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
  61 static struct acpi_driver acpi_memory_device_driver = {
  62         .name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
  63         .class = ACPI_MEMORY_DEVICE_CLASS,
  64         .ids = ACPI_MEMORY_DEVICE_HID,
  65         .ops = {
  66                 .add = acpi_memory_device_add,
  67                 .remove = acpi_memory_device_remove,
  68                 },
  69 };
  70
  71 struct acpi_memory_device {
  72         acpi_handle handle;
  73         unsigned int state;     /* State of the memory device */
  74         unsigned short caching; /* memory cache attribute */
  75         unsigned short write_protect;   /* memory read/write attribute */
  76         u64 start_addr;         /* Memory Range start physical addr */
  77         u64 length;             /* Memory Range length */
  78 };
  79
  80 static int
  81 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
  82 {
  83         acpi_status status;
  84         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  85         struct acpi_resource *resource = NULL;
  86         struct acpi_resource_address64 address64;
  87
  88
  89         /* Get the range from the _CRS */
  90         status = acpi_get_current_resources(mem_device->handle, &buffer);
  91         if (ACPI_FAILURE(status))
  92                 return -EINVAL;
  93
  94         resource = (struct acpi_resource *)buffer.pointer;
  95         status = acpi_resource_to_address64(resource, &address64);
  96         if (ACPI_SUCCESS(status)) {
  97                 if (address64.resource_type == ACPI_MEMORY_RANGE) {
  98                         /* Populate the structure */
  99                         mem_device->caching = address64.info.mem.caching;
 100                         mem_device->write_protect =
 101                             address64.info.mem.write_protect;
 102                         mem_device->start_addr = address64.minimum;
 103                         mem_device->length = address64.address_length;
 104                 }
 105         }
 106
 107         acpi_os_free(buffer.pointer);
 108         return 0;
 109 }
 110
 111 static int
 112 acpi_memory_get_device(acpi_handle handle,
 113                        struct acpi_memory_device **mem_device)
 114 {
 115         acpi_status status;
 116         acpi_handle phandle;
 117         struct acpi_device *device = NULL;
 118         struct acpi_device *pdevice = NULL;
 119
 120
 121         if (!acpi_bus_get_device(handle, &device) && device)
 122                 goto end;
 123
 124         status = acpi_get_parent(handle, &phandle);
 125         if (ACPI_FAILURE(status)) {
 126                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 127                 return -EINVAL;
 128         }
 129
 130         /* Get the parent device */
 131         status = acpi_bus_get_device(phandle, &pdevice);
 132         if (ACPI_FAILURE(status)) {
 133                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
 134                 return -EINVAL;
 135         }
 136
 137         /*
 138          * Now add the notified device.  This creates the acpi_device
 139          * and invokes .add function
 140          */
 141         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 142         if (ACPI_FAILURE(status)) {
 143                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
 144                 return -EINVAL;
 145         }
 146
 147       end:
 148         *mem_device = acpi_driver_data(device);
 149         if (!(*mem_device)) {
 150                 printk(KERN_ERR "\n driver data not found");
 151                 return -ENODEV;
 152         }
 153
 154         return 0;
 155 }
 156
 157 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 158 {
 159         unsigned long current_status;
 160
 161
 162         /* Get device present/absent information from the _STA */
 163         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
 164                                                NULL, &current_status)))
 165                 return -ENODEV;
 166         /*
 167          * Check for device status. Device should be
 168          * present/enabled/functioning.
 169          */
 170         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 171               && (current_status & ACPI_MEMORY_STA_ENABLED)
 172               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 173                 return -ENODEV;
 174
 175         return 0;
 176 }
 177
 178 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 179 {
 180         int result;
 181
 182
 183         /* Get the range from the _CRS */
 184         result = acpi_memory_get_device_resources(mem_device);
 185         if (result) {
 186                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
 187                 mem_device->state = MEMORY_INVALID_STATE;
 188                 return result;
 189         }
 190
 191         /*
 192          * Tell the VM there is more memory here...
