SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/acpi/acpi_memhotplug.c

   1 /*
   2  * Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
   3  *
   4  * All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  14  * NON INFRINGEMENT.  See the GNU General Public License for more
  15  * details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  *
  22  * ACPI based HotPlug driver that supports Memory Hotplug
  23  * This driver fields notifications from firmare for memory add
  24  * and remove operations and alerts the VM of the affected memory
  25  * ranges.
  26  */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/types.h>
  32 #include <linux/memory_hotplug.h>
  33 #include <acpi/acpi_drivers.h>
  34
  35 #define ACPI_MEMORY_DEVICE_COMPONENT            0x08000000UL
  36 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  37 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  38 #define ACPI_MEMORY_DEVICE_DRIVER_NAME          "Hotplug Mem Driver"
  39 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  40
  41 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  42
  43 ACPI_MODULE_NAME("acpi_memory")
  44     MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
  45 MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
  46 MODULE_LICENSE("GPL");
  47
  48 /* ACPI _STA method values */
  49 #define ACPI_MEMORY_STA_PRESENT         (0x00000001UL)
  50 #define ACPI_MEMORY_STA_ENABLED         (0x00000002UL)
  51 #define ACPI_MEMORY_STA_FUNCTIONAL      (0x00000008UL)
  52
  53 /* Memory Device States */
  54 #define MEMORY_INVALID_STATE    0
  55 #define MEMORY_POWER_ON_STATE   1
  56 #define MEMORY_POWER_OFF_STATE  2
  57
  58 static int acpi_memory_device_add(struct acpi_device *device);
  59 static int acpi_memory_device_remove(struct acpi_device *device, int type);
  60 static int acpi_memory_device_start(struct acpi_device *device);
  61
  62 static struct acpi_driver acpi_memory_device_driver = {
  63         .name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
  64         .class = ACPI_MEMORY_DEVICE_CLASS,
  65         .ids = ACPI_MEMORY_DEVICE_HID,
  66         .ops = {
  67                 .add = acpi_memory_device_add,
  68                 .remove = acpi_memory_device_remove,
  69                 .start = acpi_memory_device_start,
  70                 },
  71 };
  72
  73 struct acpi_memory_info {
  74         struct list_head list;
  75         u64 start_addr;         /* Memory Range start physical addr */
  76         u64 length;             /* Memory Range length */
  77         unsigned short caching; /* memory cache attribute */
  78         unsigned short write_protect;   /* memory read/write attribute */
  79         unsigned int enabled:1;
  80 };
  81
  82 struct acpi_memory_device {
  83         acpi_handle handle;
  84         unsigned int state;     /* State of the memory device */
  85         struct list_head res_list;
  86 };
  87
  88 static acpi_status
  89 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  90 {
  91         struct acpi_memory_device *mem_device = context;
  92         struct acpi_resource_address64 address64;
  93         struct acpi_memory_info *info, *new;
  94         acpi_status status;
  95
  96         status = acpi_resource_to_address64(resource, &address64);
  97         if (ACPI_FAILURE(status) ||
  98             (address64.resource_type != ACPI_MEMORY_RANGE))
  99                 return AE_OK;
 100
 101         list_for_each_entry(info, &mem_device->res_list, list) {
 102                 /* Can we combine the resource range information? */
 103                 if ((info->caching == address64.info.mem.caching) &&
 104                     (info->write_protect == address64.info.mem.write_protect) &&
 105                     (info->start_addr + info->length == address64.minimum)) {
 106                         info->length += address64.address_length;
 107                         return AE_OK;
 108                 }
 109         }
 110
 111         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 112         if (!new)
 113                 return AE_ERROR;
 114
 115         INIT_LIST_HEAD(&new->list);
 116         new->caching = address64.info.mem.caching;
 117         new->write_protect = address64.info.mem.write_protect;
 118         new->start_addr = address64.minimum;
 119         new->length = address64.address_length;
 120         list_add_tail(&new->list, &mem_device->res_list);
 121
 122         return AE_OK;
 123 }
 124
 125 static int
 126 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 127 {
 128         acpi_status status;
 129         struct acpi_memory_info *info, *n;
 130
 131         ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
 132
 133         status = acpi_walk_resources(mem_device->handle, METHOD_NAME__CRS,
 134                                      acpi_memory_get_resource, mem_device);
 135         if (ACPI_FAILURE(status)) {
 136                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 137                         kfree(info);
 138                 return -EINVAL;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int
 145 acpi_memory_get_device(acpi_handle handle,
 146                        struct acpi_memory_device **mem_device)
 147 {
 148         acpi_status status;
 149         acpi_handle phandle;
 150         struct acpi_device *device = NULL;
 151         struct acpi_device *pdevice = NULL;
