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, int type);
  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         acpi_status status;
 161         acpi_handle phandle;
 162         struct acpi_device *device = NULL;
 163         struct acpi_device *pdevice = NULL;
 164         int result;
 165
 166
 167         if (!acpi_bus_get_device(handle, &device) && device)
 168                 goto end;
 169
 170         status = acpi_get_parent(handle, &phandle);
 171         if (ACPI_FAILURE(status)) {
 172                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 173                 return -EINVAL;
 174         }
 175
 176         /* Get the parent device */
 177         result = acpi_bus_get_device(phandle, &pdevice);
 178         if (result) {
 179                 acpi_handle_warn(phandle, "Cannot get acpi bus device\n");
 180                 return -EINVAL;
 181         }
 182
 183         /*
 184          * Now add the notified device.  This creates the acpi_device
 185          * and invokes .add function
 186          */
 187         result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 188         if (result) {
 189                 acpi_handle_warn(handle, "Cannot add acpi bus\n");
 190                 return -EINVAL;
 191         }
 192
 193       end:
 194         *mem_device = acpi_driver_data(device);
 195         if (!(*mem_device)) {
 196                 dev_err(&device->dev, "driver data not found\n");
 197                 return -ENODEV;
 198         }
 199
 200         return 0;
 201 }
 202
 203 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 204 {
 205         unsigned long long current_status;
 206
 207         /* Get device present/absent information from the _STA */
 208         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 209                                                NULL, &current_status)))
 210                 return -ENODEV;
 211         /*
 212          * Check for device status. Device should be
 213          * present/enabled/functioning.
 214          */
 215         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 216               && (current_status & ACPI_STA_DEVICE_ENABLED)
 217               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 218                 return -ENODEV;
 219
 220         return 0;
 221 }
 222
 223 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 224 {
 225         int result, num_enabled = 0;
 226         struct acpi_memory_info *info;
 227         int node;
 228
 229
 230         /* Get the range from the _CRS */
 231         result = acpi_memory_get_device_resources(mem_device);
 232         if (result) {
 233                 dev_err(&mem_device->device->dev,
 234                         "get_device_resources failed\n");
 235                 mem_device->state = MEMORY_INVALID_STATE;
 236                 return result;
 237         }
 238
 239         node = acpi_get_node(mem_device->device->handle);
 240         /*
 241          * Tell the VM there is more memory here...
 242          * Note: Assume that this function returns zero on success
 243          * We don't have memory-hot-add rollback function,now.
 244          * (i.e. memory-hot-remove function)
 245          */
 246         list_for_each_entry(info, &mem_device->res_list, list) {
 247                 if (info->enabled) { /* just sanity check...*/
 248                         num_enabled++;
 249                         continue;
 250                 }
 251                 /*
 252                  * If the memory block size is zero, please ignore it.
 253                  * Don't try to do the following memory hotplug flowchart.
 254                  */
 255                 if (!info->length)
 256                         continue;
 257                 if (node < 0)
 258                         node = memory_add_physaddr_to_nid(info->start_addr);
 259
 260                 result = add_memory(node, info->start_addr, info->length);
 261
 262                 /*
 263                  * If the memory block has been used by the kernel, add_memory()
 264                  * returns -EEXIST. If add_memory() returns the other error, it
 265                  * means that this memory block is not used by the kernel.
 266                  */
 267                 if (result && result != -EEXIST) {
 268                         info->failed = 1;
 269                         continue;
 270                 }
 271
 272                 if (!result)
 273                         info->enabled = 1;
 274                 /*
 275                  * Add num_enable even if add_memory() returns -EEXIST, so the
 276                  * device is bound to this driver.
 277                  */
 278                 num_enabled++;
 279         }
 280         if (!num_enabled) {
 281                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 282                 mem_device->state = MEMORY_INVALID_STATE;
 283                 return -EINVAL;
 284         }
 285         /*
 286          * Sometimes the memory device will contain several memory blocks.
 287          * When one memory block is hot-added to the system memory, it will
 288          * be regarded as a success.