 193          * Note: Assume that this function returns zero on success
 194          */
 195         result = add_memory(mem_device->start_addr, mem_device->length);
 196         if (result) {
 197                 printk(KERN_ERR PREFIX "add_memory failed\n");
 198                 mem_device->state = MEMORY_INVALID_STATE;
 199                 return result;
 200         }
 201
 202         return result;
 203 }
 204
 205 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 206 {
 207         acpi_status status;
 208         struct acpi_object_list arg_list;
 209         union acpi_object arg;
 210         unsigned long current_status;
 211
 212
 213         /* Issue the _EJ0 command */
 214         arg_list.count = 1;
 215         arg_list.pointer = &arg;
 216         arg.type = ACPI_TYPE_INTEGER;
 217         arg.integer.value = 1;
 218         status = acpi_evaluate_object(mem_device->handle,
 219                                       "_EJ0", &arg_list, NULL);
 220         /* Return on _EJ0 failure */
 221         if (ACPI_FAILURE(status)) {
 222                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 223                 return -ENODEV;
 224         }
 225
 226         /* Evalute _STA to check if the device is disabled */
 227         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 228                                        NULL, &current_status);
 229         if (ACPI_FAILURE(status))
 230                 return -ENODEV;
 231
 232         /* Check for device status.  Device should be disabled */
 233         if (current_status & ACPI_MEMORY_STA_ENABLED)
 234                 return -EINVAL;
 235
 236         return 0;
 237 }
 238
 239 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 240 {
 241         int result;
 242         u64 start = mem_device->start_addr;
 243         u64 len = mem_device->length;
 244
 245
 246         /*
 247          * Ask the VM to offline this memory range.
 248          * Note: Assume that this function returns zero on success
 249          */
 250         result = remove_memory(start, len);
 251         if (result)
 252                 return result;
 253
 254         /* Power-off and eject the device */
 255         result = acpi_memory_powerdown_device(mem_device);
 256         if (result) {
 257                 /* Set the status of the device to invalid */
 258                 mem_device->state = MEMORY_INVALID_STATE;
 259                 return result;
 260         }
 261
 262         mem_device->state = MEMORY_POWER_OFF_STATE;
 263         return result;
 264 }
 265
 266 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 267 {
 268         struct acpi_memory_device *mem_device;
 269         struct acpi_device *device;
 270
 271
 272         switch (event) {
 273         case ACPI_NOTIFY_BUS_CHECK:
 274                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 275                                   "\nReceived BUS CHECK notification for device\n"));
 276                 /* Fall Through */
 277         case ACPI_NOTIFY_DEVICE_CHECK:
 278                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 279                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 280                                           "\nReceived DEVICE CHECK notification for device\n"));
 281                 if (acpi_memory_get_device(handle, &mem_device)) {
 282                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 283                         return;
 284                 }
 285
 286                 if (!acpi_memory_check_device(mem_device)) {
 287                         if (acpi_memory_enable_device(mem_device))
 288                                 printk(KERN_ERR PREFIX
 289                                             "Cannot enable memory device\n");
 290                 }
 291                 break;
 292         case ACPI_NOTIFY_EJECT_REQUEST:
 293                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 294                                   "\nReceived EJECT REQUEST notification for device\n"));
 295
 296                 if (acpi_bus_get_device(handle, &device)) {
 297                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 298                         break;
 299                 }
 300                 mem_device = acpi_driver_data(device);
 301                 if (!mem_device) {
 302                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 303                         break;
 304                 }
 305
 306                 /*
 307                  * Currently disabling memory device from kernel mode
 308                  * TBD: Can also be disabled from user mode scripts
 309                  * TBD: Can also be disabled by Callback registration
 310                  *      with generic sysfs driver
 311                  */
 312                 if (acpi_memory_disable_device(mem_device))
 313                         printk(KERN_ERR PREFIX
 314                                     "Disable memory device\n");
 315                 /*
 316                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 317                  */
 318                 break;
 319         default:
 320                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 321                                   "Unsupported event [0x%x]\n", event));
 322                 break;
 323         }
 324
 325         return;
 326 }
 327