 152
 153         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
 154
 155         if (!acpi_bus_get_device(handle, &device) && device)
 156                 goto end;
 157
 158         status = acpi_get_parent(handle, &phandle);
 159         if (ACPI_FAILURE(status)) {
 160                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
 161                 return_VALUE(-EINVAL);
 162         }
 163
 164         /* Get the parent device */
 165         status = acpi_bus_get_device(phandle, &pdevice);
 166         if (ACPI_FAILURE(status)) {
 167                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 168                                   "Error in acpi_bus_get_device\n"));
 169                 return_VALUE(-EINVAL);
 170         }
 171
 172         /*
 173          * Now add the notified device.  This creates the acpi_device
 174          * and invokes .add function
 175          */
 176         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 177         if (ACPI_FAILURE(status)) {
 178                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
 179                 return_VALUE(-EINVAL);
 180         }
 181
 182       end:
 183         *mem_device = acpi_driver_data(device);
 184         if (!(*mem_device)) {
 185                 printk(KERN_ERR "\n driver data not found");
 186                 return_VALUE(-ENODEV);
 187         }
 188
 189         return_VALUE(0);
 190 }
 191
 192 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 193 {
 194         unsigned long current_status;
 195
 196         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
 197
 198         /* Get device present/absent information from the _STA */
 199         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
 200                                                NULL, &current_status)))
 201                 return_VALUE(-ENODEV);
 202         /*
 203          * Check for device status. Device should be
 204          * present/enabled/functioning.
 205          */
 206         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 207               && (current_status & ACPI_MEMORY_STA_ENABLED)
 208               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 209                 return_VALUE(-ENODEV);
 210
 211         return_VALUE(0);
 212 }
 213
 214 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 215 {
 216         int result, num_enabled = 0;
 217         struct acpi_memory_info *info;
 218
 219         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
 220
 221         /* Get the range from the _CRS */
 222         result = acpi_memory_get_device_resources(mem_device);
 223         if (result) {
 224                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 225                                   "\nget_device_resources failed\n"));
 226                 mem_device->state = MEMORY_INVALID_STATE;
 227                 return result;
 228         }
 229
 230         /*
 231          * Tell the VM there is more memory here...
 232          * Note: Assume that this function returns zero on success
 233          * We don't have memory-hot-add rollback function,now.
 234          * (i.e. memory-hot-remove function)
 235          */
 236         list_for_each_entry(info, &mem_device->res_list, list) {
 237                 result = add_memory(info->start_addr, info->length);
 238                 if (result)
 239                         continue;
 240                 info->enabled = 1;
 241                 num_enabled++;
 242         }
 243         if (!num_enabled) {
 244                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 245                 mem_device->state = MEMORY_INVALID_STATE;
 246                 return -EINVAL;
 247         }
 248
 249         return result;
 250 }
 251
 252 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 253 {
 254         acpi_status status;
 255         struct acpi_object_list arg_list;
 256         union acpi_object arg;
 257         unsigned long current_status;
 258
 259         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
 260
 261         /* Issue the _EJ0 command */
 262         arg_list.count = 1;
 263         arg_list.pointer = &arg;
 264         arg.type = ACPI_TYPE_INTEGER;
 265         arg.integer.value = 1;
 266         status = acpi_evaluate_object(mem_device->handle,
 267                                       "_EJ0", &arg_list, NULL);
 268         /* Return on _EJ0 failure */
 269         if (ACPI_FAILURE(status)) {
 270                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
 271                 return_VALUE(-ENODEV);
 272         }
 273
 274         /* Evalute _STA to check if the device is disabled */
 275         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 276                                        NULL, &current_status);
 277         if (ACPI_FAILURE(status))
 278                 return_VALUE(-ENODEV);
 279
 280         /* Check for device status.  Device should be disabled */
 281         if (current_status & ACPI_MEMORY_STA_ENABLED)
 282                 return_VALUE(-EINVAL);
 283
 284         return_VALUE(0);
 285 }
 286
 287 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 288 {
 289         int result;
 290         struct acpi_memory_info *info, *n;
 291
 292         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 293
 294         /*
 295          * Ask the VM to offline this memory range.
