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
  61 static struct acpi_driver acpi_memory_device_driver = {
  62         .name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
  63         .class = ACPI_MEMORY_DEVICE_CLASS,
  64         .ids = ACPI_MEMORY_DEVICE_HID,
  65         .ops = {
  66                 .add = acpi_memory_device_add,
  67                 .remove = acpi_memory_device_remove,
  68                 },
  69 };
  70
  71 struct acpi_memory_device {
  72         acpi_handle handle;
  73         unsigned int state;     /* State of the memory device */
  74         unsigned short caching; /* memory cache attribute */
  75         unsigned short write_protect;   /* memory read/write attribute */
  76         u64 start_addr;         /* Memory Range start physical addr */
  77         u64 length;             /* Memory Range length */
  78 };
  79
  80 static int
  81 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
  82 {
  83         acpi_status status;
  84         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  85         struct acpi_resource *resource = NULL;
  86         struct acpi_resource_address64 address64;
  87
  88         ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
  89
  90         /* Get the range from the _CRS */
  91         status = acpi_get_current_resources(mem_device->handle, &buffer);
  92         if (ACPI_FAILURE(status))
  93                 return_VALUE(-EINVAL);
  94
  95         resource = (struct acpi_resource *)buffer.pointer;
  96         status = acpi_resource_to_address64(resource, &address64);
  97         if (ACPI_SUCCESS(status)) {
  98                 if (address64.resource_type == ACPI_MEMORY_RANGE) {
  99                         /* Populate the structure */
 100                         mem_device->caching = address64.info.mem.caching;
 101                         mem_device->write_protect =
 102                             address64.info.mem.write_protect;
 103                         mem_device->start_addr = address64.minimum;
 104                         mem_device->length = address64.address_length;
 105                 }
 106         }
 107
 108         acpi_os_free(buffer.pointer);
 109         return_VALUE(0);
 110 }
 111
 112 static int
 113 acpi_memory_get_device(acpi_handle handle,
 114                        struct acpi_memory_device **mem_device)
 115 {
 116         acpi_status status;
 117         acpi_handle phandle;
 118         struct acpi_device *device = NULL;
 119         struct acpi_device *pdevice = NULL;
 120
 121         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
 122
 123         if (!acpi_bus_get_device(handle, &device) && device)
 124                 goto end;
 125
 126         status = acpi_get_parent(handle, &phandle);
 127         if (ACPI_FAILURE(status)) {
 128                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
 129                 return_VALUE(-EINVAL);
 130         }
 131
 132         /* Get the parent device */
 133         status = acpi_bus_get_device(phandle, &pdevice);
 134         if (ACPI_FAILURE(status)) {
 135                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 136                                   "Error in acpi_bus_get_device\n"));
 137                 return_VALUE(-EINVAL);
 138         }
 139
 140         /*
 141          * Now add the notified device.  This creates the acpi_device
 142          * and invokes .add function
 143          */
 144         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 145         if (ACPI_FAILURE(status)) {
 146                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
 147                 return_VALUE(-EINVAL);
 148         }
 149
 150       end:
 151         *mem_device = acpi_driver_data(device);
 152         if (!(*mem_device)) {
 153                 printk(KERN_ERR "\n driver data not found");
 154                 return_VALUE(-ENODEV);
 155         }
 156
 157         return_VALUE(0);
 158 }
 159
 160 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 161 {
 162         unsigned long current_status;
 163
 164         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
 165
 166         /* Get device present/absent information from the _STA */
 167         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
 168                                                NULL, &current_status)))
 169                 return_VALUE(-ENODEV);
 170         /*
 171          * Check for device status. Device should be
 172          * present/enabled/functioning.
 173          */
 174         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 175               && (current_status & ACPI_MEMORY_STA_ENABLED)
 176               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 177                 return_VALUE(-ENODEV);
 178
 179         return_VALUE(0);
 180 }
 181
 182 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 183 {
 184         int result;
 185
 186         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
 187
 188         /* Get the range from the _CRS */
 189         result = acpi_memory_get_device_resources(mem_device);
 190         if (result) {
 191                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 192                                   "\nget_device_resources failed\n"));
 193                 mem_device->state = MEMORY_INVALID_STATE;
 194                 return result;
 195         }
 196
 197         /*
 198          * Tell the VM there is more memory here...
