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 firmware 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 <linux/slab.h>
  34 #include <linux/acpi.h>
  35 #include <acpi/acpi_drivers.h>
  36
  37 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  38 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  39 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  40
  41 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  42
  43 #undef PREFIX
  44 #define         PREFIX          "ACPI:memory_hp:"
  45
  46 ACPI_MODULE_NAME("acpi_memhotplug");
  47 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
  48 MODULE_DESCRIPTION("Hotplug Mem Driver");
  49 MODULE_LICENSE("GPL");
  50
  51 /* Memory Device States */
  52 #define MEMORY_INVALID_STATE    0
  53 #define MEMORY_POWER_ON_STATE   1
  54 #define MEMORY_POWER_OFF_STATE  2
  55
  56 static int acpi_memory_device_add(struct acpi_device *device);
  57 static int acpi_memory_device_remove(struct acpi_device *device);
  58
  59 static const struct acpi_device_id memory_device_ids[] = {
  60         {ACPI_MEMORY_DEVICE_HID, 0},
  61         {"", 0},
  62 };
  63 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
  64
  65 static struct acpi_driver acpi_memory_device_driver = {
  66         .name = "acpi_memhotplug",
  67         .class = ACPI_MEMORY_DEVICE_CLASS,
  68         .ids = memory_device_ids,
  69         .ops = {
  70                 .add = acpi_memory_device_add,
  71                 .remove = acpi_memory_device_remove,
  72                 },
  73 };
  74
  75 struct acpi_memory_info {
  76         struct list_head list;
  77         u64 start_addr;         /* Memory Range start physical addr */
  78         u64 length;             /* Memory Range length */
  79         unsigned short caching; /* memory cache attribute */
  80         unsigned short write_protect;   /* memory read/write attribute */
  81         unsigned int enabled:1;
  82         unsigned int failed:1;
  83 };
  84
  85 struct acpi_memory_device {
  86         struct acpi_device * device;
  87         unsigned int state;     /* State of the memory device */
  88         struct list_head res_list;
  89 };
  90
  91 static acpi_status
  92 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  93 {
  94         struct acpi_memory_device *mem_device = context;
  95         struct acpi_resource_address64 address64;
  96         struct acpi_memory_info *info, *new;
  97         acpi_status status;
  98
  99         status = acpi_resource_to_address64(resource, &address64);
 100         if (ACPI_FAILURE(status) ||
 101             (address64.resource_type != ACPI_MEMORY_RANGE))
 102                 return AE_OK;
 103
 104         list_for_each_entry(info, &mem_device->res_list, list) {
 105                 /* Can we combine the resource range information? */
 106                 if ((info->caching == address64.info.mem.caching) &&
 107                     (info->write_protect == address64.info.mem.write_protect) &&
 108                     (info->start_addr + info->length == address64.minimum)) {
 109                         info->length += address64.address_length;
 110                         return AE_OK;
 111                 }
 112         }
 113
 114         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 115         if (!new)
 116                 return AE_ERROR;
 117
 118         INIT_LIST_HEAD(&new->list);
 119         new->caching = address64.info.mem.caching;
 120         new->write_protect = address64.info.mem.write_protect;
 121         new->start_addr = address64.minimum;
 122         new->length = address64.address_length;
 123         list_add_tail(&new->list, &mem_device->res_list);
 124
 125         return AE_OK;
 126 }
 127
 128 static void
 129 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
 130 {
 131         struct acpi_memory_info *info, *n;
 132
 133         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 134                 kfree(info);
 135         INIT_LIST_HEAD(&mem_device->res_list);
 136 }
 137
 138 static int
 139 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 140 {
 141         acpi_status status;
 142
 143         if (!list_empty(&mem_device->res_list))
 144                 return 0;
 145
 146         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 147                                      acpi_memory_get_resource, mem_device);
 148         if (ACPI_FAILURE(status)) {
 149                 acpi_memory_free_device_resources(mem_device);
 150                 return -EINVAL;
 151         }
 152
 153         return 0;
 154 }
 155
 156 static int acpi_memory_get_device(acpi_handle handle,
 157                                   struct acpi_memory_device **mem_device)
