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         node = acpi_get_node(mem_device->device->handle);
 230         /*
 231          * Tell the VM there is more memory here...
 232          * Note: Assume that this function returns zero on success
 233          * We don't have memory-hot-add rollback function,now.
 234          * (i.e. memory-hot-remove function)
 235          */
 236         list_for_each_entry(info, &mem_device->res_list, list) {
 237                 if (info->enabled) { /* just sanity check...*/
 238                         num_enabled++;
 239                         continue;
 240                 }
 241                 /*
 242                  * If the memory block size is zero, please ignore it.
 243                  * Don't try to do the following memory hotplug flowchart.
 244                  */
 245                 if (!info->length)
 246                         continue;
 247                 if (node < 0)
 248                         node = memory_add_physaddr_to_nid(info->start_addr);
 249
 250                 result = add_memory(node, info->start_addr, info->length);
 251
 252                 /*
 253                  * If the memory block has been used by the kernel, add_memory()
 254                  * returns -EEXIST. If add_memory() returns the other error, it
 255                  * means that this memory block is not used by the kernel.
 256                  */
 257                 if (result && result != -EEXIST) {
 258                         info->failed = 1;
 259                         continue;
 260                 }
 261
 262                 if (!result)
 263                         info->enabled = 1;
 264                 /*
 265                  * Add num_enable even if add_memory() returns -EEXIST, so the
 266                  * device is bound to this driver.
 267                  */
 268                 num_enabled++;
 269         }
 270         if (!num_enabled) {
 271                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 272                 mem_device->state = MEMORY_INVALID_STATE;
 273                 return -EINVAL;
 274         }
 275         /*
 276          * Sometimes the memory device will contain several memory blocks.
 277          * When one memory block is hot-added to the system memory, it will
 278          * be regarded as a success.
 279          * Otherwise if the last memory block can't be hot-added to the system
 280          * memory, it will be failure and the memory device can't be bound with
 281          * driver.
 282          */
 283         return 0;
 284 }
 285
 286 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 287 {
 288         int result = 0;
 289         struct acpi_memory_info *info, *n;
 290
 291         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 292                 if (info->failed)
 293                         /* The kernel does not use this memory block */
 294                         continue;
 295
 296                 if (!info->enabled)
 297                         /*
 298                          * The kernel uses this memory block, but it may be not
 299                          * managed by us.
 300                          */
 301                         return -EBUSY;
 302
 303                 result = remove_memory(info->start_addr, info->length);
 304                 if (result)
 305                         return result;
 306
 307                 list_del(&info->list);
 308                 kfree(info);
 309         }
 310
 311         return result;
 312 }
 313
 314 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 315 {
 316         struct acpi_memory_device *mem_device;
 317         struct acpi_device *device;
 318         struct acpi_eject_event *ej_event = NULL;
 319         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 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                 if (acpi_bus_get_device(handle, &device)) {
 343                         acpi_handle_err(handle, "Device doesn't exist\n");
 344                         break;
 345                 }
 346                 mem_device = acpi_driver_data(device);
 347                 if (!mem_device) {
 348                         acpi_handle_err(handle, "Driver Data is NULL\n");
 349                         break;
 350                 }
 351
 352                 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 353                 if (!ej_event) {
 354                         pr_err(PREFIX "No memory, dropping EJECT\n");
 355                         break;
 356                 }
 357
 358                 ej_event->handle = handle;
 359                 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 360                 acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
 361                                         (void *)ej_event);
 362
 363                 /* eject is performed asynchronously */
 364                 return;
 365         default:
 366                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 367                                   "Unsupported event [0x%x]\n", event));
 368
 369                 /* non-hotplug event; possibly handled by other handler */
 370                 return;
 371         }
 372
 373         /* Inform firmware that the hotplug operation has completed */
 374         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
 375         return;
 376 }
 377
 378 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 379 {
 380         if (!mem_device)
 381                 return;
 382
 383         acpi_memory_free_device_resources(mem_device);