 289          * Otherwise if the last memory block can't be hot-added to the system
 290          * memory, it will be failure and the memory device can't be bound with
 291          * driver.
 292          */
 293         return 0;
 294 }
 295
 296 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 297 {
 298         int result = 0;
 299         struct acpi_memory_info *info, *n;
 300
 301         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 302                 if (info->failed)
 303                         /* The kernel does not use this memory block */
 304                         continue;
 305
 306                 if (!info->enabled)
 307                         /*
 308                          * The kernel uses this memory block, but it may be not
 309                          * managed by us.
 310                          */
 311                         return -EBUSY;
 312
 313                 result = remove_memory(info->start_addr, info->length);
 314                 if (result)
 315                         return result;
 316
 317                 list_del(&info->list);
 318                 kfree(info);
 319         }
 320
 321         return result;
 322 }
 323
 324 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 325 {
 326         struct acpi_memory_device *mem_device;
 327         struct acpi_device *device;
 328         struct acpi_eject_event *ej_event = NULL;
 329         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 330
 331         switch (event) {
 332         case ACPI_NOTIFY_BUS_CHECK:
 333                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 334                                   "\nReceived BUS CHECK notification for device\n"));
 335                 /* Fall Through */
 336         case ACPI_NOTIFY_DEVICE_CHECK:
 337                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 338                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 339                                           "\nReceived DEVICE CHECK notification for device\n"));
 340                 if (acpi_memory_get_device(handle, &mem_device)) {
 341                         acpi_handle_err(handle, "Cannot find driver data\n");
 342                         break;
 343                 }
 344
 345                 if (acpi_memory_check_device(mem_device))
 346                         break;
 347
 348                 if (acpi_memory_enable_device(mem_device)) {
 349                         acpi_handle_err(handle,"Cannot enable memory device\n");
 350                         break;
 351                 }
 352
 353                 ost_code = ACPI_OST_SC_SUCCESS;
 354                 break;
 355
 356         case ACPI_NOTIFY_EJECT_REQUEST:
 357                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 358                                   "\nReceived EJECT REQUEST notification for device\n"));
 359
 360                 if (acpi_bus_get_device(handle, &device)) {
 361                         acpi_handle_err(handle, "Device doesn't exist\n");
 362                         break;
 363                 }
 364                 mem_device = acpi_driver_data(device);
 365                 if (!mem_device) {
 366                         acpi_handle_err(handle, "Driver Data is NULL\n");
 367                         break;
 368                 }
 369
 370                 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 371                 if (!ej_event) {
 372                         pr_err(PREFIX "No memory, dropping EJECT\n");
 373                         break;
 374                 }
 375
 376                 ej_event->handle = handle;
 377                 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 378                 acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
 379                                         (void *)ej_event);
 380
 381                 /* eject is performed asynchronously */
 382                 return;
 383         default:
 384                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 385                                   "Unsupported event [0x%x]\n", event));
 386
 387                 /* non-hotplug event; possibly handled by other handler */
 388                 return;
 389         }
 390
 391         /* Inform firmware that the hotplug operation has completed */
 392         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
 393         return;
 394 }
 395
 396 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 397 {
 398         if (!mem_device)
 399                 return;
 400
 401         acpi_memory_free_device_resources(mem_device);
 402         kfree(mem_device);
 403 }
 404
 405 static int acpi_memory_device_add(struct acpi_device *device)
 406 {
 407         int result;
 408         struct acpi_memory_device *mem_device = NULL;
 409
 410
 411         if (!device)
 412                 return -EINVAL;
 413
 414         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 415         if (!mem_device)
 416                 return -ENOMEM;
 417
 418         INIT_LIST_HEAD(&mem_device->res_list);
 419         mem_device->device = device;