 158 {
 159         struct acpi_device *device = NULL;
 160         int result = 0;
 161
 162         acpi_scan_lock_acquire();
 163
 164         acpi_bus_get_device(handle, &device);
 165         if (device)
 166                 goto end;
 167
 168         /*
 169          * Now add the notified device.  This creates the acpi_device
 170          * and invokes .add function
 171          */
 172         result = acpi_bus_scan(handle);
 173         if (result) {
 174                 acpi_handle_warn(handle, "ACPI namespace scan failed\n");
 175                 result = -EINVAL;
 176                 goto out;
 177         }
 178         result = acpi_bus_get_device(handle, &device);
 179         if (result) {
 180                 acpi_handle_warn(handle, "Missing device object\n");
 181                 result = -EINVAL;
 182                 goto out;
 183         }
 184
 185  end:
 186         *mem_device = acpi_driver_data(device);
 187         if (!(*mem_device)) {
 188                 dev_err(&device->dev, "driver data not found\n");
 189                 result = -ENODEV;
 190                 goto out;
 191         }
 192
 193  out:
 194         acpi_scan_lock_release();
 195         return result;
 196 }
 197
 198 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 199 {
 200         unsigned long long current_status;
 201
 202         /* Get device present/absent information from the _STA */
 203         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 204                                                NULL, &current_status)))
 205                 return -ENODEV;
 206         /*
 207          * Check for device status. Device should be
 208          * present/enabled/functioning.
 209          */
 210         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 211               && (current_status & ACPI_STA_DEVICE_ENABLED)
 212               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 213                 return -ENODEV;
 214
 215         return 0;
 216 }
 217
 218 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 219 {
 220         int result, num_enabled = 0;
 221         struct acpi_memory_info *info;
 222         int node;
 223
 224         node = acpi_get_node(mem_device->device->handle);
 225         /*
 226          * Tell the VM there is more memory here...
 227          * Note: Assume that this function returns zero on success
 228          * We don't have memory-hot-add rollback function,now.
 229          * (i.e. memory-hot-remove function)
 230          */
 231         list_for_each_entry(info, &mem_device->res_list, list) {
 232                 if (info->enabled) { /* just sanity check...*/
 233                         num_enabled++;
 234                         continue;
 235                 }
 236                 /*
 237                  * If the memory block size is zero, please ignore it.
 238                  * Don't try to do the following memory hotplug flowchart.
 239                  */
 240                 if (!info->length)
 241                         continue;
 242                 if (node < 0)
 243                         node = memory_add_physaddr_to_nid(info->start_addr);
 244
 245                 result = add_memory(node, info->start_addr, info->length);
 246
 247                 /*
 248                  * If the memory block has been used by the kernel, add_memory()
 249                  * returns -EEXIST. If add_memory() returns the other error, it
 250                  * means that this memory block is not used by the kernel.
 251                  */
 252                 if (result && result != -EEXIST) {
 253                         info->failed = 1;
 254                         continue;
 255                 }
 256
 257                 if (!result)
 258                         info->enabled = 1;
 259                 /*
 260                  * Add num_enable even if add_memory() returns -EEXIST, so the
 261                  * device is bound to this driver.
 262                  */
 263                 num_enabled++;
 264         }
 265         if (!num_enabled) {
 266                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 267                 mem_device->state = MEMORY_INVALID_STATE;
 268                 return -EINVAL;
 269         }
 270         /*
 271          * Sometimes the memory device will contain several memory blocks.
 272          * When one memory block is hot-added to the system memory, it will
 273          * be regarded as a success.
 274          * Otherwise if the last memory block can't be hot-added to the system
 275          * memory, it will be failure and the memory device can't be bound with
 276          * driver.
