1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Module Name: evhandler - Support for Address Space handlers
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#include "acinterp.h"
15
16#define _COMPONENT ACPI_EVENTS
17ACPI_MODULE_NAME("evhandler")
18
19/* Local prototypes */
20static acpi_status
21acpi_ev_install_handler(acpi_handle obj_handle,
22 u32 level, void *context, void **return_value);
23
24/* These are the address spaces that will get default handlers */
25
26u8 acpi_gbl_default_address_spaces[ACPI_NUM_DEFAULT_SPACES] = {
27 ACPI_ADR_SPACE_SYSTEM_MEMORY,
28 ACPI_ADR_SPACE_SYSTEM_IO,
29 ACPI_ADR_SPACE_PCI_CONFIG,
30 ACPI_ADR_SPACE_DATA_TABLE
31};
32
33/*******************************************************************************
34 *
35 * FUNCTION: acpi_ev_install_region_handlers
36 *
37 * PARAMETERS: None
38 *
39 * RETURN: Status
40 *
41 * DESCRIPTION: Installs the core subsystem default address space handlers.
42 *
43 ******************************************************************************/
44
45acpi_status acpi_ev_install_region_handlers(void)
46{
47 acpi_status status;
48 u32 i;
49
50 ACPI_FUNCTION_TRACE(ev_install_region_handlers);
51
52 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
53 if (ACPI_FAILURE(status)) {
54 return_ACPI_STATUS(status);
55 }
56
57 /*
58 * All address spaces (PCI Config, EC, SMBus) are scope dependent and
59 * registration must occur for a specific device.
60 *
61 * In the case of the system memory and IO address spaces there is
62 * currently no device associated with the address space. For these we
63 * use the root.
64 *
65 * We install the default PCI config space handler at the root so that
66 * this space is immediately available even though the we have not
67 * enumerated all the PCI Root Buses yet. This is to conform to the ACPI
68 * specification which states that the PCI config space must be always
69 * available -- even though we are nowhere near ready to find the PCI root
70 * buses at this point.
71 *
72 * NOTE: We ignore AE_ALREADY_EXISTS because this means that a handler
73 * has already been installed (via acpi_install_address_space_handler).
74 * Similar for AE_SAME_HANDLER.
75 */
76 for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
77 status = acpi_ev_install_space_handler(node: acpi_gbl_root_node,
78 space_id: acpi_gbl_default_address_spaces
79 [i],
80 ACPI_DEFAULT_HANDLER,
81 NULL, NULL);
82 switch (status) {
83 case AE_OK:
84 case AE_SAME_HANDLER:
85 case AE_ALREADY_EXISTS:
86
87 /* These exceptions are all OK */
88
89 status = AE_OK;
90 break;
91
92 default:
93
94 goto unlock_and_exit;
95 }
96 }
97
98unlock_and_exit:
99 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
100 return_ACPI_STATUS(status);
101}
102
103/*******************************************************************************
104 *
105 * FUNCTION: acpi_ev_has_default_handler
106 *
107 * PARAMETERS: node - Namespace node for the device
108 * space_id - The address space ID
109 *
110 * RETURN: TRUE if default handler is installed, FALSE otherwise
111 *
112 * DESCRIPTION: Check if the default handler is installed for the requested
113 * space ID.
114 *
115 ******************************************************************************/
116
117u8
118acpi_ev_has_default_handler(struct acpi_namespace_node *node,
119 acpi_adr_space_type space_id)
120{
121 union acpi_operand_object *obj_desc;
122 union acpi_operand_object *handler_obj;
123
124 /* Must have an existing internal object */
125
126 obj_desc = acpi_ns_get_attached_object(node);
127 if (obj_desc) {
128 handler_obj = obj_desc->common_notify.handler;
129
130 /* Walk the linked list of handlers for this object */
131
132 while (handler_obj) {
133 if (handler_obj->address_space.space_id == space_id) {
134 if (handler_obj->address_space.handler_flags &
135 ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
136 return (TRUE);
137 }
138 }
139
140 handler_obj = handler_obj->address_space.next;
141 }
142 }
143
144 return (FALSE);
145}
146
147/*******************************************************************************
148 *
149 * FUNCTION: acpi_ev_install_handler
150 *
151 * PARAMETERS: walk_namespace callback
152 *
153 * DESCRIPTION: This routine installs an address handler into objects that are
154 * of type Region or Device.
