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         int node;
 219
 220         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
 221
 222         /* Get the range from the _CRS */
 223         result = acpi_memory_get_device_resources(mem_device);
 224         if (result) {
 225                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 226                                   "\nget_device_resources failed\n"));
 227                 mem_device->state = MEMORY_INVALID_STATE;
 228                 return result;
 229         }
 230
 231         node = acpi_get_node(mem_device->handle);
 232         /*
 233          * Tell the VM there is more memory here...
 234          * Note: Assume that this function returns zero on success
 235          * We don't have memory-hot-add rollback function,now.
 236          * (i.e. memory-hot-remove function)
 237          */
 238         list_for_each_entry(info, &mem_device->res_list, list) {
 239                 u64 start_pfn, end_pfn;
 240
 241                 start_pfn = info->start_addr >> PAGE_SHIFT;
 242                 end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
 243
 244                 if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
 245                         /* already enabled. try next area */
 246                         num_enabled++;
 247                         continue;
 248                 }
 249
 250                 result = add_memory(node, info->start_addr, info->length);
 251                 if (result)
 252                         continue;
 253                 info->enabled = 1;
 254                 num_enabled++;
 255         }
 256         if (!num_enabled) {
 257                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 258                 mem_device->state = MEMORY_INVALID_STATE;
 259                 return -EINVAL;
 260         }
 261
 262         return result;
 263 }
 264
 265 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 266 {
 267         acpi_status status;
 268         struct acpi_object_list arg_list;
 269         union acpi_object arg;
 270         unsigned long current_status;
 271
 272         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
 273
 274         /* Issue the _EJ0 command */
 275         arg_list.count = 1;
 276         arg_list.pointer = &arg;
 277         arg.type = ACPI_TYPE_INTEGER;
 278         arg.integer.value = 1;
 279         status = acpi_evaluate_object(mem_device->handle,
 280                                       "_EJ0", &arg_list, NULL);
 281         /* Return on _EJ0 failure */
 282         if (ACPI_FAILURE(status)) {
 283                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
 284                 return_VALUE(-ENODEV);
 285         }
 286
 287         /* Evalute _STA to check if the device is disabled */
 288         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 289                                        NULL, &current_status);
 290         if (ACPI_FAILURE(status))
 291                 return_VALUE(-ENODEV);
 292
 293         /* Check for device status.  Device should be disabled */
 294         if (current_status & ACPI_MEMORY_STA_ENABLED)
 295                 return_VALUE(-EINVAL);
 296
 297         return_VALUE(0);
 298 }
 299
 300 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 301 {
 302         int result;
 303         struct acpi_memory_info *info, *n;
 304
 305         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 306
 307         /*
 308          * Ask the VM to offline this memory range.
 309          * Note: Assume that this function returns zero on success
 310          */
 311         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 312                 if (info->enabled) {
 313                         result = remove_memory(info->start_addr, info->length);
 314                         if (result)
 315                                 return result;
 316                 }
 317                 kfree(info);
 318         }
 319
 320         /* Power-off and eject the device */
 321         result = acpi_memory_powerdown_device(mem_device);
 322         if (result) {
 323                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 324                                   "Device Power Down failed.\n"));
 325                 /* Set the status of the device to invalid */
 326                 mem_device->state = MEMORY_INVALID_STATE;
 327                 return result;
 328         }
 329
 330         mem_device->state = MEMORY_POWER_OFF_STATE;
 331         return result;
 332 }
 333
 334 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 335 {
 336         struct acpi_memory_device *mem_device;
 337         struct acpi_device *device;
 338
 339         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
 340
 341         switch (event) {
 342         case ACPI_NOTIFY_BUS_CHECK:
 343                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 344                                   "\nReceived BUS CHECK notification for device\n"));
 345                 /* Fall Through */
 346         case ACPI_NOTIFY_DEVICE_CHECK:
 347                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 348                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                                           "\nReceived DEVICE CHECK notification for device\n"));
 350                 if (acpi_memory_get_device(handle, &mem_device)) {
 351                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 352                                           "Error in finding driver data\n"));
 353                         return_VOID;
 354                 }
 355
 356                 if (!acpi_memory_check_device(mem_device)) {
 357                         if (acpi_memory_enable_device(mem_device))
 358                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 359                                                   "Error in acpi_memory_enable_device\n"));
 360                 }
 361                 break;
 362         case ACPI_NOTIFY_EJECT_REQUEST:
 363                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 364                                   "\nReceived EJECT REQUEST notification for device\n"));
 365
 366                 if (acpi_bus_get_device(handle, &device)) {
 367                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 368                                           "Device doesn't exist\n"));
 369                         break;
 370                 }
 371                 mem_device = acpi_driver_data(device);
 372                 if (!mem_device) {
 373                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 374                                           "Driver Data is NULL\n"));
 375                         break;
 376                 }
 377
 378                 /*
 379                  * Currently disabling memory device from kernel mode
 380                  * TBD: Can also be disabled from user mode scripts
 381                  * TBD: Can also be disabled by Callback registration
 382                  *      with generic sysfs driver
 383                  */
 384                 if (acpi_memory_disable_device(mem_device))
 385                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 386                                           "Error in acpi_memory_disable_device\n"));
 387                 /*
 388                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 389                  */
