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 <acpi/acpi_drivers.h>
  34
  35 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  36 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  37 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  38
  39 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  40
  41 ACPI_MODULE_NAME("acpi_memhotplug");
  42 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
  43 MODULE_DESCRIPTION("Hotplug Mem Driver");
  44 MODULE_LICENSE("GPL");
  45
  46 /* Memory Device States */
  47 #define MEMORY_INVALID_STATE    0
  48 #define MEMORY_POWER_ON_STATE   1
  49 #define MEMORY_POWER_OFF_STATE  2
  50
  51 static int acpi_memory_device_add(struct acpi_device *device);
  52 static int acpi_memory_device_remove(struct acpi_device *device, int type);
  53
  54 static const struct acpi_device_id memory_device_ids[] = {
  55         {ACPI_MEMORY_DEVICE_HID, 0},
  56         {"", 0},
  57 };
  58 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
  59
  60 static struct acpi_driver acpi_memory_device_driver = {
  61         .name = "acpi_memhotplug",
  62         .class = ACPI_MEMORY_DEVICE_CLASS,
  63         .ids = memory_device_ids,
  64         .ops = {
  65                 .add = acpi_memory_device_add,
  66                 .remove = acpi_memory_device_remove,
  67                 },
  68 };
  69
  70 struct acpi_memory_info {
  71         struct list_head list;
  72         u64 start_addr;         /* Memory Range start physical addr */
  73         u64 length;             /* Memory Range length */
  74         unsigned short caching; /* memory cache attribute */
  75         unsigned short write_protect;   /* memory read/write attribute */
  76         unsigned int enabled:1;
  77 };
  78
  79 struct acpi_memory_device {
  80         struct acpi_device * device;
  81         unsigned int state;     /* State of the memory device */
  82         struct list_head res_list;
  83 };
  84
  85 static int acpi_hotmem_initialized;
  86
  87 static acpi_status
  88 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  89 {
  90         struct acpi_memory_device *mem_device = context;
  91         struct acpi_resource_address64 address64;
  92         struct acpi_memory_info *info, *new;
  93         acpi_status status;
  94
  95         status = acpi_resource_to_address64(resource, &address64);
  96         if (ACPI_FAILURE(status) ||
  97             (address64.resource_type != ACPI_MEMORY_RANGE))
  98                 return AE_OK;
  99
 100         list_for_each_entry(info, &mem_device->res_list, list) {
 101                 /* Can we combine the resource range information? */
 102                 if ((info->caching == address64.info.mem.caching) &&
 103                     (info->write_protect == address64.info.mem.write_protect) &&
 104                     (info->start_addr + info->length == address64.minimum)) {
 105                         info->length += address64.address_length;
 106                         return AE_OK;
 107                 }
 108         }
 109
 110         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 111         if (!new)
 112                 return AE_ERROR;
 113
 114         INIT_LIST_HEAD(&new->list);
 115         new->caching = address64.info.mem.caching;
 116         new->write_protect = address64.info.mem.write_protect;
 117         new->start_addr = address64.minimum;
 118         new->length = address64.address_length;
 119         list_add_tail(&new->list, &mem_device->res_list);
 120
 121         return AE_OK;
 122 }
 123
 124 static int
 125 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 126 {
 127         acpi_status status;
 128         struct acpi_memory_info *info, *n;
 129
 130
 131         if (!list_empty(&mem_device->res_list))
 132                 return 0;
 133
 134         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 135                                      acpi_memory_get_resource, mem_device);
 136         if (ACPI_FAILURE(status)) {
 137                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 138                         kfree(info);
 139                 INIT_LIST_HEAD(&mem_device->res_list);
 140                 return -EINVAL;
 141         }
 142
 143         return 0;
 144 }
 145
 146 static int
 147 acpi_memory_get_device(acpi_handle handle,
 148                        struct acpi_memory_device **mem_device)
 149 {
 150         acpi_status status;
 151         acpi_handle phandle;
 152         struct acpi_device *device = NULL;
 153         struct acpi_device *pdevice = NULL;
 154
 155
 156         if (!acpi_bus_get_device(handle, &device) && device)
 157                 goto end;
 158
 159         status = acpi_get_parent(handle, &phandle);
 160         if (ACPI_FAILURE(status)) {
 161                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 162                 return -EINVAL;
 163         }
 164
