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                 u64 start_pfn, end_pfn;
 238
 239                 start_pfn = info->start_addr >> PAGE_SHIFT;
 240                 end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
 241
 242                 if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
 243                         /* already enabled. try next area */
 244                         num_enabled++;
 245                         continue;
 246                 }
 247
 248                 result = add_memory(info->start_addr, info->length);
 249                 if (result)
 250                         continue;
 251                 info->enabled = 1;
 252                 num_enabled++;
 253         }
 254         if (!num_enabled) {
 255                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 256                 mem_device->state = MEMORY_INVALID_STATE;
 257                 return -EINVAL;
 258         }
 259
 260         return result;
 261 }
 262
 263 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 264 {
 265         acpi_status status;
 266         struct acpi_object_list arg_list;
 267         union acpi_object arg;
 268         unsigned long current_status;
 269
 270         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
 271
 272         /* Issue the _EJ0 command */
 273         arg_list.count = 1;
 274         arg_list.pointer = &arg;
 275         arg.type = ACPI_TYPE_INTEGER;
 276         arg.integer.value = 1;
 277         status = acpi_evaluate_object(mem_device->handle,
 278                                       "_EJ0", &arg_list, NULL);
 279         /* Return on _EJ0 failure */
 280         if (ACPI_FAILURE(status)) {
 281                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
 282                 return_VALUE(-ENODEV);
 283         }
 284
 285         /* Evalute _STA to check if the device is disabled */
 286         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 287                                        NULL, &current_status);
 288         if (ACPI_FAILURE(status))
 289                 return_VALUE(-ENODEV);
 290
 291         /* Check for device status.  Device should be disabled */
 292         if (current_status & ACPI_MEMORY_STA_ENABLED)
 293                 return_VALUE(-EINVAL);
 294
 295         return_VALUE(0);
 296 }
 297
 298 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 299 {
 300         int result;
 301         struct acpi_memory_info *info, *n;
 302
 303         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 304
 305         /*
 306          * Ask the VM to offline this memory range.
 307          * Note: Assume that this function returns zero on success
 308          */
 309         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 310                 if (info->enabled) {
 311                         result = remove_memory(info->start_addr, info->length);
 312                         if (result)
 313                                 return result;
 314                 }
 315                 kfree(info);
 316         }
 317
 318         /* Power-off and eject the device */
 319         result = acpi_memory_powerdown_device(mem_device);
 320         if (result) {
 321                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 322                                   "Device Power Down failed.\n"));
 323                 /* Set the status of the device to invalid */
 324                 mem_device->state = MEMORY_INVALID_STATE;
 325                 return result;
 326         }
 327
 328         mem_device->state = MEMORY_POWER_OFF_STATE;
 329         return result;
 330 }
 331
 332 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 333 {
 334         struct acpi_memory_device *mem_device;
 335         struct acpi_device *device;
 336
 337         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
 338
 339         switch (event) {
 340         case ACPI_NOTIFY_BUS_CHECK:
 341                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 342                                   "\nReceived BUS CHECK notification for device\n"));
 343                 /* Fall Through */
 344         case ACPI_NOTIFY_DEVICE_CHECK:
 345                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 346                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 347                                           "\nReceived DEVICE CHECK notification for device\n"));
 348                 if (acpi_memory_get_device(handle, &mem_device)) {
 349                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 350                                           "Error in finding driver data\n"));
 351                         return_VOID;
 352                 }
 353
 354                 if (!acpi_memory_check_device(mem_device)) {
 355                         if (acpi_memory_enable_device(mem_device))
 356                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 357                                                   "Error in acpi_memory_enable_device\n"));
 358                 }
 359                 break;
 360         case ACPI_NOTIFY_EJECT_REQUEST:
 361                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 362                                   "\nReceived EJECT REQUEST notification for device\n"));
 363
 364                 if (acpi_bus_get_device(handle, &device)) {
 365                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 366                                           "Device doesn't exist\n"));
 367                         break;
 368                 }
 369                 mem_device = acpi_driver_data(device);
 370                 if (!mem_device) {
 371                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 372                                           "Driver Data is NULL\n"));
 373                         break;
 374                 }
 375
 376                 /*
 377                  * Currently disabling memory device from kernel mode
 378                  * TBD: Can also be disabled from user mode scripts
 379                  * TBD: Can also be disabled by Callback registration
 380                  *      with generic sysfs driver
 381                  */
 382                 if (acpi_memory_disable_device(mem_device))
 383                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 384                                           "Error in acpi_memory_disable_device\n"));
 385                 /*
 386                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 387                  */
 388                 break;
 389         default:
 390                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 391                                   "Unsupported event [0x%x]\n", event));
 392                 break;
 393         }
 394
 395         return_VOID;
 396 }
 397
 398 static int acpi_memory_device_add(struct acpi_device *device)
 399 {
 400         int result;
 401         struct acpi_memory_device *mem_device = NULL;