 420         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 421         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 422         device->driver_data = mem_device;
 423
 424         /* Get the range from the _CRS */
 425         result = acpi_memory_get_device_resources(mem_device);
 426         if (result) {
 427                 kfree(mem_device);
 428                 return result;
 429         }
 430
 431         /* Set the device state */
 432         mem_device->state = MEMORY_POWER_ON_STATE;
 433
 434         pr_debug("%s\n", acpi_device_name(device));
 435
 436         if (!acpi_memory_check_device(mem_device)) {
 437                 /* call add_memory func */
 438                 result = acpi_memory_enable_device(mem_device);
 439                 if (result) {
 440                         dev_err(&device->dev,
 441                                 "Error in acpi_memory_enable_device\n");
 442                         acpi_memory_device_free(mem_device);
 443                 }
 444         }
 445         return result;
 446 }
 447
 448 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 449 {
 450         struct acpi_memory_device *mem_device = NULL;
 451         int result;
 452
 453         if (!device || !acpi_driver_data(device))
 454                 return -EINVAL;
 455
 456         mem_device = acpi_driver_data(device);
 457
 458         result = acpi_memory_remove_memory(mem_device);
 459         if (result)
 460                 return result;
 461
 462         acpi_memory_device_free(mem_device);
 463
 464         return 0;
 465 }
 466
 467 /*
 468  * Helper function to check for memory device
 469  */
 470 static acpi_status is_memory_device(acpi_handle handle)
 471 {
 472         char *hardware_id;
 473         acpi_status status;
 474         struct acpi_device_info *info;
 475
 476         status = acpi_get_object_info(handle, &info);
 477         if (ACPI_FAILURE(status))
 478                 return status;
 479
 480         if (!(info->valid & ACPI_VALID_HID)) {
 481                 kfree(info);
 482                 return AE_ERROR;
 483         }
 484
 485         hardware_id = info->hardware_id.string;
 486         if ((hardware_id == NULL) ||
 487             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 488                 status = AE_ERROR;
 489
 490         kfree(info);
 491         return status;
 492 }
 493
 494 static acpi_status
 495 acpi_memory_register_notify_handler(acpi_handle handle,
 496                                     u32 level, void *ctxt, void **retv)
 497 {
 498         acpi_status status;
 499
 500
 501         status = is_memory_device(handle);
 502         if (ACPI_FAILURE(status))
 503                 return AE_OK;   /* continue */
 504
 505         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 506                                              acpi_memory_device_notify, NULL);
 507         /* continue */
 508         return AE_OK;
 509 }
 510
 511 static acpi_status
 512 acpi_memory_deregister_notify_handler(acpi_handle handle,
 513                                       u32 level, void *ctxt, void **retv)
 514 {
 515         acpi_status status;
 516
 517
 518         status = is_memory_device(handle);
 519         if (ACPI_FAILURE(status))
 520                 return AE_OK;   /* continue */
 521
 522         status = acpi_remove_notify_handler(handle,
 523                                             ACPI_SYSTEM_NOTIFY,
 524                                             acpi_memory_device_notify);
 525
 526         return AE_OK;   /* continue */
 527 }
 528
 529 static int __init acpi_memory_device_init(void)
 530 {
 531         int result;
 532         acpi_status status;
 533
 534
 535         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 536
 537         if (result < 0)
 538                 return -ENODEV;
 539
 540         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 541                                      ACPI_UINT32_MAX,
 542                                      acpi_memory_register_notify_handler, NULL,
 543                                      NULL, NULL);
 544
 545         if (ACPI_FAILURE(status)) {
 546                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 547                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 548                 return -ENODEV;
 549         }
 550
 551         return 0;
 552 }
 553
 554 static void __exit acpi_memory_device_exit(void)
 555 {
 556         acpi_status status;
 557
 558
 559         /*
 560          * Adding this to un-install notification handlers for all the device
 561          * handles.
 562          */
 563         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 564                                      ACPI_UINT32_MAX,
 565                                      acpi_memory_deregister_notify_handler, NULL,
 566                                      NULL, NULL);
 567
 568         if (ACPI_FAILURE(status))
 569                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 570
 571         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 572
 573         return;
 574 }
 575
 576 module_init(acpi_memory_device_init);
 577 module_exit(acpi_memory_device_exit);