155 *
156 * If the Object is a Device, and the device has a handler of
157 * the same type then the search is terminated in that branch.
158 *
159 * This is because the existing handler is closer in proximity
160 * to any more regions than the one we are trying to install.
161 *
162 ******************************************************************************/
163
164static acpi_status
165acpi_ev_install_handler(acpi_handle obj_handle,
166 u32 level, void *context, void **return_value)
167{
168 union acpi_operand_object *handler_obj;
169 union acpi_operand_object *next_handler_obj;
170 union acpi_operand_object *obj_desc;
171 struct acpi_namespace_node *node;
172 acpi_status status;
173
174 ACPI_FUNCTION_NAME(ev_install_handler);
175
176 handler_obj = (union acpi_operand_object *)context;
177
178 /* Parameter validation */
179
180 if (!handler_obj) {
181 return (AE_OK);
182 }
183
184 /* Convert and validate the device handle */
185
186 node = acpi_ns_validate_handle(handle: obj_handle);
187 if (!node) {
188 return (AE_BAD_PARAMETER);
189 }
190
191 /*
192 * We only care about regions and objects that are allowed to have
193 * address space handlers
194 */
195 if ((node->type != ACPI_TYPE_DEVICE) &&
196 (node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
197 return (AE_OK);
198 }
199
200 /* Check for an existing internal object */
201
202 obj_desc = acpi_ns_get_attached_object(node);
203 if (!obj_desc) {
204
205 /* No object, just exit */
206
207 return (AE_OK);
208 }
209
210 /* Devices are handled different than regions */
211
212 if (obj_desc->common.type == ACPI_TYPE_DEVICE) {
213
214 /* Check if this Device already has a handler for this address space */
215
216 next_handler_obj =
217 acpi_ev_find_region_handler(space_id: handler_obj->address_space.
218 space_id,
219 handler_obj: obj_desc->common_notify.
220 handler);
221 if (next_handler_obj) {
222
223 /* Found a handler, is it for the same address space? */
224
225 ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
226 "Found handler for region [%s] in device %p(%p) handler %p\n",
227 acpi_ut_get_region_name(handler_obj->
228 address_space.
229 space_id),
230 obj_desc, next_handler_obj,
231 handler_obj));
232
233 /*
234 * Since the object we found it on was a device, then it means
235 * that someone has already installed a handler for the branch
236 * of the namespace from this device on. Just bail out telling
237 * the walk routine to not traverse this branch. This preserves
238 * the scoping rule for handlers.
239 */
240 return (AE_CTRL_DEPTH);
241 }
242
243 /*
244 * As long as the device didn't have a handler for this space we
245 * don't care about it. We just ignore it and proceed.
246 */
247 return (AE_OK);
248 }
249
250 /* Object is a Region */
251
252 if (obj_desc->region.space_id != handler_obj->address_space.space_id) {
253
254 /* This region is for a different address space, just ignore it */
255
256 return (AE_OK);
257 }
258
259 /*
260 * Now we have a region and it is for the handler's address space type.
261 *
262 * First disconnect region for any previous handler (if any)
263 */
264 acpi_ev_detach_region(region_obj: obj_desc, FALSE);
265
266 /* Connect the region to the new handler */
267
268 status = acpi_ev_attach_region(handler_obj, region_obj: obj_desc, FALSE);
269 return (status);
270}
271
272/*******************************************************************************
273 *
274 * FUNCTION: acpi_ev_find_region_handler
275 *
276 * PARAMETERS: space_id - The address space ID
277 * handler_obj - Head of the handler object list
278 *
279 * RETURN: Matching handler object. NULL if space ID not matched
280 *
281 * DESCRIPTION: Search a handler object list for a match on the address
282 * space ID.