 199          * Note: Assume that this function returns zero on success
 200          */
 201         result = add_memory(mem_device->start_addr, mem_device->length);
 202         if (result) {
 203                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 204                 mem_device->state = MEMORY_INVALID_STATE;
 205                 return result;
 206         }
 207
 208         return result;
 209 }
 210
 211 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 212 {
 213         acpi_status status;
 214         struct acpi_object_list arg_list;
 215         union acpi_object arg;
 216         unsigned long current_status;
 217
 218         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
 219
 220         /* Issue the _EJ0 command */
 221         arg_list.count = 1;
 222         arg_list.pointer = &arg;
 223         arg.type = ACPI_TYPE_INTEGER;
 224         arg.integer.value = 1;
 225         status = acpi_evaluate_object(mem_device->handle,
 226                                       "_EJ0", &arg_list, NULL);
 227         /* Return on _EJ0 failure */
 228         if (ACPI_FAILURE(status)) {
 229                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
 230                 return_VALUE(-ENODEV);
 231         }
 232
 233         /* Evalute _STA to check if the device is disabled */
 234         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 235                                        NULL, &current_status);
 236         if (ACPI_FAILURE(status))
 237                 return_VALUE(-ENODEV);
 238
 239         /* Check for device status.  Device should be disabled */
 240         if (current_status & ACPI_MEMORY_STA_ENABLED)
 241                 return_VALUE(-EINVAL);
 242
 243         return_VALUE(0);
 244 }
 245
 246 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 247 {
 248         int result;
 249         u64 start = mem_device->start_addr;
 250         u64 len = mem_device->length;
 251
 252         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 253
 254         /*
 255          * Ask the VM to offline this memory range.
 256          * Note: Assume that this function returns zero on success
 257          */
 258         result = remove_memory(start, len);
 259         if (result) {
 260                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n"));
 261                 return_VALUE(result);
 262         }
 263
 264         /* Power-off and eject the device */
 265         result = acpi_memory_powerdown_device(mem_device);
 266         if (result) {
 267                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 268                                   "Device Power Down failed.\n"));
 269                 /* Set the status of the device to invalid */
 270                 mem_device->state = MEMORY_INVALID_STATE;
 271                 return result;
 272         }
 273
 274         mem_device->state = MEMORY_POWER_OFF_STATE;
 275         return result;
 276 }
 277
 278 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 279 {
 280         struct acpi_memory_device *mem_device;
 281         struct acpi_device *device;
 282
 283         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
 284
 285         switch (event) {
 286         case ACPI_NOTIFY_BUS_CHECK:
 287                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 288                                   "\nReceived BUS CHECK notification for device\n"));
 289                 /* Fall Through */
 290         case ACPI_NOTIFY_DEVICE_CHECK:
 291                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 292                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 293                                           "\nReceived DEVICE CHECK notification for device\n"));
 294                 if (acpi_memory_get_device(handle, &mem_device)) {
 295                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 296                                           "Error in finding driver data\n"));
 297                         return_VOID;
 298                 }
 299
 300                 if (!acpi_memory_check_device(mem_device)) {
 301                         if (acpi_memory_enable_device(mem_device))
 302                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 303                                                   "Error in acpi_memory_enable_device\n"));
 304                 }
 305                 break;
 306         case ACPI_NOTIFY_EJECT_REQUEST:
 307                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 308                                   "\nReceived EJECT REQUEST notification for device\n"));
 309
 310                 if (acpi_bus_get_device(handle, &device)) {
 311                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 312                                           "Device doesn't exist\n"));
 313                         break;
 314                 }
 315                 mem_device = acpi_driver_data(device);
 316                 if (!mem_device) {
 317                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 318                                           "Driver Data is NULL\n"));
 319                         break;
 320                 }
 321
 322                 /*
 323                  * Currently disabling memory device from kernel mode
 324                  * TBD: Can also be disabled from user mode scripts
 325                  * TBD: Can also be disabled by Callback registration
 326                  *      with generic sysfs driver
 327                  */
 328                 if (acpi_memory_disable_device(mem_device))
 329                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 330                                           "Error in acpi_memory_disable_device\n"));
 331                 /*
 332                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 333                  */
 334                 break;
 335         default:
 336                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 337                                   "Unsupported event [0x%x]\n", event));
 338                 break;
 339         }
 340
 341         return_VOID;
 342 }
 343
 344 static int acpi_memory_device_add(struct acpi_device *device)
 345 {
 346         int result;
