drivers/acpi/acpica/evhandler.c

   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 - 2019, 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 = NULL;
 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         handler_obj->address_space.space_id = (u8)space_id;
 493         handler_obj->address_space.handler_flags = flags;
 494         handler_obj->address_space.region_list = NULL;
 495         handler_obj->address_space.node = node;
 496         handler_obj->address_space.handler = handler;
 497         handler_obj->address_space.context = context;
 498         handler_obj->address_space.setup = setup;
 499
 500         /* Install at head of Device.address_space list */
 501
 502         handler_obj->address_space.next = obj_desc->common_notify.handler;
 503
 504         /*
 505          * The Device object is the first reference on the handler_obj.
 506          * Each region that uses the handler adds a reference.
 507          */
 508         obj_desc->common_notify.handler = handler_obj;
 509
 510         /*
 511          * Walk the namespace finding all of the regions this handler will
 512          * manage.
 513          *
 514          * Start at the device and search the branch toward the leaf nodes
 515          * until either the leaf is encountered or a device is detected that
 516          * has an address handler of the same type.
 517          *
 518          * In either case, back up and search down the remainder of the branch
 519          */
 520         status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node,
 521                                         ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
 522                                         acpi_ev_install_handler, NULL,
 523                                         handler_obj, NULL);
 524
 525 unlock_and_exit:
 526         return_ACPI_STATUS(status);
 527 }