 165         /* Get the parent device */
 166         status = acpi_bus_get_device(phandle, &pdevice);
 167         if (ACPI_FAILURE(status)) {
 168                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
 169                 return -EINVAL;
 170         }
 171
 172         /*
 173          * Now add the notified device.  This creates the acpi_device
 174          * and invokes .add function
 175          */
 176         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 177         if (ACPI_FAILURE(status)) {
 178                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
 179                 return -EINVAL;
 180         }
 181
 182       end:
 183         *mem_device = acpi_driver_data(device);
 184         if (!(*mem_device)) {
 185                 printk(KERN_ERR "\n driver data not found");
 186                 return -ENODEV;
 187         }
 188
 189         return 0;
 190 }
 191
 192 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 193 {
 194         unsigned long long current_status;
 195
 196         /* Get device present/absent information from the _STA */
 197         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 198                                                NULL, &current_status)))
 199                 return -ENODEV;
 200         /*
 201          * Check for device status. Device should be
 202          * present/enabled/functioning.
 203          */
 204         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 205               && (current_status & ACPI_STA_DEVICE_ENABLED)
 206               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 207                 return -ENODEV;
 208
 209         return 0;
 210 }
 211
 212 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 213 {
 214         int result, num_enabled = 0;
 215         struct acpi_memory_info *info;
 216         int node;
 217
 218
 219         /* Get the range from the _CRS */
 220         result = acpi_memory_get_device_resources(mem_device);
 221         if (result) {
 222                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
 223                 mem_device->state = MEMORY_INVALID_STATE;
 224                 return result;
 225         }
 226
 227         node = acpi_get_node(mem_device->device->handle);
 228         /*
 229          * Tell the VM there is more memory here...
 230          * Note: Assume that this function returns zero on success
 231          * We don't have memory-hot-add rollback function,now.
 232          * (i.e. memory-hot-remove function)
 233          */
 234         list_for_each_entry(info, &mem_device->res_list, list) {
 235                 if (info->enabled) { /* just sanity check...*/
 236                         num_enabled++;
 237                         continue;
 238                 }
 239
 240                 if (node < 0)
 241                         node = memory_add_physaddr_to_nid(info->start_addr);
 242
 243                 result = add_memory(node, info->start_addr, info->length);
 244                 if (result)
 245                         continue;
 246                 info->enabled = 1;
 247                 num_enabled++;
 248         }
 249         if (!num_enabled) {
 250                 printk(KERN_ERR PREFIX "add_memory failed\n");
 251                 mem_device->state = MEMORY_INVALID_STATE;
 252                 return -EINVAL;
 253         }
 254
 255         return result;
 256 }
 257
 258 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 259 {
 260         acpi_status status;
 261         struct acpi_object_list arg_list;
 262         union acpi_object arg;
 263         unsigned long long current_status;
 264
 265
 266         /* Issue the _EJ0 command */
 267         arg_list.count = 1;
 268         arg_list.pointer = &arg;
 269         arg.type = ACPI_TYPE_INTEGER;
 270         arg.integer.value = 1;
 271         status = acpi_evaluate_object(mem_device->device->handle,
 272                                       "_EJ0", &arg_list, NULL);
 273         /* Return on _EJ0 failure */
 274         if (ACPI_FAILURE(status)) {
 275                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 276                 return -ENODEV;
 277         }
 278
 279         /* Evalute _STA to check if the device is disabled */
 280         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
 281                                        NULL, &current_status);
 282         if (ACPI_FAILURE(status))
 283                 return -ENODEV;
 284
 285         /* Check for device status.  Device should be disabled */
 286         if (current_status & ACPI_STA_DEVICE_ENABLED)
 287                 return -EINVAL;
 288
 289         return 0;
 290 }
 291
 292 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 293 {
 294         int result;
 295         struct acpi_memory_info *info, *n;
 296
 297
 298         /*
 299          * Ask the VM to offline this memory range.