 277          */
 278         return 0;
 279 }
 280
 281 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 282 {
 283         int result = 0, nid;
 284         struct acpi_memory_info *info, *n;
 285
 286         nid = acpi_get_node(mem_device->device->handle);
 287
 288         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 289                 if (info->failed)
 290                         /* The kernel does not use this memory block */
 291                         continue;
 292
 293                 if (!info->enabled)
 294                         /*
 295                          * The kernel uses this memory block, but it may be not
 296                          * managed by us.
 297                          */
 298                         return -EBUSY;
 299
 300                 if (nid < 0)
 301                         nid = memory_add_physaddr_to_nid(info->start_addr);
 302                 result = remove_memory(nid, info->start_addr, info->length);
 303                 if (result)
 304                         return result;
 305
 306                 list_del(&info->list);
 307                 kfree(info);
 308         }
 309
 310         return result;
 311 }
 312
 313 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 314 {
 315         struct acpi_memory_device *mem_device;
 316         struct acpi_device *device;
 317         struct acpi_eject_event *ej_event = NULL;
 318         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 319         acpi_status status;
 320
 321         switch (event) {
 322         case ACPI_NOTIFY_BUS_CHECK:
 323                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 324                                   "\nReceived BUS CHECK notification for device\n"));
 325                 /* Fall Through */
 326         case ACPI_NOTIFY_DEVICE_CHECK:
 327                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 328                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 329                                           "\nReceived DEVICE CHECK notification for device\n"));
 330                 if (acpi_memory_get_device(handle, &mem_device)) {
 331                         acpi_handle_err(handle, "Cannot find driver data\n");
 332                         break;
 333                 }
 334
 335                 ost_code = ACPI_OST_SC_SUCCESS;
 336                 break;
 337
 338         case ACPI_NOTIFY_EJECT_REQUEST:
 339                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 340                                   "\nReceived EJECT REQUEST notification for device\n"));
 341
 342                 status = AE_ERROR;
 343                 acpi_scan_lock_acquire();
 344
 345                 if (acpi_bus_get_device(handle, &device)) {
 346                         acpi_handle_err(handle, "Device doesn't exist\n");
 347                         goto unlock;
 348                 }
 349                 mem_device = acpi_driver_data(device);
 350                 if (!mem_device) {
 351                         acpi_handle_err(handle, "Driver Data is NULL\n");
 352                         goto unlock;
 353                 }
 354
 355                 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 356                 if (!ej_event) {
 357                         pr_err(PREFIX "No memory, dropping EJECT\n");
 358                         goto unlock;
 359                 }
 360
 361                 get_device(&device->dev);
 362                 ej_event->device = device;
 363                 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 364                 /* The eject is carried out asynchronously. */
 365                 status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
 366                                                  ej_event);
 367                 if (ACPI_FAILURE(status)) {
 368                         put_device(&device->dev);
 369                         kfree(ej_event);
 370                 }
 371
 372  unlock:
 373                 acpi_scan_lock_release();
 374                 if (ACPI_SUCCESS(status))
 375                         return;
 376         default:
 377                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 378                                   "Unsupported event [0x%x]\n", event));
 379
 380                 /* non-hotplug event; possibly handled by other handler */
 381                 return;
 382         }
 383
 384         /* Inform firmware that the hotplug operation has completed */
 385         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
 386 }
 387
 388 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 389 {
 390         if (!mem_device)
 391                 return;
 392
 393         acpi_memory_free_device_resources(mem_device);
 394         kfree(mem_device);
 395 }
 396
 397 static int acpi_memory_device_add(struct acpi_device *device)
 398 {
 399         int result;
 400         struct acpi_memory_device *mem_device = NULL;
 401
 402
 403         if (!device)
 404                 return -EINVAL;
 405
 406         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 407         if (!mem_device)
 408                 return -ENOMEM;
 409
 410         INIT_LIST_HEAD(&mem_device->res_list);
 411         mem_device->device = device;