 296          * Note: Assume that this function returns zero on success
 297          */
 298         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 299                 if (info->enabled) {
 300                         result = remove_memory(info->start_addr, info->length);
 301                         if (result)
 302                                 return result;
 303                 }
 304                 kfree(info);
 305         }
 306
 307         /* Power-off and eject the device */
 308         result = acpi_memory_powerdown_device(mem_device);
 309         if (result) {
 310                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 311                                   "Device Power Down failed.\n"));
 312                 /* Set the status of the device to invalid */
 313                 mem_device->state = MEMORY_INVALID_STATE;
 314                 return result;
 315         }
 316
 317         mem_device->state = MEMORY_POWER_OFF_STATE;
 318         return result;
 319 }
 320
 321 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 322 {
 323         struct acpi_memory_device *mem_device;
 324         struct acpi_device *device;
 325
 326         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
 327
 328         switch (event) {
 329         case ACPI_NOTIFY_BUS_CHECK:
 330                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 331                                   "\nReceived BUS CHECK notification for device\n"));
 332                 /* Fall Through */
 333         case ACPI_NOTIFY_DEVICE_CHECK:
 334                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 335                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 336                                           "\nReceived DEVICE CHECK notification for device\n"));
 337                 if (acpi_memory_get_device(handle, &mem_device)) {
 338                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 339                                           "Error in finding driver data\n"));
 340                         return_VOID;
 341                 }
 342
 343                 if (!acpi_memory_check_device(mem_device)) {
 344                         if (acpi_memory_enable_device(mem_device))
 345                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 346                                                   "Error in acpi_memory_enable_device\n"));
 347                 }
 348                 break;
 349         case ACPI_NOTIFY_EJECT_REQUEST:
 350                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 351                                   "\nReceived EJECT REQUEST notification for device\n"));
 352
 353                 if (acpi_bus_get_device(handle, &device)) {
 354                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 355                                           "Device doesn't exist\n"));
 356                         break;
 357                 }
 358                 mem_device = acpi_driver_data(device);
 359                 if (!mem_device) {
 360                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 361                                           "Driver Data is NULL\n"));
 362                         break;
 363                 }
 364
 365                 /*
 366                  * Currently disabling memory device from kernel mode
 367                  * TBD: Can also be disabled from user mode scripts
 368                  * TBD: Can also be disabled by Callback registration
 369                  *      with generic sysfs driver
 370                  */
 371                 if (acpi_memory_disable_device(mem_device))
 372                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 373                                           "Error in acpi_memory_disable_device\n"));
 374                 /*
 375                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 376                  */
 377                 break;
 378         default:
 379                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 380                                   "Unsupported event [0x%x]\n", event));
 381                 break;
 382         }
 383
 384         return_VOID;
 385 }
 386
 387 static int acpi_memory_device_add(struct acpi_device *device)
 388 {
 389         int result;
 390         struct acpi_memory_device *mem_device = NULL;
 391
 392         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
 393
 394         if (!device)
 395                 return_VALUE(-EINVAL);
 396
 397         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 398         if (!mem_device)
 399                 return_VALUE(-ENOMEM);
 400         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 401
 402         INIT_LIST_HEAD(&mem_device->res_list);
 403         mem_device->handle = device->handle;
 404         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 405         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 406         acpi_driver_data(device) = mem_device;
 407
 408         /* Get the range from the _CRS */
 409         result = acpi_memory_get_device_resources(mem_device);
 410         if (result) {
 411                 kfree(mem_device);
 412                 return_VALUE(result);
 413         }
 414
 415         /* Set the device state */
 416         mem_device->state = MEMORY_POWER_ON_STATE;
 417
 418         printk(KERN_INFO "%s \n", acpi_device_name(device));
 419
 420         return_VALUE(result);
 421 }
 422
 423 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 424 {
 425         struct acpi_memory_device *mem_device = NULL;
 426
 427         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
