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
 157 acpi_memory_get_device(acpi_handle handle,
 158                        struct acpi_memory_device **mem_device)
 159 {
 160         struct acpi_device *device = NULL;
 161         int result;
 162
 163         if (!acpi_bus_get_device(handle, &device) && device)
 164                 goto end;
 165
 166         /*
 167          * Now add the notified device.  This creates the acpi_device
 168          * and invokes .add function
 169          */
 170         result = acpi_bus_scan(handle);
 171         if (result) {
 172                 acpi_handle_warn(handle, "Cannot add acpi bus\n");
 173                 return -EINVAL;
 174         }
 175         result = acpi_bus_get_device(handle, &device);
 176         if (result) {
 177                 acpi_handle_warn(handle, "Missing device object\n");
 178                 return -EINVAL;
 179         }
 180
 181       end:
 182         *mem_device = acpi_driver_data(device);
 183         if (!(*mem_device)) {
 184                 dev_err(&device->dev, "driver data not found\n");
 185                 return -ENODEV;
 186         }
 187
 188         return 0;
 189 }
 190
 191 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 192 {
 193         unsigned long long current_status;
 194
 195         /* Get device present/absent information from the _STA */
 196         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 197                                                NULL, &current_status)))
 198                 return -ENODEV;
 199         /*
 200          * Check for device status. Device should be
 201          * present/enabled/functioning.
 202          */
 203         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 204               && (current_status & ACPI_STA_DEVICE_ENABLED)
 205               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 206                 return -ENODEV;
 207
 208         return 0;
 209 }
 210
 211 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 212 {
 213         int result, num_enabled = 0;
 214         struct acpi_memory_info *info;
 215         int node;
 216
 217         node = acpi_get_node(mem_device->device->handle);
 218         /*
 219          * Tell the VM there is more memory here...
 220          * Note: Assume that this function returns zero on success
 221          * We don't have memory-hot-add rollback function,now.
 222          * (i.e. memory-hot-remove function)
 223          */
 224         list_for_each_entry(info, &mem_device->res_list, list) {
 225                 if (info->enabled) { /* just sanity check...*/
 226                         num_enabled++;
 227                         continue;
 228                 }
 229                 /*
 230                  * If the memory block size is zero, please ignore it.
 231                  * Don't try to do the following memory hotplug flowchart.
 232                  */
 233                 if (!info->length)
 234                         continue;
 235                 if (node < 0)
 236                         node = memory_add_physaddr_to_nid(info->start_addr);
 237
 238                 result = add_memory(node, info->start_addr, info->length);
 239
 240                 /*
 241                  * If the memory block has been used by the kernel, add_memory()
 242                  * returns -EEXIST. If add_memory() returns the other error, it
 243                  * means that this memory block is not used by the kernel.
 244                  */
 245                 if (result && result != -EEXIST) {
 246                         info->failed = 1;
 247                         continue;
 248                 }
 249
 250                 if (!result)
 251                         info->enabled = 1;
 252                 /*
 253                  * Add num_enable even if add_memory() returns -EEXIST, so the
 254                  * device is bound to this driver.
 255                  */
 256                 num_enabled++;
 257         }
 258         if (!num_enabled) {
 259                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 260                 mem_device->state = MEMORY_INVALID_STATE;
 261                 return -EINVAL;
 262         }
 263         /*
 264          * Sometimes the memory device will contain several memory blocks.
 265          * When one memory block is hot-added to the system memory, it will
 266          * be regarded as a success.
 267          * Otherwise if the last memory block can't be hot-added to the system
 268          * memory, it will be failure and the memory device can't be bound with
 269          * driver.
 270          */
 271         return 0;
 272 }
 273
 274 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 275 {
 276         int result = 0;
 277         struct acpi_memory_info *info, *n;
 278
 279         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 280                 if (info->failed)
 281                         /* The kernel does not use this memory block */
 282                         continue;
 283
 284                 if (!info->enabled)
 285                         /*
 286                          * The kernel uses this memory block, but it may be not
 287                          * managed by us.
