xref: /openbmc/linux/drivers/acpi/acpica/evhandler.c (revision ffcdf473)
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 - 2023, 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
17 ACPI_MODULE_NAME("evhandler")
18 
19 /* Local prototypes */
20 static acpi_status
21 acpi_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 
26 u8 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 
45 acpi_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(acpi_gbl_root_node,
78 						       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 
98 unlock_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 
117 u8
118 acpi_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 
164 static acpi_status
165 acpi_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(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(handler_obj->address_space.
218 						space_id,
219 						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(obj_desc, FALSE);
265 
266 	/* Connect the region to the new handler */
267 
268 	status = acpi_ev_attach_region(handler_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 
286 union 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 
327 acpi_status
328 acpi_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 							  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, obj_desc, type);
461 
462 		/* Remove local reference to the object */
463 
464 		acpi_ut_remove_reference(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(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, node,
528 					ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
529 					acpi_ev_install_handler, NULL,
530 					handler_obj, NULL);
531 
532 unlock_and_exit:
533 	return_ACPI_STATUS(status);
534 }
535