 328 static int acpi_memory_device_add(struct acpi_device *device)
 329 {
 330         int result;
 331         struct acpi_memory_device *mem_device = NULL;
 332
 333
 334         if (!device)
 335                 return -EINVAL;
 336
 337         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 338         if (!mem_device)
 339                 return -ENOMEM;
 340         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 341
 342         mem_device->handle = device->handle;
 343         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 344         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 345         acpi_driver_data(device) = mem_device;
 346
 347         /* Get the range from the _CRS */
 348         result = acpi_memory_get_device_resources(mem_device);
 349         if (result) {
 350                 kfree(mem_device);
 351                 return result;
 352         }
 353
 354         /* Set the device state */
 355         mem_device->state = MEMORY_POWER_ON_STATE;
 356
 357         printk(KERN_INFO "%s \n", acpi_device_name(device));
 358
 359         return result;
 360 }
 361
 362 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 363 {
 364         struct acpi_memory_device *mem_device = NULL;
 365
 366
 367         if (!device || !acpi_driver_data(device))
 368                 return -EINVAL;
 369
 370         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 371         kfree(mem_device);
 372
 373         return 0;
 374 }
 375
 376 /*
 377  * Helper function to check for memory device
 378  */
 379 static acpi_status is_memory_device(acpi_handle handle)
 380 {
 381         char *hardware_id;
 382         acpi_status status;
 383         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 384         struct acpi_device_info *info;
 385
 386
 387         status = acpi_get_object_info(handle, &buffer);
 388         if (ACPI_FAILURE(status))
 389                 return status;
 390
 391         info = buffer.pointer;
 392         if (!(info->valid & ACPI_VALID_HID)) {
 393                 acpi_os_free(buffer.pointer);
 394                 return AE_ERROR;
 395         }
 396
 397         hardware_id = info->hardware_id.value;
 398         if ((hardware_id == NULL) ||
 399             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 400                 status = AE_ERROR;
 401
 402         acpi_os_free(buffer.pointer);
 403         return status;
 404 }
 405
 406 static acpi_status
 407 acpi_memory_register_notify_handler(acpi_handle handle,
 408                                     u32 level, void *ctxt, void **retv)
 409 {
 410         acpi_status status;
 411
 412
 413         status = is_memory_device(handle);
 414         if (ACPI_FAILURE(status)){
 415                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
 416                 return AE_OK;   /* continue */
 417         }
 418
 419         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 420                                              acpi_memory_device_notify, NULL);
 421         /* continue */
 422         return AE_OK;
 423 }
 424
 425 static acpi_status
 426 acpi_memory_deregister_notify_handler(acpi_handle handle,
 427                                       u32 level, void *ctxt, void **retv)
 428 {
 429         acpi_status status;
 430
 431
 432         status = is_memory_device(handle);
 433         if (ACPI_FAILURE(status)){
 434                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
 435                 return AE_OK;   /* continue */
 436         }
 437
 438         status = acpi_remove_notify_handler(handle,
 439                                             ACPI_SYSTEM_NOTIFY,
 440                                             acpi_memory_device_notify);
 441
 442         return AE_OK;   /* continue */
 443 }
 444
 445 static int __init acpi_memory_device_init(void)
 446 {
 447         int result;
 448         acpi_status status;
 449
 450
 451         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 452
 453         if (result < 0)
 454                 return -ENODEV;
 455
 456         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 457                                      ACPI_UINT32_MAX,
 458                                      acpi_memory_register_notify_handler,
 459                                      NULL, NULL);
 460
 461         if (ACPI_FAILURE(status)) {
 462                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 463                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 464                 return -ENODEV;
 465         }
 466
 467         return 0;
 468 }
 469
 470 static void __exit acpi_memory_device_exit(void)
 471 {
 472         acpi_status status;
 473
 474
 475         /*
 476          * Adding this to un-install notification handlers for all the device
 477          * handles.
 478          */
 479         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 480                                      ACPI_UINT32_MAX,
 481                                      acpi_memory_deregister_notify_handler,
 482                                      NULL, NULL);
 483
 484         if (ACPI_FAILURE(status))
 485                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 486
 487         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 488
 489         return;
 490 }
 491
 492 module_init(acpi_memory_device_init);
 493 module_exit(acpi_memory_device_exit);