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         struct acpi_device * device;
  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
 132         if (!list_empty(&mem_device->res_list))
 133                 return 0;
 134
 135         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 136                                      acpi_memory_get_resource, mem_device);
 137         if (ACPI_FAILURE(status)) {
 138                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 139                         kfree(info);
 140                 INIT_LIST_HEAD(&mem_device->res_list);
 141                 return -EINVAL;
 142         }
 143
 144         return 0;
 145 }
 146
 147 static int
 148 acpi_memory_get_device(acpi_handle handle,
 149                        struct acpi_memory_device **mem_device)
 150 {
 151         acpi_status status;
 152         acpi_handle phandle;
 153         struct acpi_device *device = NULL;
 154         struct acpi_device *pdevice = NULL;
 155
 156
 157         if (!acpi_bus_get_device(handle, &device) && device)
 158                 goto end;
 159
 160         status = acpi_get_parent(handle, &phandle);
 161         if (ACPI_FAILURE(status)) {
 162                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 163                 return -EINVAL;
 164         }
 165
 166         /* Get the parent device */
 167         status = acpi_bus_get_device(phandle, &pdevice);
 168         if (ACPI_FAILURE(status)) {
 169                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
 170                 return -EINVAL;
 171         }
 172
 173         /*
 174          * Now add the notified device.  This creates the acpi_device
 175          * and invokes .add function
 176          */
 177         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 178         if (ACPI_FAILURE(status)) {
 179                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
 180                 return -EINVAL;
 181         }
 182
 183       end:
 184         *mem_device = acpi_driver_data(device);
 185         if (!(*mem_device)) {
 186                 printk(KERN_ERR "\n driver data not found");
 187                 return -ENODEV;
 188         }
 189
 190         return 0;
 191 }
 192
 193 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 194 {
 195         unsigned long current_status;
 196
 197
 198         /* Get device present/absent information from the _STA */
 199         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 200                                                NULL, &current_status)))
 201                 return -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 -ENODEV;
 210
 211         return 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
 221         /* Get the range from the _CRS */
 222         result = acpi_memory_get_device_resources(mem_device);
 223         if (result) {
 224                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
 225                 mem_device->state = MEMORY_INVALID_STATE;
 226                 return result;
 227         }
 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 (node < 0)
 243                         node = memory_add_physaddr_to_nid(info->start_addr);
 244
 245                 result = add_memory(node, info->start_addr, info->length);
 246                 if (result)
 247                         continue;
 248                 info->enabled = 1;
 249                 num_enabled++;
 250         }
 251         if (!num_enabled) {
 252                 printk(KERN_ERR PREFIX "add_memory failed\n");
 253                 mem_device->state = MEMORY_INVALID_STATE;
 254                 return -EINVAL;
 255         }
 256
 257         return result;
 258 }
 259
 260 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 261 {
 262         acpi_status status;
 263         struct acpi_object_list arg_list;
 264         union acpi_object arg;
 265         unsigned long current_status;
 266
 267
 268         /* Issue the _EJ0 command */
 269         arg_list.count = 1;
 270         arg_list.pointer = &arg;
 271         arg.type = ACPI_TYPE_INTEGER;
 272         arg.integer.value = 1;
 273         status = acpi_evaluate_object(mem_device->device->handle,
 274                                       "_EJ0", &arg_list, NULL);
 275         /* Return on _EJ0 failure */
 276         if (ACPI_FAILURE(status)) {
 277                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 278                 return -ENODEV;
 279         }
 280
 281         /* Evalute _STA to check if the device is disabled */
 282         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
 283                                        NULL, &current_status);
 284         if (ACPI_FAILURE(status))
 285                 return -ENODEV;
 286
 287         /* Check for device status.  Device should be disabled */
 288         if (current_status & ACPI_MEMORY_STA_ENABLED)
 289                 return -EINVAL;
 290
 291         return 0;
 292 }
 293
 294 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 295 {
 296         int result;
 297         struct acpi_memory_info *info, *n;
 298
 299
 300         /*
 301          * Ask the VM to offline this memory range.
