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                 result = add_memory(node, info->start_addr, info->length);
 242                 if (result)
 243                         continue;
 244                 info->enabled = 1;
 245                 num_enabled++;
 246         }
 247         if (!num_enabled) {
 248                 printk(KERN_ERR PREFIX "add_memory failed\n");
 249                 mem_device->state = MEMORY_INVALID_STATE;
 250                 return -EINVAL;
 251         }
 252
 253         return result;
 254 }
 255
 256 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 257 {
 258         acpi_status status;
 259         struct acpi_object_list arg_list;
 260         union acpi_object arg;
 261         unsigned long current_status;
 262
 263
 264         /* Issue the _EJ0 command */
 265         arg_list.count = 1;
 266         arg_list.pointer = &arg;
 267         arg.type = ACPI_TYPE_INTEGER;
 268         arg.integer.value = 1;
 269         status = acpi_evaluate_object(mem_device->device->handle,
 270                                       "_EJ0", &arg_list, NULL);
 271         /* Return on _EJ0 failure */
 272         if (ACPI_FAILURE(status)) {
 273                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 274                 return -ENODEV;
 275         }
 276
 277         /* Evalute _STA to check if the device is disabled */
 278         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
 279                                        NULL, &current_status);
 280         if (ACPI_FAILURE(status))
 281                 return -ENODEV;
 282
 283         /* Check for device status.  Device should be disabled */
 284         if (current_status & ACPI_MEMORY_STA_ENABLED)
 285                 return -EINVAL;
 286
 287         return 0;
 288 }
 289
 290 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 291 {
 292         int result;
 293         struct acpi_memory_info *info, *n;
 294
 295
 296         /*
 297          * Ask the VM to offline this memory range.
 298          * Note: Assume that this function returns zero on success
 299          */
 300         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 301                 if (info->enabled) {
 302                         result = remove_memory(info->start_addr, info->length);
 303                         if (result)
 304                                 return result;
 305                 }
 306                 kfree(info);
 307         }
 308
 309         /* Power-off and eject the device */
 310         result = acpi_memory_powerdown_device(mem_device);
 311         if (result) {
 312                 /* Set the status of the device to invalid */
 313                 mem_device->state = MEMORY_INVALID_STATE;
 314                 return result;
 315         }
 316
 317         mem_device->state = MEMORY_POWER_OFF_STATE;
 318         return result;
 319 }
 320
 321 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 322 {
 323         struct acpi_memory_device *mem_device;
 324         struct acpi_device *device;
 325
 326
 327         switch (event) {
 328         case ACPI_NOTIFY_BUS_CHECK:
 329                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 330                                   "\nReceived BUS CHECK notification for device\n"));
 331                 /* Fall Through */
 332         case ACPI_NOTIFY_DEVICE_CHECK:
 333                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 334                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 335                                           "\nReceived DEVICE CHECK notification for device\n"));
 336                 if (acpi_memory_get_device(handle, &mem_device)) {
 337                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 338                         return;
 339                 }
 340
 341                 if (!acpi_memory_check_device(mem_device)) {
 342                         if (acpi_memory_enable_device(mem_device))
 343                                 printk(KERN_ERR PREFIX
 344                                             "Cannot enable memory device\n");
 345                 }
 346                 break;
 347         case ACPI_NOTIFY_EJECT_REQUEST:
 348                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                                   "\nReceived EJECT REQUEST notification for device\n"));
 350
 351                 if (acpi_bus_get_device(handle, &device)) {
 352                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 353                         break;
 354                 }
 355                 mem_device = acpi_driver_data(device);
 356                 if (!mem_device) {
 357                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 358                         break;
 359                 }
 360
 361                 /*
 362                  * Currently disabling memory device from kernel mode
 363                  * TBD: Can also be disabled from user mode scripts
 364                  * TBD: Can also be disabled by Callback registration
 365                  *      with generic sysfs driver
 366                  */
 367                 if (acpi_memory_disable_device(mem_device))
 368                         printk(KERN_ERR PREFIX
 369                                     "Disable memory device\n");
 370                 /*
 371                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 372                  */
 373                 break;
 374         default:
 375                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 376                                   "Unsupported event [0x%x]\n", event));
 377                 break;
 378         }
 379
 380         return;
 381 }
 382
 383 static int acpi_memory_device_add(struct acpi_device *device)
 384 {
 385         int result;
 386         struct acpi_memory_device *mem_device = NULL;
 387
 388
 389         if (!device)
 390                 return -EINVAL;
 391
 392         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 393         if (!mem_device)
 394                 return -ENOMEM;
 395         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 396
 397         INIT_LIST_HEAD(&mem_device->res_list);
 398         mem_device->device = device;
 399         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 400         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 401         acpi_driver_data(device) = mem_device;
 402
 403         /* Get the range from the _CRS */
 404         result = acpi_memory_get_device_resources(mem_device);
 405         if (result) {
 406                 kfree(mem_device);
 407                 return result;
 408         }
 409
 410         /* Set the device state */
 411         mem_device->state = MEMORY_POWER_ON_STATE;
 412
 413         printk(KERN_INFO "%s \n", acpi_device_name(device));
 414
 415         return result;
 416 }
 417
 418 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 419 {
 420         struct acpi_memory_device *mem_device = NULL;
 421
 422
 423         if (!device || !acpi_driver_data(device))
 424                 return -EINVAL;
 425
 426         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 427         kfree(mem_device);
 428
 429         return 0;
 430 }
 431
 432 static int acpi_memory_device_start (struct acpi_device *device)
 433 {
 434         struct acpi_memory_device *mem_device;
 435         int result = 0;
 436
 437         mem_device = acpi_driver_data(device);
 438
 439         if (!acpi_memory_check_device(mem_device)) {
 440                 /* call add_memory func */
 441                 result = acpi_memory_enable_device(mem_device);
 442                 if (result)
 443                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 444                                 "Error in acpi_memory_enable_device\n"));
 445         }
 446         return result;
 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         return 0;
 537 }
 538
 539 static void __exit acpi_memory_device_exit(void)
 540 {
 541         acpi_status status;
 542
 543
 544         /*
 545          * Adding this to un-install notification handlers for all the device
 546          * handles.
 547          */
 548         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 549                                      ACPI_UINT32_MAX,
 550                                      acpi_memory_deregister_notify_handler,
 551                                      NULL, NULL);
 552
 553         if (ACPI_FAILURE(status))
 554                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 555
 556         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 557
 558         return;
 559 }
 560
 561 module_init(acpi_memory_device_init);
 562 module_exit(acpi_memory_device_exit);