 428
 429         if (!device || !acpi_driver_data(device))
 430                 return_VALUE(-EINVAL);
 431
 432         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 433         kfree(mem_device);
 434
 435         return_VALUE(0);
 436 }
 437
 438 static int acpi_memory_device_start (struct acpi_device *device)
 439 {
 440         struct acpi_memory_device *mem_device;
 441         int result = 0;
 442
 443         ACPI_FUNCTION_TRACE("acpi_memory_device_start");
 444
 445         mem_device = acpi_driver_data(device);
 446
 447         if (!acpi_memory_check_device(mem_device)) {
 448                 /* call add_memory func */
 449                 result = acpi_memory_enable_device(mem_device);
 450                 if (result)
 451                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 452                                 "Error in acpi_memory_enable_device\n"));
 453         }
 454         return_VALUE(result);
 455 }
 456
 457 /*
 458  * Helper function to check for memory device
 459  */
 460 static acpi_status is_memory_device(acpi_handle handle)
 461 {
 462         char *hardware_id;
 463         acpi_status status;
 464         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 465         struct acpi_device_info *info;
 466
 467         ACPI_FUNCTION_TRACE("is_memory_device");
 468
 469         status = acpi_get_object_info(handle, &buffer);
 470         if (ACPI_FAILURE(status))
 471                 return_ACPI_STATUS(AE_ERROR);
 472
 473         info = buffer.pointer;
 474         if (!(info->valid & ACPI_VALID_HID)) {
 475                 acpi_os_free(buffer.pointer);
 476                 return_ACPI_STATUS(AE_ERROR);
 477         }
 478
 479         hardware_id = info->hardware_id.value;
 480         if ((hardware_id == NULL) ||
 481             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 482                 status = AE_ERROR;
 483
 484         acpi_os_free(buffer.pointer);
 485         return_ACPI_STATUS(status);
 486 }
 487
 488 static acpi_status
 489 acpi_memory_register_notify_handler(acpi_handle handle,
 490                                     u32 level, void *ctxt, void **retv)
 491 {
 492         acpi_status status;
 493
 494         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
 495
 496         status = is_memory_device(handle);
 497         if (ACPI_FAILURE(status))
 498                 return_ACPI_STATUS(AE_OK);      /* continue */
 499
 500         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 501                                              acpi_memory_device_notify, NULL);
 502         if (ACPI_FAILURE(status)) {
 503                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 504                                   "Error installing notify handler\n"));
 505                 return_ACPI_STATUS(AE_OK);      /* continue */
 506         }
 507
 508         return_ACPI_STATUS(status);
 509 }
 510
 511 static acpi_status
 512 acpi_memory_deregister_notify_handler(acpi_handle handle,
 513                                       u32 level, void *ctxt, void **retv)
 514 {
 515         acpi_status status;
 516
 517         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
 518
 519         status = is_memory_device(handle);
 520         if (ACPI_FAILURE(status))
 521                 return_ACPI_STATUS(AE_OK);      /* continue */
 522
 523         status = acpi_remove_notify_handler(handle,
 524                                             ACPI_SYSTEM_NOTIFY,
 525                                             acpi_memory_device_notify);
 526         if (ACPI_FAILURE(status)) {
 527                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 528                                   "Error removing notify handler\n"));
 529                 return_ACPI_STATUS(AE_OK);      /* continue */
 530         }
 531
 532         return_ACPI_STATUS(status);
 533 }
 534
 535 static int __init acpi_memory_device_init(void)
 536 {
 537         int result;
 538         acpi_status status;
 539
 540         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
 541
 542         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 543
 544         if (result < 0)
 545                 return_VALUE(-ENODEV);
 546
 547         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 548                                      ACPI_UINT32_MAX,
 549                                      acpi_memory_register_notify_handler,
 550                                      NULL, NULL);
 551
 552         if (ACPI_FAILURE(status)) {
 553                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 554                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 555                 return_VALUE(-ENODEV);
 556         }
 557
 558         return_VALUE(0);
 559 }
 560
 561 static void __exit acpi_memory_device_exit(void)
 562 {
 563         acpi_status status;
 564
 565         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
 566
 567         /*
 568          * Adding this to un-install notification handlers for all the device
 569          * handles.
 570          */
 571         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 572                                      ACPI_UINT32_MAX,
 573                                      acpi_memory_deregister_notify_handler,
 574                                      NULL, NULL);
 575
 576         if (ACPI_FAILURE(status))
 577                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 578
 579         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 580
 581         return_VOID;
 582 }
 583
 584 module_init(acpi_memory_device_init);
 585 module_exit(acpi_memory_device_exit);