 412         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 413         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 414         device->driver_data = mem_device;
 415
 416         /* Get the range from the _CRS */
 417         result = acpi_memory_get_device_resources(mem_device);
 418         if (result) {
 419                 kfree(mem_device);
 420                 return result;
 421         }
 422
 423         /* Set the device state */
 424         mem_device->state = MEMORY_POWER_ON_STATE;
 425
 426         pr_debug("%s\n", acpi_device_name(device));
 427
 428         if (!acpi_memory_check_device(mem_device)) {
 429                 /* call add_memory func */
 430                 result = acpi_memory_enable_device(mem_device);
 431                 if (result) {
 432                         dev_err(&device->dev,
 433                                 "Error in acpi_memory_enable_device\n");
 434                         acpi_memory_device_free(mem_device);
 435                 }
 436         }
 437         return result;
 438 }
 439
 440 static int acpi_memory_device_remove(struct acpi_device *device)
 441 {
 442         struct acpi_memory_device *mem_device = NULL;
 443         int result;
 444
 445         if (!device || !acpi_driver_data(device))
 446                 return -EINVAL;
 447
 448         mem_device = acpi_driver_data(device);
 449
 450         result = acpi_memory_remove_memory(mem_device);
 451         if (result)
 452                 return result;
 453
 454         acpi_memory_device_free(mem_device);
 455
 456         return 0;
 457 }
 458
 459 /*
 460  * Helper function to check for memory device
 461  */
 462 static acpi_status is_memory_device(acpi_handle handle)
 463 {
 464         char *hardware_id;
 465         acpi_status status;
 466         struct acpi_device_info *info;
 467
 468         status = acpi_get_object_info(handle, &info);
 469         if (ACPI_FAILURE(status))
 470                 return status;
 471
 472         if (!(info->valid & ACPI_VALID_HID)) {
 473                 kfree(info);
 474                 return AE_ERROR;
 475         }
 476
 477         hardware_id = info->hardware_id.string;
 478         if ((hardware_id == NULL) ||
 479             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 480                 status = AE_ERROR;
 481
 482         kfree(info);
 483         return status;
 484 }
 485
 486 static acpi_status
 487 acpi_memory_register_notify_handler(acpi_handle handle,
 488                                     u32 level, void *ctxt, void **retv)
 489 {
 490         acpi_status status;
 491
 492
 493         status = is_memory_device(handle);
 494         if (ACPI_FAILURE(status))
 495                 return AE_OK;   /* continue */
 496
 497         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 498                                              acpi_memory_device_notify, NULL);
 499         /* continue */
 500         return AE_OK;
 501 }
 502
 503 static acpi_status
 504 acpi_memory_deregister_notify_handler(acpi_handle handle,
 505                                       u32 level, void *ctxt, void **retv)
 506 {
 507         acpi_status status;
 508
 509
 510         status = is_memory_device(handle);
 511         if (ACPI_FAILURE(status))
 512                 return AE_OK;   /* continue */
 513
 514         status = acpi_remove_notify_handler(handle,
 515                                             ACPI_SYSTEM_NOTIFY,
 516                                             acpi_memory_device_notify);
 517
 518         return AE_OK;   /* continue */
 519 }
 520
 521 static int __init acpi_memory_device_init(void)
 522 {
 523         int result;
 524         acpi_status status;
 525
 526
 527         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 528
 529         if (result < 0)
 530                 return -ENODEV;
 531
 532         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 533                                      ACPI_UINT32_MAX,
 534                                      acpi_memory_register_notify_handler, NULL,
 535                                      NULL, NULL);
 536
 537         if (ACPI_FAILURE(status)) {
 538                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 539                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 540                 return -ENODEV;
 541         }
 542
 543         return 0;
 544 }
 545
 546 static void __exit acpi_memory_device_exit(void)
 547 {
 548         acpi_status status;
 549
 550
 551         /*
 552          * Adding this to un-install notification handlers for all the device
 553          * handles.
 554          */
 555         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 556                                      ACPI_UINT32_MAX,
 557                                      acpi_memory_deregister_notify_handler, NULL,
 558                                      NULL, NULL);
 559
 560         if (ACPI_FAILURE(status))
 561                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 562
 563         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 564
 565         return;
 566 }
 567
 568 module_init(acpi_memory_device_init);
 569 module_exit(acpi_memory_device_exit);