283 *
284 ******************************************************************************/
285
286union acpi_operand_object *acpi_ev_find_region_handler(acpi_adr_space_type
287 space_id,
288 union acpi_operand_object
289 *handler_obj)
290{
291
292 /* Walk the handler list for this device */
293
294 while (handler_obj) {
295
296 /* Same space_id indicates a handler is installed */
297
298 if (handler_obj->address_space.space_id == space_id) {
299 return (handler_obj);
300 }
301
302 /* Next handler object */
303
304 handler_obj = handler_obj->address_space.next;
305 }
306
307 return (NULL);
308}
309
310/*******************************************************************************
311 *
312 * FUNCTION: acpi_ev_install_space_handler
313 *
314 * PARAMETERS: node - Namespace node for the device
315 * space_id - The address space ID
316 * handler - Address of the handler
317 * setup - Address of the setup function
318 * context - Value passed to the handler on each access
319 *
320 * RETURN: Status
321 *
322 * DESCRIPTION: Install a handler for all op_regions of a given space_id.
323 * Assumes namespace is locked
324 *
325 ******************************************************************************/
326
327acpi_status
328acpi_ev_install_space_handler(struct acpi_namespace_node *node,
329 acpi_adr_space_type space_id,
330 acpi_adr_space_handler handler,
331 acpi_adr_space_setup setup, void *context)
332{
333 union acpi_operand_object *obj_desc;
334 union acpi_operand_object *handler_obj;
335 acpi_status status = AE_OK;
336 acpi_object_type type;
337 u8 flags = 0;
338
339 ACPI_FUNCTION_TRACE(ev_install_space_handler);
340
341 /*
342 * This registration is valid for only the types below and the root.
343 * The root node is where the default handlers get installed.
344 */
345 if ((node->type != ACPI_TYPE_DEVICE) &&
346 (node->type != ACPI_TYPE_PROCESSOR) &&
347 (node->type != ACPI_TYPE_THERMAL) && (node != acpi_gbl_root_node)) {
348 status = AE_BAD_PARAMETER;
349 goto unlock_and_exit;
350 }
351
352 if (handler == ACPI_DEFAULT_HANDLER) {
353 flags = ACPI_ADDR_HANDLER_DEFAULT_INSTALLED;
354
355 switch (space_id) {
356 case ACPI_ADR_SPACE_SYSTEM_MEMORY:
357
358 handler = acpi_ex_system_memory_space_handler;
359 setup = acpi_ev_system_memory_region_setup;
360 break;
361
362 case ACPI_ADR_SPACE_SYSTEM_IO:
363
364 handler = acpi_ex_system_io_space_handler;
365 setup = acpi_ev_io_space_region_setup;
366 break;
367#ifdef ACPI_PCI_CONFIGURED
368 case ACPI_ADR_SPACE_PCI_CONFIG:
369
370 handler = acpi_ex_pci_config_space_handler;
371 setup = acpi_ev_pci_config_region_setup;
372 break;
373#endif
374 case ACPI_ADR_SPACE_CMOS:
375
376 handler = acpi_ex_cmos_space_handler;
377 setup = acpi_ev_cmos_region_setup;
378 break;
379#ifdef ACPI_PCI_CONFIGURED
380 case ACPI_ADR_SPACE_PCI_BAR_TARGET:
381
382 handler = acpi_ex_pci_bar_space_handler;
383 setup = acpi_ev_pci_bar_region_setup;
384 break;
385#endif
386 case ACPI_ADR_SPACE_DATA_TABLE:
387
388 handler = acpi_ex_data_table_space_handler;
389 setup = acpi_ev_data_table_region_setup;
390 break;
391
392 default:
393
394 status = AE_BAD_PARAMETER;
395 goto unlock_and_exit;
396 }
397 }
398
399 /* If the caller hasn't specified a setup routine, use the default */
400
401 if (!setup) {
402 setup = acpi_ev_default_region_setup;
403 }
404
405 /* Check for an existing internal object */
406
407 obj_desc = acpi_ns_get_attached_object(node);
408 if (obj_desc) {
409 /*
410 * The attached device object already exists. Now make sure
411 * the handler is not already installed.