 390                 break;
 391         default:
 392                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 393                                   "Unsupported event [0x%x]\n", event));
 394                 break;
 395         }
 396
 397         return_VOID;
 398 }
 399
 400 static int acpi_memory_device_add(struct acpi_device *device)
 401 {
 402         int result;
 403         struct acpi_memory_device *mem_device = NULL;
 404
 405         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
 406
 407         if (!device)
 408                 return_VALUE(-EINVAL);
 409
 410         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 411         if (!mem_device)
 412                 return_VALUE(-ENOMEM);
 413         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 414
 415         INIT_LIST_HEAD(&mem_device->res_list);
 416         mem_device->handle = device->handle;
 417         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 418         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 419         acpi_driver_data(device) = mem_device;
 420
 421         /* Get the range from the _CRS */
 422         result = acpi_memory_get_device_resources(mem_device);
 423         if (result) {
 424                 kfree(mem_device);
 425                 return_VALUE(result);
 426         }
 427
 428         /* Set the device state */
 429         mem_device->state = MEMORY_POWER_ON_STATE;
 430
 431         printk(KERN_INFO "%s \n", acpi_device_name(device));
 432
 433         return_VALUE(result);
 434 }
 435
 436 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 437 {
 438         struct acpi_memory_device *mem_device = NULL;
 439
 440         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
 441
 442         if (!device || !acpi_driver_data(device))
 443                 return_VALUE(-EINVAL);
 444
 445         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 446         kfree(mem_device);
 447
 448         return_VALUE(0);
 449 }
 450
 451 static int acpi_memory_device_start (struct acpi_device *device)
 452 {
 453         struct acpi_memory_device *mem_device;
 454         int result = 0;
 455
 456         ACPI_FUNCTION_TRACE("acpi_memory_device_start");
 457
 458         mem_device = acpi_driver_data(device);
 459
 460         if (!acpi_memory_check_device(mem_device)) {
 461                 /* call add_memory func */
 462                 result = acpi_memory_enable_device(mem_device);
 463                 if (result)
 464                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 465                                 "Error in acpi_memory_enable_device\n"));
 466         }
 467         return_VALUE(result);
 468 }
 469
 470 /*
 471  * Helper function to check for memory device
 472  */
 473 static acpi_status is_memory_device(acpi_handle handle)
 474 {
 475         char *hardware_id;
 476         acpi_status status;
 477         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 478         struct acpi_device_info *info;
 479
 480         ACPI_FUNCTION_TRACE("is_memory_device");
 481
 482         status = acpi_get_object_info(handle, &buffer);
 483         if (ACPI_FAILURE(status))
 484                 return_ACPI_STATUS(AE_ERROR);
 485
 486         info = buffer.pointer;
 487         if (!(info->valid & ACPI_VALID_HID)) {
 488                 acpi_os_free(buffer.pointer);
 489                 return_ACPI_STATUS(AE_ERROR);
 490         }
 491
 492         hardware_id = info->hardware_id.value;
 493         if ((hardware_id == NULL) ||
 494             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 495                 status = AE_ERROR;
 496
 497         acpi_os_free(buffer.pointer);
 498         return_ACPI_STATUS(status);
 499 }
 500
 501 static acpi_status
 502 acpi_memory_register_notify_handler(acpi_handle handle,
 503                                     u32 level, void *ctxt, void **retv)
 504 {
 505         acpi_status status;
 506
 507         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
 508
 509         status = is_memory_device(handle);
 510         if (ACPI_FAILURE(status))
 511                 return_ACPI_STATUS(AE_OK);      /* continue */
 512
 513         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 514                                              acpi_memory_device_notify, NULL);
 515         if (ACPI_FAILURE(status)) {
 516                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 517                                   "Error installing notify handler\n"));
 518                 return_ACPI_STATUS(AE_OK);      /* continue */
 519         }
 520
 521         return_ACPI_STATUS(status);
 522 }
 523
 524 static acpi_status
 525 acpi_memory_deregister_notify_handler(acpi_handle handle,
 526                                       u32 level, void *ctxt, void **retv)
 527 {
 528         acpi_status status;
 529
 530         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
 531
 532         status = is_memory_device(handle);
 533         if (ACPI_FAILURE(status))
 534                 return_ACPI_STATUS(AE_OK);      /* continue */
 535
 536         status = acpi_remove_notify_handler(handle,
 537                                             ACPI_SYSTEM_NOTIFY,
 538                                             acpi_memory_device_notify);
 539         if (ACPI_FAILURE(status)) {
 540                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 541                                   "Error removing notify handler\n"));
 542                 return_ACPI_STATUS(AE_OK);      /* continue */
 543         }
 544
 545         return_ACPI_STATUS(status);
 546 }
 547
 548 static int __init acpi_memory_device_init(void)
 549 {
 550         int result;
 551         acpi_status status;
 552
 553         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
 554
 555         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 556
 557         if (result < 0)
 558                 return_VALUE(-ENODEV);
 559
 560         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 561                                      ACPI_UINT32_MAX,
 562                                      acpi_memory_register_notify_handler,
 563                                      NULL, NULL);
 564
 565         if (ACPI_FAILURE(status)) {
 566                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 567                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 568                 return_VALUE(-ENODEV);
 569         }
 570
 571         return_VALUE(0);
 572 }
 573
 574 static void __exit acpi_memory_device_exit(void)
 575 {
 576         acpi_status status;
 577
 578         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
 579
 580         /*
 581          * Adding this to un-install notification handlers for all the device
 582          * handles.
 583          */
 584         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 585                                      ACPI_UINT32_MAX,
 586                                      acpi_memory_deregister_notify_handler,
 587                                      NULL, NULL);
 588
 589         if (ACPI_FAILURE(status))
 590                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 591
 592         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 593
 594         return_VOID;
 595 }
 596
 597 module_init(acpi_memory_device_init);
 598 module_exit(acpi_memory_device_exit);