 302          * Note: Assume that this function returns zero on success
 303          */
 304         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 305                 if (info->enabled) {
 306                         result = remove_memory(info->start_addr, info->length);
 307                         if (result)
 308                                 return result;
 309                 }
 310                 kfree(info);
 311         }
 312
 313         /* Power-off and eject the device */
 314         result = acpi_memory_powerdown_device(mem_device);
 315         if (result) {
 316                 /* Set the status of the device to invalid */
 317                 mem_device->state = MEMORY_INVALID_STATE;
 318                 return result;
 319         }
 320
 321         mem_device->state = MEMORY_POWER_OFF_STATE;
 322         return result;
 323 }
 324
 325 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 326 {
 327         struct acpi_memory_device *mem_device;
 328         struct acpi_device *device;
 329
 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                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 342                         return;
 343                 }
 344
 345                 if (!acpi_memory_check_device(mem_device)) {
 346                         if (acpi_memory_enable_device(mem_device))
 347                                 printk(KERN_ERR PREFIX
 348                                             "Cannot enable memory device\n");
 349                 }
 350                 break;
 351         case ACPI_NOTIFY_EJECT_REQUEST:
 352                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 353                                   "\nReceived EJECT REQUEST notification for device\n"));
 354
 355                 if (acpi_bus_get_device(handle, &device)) {
 356                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 357                         break;
 358                 }
 359                 mem_device = acpi_driver_data(device);
 360                 if (!mem_device) {
 361                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 362                         break;
 363                 }
 364
 365                 /*
 366                  * Currently disabling memory device from kernel mode
 367                  * TBD: Can also be disabled from user mode scripts
 368                  * TBD: Can also be disabled by Callback registration
 369                  *      with generic sysfs driver
 370                  */
 371                 if (acpi_memory_disable_device(mem_device))
 372                         printk(KERN_ERR PREFIX
 373                                     "Disable memory device\n");
 374                 /*
 375                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 376                  */
 377                 break;
 378         default:
 379                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 380                                   "Unsupported event [0x%x]\n", event));
 381                 break;
 382         }
 383
 384         return;
 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 = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 397         if (!mem_device)
 398                 return -ENOMEM;
 399         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 400
 401         INIT_LIST_HEAD(&mem_device->res_list);
 402         mem_device->device = device;
 403         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 404         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 405         acpi_driver_data(device) = mem_device;
 406
 407         /* Get the range from the _CRS */
 408         result = acpi_memory_get_device_resources(mem_device);
 409         if (result) {
 410                 kfree(mem_device);
 411                 return result;
 412         }
 413
 414         /* Set the device state */
 415         mem_device->state = MEMORY_POWER_ON_STATE;
 416
 417         printk(KERN_INFO "%s \n", acpi_device_name(device));
 418
 419         return result;
 420 }
 421
 422 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 423 {
 424         struct acpi_memory_device *mem_device = NULL;
 425
 426
 427         if (!device || !acpi_driver_data(device))
 428                 return -EINVAL;
 429
 430         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 431         kfree(mem_device);
 432
 433         return 0;
 434 }
 435
 436 static int acpi_memory_device_start (struct acpi_device *device)
 437 {
 438         struct acpi_memory_device *mem_device;
 439         int result = 0;
 440
 441         mem_device = acpi_driver_data(device);
 442
 443         if (!acpi_memory_check_device(mem_device)) {
 444                 /* call add_memory func */
 445                 result = acpi_memory_enable_device(mem_device);
 446                 if (result)
 447                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 448                                 "Error in acpi_memory_enable_device\n"));
 449         }
 450         return result;
 451 }
 452
 453 /*
 454  * Helper function to check for memory device
 455  */
 456 static acpi_status is_memory_device(acpi_handle handle)
 457 {
 458         char *hardware_id;
 459         acpi_status status;
 460         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 461         struct acpi_device_info *info;
 462
 463
 464         status = acpi_get_object_info(handle, &buffer);
 465         if (ACPI_FAILURE(status))
 466                 return status;
 467
 468         info = buffer.pointer;
 469         if (!(info->valid & ACPI_VALID_HID)) {
 470                 kfree(buffer.pointer);
 471                 return AE_ERROR;
 472         }
 473
 474         hardware_id = info->hardware_id.value;
 475         if ((hardware_id == NULL) ||
 476             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 477                 status = AE_ERROR;
 478
 479         kfree(buffer.pointer);
 480         return status;
 481 }
 482
 483 static acpi_status
 484 acpi_memory_register_notify_handler(acpi_handle handle,
 485                                     u32 level, void *ctxt, void **retv)
 486 {
 487         acpi_status status;
 488
 489
 490         status = is_memory_device(handle);
 491         if (ACPI_FAILURE(status))
 492                 return AE_OK;   /* continue */
 493
 494         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 495                                              acpi_memory_device_notify, NULL);
 496         /* continue */
 497         return AE_OK;
 498 }
 499
 500 static acpi_status
 501 acpi_memory_deregister_notify_handler(acpi_handle handle,
 502                                       u32 level, void *ctxt, void **retv)
 503 {
 504         acpi_status status;
 505
 506
 507         status = is_memory_device(handle);
 508         if (ACPI_FAILURE(status))
 509                 return AE_OK;   /* continue */
 510
 511         status = acpi_remove_notify_handler(handle,
 512                                             ACPI_SYSTEM_NOTIFY,
 513                                             acpi_memory_device_notify);
 514
 515         return AE_OK;   /* continue */
 516 }
 517
 518 static int __init acpi_memory_device_init(void)
 519 {
 520         int result;
 521         acpi_status status;
 522
 523
 524         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 525
 526         if (result < 0)
 527                 return -ENODEV;
 528
 529         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 530                                      ACPI_UINT32_MAX,
 531                                      acpi_memory_register_notify_handler,
 532                                      NULL, NULL);
 533
 534         if (ACPI_FAILURE(status)) {
 535                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 536                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 537                 return -ENODEV;
 538         }
 539
 540         return 0;
 541 }
 542
 543 static void __exit acpi_memory_device_exit(void)
 544 {
 545         acpi_status status;
 546
 547
 548         /*
 549          * Adding this to un-install notification handlers for all the device
 550          * handles.
 551          */
 552         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 553                                      ACPI_UINT32_MAX,
 554                                      acpi_memory_deregister_notify_handler,
 555                                      NULL, NULL);
 556
 557         if (ACPI_FAILURE(status))
 558                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 559
 560         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 561
 562         return;
 563 }
 564
 565 module_init(acpi_memory_device_init);
 566 module_exit(acpi_memory_device_exit);