412 */
413 handler_obj = acpi_ev_find_region_handler(space_id,
414 handler_obj: obj_desc->
415 common_notify.
416 handler);
417
418 if (handler_obj) {
419 if (handler_obj->address_space.handler == handler) {
420 /*
421 * It is (relatively) OK to attempt to install the SAME
422 * handler twice. This can easily happen with the
423 * PCI_Config space.
424 */
425 status = AE_SAME_HANDLER;
426 goto unlock_and_exit;
427 } else {
428 /* A handler is already installed */
429
430 status = AE_ALREADY_EXISTS;
431 }
432
433 goto unlock_and_exit;
434 }
435 } else {
436 ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
437 "Creating object on Device %p while installing handler\n",
438 node));
439
440 /* obj_desc does not exist, create one */
441
442 if (node->type == ACPI_TYPE_ANY) {
443 type = ACPI_TYPE_DEVICE;
444 } else {
445 type = node->type;
446 }
447
448 obj_desc = acpi_ut_create_internal_object(type);
449 if (!obj_desc) {
450 status = AE_NO_MEMORY;
451 goto unlock_and_exit;
452 }
453
454 /* Init new descriptor */
455
456 obj_desc->common.type = (u8)type;
457
458 /* Attach the new object to the Node */
459
460 status = acpi_ns_attach_object(node, object: obj_desc, type);
461
462 /* Remove local reference to the object */
463
464 acpi_ut_remove_reference(object: obj_desc);
465
466 if (ACPI_FAILURE(status)) {
467 goto unlock_and_exit;
468 }
469 }
470
471 ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
472 "Installing address handler for region %s(%X) "
473 "on Device %4.4s %p(%p)\n",
474 acpi_ut_get_region_name(space_id), space_id,
475 acpi_ut_get_node_name(node), node, obj_desc));
476
477 /*
478 * Install the handler
479 *
480 * At this point there is no existing handler. Just allocate the object
481 * for the handler and link it into the list.
482 */
483 handler_obj =
484 acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_ADDRESS_HANDLER);
485 if (!handler_obj) {
486 status = AE_NO_MEMORY;
487 goto unlock_and_exit;
488 }
489
490 /* Init handler obj */
491
492 status =
493 acpi_os_create_mutex(&handler_obj->address_space.context_mutex);
494 if (ACPI_FAILURE(status)) {
495 acpi_ut_remove_reference(object: handler_obj);
496 goto unlock_and_exit;
497 }
498
499 handler_obj->address_space.space_id = (u8)space_id;
500 handler_obj->address_space.handler_flags = flags;
501 handler_obj->address_space.region_list = NULL;
502 handler_obj->address_space.node = node;
503 handler_obj->address_space.handler = handler;
504 handler_obj->address_space.context = context;
505 handler_obj->address_space.setup = setup;
506
507 /* Install at head of Device.address_space list */
508
509 handler_obj->address_space.next = obj_desc->common_notify.handler;
510
511 /*
512 * The Device object is the first reference on the handler_obj.
513 * Each region that uses the handler adds a reference.
514 */
515 obj_desc->common_notify.handler = handler_obj;
516
517 /*
518 * Walk the namespace finding all of the regions this handler will
519 * manage.
520 *
521 * Start at the device and search the branch toward the leaf nodes
522 * until either the leaf is encountered or a device is detected that
523 * has an address handler of the same type.
524 *
525 * In either case, back up and search down the remainder of the branch
526 */
527 status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, start_object: node,
528 ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
529 descending_callback: acpi_ev_install_handler, NULL,
530 context: handler_obj, NULL);
531
532unlock_and_exit:
533 return_ACPI_STATUS(status);
534}
535