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         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 133                                      acpi_memory_get_resource, mem_device);
 134         if (ACPI_FAILURE(status)) {
 135                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 136                         kfree(info);
 137                 return -EINVAL;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int
 144 acpi_memory_get_device(acpi_handle handle,
 145                        struct acpi_memory_device **mem_device)
 146 {
 147         acpi_status status;
 148         acpi_handle phandle;
 149         struct acpi_device *device = NULL;
 150         struct acpi_device *pdevice = NULL;
 151
 152
 153         if (!acpi_bus_get_device(handle, &device) && device)
 154                 goto end;
 155
 156         status = acpi_get_parent(handle, &phandle);
 157         if (ACPI_FAILURE(status)) {
 158                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 159                 return -EINVAL;
 160         }
 161
 162         /* Get the parent device */
 163         status = acpi_bus_get_device(phandle, &pdevice);
 164         if (ACPI_FAILURE(status)) {
 165                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
 166                 return -EINVAL;
 167         }
 168
 169         /*
 170          * Now add the notified device.  This creates the acpi_device
 171          * and invokes .add function
 172          */
 173         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 174         if (ACPI_FAILURE(status)) {
 175                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
 176                 return -EINVAL;
 177         }
 178
 179       end:
 180         *mem_device = acpi_driver_data(device);
 181         if (!(*mem_device)) {
 182                 printk(KERN_ERR "\n driver data not found");
 183                 return -ENODEV;
 184         }
 185
 186         return 0;
 187 }
 188
 189 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 190 {
 191         unsigned long current_status;
 192
 193
 194         /* Get device present/absent information from the _STA */
 195         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 196                                                NULL, &current_status)))
 197                 return -ENODEV;
 198         /*
 199          * Check for device status. Device should be
 200          * present/enabled/functioning.
 201          */
 202         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 203               && (current_status & ACPI_MEMORY_STA_ENABLED)
 204               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 205                 return -ENODEV;
 206
 207         return 0;
 208 }
 209
 210 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 211 {
 212         int result, num_enabled = 0;
 213         struct acpi_memory_info *info;
 214         int node;
 215
 216
 217         /* Get the range from the _CRS */
 218         result = acpi_memory_get_device_resources(mem_device);
 219         if (result) {
 220                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
 221                 mem_device->state = MEMORY_INVALID_STATE;
 222                 return result;
 223         }
 224
 225         node = acpi_get_node(mem_device->device->handle);
 226         /*
 227          * Tell the VM there is more memory here...
 228          * Note: Assume that this function returns zero on success
 229          * We don't have memory-hot-add rollback function,now.
 230          * (i.e. memory-hot-remove function)
 231          */
 232         list_for_each_entry(info, &mem_device->res_list, list) {
 233                 if (info->enabled) { /* just sanity check...*/
 234                         num_enabled++;
 235                         continue;
 236                 }
 237                 result = add_memory(node, info->start_addr, info->length);
 238                 if (result)
 239                         continue;
 240                 info->enabled = 1;
 241                 num_enabled++;
 242         }
 243         if (!num_enabled) {
 244                 printk(KERN_ERR PREFIX "add_memory failed\n");
 245                 mem_device->state = MEMORY_INVALID_STATE;
 246                 return -EINVAL;
 247         }
 248
 249         return result;
 250 }
 251
 252 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 253 {
 254         acpi_status status;
 255         struct acpi_object_list arg_list;
 256         union acpi_object arg;
 257         unsigned long current_status;
 258
 259
 260         /* Issue the _EJ0 command */
 261         arg_list.count = 1;
 262         arg_list.pointer = &arg;
 263         arg.type = ACPI_TYPE_INTEGER;
 264         arg.integer.value = 1;
 265         status = acpi_evaluate_object(mem_device->device->handle,
 266                                       "_EJ0", &arg_list, NULL);
 267         /* Return on _EJ0 failure */
 268         if (ACPI_FAILURE(status)) {
 269                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 270                 return -ENODEV;
 271         }
 272
 273         /* Evalute _STA to check if the device is disabled */
 274         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
 275                                        NULL, &current_status);
 276         if (ACPI_FAILURE(status))
 277                 return -ENODEV;
 278
 279         /* Check for device status.  Device should be disabled */
 280         if (current_status & ACPI_MEMORY_STA_ENABLED)
 281                 return -EINVAL;
 282
 283         return 0;
 284 }
 285
 286 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 287 {
 288         int result;
 289         struct acpi_memory_info *info, *n;
 290
 291
 292         /*
 293          * Ask the VM to offline this memory range.
