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