 384         kfree(mem_device);
 385 }
 386
 387 static int acpi_memory_device_add(struct acpi_device *device)
 388 {
 389         int result;
 390         struct acpi_memory_device *mem_device = NULL;
 391
 392
 393         if (!device)
 394                 return -EINVAL;
 395
 396         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 397         if (!mem_device)
 398                 return -ENOMEM;
 399
 400         INIT_LIST_HEAD(&mem_device->res_list);
 401         mem_device->device = device;
 402         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 403         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 404         device->driver_data = 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 result;
 411         }
 412
 413         /* Set the device state */
 414         mem_device->state = MEMORY_POWER_ON_STATE;
 415
 416         pr_debug("%s\n", acpi_device_name(device));
 417
 418         if (!acpi_memory_check_device(mem_device)) {
 419                 /* call add_memory func */
 420                 result = acpi_memory_enable_device(mem_device);
 421                 if (result) {
 422                         dev_err(&device->dev,
 423                                 "Error in acpi_memory_enable_device\n");
 424                         acpi_memory_device_free(mem_device);
 425                 }
 426         }
 427         return result;
 428 }
 429
 430 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 431 {
 432         struct acpi_memory_device *mem_device = NULL;
 433         int result;
 434
 435         if (!device || !acpi_driver_data(device))
 436                 return -EINVAL;
 437
 438         mem_device = acpi_driver_data(device);
 439
 440         result = acpi_memory_remove_memory(mem_device);
 441         if (result)
 442                 return result;
 443
 444         acpi_memory_device_free(mem_device);
 445
 446         return 0;
 447 }
 448
 449 /*
 450  * Helper function to check for memory device
 451  */
 452 static acpi_status is_memory_device(acpi_handle handle)
 453 {
 454         char *hardware_id;
 455         acpi_status status;
 456         struct acpi_device_info *info;
 457
 458         status = acpi_get_object_info(handle, &info);
 459         if (ACPI_FAILURE(status))
 460                 return status;
 461
 462         if (!(info->valid & ACPI_VALID_HID)) {
 463                 kfree(info);
 464                 return AE_ERROR;
 465         }
 466
 467         hardware_id = info->hardware_id.string;
 468         if ((hardware_id == NULL) ||
 469             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 470                 status = AE_ERROR;
 471
 472         kfree(info);
 473         return status;
 474 }
 475
 476 static acpi_status
 477 acpi_memory_register_notify_handler(acpi_handle handle,
 478                                     u32 level, void *ctxt, void **retv)
 479 {
 480         acpi_status status;
 481
 482
 483         status = is_memory_device(handle);
 484         if (ACPI_FAILURE(status))
 485                 return AE_OK;   /* continue */
 486
 487         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 488                                              acpi_memory_device_notify, NULL);
 489         /* continue */
 490         return AE_OK;
 491 }
 492
 493 static acpi_status
 494 acpi_memory_deregister_notify_handler(acpi_handle handle,
 495                                       u32 level, void *ctxt, void **retv)
 496 {
 497         acpi_status status;
 498
 499
 500         status = is_memory_device(handle);
 501         if (ACPI_FAILURE(status))
 502                 return AE_OK;   /* continue */
 503
 504         status = acpi_remove_notify_handler(handle,
 505                                             ACPI_SYSTEM_NOTIFY,
 506                                             acpi_memory_device_notify);
 507
 508         return AE_OK;   /* continue */
 509 }
 510
 511 static int __init acpi_memory_device_init(void)
 512 {
 513         int result;
 514         acpi_status status;
 515
 516
 517         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 518
 519         if (result < 0)
 520                 return -ENODEV;
 521
 522         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 523                                      ACPI_UINT32_MAX,
 524                                      acpi_memory_register_notify_handler, NULL,
 525                                      NULL, NULL);
 526
 527         if (ACPI_FAILURE(status)) {
 528                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 529                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 530                 return -ENODEV;
 531         }
 532
 533         return 0;
 534 }
 535
 536 static void __exit acpi_memory_device_exit(void)
 537 {
 538         acpi_status status;
 539
 540
 541         /*
 542          * Adding this to un-install notification handlers for all the device
 543          * handles.
 544          */
 545         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 546                                      ACPI_UINT32_MAX,
 547                                      acpi_memory_deregister_notify_handler, NULL,
 548                                      NULL, NULL);
 549
 550         if (ACPI_FAILURE(status))
 551                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 552
 553         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 554
 555         return;
 556 }
 557
 558 module_init(acpi_memory_device_init);
 559 module_exit(acpi_memory_device_exit);