Exit if there are no GPE registers */
174
175 if ((register_count0 + register_count1) == 0) {
176
177 /* GPEs are not required by ACPI, this is OK */
178
179 ACPI_DEBUG_PRINT((ACPI_DB_INIT,
180 "There are no GPE blocks defined in the FADT\n"));
181 goto cleanup;
182 }
183
184cleanup:
185 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
186 return_ACPI_STATUS(AE_OK);
187}
188
189/*******************************************************************************
190 *
191 * FUNCTION: acpi_ev_update_gpes
192 *
193 * PARAMETERS: table_owner_id - ID of the newly-loaded ACPI table
194 *
195 * RETURN: None
196 *
197 * DESCRIPTION: Check for new GPE methods (_Lxx/_Exx) made available as a
198 * result of a Load() or load_table() operation. If new GPE
199 * methods have been installed, register the new methods.
200 *
201 ******************************************************************************/
202
203void acpi_ev_update_gpes(acpi_owner_id table_owner_id)
204{
205 struct acpi_gpe_xrupt_info *gpe_xrupt_info;
206 struct acpi_gpe_block_info *gpe_block;
207 struct acpi_gpe_walk_info walk_info;
208 acpi_status status = AE_OK;
209
210 /*
211 * Find any _Lxx/_Exx GPE methods that have just been loaded.
212 *
213 * Any GPEs that correspond to new _Lxx/_Exx methods are immediately
214 * enabled.
215 *
216 * Examine the namespace underneath each gpe_device within the
217 * gpe_block lists.
218 */
219 status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
220 if (ACPI_FAILURE(status)) {
221 return;
222 }
223
224 walk_info.count = 0;
225 walk_info.owner_id = table_owner_id;
226 walk_info.execute_by_owner_id = TRUE;
227
228 /* Walk the interrupt level descriptor list */
229
230 gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
231 while (gpe_xrupt_info) {
232
233 /* Walk all Gpe Blocks attached to this interrupt level */
234
235 gpe_block = gpe_xrupt_info->gpe_block_list_head;
236 while (gpe_block) {
237 walk_info.gpe_block = gpe_block;
238 walk_info.gpe_device = gpe_block->node;
239
240 status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD,
241 start_object: walk_info.gpe_device,
242 ACPI_UINT32_MAX,
243 ACPI_NS_WALK_NO_UNLOCK,
244 descending_callback: acpi_ev_match_gpe_method,
245 NULL, context: &walk_info, NULL);
246 if (ACPI_FAILURE(status)) {
247 ACPI_EXCEPTION((AE_INFO, status,
248 "While decoding _Lxx/_Exx methods"));
249 }
250
251 gpe_block = gpe_block->next;
252 }
253
254 gpe_xrupt_info = gpe_xrupt_info->next;
255 }
256
257 if (walk_info.count) {
258 ACPI_INFO(("Enabled %u new GPEs", walk_info.count));
259 }
260
261 (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
262 return;
263}
264
265/*******************************************************************************
266 *
267 * FUNCTION: acpi_ev_match_gpe_method
268 *
269 * PARAMETERS: Callback from walk_namespace
270 *
271 * RETURN: Status
272 *
273 * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
274 * control method under the _GPE portion of the namespace.
275 * Extract the name and GPE type from the object, saving this
276 * information for quick lookup during GPE dispatch. Allows a
277 * per-owner_id evaluation if execute_by_owner_id is TRUE in the
278 * walk_info parameter block.
279 *
280 * The name of each GPE control method is of the form:
281 * "_Lxx" or "_Exx", where:
282 * L - means that the GPE is level triggered
283 * E - means that the GPE is edge triggered
284 * xx - is the GPE number [in HEX]
285 *
286 * If walk_info->execute_by_owner_id is TRUE, we only execute examine GPE methods
287 * with that owner.
