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_info {
  72         struct list_head list;
  73         u64 start_addr;         /* Memory Range start physical addr */
  74         u64 length;             /* Memory Range length */
  75         unsigned short caching; /* memory cache attribute */
  76         unsigned short write_protect;   /* memory read/write attribute */
  77         unsigned int enabled:1;
  78 };
  79
  80 struct acpi_memory_device {
  81         acpi_handle handle;
  82         unsigned int state;     /* State of the memory device */
  83         struct list_head res_list;
  84 };
  85
  86 static acpi_status
  87 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  88 {
  89         struct acpi_memory_device *mem_device = context;
  90         struct acpi_resource_address64 address64;
  91         struct acpi_memory_info *info, *new;
  92         acpi_status status;
  93
  94         status = acpi_resource_to_address64(resource, &address64);
  95         if (ACPI_FAILURE(status) ||
  96             (address64.resource_type != ACPI_MEMORY_RANGE))
  97                 return AE_OK;
  98
  99         list_for_each_entry(info, &mem_device->res_list, list) {
 100                 /* Can we combine the resource range information? */
 101                 if ((info->caching == address64.info.mem.caching) &&
 102                     (info->write_protect == address64.info.mem.write_protect) &&
 103                     (info->start_addr + info->length == address64.minimum)) {
 104                         info->length += address64.address_length;
 105                         return AE_OK;
 106                 }
 107         }
 108
 109         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 110         if (!new)
 111                 return AE_ERROR;
 112
 113         INIT_LIST_HEAD(&new->list);
 114         new->caching = address64.info.mem.caching;
 115         new->write_protect = address64.info.mem.write_protect;
 116         new->start_addr = address64.minimum;
 117         new->length = address64.address_length;
 118         list_add_tail(&new->list, &mem_device->res_list);
 119
 120         return AE_OK;
 121 }
 122
 123 static int
 124 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 125 {
 126         acpi_status status;
 127         struct acpi_memory_info *info, *n;
 128
 129         ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
 130
 131         status = acpi_walk_resources(mem_device->handle, METHOD_NAME__CRS,
 132                                      acpi_memory_get_resource, mem_device);
 133         if (ACPI_FAILURE(status)) {
 134                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 135                         kfree(info);
 136                 return -EINVAL;
 137         }
 138
 139         return 0;
 140 }
 141
 142 static int
 143 acpi_memory_get_device(acpi_handle handle,
 144                        struct acpi_memory_device **mem_device)
 145 {
 146         acpi_status status;
 147         acpi_handle phandle;
 148         struct acpi_device *device = NULL;
 149         struct acpi_device *pdevice = NULL;
 150
 151         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
 152
 153         if (!acpi_bus_get_device(handle, &device) && device)
 154                 goto end;
 155
 156         status = acpi_get_parent(handle, &phandle);
 157         if (ACPI_FAILURE(status)) {
 158                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
 159                 return_VALUE(-EINVAL);
 160         }
 161
 162         /* Get the parent device */
 163         status = acpi_bus_get_device(phandle, &pdevice);
 164         if (ACPI_FAILURE(status)) {
 165                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 166                                   "Error in acpi_bus_get_device\n"));
 167                 return_VALUE(-EINVAL);
 168         }
 169
 170         /*
 171          * Now add the notified device.  This creates the acpi_device
 172          * and invokes .add function
 173          */
 174         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 175         if (ACPI_FAILURE(status)) {
 176                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
 177                 return_VALUE(-EINVAL);
 178         }
 179
 180       end:
 181         *mem_device = acpi_driver_data(device);
 182         if (!(*mem_device)) {
 183                 printk(KERN_ERR "\n driver data not found");
 184                 return_VALUE(-ENODEV);
 185         }
 186
 187         return_VALUE(0);
 188 }
 189
 190 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 191 {
 192         unsigned long current_status;
 193
 194         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
 195
 196         /* Get device present/absent information from the _STA */
 197         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
 198                                                NULL, &current_status)))
 199                 return_VALUE(-ENODEV);
 200         /*
 201          * Check for device status. Device should be
 202          * present/enabled/functioning.
 203          */
 204         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 205               && (current_status & ACPI_MEMORY_STA_ENABLED)
 206               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 207                 return_VALUE(-ENODEV);
 208
 209         return_VALUE(0);
 210 }
 211
 212 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 213 {
 214         int result, num_enabled = 0;
 215         struct acpi_memory_info *info;
 216
 217         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
 218
 219         /* Get the range from the _CRS */
 220         result = acpi_memory_get_device_resources(mem_device);
 221         if (result) {
 222                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 223                                   "\nget_device_resources failed\n"));
 224                 mem_device->state = MEMORY_INVALID_STATE;
 225                 return result;
 226         }
 227
 228         /*
 229          * Tell the VM there is more memory here...
 230          * Note: Assume that this function returns zero on success
 231          * We don't have memory-hot-add rollback function,now.