 288                          */
 289                         return -EBUSY;
 290
 291                 result = remove_memory(info->start_addr, info->length);
 292                 if (result)
 293                         return result;
 294
 295                 list_del(&info->list);
 296                 kfree(info);
 297         }
 298
 299         return result;
 300 }
 301
 302 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 303 {
 304         struct acpi_memory_device *mem_device;
 305         struct acpi_device *device;
 306         struct acpi_eject_event *ej_event = NULL;
 307         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 308
 309         switch (event) {
 310         case ACPI_NOTIFY_BUS_CHECK:
 311                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 312                                   "\nReceived BUS CHECK notification for device\n"));
 313                 /* Fall Through */
 314         case ACPI_NOTIFY_DEVICE_CHECK:
 315                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 316                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 317                                           "\nReceived DEVICE CHECK notification for device\n"));
 318                 if (acpi_memory_get_device(handle, &mem_device)) {
 319                         acpi_handle_err(handle, "Cannot find driver data\n");
 320                         break;
 321                 }
 322
 323                 ost_code = ACPI_OST_SC_SUCCESS;
 324                 break;
 325
 326         case ACPI_NOTIFY_EJECT_REQUEST:
 327                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 328                                   "\nReceived EJECT REQUEST notification for device\n"));
 329
 330                 if (acpi_bus_get_device(handle, &device)) {
 331                         acpi_handle_err(handle, "Device doesn't exist\n");
 332                         break;
 333                 }
 334                 mem_device = acpi_driver_data(device);
 335                 if (!mem_device) {
 336                         acpi_handle_err(handle, "Driver Data is NULL\n");
 337                         break;
 338                 }
 339
 340                 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 341                 if (!ej_event) {
 342                         pr_err(PREFIX "No memory, dropping EJECT\n");
 343                         break;
 344                 }
 345
 346                 ej_event->device = device;
 347                 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 348                 acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
 349                                         (void *)ej_event);
 350
 351                 /* eject is performed asynchronously */
 352                 return;
 353         default:
 354                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 355                                   "Unsupported event [0x%x]\n", event));
 356
 357                 /* non-hotplug event; possibly handled by other handler */
 358                 return;
 359         }
 360
 361         /* Inform firmware that the hotplug operation has completed */
 362         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
 363         return;
 364 }
 365
 366 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 367 {
 368         if (!mem_device)
 369                 return;
 370
 371         acpi_memory_free_device_resources(mem_device);
 372         kfree(mem_device);
 373 }
 374
 375 static int acpi_memory_device_add(struct acpi_device *device)
 376 {
 377         int result;
 378         struct acpi_memory_device *mem_device = NULL;
 379
 380
 381         if (!device)
 382                 return -EINVAL;
 383
 384         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 385         if (!mem_device)
 386                 return -ENOMEM;
 387
 388         INIT_LIST_HEAD(&mem_device->res_list);
 389         mem_device->device = device;
 390         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 391         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 392         device->driver_data = mem_device;
 393
 394         /* Get the range from the _CRS */
 395         result = acpi_memory_get_device_resources(mem_device);
 396         if (result) {
 397                 kfree(mem_device);
 398                 return result;
 399         }
 400
 401         /* Set the device state */
 402         mem_device->state = MEMORY_POWER_ON_STATE;
 403
 404         pr_debug("%s\n", acpi_device_name(device));
 405
 406         if (!acpi_memory_check_device(mem_device)) {
 407                 /* call add_memory func */
 408                 result = acpi_memory_enable_device(mem_device);
 409                 if (result) {
 410                         dev_err(&device->dev,
 411                                 "Error in acpi_memory_enable_device\n");
 412                         acpi_memory_device_free(mem_device);
 413                 }
 414         }
 415         return result;
 416 }
 417
 418 static int acpi_memory_device_remove(struct acpi_device *device)
 419 {
 420         struct acpi_memory_device *mem_device = NULL;
 421         int result;
 422
 423         if (!device || !acpi_driver_data(device))
 424                 return -EINVAL;
 425
 426         mem_device = acpi_driver_data(device);
 427
 428         result = acpi_memory_remove_memory(mem_device);
 429         if (result)
 430                 return result;
 431
 432         acpi_memory_device_free(mem_device);
 433
 434         return 0;
 435 }
 436
 437 /*
 438  * Helper function to check for memory device
 439  */
 440 static acpi_status is_memory_device(acpi_handle handle)
 441 {
 442         char *hardware_id;
 443         acpi_status status;
 444         struct acpi_device_info *info;
 445
 446         status = acpi_get_object_info(handle, &info);
 447         if (ACPI_FAILURE(status))
 448                 return status;
 449
 450         if (!(info->valid & ACPI_VALID_HID)) {
 451                 kfree(info);
 452                 return AE_ERROR;
 453         }
 454
 455         hardware_id = info->hardware_id.string;
 456         if ((hardware_id == NULL) ||
 457             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 458                 status = AE_ERROR;
 459
 460         kfree(info);
 461         return status;
 462 }
 463
 464 static acpi_status
 465 acpi_memory_register_notify_handler(acpi_handle handle,
 466                                     u32 level, void *ctxt, void **retv)
 467 {
 468         acpi_status status;
 469
 470
 471         status = is_memory_device(handle);
 472         if (ACPI_FAILURE(status))
 473                 return AE_OK;   /* continue */
 474
 475         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 476                                              acpi_memory_device_notify, NULL);
 477         /* continue */
 478         return AE_OK;
 479 }
 480
 481 static acpi_status
 482 acpi_memory_deregister_notify_handler(acpi_handle handle,
 483                                       u32 level, void *ctxt, void **retv)
 484 {
 485         acpi_status status;
 486
 487
 488         status = is_memory_device(handle);
 489         if (ACPI_FAILURE(status))
 490                 return AE_OK;   /* continue */
 491
 492         status = acpi_remove_notify_handler(handle,
 493                                             ACPI_SYSTEM_NOTIFY,
 494                                             acpi_memory_device_notify);
 495
 496         return AE_OK;   /* continue */
 497 }
 498
 499 static int __init acpi_memory_device_init(void)
 500 {
 501         int result;
 502         acpi_status status;
 503
 504
 505         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 506
 507         if (result < 0)
 508                 return -ENODEV;
 509
 510         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 511                                      ACPI_UINT32_MAX,
 512                                      acpi_memory_register_notify_handler, NULL,
 513                                      NULL, NULL);
 514
 515         if (ACPI_FAILURE(status)) {
 516                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 517                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 518                 return -ENODEV;
 519         }
 520
 521         return 0;
 522 }
 523
 524 static void __exit acpi_memory_device_exit(void)
 525 {
 526         acpi_status status;
 527
 528
 529         /*
 530          * Adding this to un-install notification handlers for all the device
 531          * handles.
 532          */
 533         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 534                                      ACPI_UINT32_MAX,
 535                                      acpi_memory_deregister_notify_handler, NULL,
 536                                      NULL, NULL);
 537
 538         if (ACPI_FAILURE(status))
 539                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 540
 541         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 542
 543         return;
 544 }
 545
 546 module_init(acpi_memory_device_init);
 547 module_exit(acpi_memory_device_exit);