288 *
289 ******************************************************************************/
290
291acpi_status
292acpi_ev_match_gpe_method(acpi_handle obj_handle,
293 u32 level, void *context, void **return_value)
294{
295 struct acpi_namespace_node *method_node =
296 ACPI_CAST_PTR(struct acpi_namespace_node, obj_handle);
297 struct acpi_gpe_walk_info *walk_info =
298 ACPI_CAST_PTR(struct acpi_gpe_walk_info, context);
299 struct acpi_gpe_event_info *gpe_event_info;
300 acpi_status status;
301 u32 gpe_number;
302 u8 temp_gpe_number;
303 char name[ACPI_NAMESEG_SIZE + 1];
304 u8 type;
305
306 ACPI_FUNCTION_TRACE(ev_match_gpe_method);
307
308 /* Check if requested owner_id matches this owner_id */
309
310 if ((walk_info->execute_by_owner_id) &&
311 (method_node->owner_id != walk_info->owner_id)) {
312 return_ACPI_STATUS(AE_OK);
313 }
314
315 /*
316 * Match and decode the _Lxx and _Exx GPE method names
317 *
318 * 1) Extract the method name and null terminate it
319 */
320 ACPI_MOVE_32_TO_32(name, &method_node->name.integer);
321 name[ACPI_NAMESEG_SIZE] = 0;
322
323 /* 2) Name must begin with an underscore */
324
325 if (name[0] != '_') {
326 return_ACPI_STATUS(AE_OK); /* Ignore this method */
327 }
328
329 /*
330 * 3) Edge/Level determination is based on the 2nd character
331 * of the method name
332 */
333 switch (name[1]) {
334 case 'L':
335
336 type = ACPI_GPE_LEVEL_TRIGGERED;
337 break;
338
339 case 'E':
340
341 type = ACPI_GPE_EDGE_TRIGGERED;
342 break;
343
344 default:
345
346 /* Unknown method type, just ignore it */
347
348 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
349 "Ignoring unknown GPE method type: %s "
350 "(name not of form _Lxx or _Exx)", name));
351 return_ACPI_STATUS(AE_OK);
352 }
353
354 /* 4) The last two characters of the name are the hex GPE Number */
355
356 status = acpi_ut_ascii_to_hex_byte(two_ascii_chars: &name[2], return_byte: &temp_gpe_number);
357 if (ACPI_FAILURE(status)) {
358
359 /* Conversion failed; invalid method, just ignore it */
360
361 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
362 "Could not extract GPE number from name: %s "
363 "(name is not of form _Lxx or _Exx)", name));
364 return_ACPI_STATUS(AE_OK);
365 }
366
367 /* Ensure that we have a valid GPE number for this GPE block */
368
369 gpe_number = (u32)temp_gpe_number;
370 gpe_event_info =
371 acpi_ev_low_get_gpe_info(gpe_number, gpe_block: walk_info->gpe_block);
372 if (!gpe_event_info) {
373 /*
374 * This gpe_number is not valid for this GPE block, just ignore it.
375 * However, it may be valid for a different GPE block, since GPE0
376 * and GPE1 methods both appear under \_GPE.
377 */
378 return_ACPI_STATUS(AE_OK);
379 }
380
381 if ((ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
382 ACPI_GPE_DISPATCH_HANDLER) ||
383 (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
384 ACPI_GPE_DISPATCH_RAW_HANDLER)) {
385
386 /* If there is already a handler, ignore this GPE method */
387
388 return_ACPI_STATUS(AE_OK);
389 }
390
391 if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
392 ACPI_GPE_DISPATCH_METHOD) {
393 /*
394 * If there is already a method, ignore this method. But check
395 * for a type mismatch (if both the _Lxx AND _Exx exist)
396 */
397 if (type != (gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK)) {
398 ACPI_ERROR((AE_INFO,
399 "For GPE 0x%.2X, found both _L%2.2X and _E%2.2X methods",
400 gpe_number, gpe_number, gpe_number));
401 }
402 return_ACPI_STATUS(AE_OK);
403 }
404
405 /* Disable the GPE in case it's been enabled already. */
406
407 (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
408
409 /*
410 * Add the GPE information from above to the gpe_event_info block for
411 * use during dispatch of this GPE.
412 */
413 gpe_event_info->flags &= ~(ACPI_GPE_DISPATCH_MASK);
414 gpe_event_info->flags |= (u8)(type | ACPI_GPE_DISPATCH_METHOD);
415 gpe_event_info->dispatch.method_node = method_node;
416 walk_info->count++;
417
418 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
419 "Registered GPE method %s as GPE number 0x%.2X\n",
420 name, gpe_number));
421 return_ACPI_STATUS(AE_OK);
422}
423
424#endif /* !ACPI_REDUCED_HARDWARE */
425