 300          * Note: Assume that this function returns zero on success
 301          */
 302         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 303                 if (info->enabled) {
 304                         result = remove_memory(info->start_addr, info->length);
 305                         if (result)
 306                                 return result;
 307                 }
 308                 kfree(info);
 309         }
 310
 311         /* Power-off and eject the device */
 312         result = acpi_memory_powerdown_device(mem_device);
 313         if (result) {
 314                 /* Set the status of the device to invalid */
 315                 mem_device->state = MEMORY_INVALID_STATE;
 316                 return result;
 317         }
 318
 319         mem_device->state = MEMORY_POWER_OFF_STATE;
 320         return result;
 321 }
 322
 323 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 324 {
 325         struct acpi_memory_device *mem_device;
 326         struct acpi_device *device;
 327
 328
 329         switch (event) {
 330         case ACPI_NOTIFY_BUS_CHECK:
 331                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 332                                   "\nReceived BUS CHECK notification for device\n"));
 333                 /* Fall Through */
 334         case ACPI_NOTIFY_DEVICE_CHECK:
 335                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 336                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 337                                           "\nReceived DEVICE CHECK notification for device\n"));
 338                 if (acpi_memory_get_device(handle, &mem_device)) {
 339                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 340                         return;
 341                 }
 342
 343                 if (!acpi_memory_check_device(mem_device)) {
 344                         if (acpi_memory_enable_device(mem_device))
 345                                 printk(KERN_ERR PREFIX
 346                                             "Cannot enable memory device\n");
 347                 }
 348                 break;
 349         case ACPI_NOTIFY_EJECT_REQUEST:
 350                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 351                                   "\nReceived EJECT REQUEST notification for device\n"));
 352
 353                 if (acpi_bus_get_device(handle, &device)) {
 354                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 355                         break;
 356                 }
 357                 mem_device = acpi_driver_data(device);
 358                 if (!mem_device) {
 359                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 360                         break;
 361                 }
 362
 363                 /*
 364                  * Currently disabling memory device from kernel mode
 365                  * TBD: Can also be disabled from user mode scripts
 366                  * TBD: Can also be disabled by Callback registration
 367                  *      with generic sysfs driver
 368                  */
 369                 if (acpi_memory_disable_device(mem_device))
 370                         printk(KERN_ERR PREFIX
 371                                     "Disable memory device\n");
 372                 /*
 373                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 374                  */
 375                 break;
 376         default:
 377                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 378                                   "Unsupported event [0x%x]\n", event));
 379                 break;
 380         }
 381
 382         return;
 383 }
 384
 385 static int acpi_memory_device_add(struct acpi_device *device)
 386 {
 387         int result;
 388         struct acpi_memory_device *mem_device = NULL;
 389
 390
 391         if (!device)
 392                 return -EINVAL;
 393
 394         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 395         if (!mem_device)
 396                 return -ENOMEM;
 397
 398         INIT_LIST_HEAD(&mem_device->res_list);
 399         mem_device->device = device;
 400         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 401         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 402         device->driver_data = mem_device;
 403
 404         /* Get the range from the _CRS */
 405         result = acpi_memory_get_device_resources(mem_device);
 406         if (result) {
 407                 kfree(mem_device);
 408                 return result;
 409         }
 410
 411         /* Set the device state */
 412         mem_device->state = MEMORY_POWER_ON_STATE;
 413
 414         printk(KERN_DEBUG "%s \n", acpi_device_name(device));
 415
 416         /*
 417          * Early boot code has recognized memory area by EFI/E820.