 232          * (i.e. memory-hot-remove function)
 233          */
 234         list_for_each_entry(info, &mem_device->res_list, list) {
 235                 result = add_memory(info->start_addr, info->length);
 236                 if (result)
 237                         continue;
 238                 info->enabled = 1;
 239                 num_enabled++;
 240         }
 241         if (!num_enabled) {
 242                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 243                 mem_device->state = MEMORY_INVALID_STATE;
 244                 return -EINVAL;
 245         }
 246
 247         return result;
 248 }
 249
 250 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 251 {
 252         acpi_status status;
 253         struct acpi_object_list arg_list;
 254         union acpi_object arg;
 255         unsigned long current_status;
 256
 257         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
 258
 259         /* Issue the _EJ0 command */
 260         arg_list.count = 1;
 261         arg_list.pointer = &arg;
 262         arg.type = ACPI_TYPE_INTEGER;
 263         arg.integer.value = 1;
 264         status = acpi_evaluate_object(mem_device->handle,
 265                                       "_EJ0", &arg_list, NULL);
 266         /* Return on _EJ0 failure */
 267         if (ACPI_FAILURE(status)) {
 268                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
 269                 return_VALUE(-ENODEV);
 270         }
 271
 272         /* Evalute _STA to check if the device is disabled */
 273         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 274                                        NULL, &current_status);
 275         if (ACPI_FAILURE(status))
 276                 return_VALUE(-ENODEV);
 277
 278         /* Check for device status.  Device should be disabled */
 279         if (current_status & ACPI_MEMORY_STA_ENABLED)
 280                 return_VALUE(-EINVAL);
 281
 282         return_VALUE(0);
 283 }
 284
 285 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 286 {
 287         int result;
 288         struct acpi_memory_info *info, *n;
 289
 290         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 291
 292         /*
 293          * Ask the VM to offline this memory range.
 294          * Note: Assume that this function returns zero on success
 295          */
 296         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 297                 if (info->enabled) {
 298                         result = remove_memory(info->start_addr, info->length);
 299                         if (result)
 300                                 return result;
 301                 }
 302                 kfree(info);
 303         }
 304
 305         /* Power-off and eject the device */
 306         result = acpi_memory_powerdown_device(mem_device);
 307         if (result) {
 308                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 309                                   "Device Power Down failed.\n"));
 310                 /* Set the status of the device to invalid */
 311                 mem_device->state = MEMORY_INVALID_STATE;
 312                 return result;
 313         }
 314
 315         mem_device->state = MEMORY_POWER_OFF_STATE;
 316         return result;
 317 }
 318
 319 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 320 {
 321         struct acpi_memory_device *mem_device;
 322         struct acpi_device *device;
 323
 324         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
 325
 326         switch (event) {
 327         case ACPI_NOTIFY_BUS_CHECK:
 328                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 329                                   "\nReceived BUS CHECK notification for device\n"));
 330                 /* Fall Through */
 331         case ACPI_NOTIFY_DEVICE_CHECK:
 332                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 333                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 334                                           "\nReceived DEVICE CHECK notification for device\n"));
 335                 if (acpi_memory_get_device(handle, &mem_device)) {
 336                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 337                                           "Error in finding driver data\n"));
 338                         return_VOID;
 339                 }
 340
 341                 if (!acpi_memory_check_device(mem_device)) {
 342                         if (acpi_memory_enable_device(mem_device))
 343                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 344                                                   "Error in acpi_memory_enable_device\n"));
 345                 }
 346                 break;
 347         case ACPI_NOTIFY_EJECT_REQUEST:
 348                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                                   "\nReceived EJECT REQUEST notification for device\n"));
 350
 351                 if (acpi_bus_get_device(handle, &device)) {
 352                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 353                                           "Device doesn't exist\n"));
 354                         break;
 355                 }
 356                 mem_device = acpi_driver_data(device);
 357                 if (!mem_device) {
 358                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 359                                           "Driver Data is NULL\n"));
 360                         break;
 361                 }
 362
 363                 /*
 364                  * Currently disabling memory device from kernel mode
 365                  * TBD: Can also be disabled from user mode scripts
 366                  * TBD: Can also be disabled by Callback registration
 367                  *      with generic sysfs driver
 368                  */
 369                 if (acpi_memory_disable_device(mem_device))
 370                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 371                                           "Error in acpi_memory_disable_device\n"));
 372                 /*
 373                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 374                  */
 375                 break;
 376         default:
 377                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 378                                   "Unsupported event [0x%x]\n", event));
 379                 break;
 380         }
 381