 294          * Note: Assume that this function returns zero on success
 295          */
 296         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 297                 if (info->enabled) {
 298                         result = remove_memory(info->start_addr, info->length);
 299                         if (result)
 300                                 return result;
 301                 }
 302                 kfree(info);
 303         }
 304
 305         /* Power-off and eject the device */
 306         result = acpi_memory_powerdown_device(mem_device);
 307         if (result) {
 308                 /* Set the status of the device to invalid */
 309                 mem_device->state = MEMORY_INVALID_STATE;
 310                 return result;
 311         }
 312
 313         mem_device->state = MEMORY_POWER_OFF_STATE;
 314         return result;
 315 }
 316
 317 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 318 {
 319         struct acpi_memory_device *mem_device;
 320         struct acpi_device *device;
 321
 322
 323         switch (event) {
 324         case ACPI_NOTIFY_BUS_CHECK:
 325                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 326                                   "\nReceived BUS CHECK notification for device\n"));
 327                 /* Fall Through */
 328         case ACPI_NOTIFY_DEVICE_CHECK:
 329                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 330                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 331                                           "\nReceived DEVICE CHECK notification for device\n"));
 332                 if (acpi_memory_get_device(handle, &mem_device)) {
 333                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 334                         return;
 335                 }
 336
 337                 if (!acpi_memory_check_device(mem_device)) {
 338                         if (acpi_memory_enable_device(mem_device))
 339                                 printk(KERN_ERR PREFIX
 340                                             "Cannot enable memory device\n");
 341                 }
 342                 break;
 343         case ACPI_NOTIFY_EJECT_REQUEST:
 344                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 345                                   "\nReceived EJECT REQUEST notification for device\n"));
 346
 347                 if (acpi_bus_get_device(handle, &device)) {
 348                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 349                         break;
 350                 }
 351                 mem_device = acpi_driver_data(device);
 352                 if (!mem_device) {
 353                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 354                         break;
 355                 }
 356
 357                 /*
 358                  * Currently disabling memory device from kernel mode
 359                  * TBD: Can also be disabled from user mode scripts
 360                  * TBD: Can also be disabled by Callback registration
 361                  *      with generic sysfs driver
 362                  */
 363                 if (acpi_memory_disable_device(mem_device))
 364                         printk(KERN_ERR PREFIX
 365                                     "Disable memory device\n");
 366                 /*
 367                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 368                  */
 369                 break;
 370         default:
 371                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 372                                   "Unsupported event [0x%x]\n", event));
 373                 break;
 374         }
 375
 376         return;
 377 }
 378
 379 static int acpi_memory_device_add(struct acpi_device *device)
 380 {
 381         int result;
 382         struct acpi_memory_device *mem_device = NULL;
 383
 384
 385         if (!device)
 386                 return -EINVAL;
 387
 388         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 389         if (!mem_device)
 390                 return -ENOMEM;
 391         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 392
 393         INIT_LIST_HEAD(&mem_device->res_list);
 394         mem_device->device = device;
 395         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 396         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 397         acpi_driver_data(device) = mem_device;
 398
 399         /* Get the range from the _CRS */
 400         result = acpi_memory_get_device_resources(mem_device);
 401         if (result) {
 402                 kfree(mem_device);
 403                 return result;
 404         }
 405
 406         /* Set the device state */
 407         mem_device->state = MEMORY_POWER_ON_STATE;
 408
 409         printk(KERN_INFO "%s \n", acpi_device_name(device));
 410
 411         return result;
 412 }
 413
 414 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 415 {
 416         struct acpi_memory_device *mem_device = NULL;
 417
 418
 419         if (!device || !acpi_driver_data(device))
 420                 return -EINVAL;
 421
 422         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 423         kfree(mem_device);
 424
 425         return 0;
 426 }
 427
 428 static int acpi_memory_device_start (struct acpi_device *device)
 429 {
 430         struct acpi_memory_device *mem_device;
 431         int result = 0;
 432
 433         mem_device = acpi_driver_data(device);
 434
 435         if (!acpi_memory_check_device(mem_device)) {
 436                 /* call add_memory func */
 437                 result = acpi_memory_enable_device(mem_device);
 438                 if (result)
 439                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 440                                 "Error in acpi_memory_enable_device\n"));
 441         }
 442         return result;
 443 }
 444
 445 /*
 446  * Helper function to check for memory device
 447  */
 448 static acpi_status is_memory_device(acpi_handle handle)
 449 {
 450         char *hardware_id;
 451         acpi_status status;
 452         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 453         struct acpi_device_info *info;
 454
 455
 456         status = acpi_get_object_info(handle, &buffer);
 457         if (ACPI_FAILURE(status))
 458                 return status;
 459
 460         info = buffer.pointer;
 461         if (!(info->valid & ACPI_VALID_HID)) {
 462                 kfree(buffer.pointer);
 463                 return AE_ERROR;
 464         }
 465
 466         hardware_id = info->hardware_id.value;
 467         if ((hardware_id == NULL) ||
 468             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 469                 status = AE_ERROR;
 470
 471         kfree(buffer.pointer);
 472         return status;
 473 }
 474
 475 static acpi_status
 476 acpi_memory_register_notify_handler(acpi_handle handle,
 477                                     u32 level, void *ctxt, void **retv)
 478 {
 479         acpi_status status;
 480
 481
 482         status = is_memory_device(handle);
 483         if (ACPI_FAILURE(status)){
 484                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
 485                 return AE_OK;   /* continue */
 486         }
 487
 488         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 489                                              acpi_memory_device_notify, NULL);
 490         /* continue */
 491         return AE_OK;
 492 }
 493
 494 static acpi_status
 495 acpi_memory_deregister_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                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
 504                 return AE_OK;   /* continue */
 505         }
 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);