 418          * If DSDT shows these memory devices on boot, hotplug is not necessary
 419          * for them. So, it just returns until completion of this driver's
 420          * start up.
 421          */
 422         if (!acpi_hotmem_initialized)
 423                 return 0;
 424
 425         if (!acpi_memory_check_device(mem_device)) {
 426                 /* call add_memory func */
 427                 result = acpi_memory_enable_device(mem_device);
 428                 if (result)
 429                         printk(KERN_ERR PREFIX
 430                                 "Error in acpi_memory_enable_device\n");
 431         }
 432         return result;
 433 }
 434
 435 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 436 {
 437         struct acpi_memory_device *mem_device = NULL;
 438
 439
 440         if (!device || !acpi_driver_data(device))
 441                 return -EINVAL;
 442
 443         mem_device = acpi_driver_data(device);
 444         kfree(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_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 457         struct acpi_device_info *info;
 458
 459
 460         status = acpi_get_object_info(handle, &buffer);
 461         if (ACPI_FAILURE(status))
 462                 return status;
 463
 464         info = buffer.pointer;
 465         if (!(info->valid & ACPI_VALID_HID)) {
 466                 kfree(buffer.pointer);
 467                 return AE_ERROR;
 468         }
 469
 470         hardware_id = info->hardware_id.value;
 471         if ((hardware_id == NULL) ||
 472             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 473                 status = AE_ERROR;
 474
 475         kfree(buffer.pointer);
 476         return status;
 477 }
 478
 479 static acpi_status
 480 acpi_memory_register_notify_handler(acpi_handle handle,
 481                                     u32 level, void *ctxt, void **retv)
 482 {
 483         acpi_status status;
 484
 485
 486         status = is_memory_device(handle);
 487         if (ACPI_FAILURE(status))
 488                 return AE_OK;   /* continue */
 489
 490         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 491                                              acpi_memory_device_notify, NULL);
 492         /* continue */
 493         return AE_OK;
 494 }
 495
 496 static acpi_status
 497 acpi_memory_deregister_notify_handler(acpi_handle handle,
 498                                       u32 level, void *ctxt, void **retv)
 499 {
 500         acpi_status status;
 501
 502
 503         status = is_memory_device(handle);
 504         if (ACPI_FAILURE(status))
 505                 return AE_OK;   /* continue */
 506
 507         status = acpi_remove_notify_handler(handle,
 508                                             ACPI_SYSTEM_NOTIFY,
 509                                             acpi_memory_device_notify);
 510
 511         return AE_OK;   /* continue */
 512 }
 513
 514 static int __init acpi_memory_device_init(void)
 515 {
 516         int result;
 517         acpi_status status;
 518
 519
 520         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 521
 522         if (result < 0)
 523                 return -ENODEV;
 524
 525         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 526                                      ACPI_UINT32_MAX,
 527                                      acpi_memory_register_notify_handler,
 528                                      NULL, NULL);
 529
 530         if (ACPI_FAILURE(status)) {
 531                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 532                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 533                 return -ENODEV;
 534         }
 535
 536         acpi_hotmem_initialized = 1;
 537         return 0;
 538 }
 539
 540 static void __exit acpi_memory_device_exit(void)
 541 {
 542         acpi_status status;
 543
 544
 545         /*
 546          * Adding this to un-install notification handlers for all the device
 547          * handles.
 548          */
 549         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 550                                      ACPI_UINT32_MAX,
 551                                      acpi_memory_deregister_notify_handler,
 552                                      NULL, NULL);
 553
 554         if (ACPI_FAILURE(status))
 555                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 556
 557         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 558
 559         return;
 560 }
 561
 562 module_init(acpi_memory_device_init);
 563 module_exit(acpi_memory_device_exit);