 402
 403         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
 404
 405         if (!device)
 406                 return_VALUE(-EINVAL);
 407
 408         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 409         if (!mem_device)
 410                 return_VALUE(-ENOMEM);
 411         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 412
 413         INIT_LIST_HEAD(&mem_device->res_list);
 414         mem_device->handle = device->handle;
 415         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 416         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 417         acpi_driver_data(device) = mem_device;
 418
 419         /* Get the range from the _CRS */
 420         result = acpi_memory_get_device_resources(mem_device);
 421         if (result) {
 422                 kfree(mem_device);
 423                 return_VALUE(result);
 424         }
 425
 426         /* Set the device state */
 427         mem_device->state = MEMORY_POWER_ON_STATE;
 428
 429         printk(KERN_INFO "%s \n", acpi_device_name(device));
 430
 431         return_VALUE(result);
 432 }
 433
 434 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 435 {
 436         struct acpi_memory_device *mem_device = NULL;
 437
 438         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
 439
 440         if (!device || !acpi_driver_data(device))
 441                 return_VALUE(-EINVAL);
 442
 443         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 444         kfree(mem_device);
 445
 446         return_VALUE(0);
 447 }
 448
 449 static int acpi_memory_device_start (struct acpi_device *device)
 450 {
 451         struct acpi_memory_device *mem_device;
 452         int result = 0;
 453
 454         ACPI_FUNCTION_TRACE("acpi_memory_device_start");
 455
 456         mem_device = acpi_driver_data(device);
 457
 458         if (!acpi_memory_check_device(mem_device)) {
 459                 /* call add_memory func */
 460                 result = acpi_memory_enable_device(mem_device);
 461                 if (result)
 462                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 463                                 "Error in acpi_memory_enable_device\n"));
 464         }
 465         return_VALUE(result);
 466 }
 467
 468 /*
 469  * Helper function to check for memory device
 470  */
 471 static acpi_status is_memory_device(acpi_handle handle)
 472 {
 473         char *hardware_id;
 474         acpi_status status;
 475         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 476         struct acpi_device_info *info;
 477
 478         ACPI_FUNCTION_TRACE("is_memory_device");
 479
 480         status = acpi_get_object_info(handle, &buffer);
 481         if (ACPI_FAILURE(status))
 482                 return_ACPI_STATUS(AE_ERROR);
 483
 484         info = buffer.pointer;
 485         if (!(info->valid & ACPI_VALID_HID)) {
 486                 acpi_os_free(buffer.pointer);
 487                 return_ACPI_STATUS(AE_ERROR);
 488         }
 489
 490         hardware_id = info->hardware_id.value;
 491         if ((hardware_id == NULL) ||
 492             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 493                 status = AE_ERROR;
 494
 495         acpi_os_free(buffer.pointer);
 496         return_ACPI_STATUS(status);
 497 }
 498
 499 static acpi_status
 500 acpi_memory_register_notify_handler(acpi_handle handle,
 501                                     u32 level, void *ctxt, void **retv)
 502 {
 503         acpi_status status;
 504
 505         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
 506
 507         status = is_memory_device(handle);
 508         if (ACPI_FAILURE(status))
 509                 return_ACPI_STATUS(AE_OK);      /* continue */
 510
 511         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 512                                              acpi_memory_device_notify, NULL);
 513         if (ACPI_FAILURE(status)) {
 514                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 515                                   "Error installing notify handler\n"));
 516                 return_ACPI_STATUS(AE_OK);      /* continue */
 517         }
 518
 519         return_ACPI_STATUS(status);
 520 }
 521
 522 static acpi_status
 523 acpi_memory_deregister_notify_handler(acpi_handle handle,
 524                                       u32 level, void *ctxt, void **retv)
 525 {
 526         acpi_status status;
 527
 528         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
 529
 530         status = is_memory_device(handle);
 531         if (ACPI_FAILURE(status))
 532                 return_ACPI_STATUS(AE_OK);      /* continue */
 533
 534         status = acpi_remove_notify_handler(handle,
 535                                             ACPI_SYSTEM_NOTIFY,
 536                                             acpi_memory_device_notify);
 537         if (ACPI_FAILURE(status)) {
 538                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 539                                   "Error removing notify handler\n"));
 540                 return_ACPI_STATUS(AE_OK);      /* continue */
 541         }
 542
 543         return_ACPI_STATUS(status);
 544 }
 545
 546 static int __init acpi_memory_device_init(void)
 547 {
 548         int result;
 549         acpi_status status;
 550
 551         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
 552
 553         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 554
 555         if (result < 0)
 556                 return_VALUE(-ENODEV);
 557
 558         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 559                                      ACPI_UINT32_MAX,
 560                                      acpi_memory_register_notify_handler,
 561                                      NULL, NULL);
 562
 563         if (ACPI_FAILURE(status)) {
 564                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 565                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 566                 return_VALUE(-ENODEV);
 567         }
 568
 569         return_VALUE(0);
 570 }
 571
 572 static void __exit acpi_memory_device_exit(void)
 573 {
 574         acpi_status status;
 575
 576         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
 577
 578         /*
 579          * Adding this to un-install notification handlers for all the device
 580          * handles.
 581          */
 582         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 583                                      ACPI_UINT32_MAX,
 584                                      acpi_memory_deregister_notify_handler,
 585                                      NULL, NULL);
 586
 587         if (ACPI_FAILURE(status))
 588                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 589
 590         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 591
 592         return_VOID;
 593 }
 594
 595 module_init(acpi_memory_device_init);
 596 module_exit(acpi_memory_device_exit);