 347         struct acpi_memory_device *mem_device = NULL;
 348
 349         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
 350
 351         if (!device)
 352                 return_VALUE(-EINVAL);
 353
 354         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 355         if (!mem_device)
 356                 return_VALUE(-ENOMEM);
 357         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 358
 359         mem_device->handle = device->handle;
 360         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 361         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 362         acpi_driver_data(device) = mem_device;
 363
 364         /* Get the range from the _CRS */
 365         result = acpi_memory_get_device_resources(mem_device);
 366         if (result) {
 367                 kfree(mem_device);
 368                 return_VALUE(result);
 369         }
 370
 371         /* Set the device state */
 372         mem_device->state = MEMORY_POWER_ON_STATE;
 373
 374         printk(KERN_INFO "%s \n", acpi_device_name(device));
 375
 376         return_VALUE(result);
 377 }
 378
 379 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 380 {
 381         struct acpi_memory_device *mem_device = NULL;
 382
 383         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
 384
 385         if (!device || !acpi_driver_data(device))
 386                 return_VALUE(-EINVAL);
 387
 388         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 389         kfree(mem_device);
 390
 391         return_VALUE(0);
 392 }
 393
 394 /*
 395  * Helper function to check for memory device
 396  */
 397 static acpi_status is_memory_device(acpi_handle handle)
 398 {
 399         char *hardware_id;
 400         acpi_status status;
 401         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 402         struct acpi_device_info *info;
 403
 404         ACPI_FUNCTION_TRACE("is_memory_device");
 405
 406         status = acpi_get_object_info(handle, &buffer);
 407         if (ACPI_FAILURE(status))
 408                 return_ACPI_STATUS(AE_ERROR);
 409
 410         info = buffer.pointer;
 411         if (!(info->valid & ACPI_VALID_HID)) {
 412                 acpi_os_free(buffer.pointer);
 413                 return_ACPI_STATUS(AE_ERROR);
 414         }
 415
 416         hardware_id = info->hardware_id.value;
 417         if ((hardware_id == NULL) ||
 418             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 419                 status = AE_ERROR;
 420
 421         acpi_os_free(buffer.pointer);
 422         return_ACPI_STATUS(status);
 423 }
 424
 425 static acpi_status
 426 acpi_memory_register_notify_handler(acpi_handle handle,
 427                                     u32 level, void *ctxt, void **retv)
 428 {
 429         acpi_status status;
 430
 431         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
 432
 433         status = is_memory_device(handle);
 434         if (ACPI_FAILURE(status))
 435                 return_ACPI_STATUS(AE_OK);      /* continue */
 436
 437         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 438                                              acpi_memory_device_notify, NULL);
 439         if (ACPI_FAILURE(status)) {
 440                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 441                                   "Error installing notify handler\n"));
 442                 return_ACPI_STATUS(AE_OK);      /* continue */
 443         }
 444
 445         return_ACPI_STATUS(status);
 446 }
 447
 448 static acpi_status
 449 acpi_memory_deregister_notify_handler(acpi_handle handle,
 450                                       u32 level, void *ctxt, void **retv)
 451 {
 452         acpi_status status;
 453
 454         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
 455
 456         status = is_memory_device(handle);
 457         if (ACPI_FAILURE(status))
 458                 return_ACPI_STATUS(AE_OK);      /* continue */
 459
 460         status = acpi_remove_notify_handler(handle,
 461                                             ACPI_SYSTEM_NOTIFY,
 462                                             acpi_memory_device_notify);
 463         if (ACPI_FAILURE(status)) {
 464                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 465                                   "Error removing notify handler\n"));
 466                 return_ACPI_STATUS(AE_OK);      /* continue */
 467         }
 468
 469         return_ACPI_STATUS(status);
 470 }
 471
 472 static int __init acpi_memory_device_init(void)
 473 {
 474         int result;
 475         acpi_status status;
 476
 477         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
 478
 479         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 480
 481         if (result < 0)
 482                 return_VALUE(-ENODEV);
 483
 484         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 485                                      ACPI_UINT32_MAX,
 486                                      acpi_memory_register_notify_handler,
 487                                      NULL, NULL);
 488
 489         if (ACPI_FAILURE(status)) {
 490                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 491                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 492                 return_VALUE(-ENODEV);
 493         }
 494
 495         return_VALUE(0);
 496 }
 497
 498 static void __exit acpi_memory_device_exit(void)
 499 {
 500         acpi_status status;
 501
 502         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
 503
 504         /*
 505          * Adding this to un-install notification handlers for all the device
 506          * handles.
 507          */
 508         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 509                                      ACPI_UINT32_MAX,
 510                                      acpi_memory_deregister_notify_handler,
 511                                      NULL, NULL);
 512
 513         if (ACPI_FAILURE(status))
 514                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 515
 516         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 517
 518         return_VOID;
 519 }
 520
 521 module_init(acpi_memory_device_init);
 522 module_exit(acpi_memory_device_exit);