 382         return_VOID;
 383 }
 384
 385 static int acpi_memory_device_add(struct acpi_device *device)
 386 {
 387         int result;
 388         struct acpi_memory_device *mem_device = NULL;
 389
 390         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
 391
 392         if (!device)
 393                 return_VALUE(-EINVAL);
 394
 395         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 396         if (!mem_device)
 397                 return_VALUE(-ENOMEM);
 398         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 399
 400         INIT_LIST_HEAD(&mem_device->res_list);
 401         mem_device->handle = device->handle;
 402         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 403         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 404         acpi_driver_data(device) = mem_device;
 405
 406         /* Get the range from the _CRS */
 407         result = acpi_memory_get_device_resources(mem_device);
 408         if (result) {
 409                 kfree(mem_device);
 410                 return_VALUE(result);
 411         }
 412
 413         /* Set the device state */
 414         mem_device->state = MEMORY_POWER_ON_STATE;
 415
 416         printk(KERN_INFO "%s \n", acpi_device_name(device));
 417
 418         return_VALUE(result);
 419 }
 420
 421 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 422 {
 423         struct acpi_memory_device *mem_device = NULL;
 424
 425         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
 426
 427         if (!device || !acpi_driver_data(device))
 428                 return_VALUE(-EINVAL);
 429
 430         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 431         kfree(mem_device);
 432
 433         return_VALUE(0);
 434 }
 435
 436 /*
 437  * Helper function to check for memory device
 438  */
 439 static acpi_status is_memory_device(acpi_handle handle)
 440 {
 441         char *hardware_id;
 442         acpi_status status;
 443         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 444         struct acpi_device_info *info;
 445
 446         ACPI_FUNCTION_TRACE("is_memory_device");
 447
 448         status = acpi_get_object_info(handle, &buffer);
 449         if (ACPI_FAILURE(status))
 450                 return_ACPI_STATUS(AE_ERROR);
 451
 452         info = buffer.pointer;
 453         if (!(info->valid & ACPI_VALID_HID)) {
 454                 acpi_os_free(buffer.pointer);
 455                 return_ACPI_STATUS(AE_ERROR);
 456         }
 457
 458         hardware_id = info->hardware_id.value;
 459         if ((hardware_id == NULL) ||
 460             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 461                 status = AE_ERROR;
 462
 463         acpi_os_free(buffer.pointer);
 464         return_ACPI_STATUS(status);
 465 }
 466
 467 static acpi_status
 468 acpi_memory_register_notify_handler(acpi_handle handle,
 469                                     u32 level, void *ctxt, void **retv)
 470 {
 471         acpi_status status;
 472
 473         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
 474
 475         status = is_memory_device(handle);
 476         if (ACPI_FAILURE(status))
 477                 return_ACPI_STATUS(AE_OK);      /* continue */
 478
 479         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 480                                              acpi_memory_device_notify, NULL);
 481         if (ACPI_FAILURE(status)) {
 482                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 483                                   "Error installing notify handler\n"));
 484                 return_ACPI_STATUS(AE_OK);      /* continue */
 485         }
 486
 487         return_ACPI_STATUS(status);
 488 }
 489
 490 static acpi_status
 491 acpi_memory_deregister_notify_handler(acpi_handle handle,
 492                                       u32 level, void *ctxt, void **retv)
 493 {
 494         acpi_status status;
 495
 496         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
 497
 498         status = is_memory_device(handle);
 499         if (ACPI_FAILURE(status))
 500                 return_ACPI_STATUS(AE_OK);      /* continue */
 501
 502         status = acpi_remove_notify_handler(handle,
 503                                             ACPI_SYSTEM_NOTIFY,
 504                                             acpi_memory_device_notify);
 505         if (ACPI_FAILURE(status)) {
 506                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 507                                   "Error removing notify handler\n"));
 508                 return_ACPI_STATUS(AE_OK);      /* continue */
 509         }
 510
 511         return_ACPI_STATUS(status);
 512 }
 513
 514 static int __init acpi_memory_device_init(void)
 515 {
 516         int result;
 517         acpi_status status;
 518
 519         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
 520
 521         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 522
 523         if (result < 0)
 524                 return_VALUE(-ENODEV);
 525
 526         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 527                                      ACPI_UINT32_MAX,
 528                                      acpi_memory_register_notify_handler,
 529                                      NULL, NULL);
 530
 531         if (ACPI_FAILURE(status)) {
 532                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 533                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 534                 return_VALUE(-ENODEV);
 535         }
 536
 537         return_VALUE(0);
 538 }
 539
 540 static void __exit acpi_memory_device_exit(void)
 541 {
 542         acpi_status status;
 543
 544         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
 545
 546         /*
 547          * Adding this to un-install notification handlers for all the device
 548          * handles.
 549          */
 550         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 551                                      ACPI_UINT32_MAX,
 552                                      acpi_memory_deregister_notify_handler,
 553                                      NULL, NULL);
 554
 555         if (ACPI_FAILURE(status))
 556                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 557
 558         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 559
 560         return_VOID;
 561 }
 562
 563 module_init(acpi_memory_device_init);
 564 module_exit(acpi_memory_device_exit);