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 cache_attribute; /* memory cache attribute */
  75         unsigned short read_write_attribute;    /* memory read/write attribute */
  76         u64 start_addr;         /* Memory Range start physical addr */
  77         u64 end_addr;           /* Memory Range end physical addr */
  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         ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
  89
  90         /* Get the range from the _CRS */
  91         status = acpi_get_current_resources(mem_device->handle, &buffer);
  92         if (ACPI_FAILURE(status))
  93                 return_VALUE(-EINVAL);
  94
  95         resource = (struct acpi_resource *)buffer.pointer;
  96         status = acpi_resource_to_address64(resource, &address64);
  97         if (ACPI_SUCCESS(status)) {
  98                 if (address64.resource_type == ACPI_MEMORY_RANGE) {
  99                         /* Populate the structure */
 100                         mem_device->cache_attribute =
 101                             address64.attribute.memory.cache_attribute;
 102                         mem_device->read_write_attribute =
 103                             address64.attribute.memory.read_write_attribute;
 104                         mem_device->start_addr = address64.minimum;
 105                         mem_device->end_addr = address64.maximum;
 106                 }
 107         }
 108
 109         acpi_os_free(buffer.pointer);
 110         return_VALUE(0);
 111 }
 112
 113 static int
 114 acpi_memory_get_device(acpi_handle handle,
 115                        struct acpi_memory_device **mem_device)
 116 {
 117         acpi_status status;
 118         acpi_handle phandle;
 119         struct acpi_device *device = NULL;
 120         struct acpi_device *pdevice = NULL;
 121
 122         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
 123
 124         if (!acpi_bus_get_device(handle, &device) && device)
 125                 goto end;
 126
 127         status = acpi_get_parent(handle, &phandle);
 128         if (ACPI_FAILURE(status)) {
 129                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
 130                 return_VALUE(-EINVAL);
 131         }
 132
 133         /* Get the parent device */
 134         status = acpi_bus_get_device(phandle, &pdevice);
 135         if (ACPI_FAILURE(status)) {
 136                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 137                                   "Error in acpi_bus_get_device\n"));
 138                 return_VALUE(-EINVAL);
 139         }
 140
 141         /*
 142          * Now add the notified device.  This creates the acpi_device
 143          * and invokes .add function
 144          */
 145         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 146         if (ACPI_FAILURE(status)) {
 147                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
 148                 return_VALUE(-EINVAL);
 149         }
 150
 151       end:
 152         *mem_device = acpi_driver_data(device);
 153         if (!(*mem_device)) {
 154                 printk(KERN_ERR "\n driver data not found");
 155                 return_VALUE(-ENODEV);
 156         }
 157
 158         return_VALUE(0);
 159 }
 160
 161 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 162 {
 163         unsigned long current_status;
 164
 165         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
 166
 167         /* Get device present/absent information from the _STA */
 168         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
 169                                                NULL, &current_status)))
 170                 return_VALUE(-ENODEV);
 171         /*
 172          * Check for device status. Device should be
 173          * present/enabled/functioning.
 174          */
 175         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 176               && (current_status & ACPI_MEMORY_STA_ENABLED)
 177               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 178                 return_VALUE(-ENODEV);
 179
 180         return_VALUE(0);
 181 }
 182
 183 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 184 {
 185         int result;
 186
 187         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
 188
 189         /* Get the range from the _CRS */
 190         result = acpi_memory_get_device_resources(mem_device);
 191         if (result) {
 192                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 193                                   "\nget_device_resources failed\n"));
 194                 mem_device->state = MEMORY_INVALID_STATE;
 195                 return result;
 196         }
 197
 198         /*
 199          * Tell the VM there is more memory here...
 200          * Note: Assume that this function returns zero on success
 201          */
 202         result = add_memory(mem_device->start_addr,
 203                             (mem_device->end_addr - mem_device->start_addr) + 1);
 204         if (result) {
 205                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 206                 mem_device->state = MEMORY_INVALID_STATE;
 207                 return result;
 208         }
 209
 210         return result;
 211 }
 212
 213 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 214 {
 215         acpi_status status;
 216         struct acpi_object_list arg_list;
 217         union acpi_object arg;
 218         unsigned long current_status;
 219
 220         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
 221
 222         /* Issue the _EJ0 command */
 223         arg_list.count = 1;
 224         arg_list.pointer = &arg;
 225         arg.type = ACPI_TYPE_INTEGER;
 226         arg.integer.value = 1;
 227         status = acpi_evaluate_object(mem_device->handle,
 228                                       "_EJ0", &arg_list, NULL);
 229         /* Return on _EJ0 failure */
 230         if (ACPI_FAILURE(status)) {
 231                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
 232                 return_VALUE(-ENODEV);
 233         }
 234
 235         /* Evalute _STA to check if the device is disabled */
 236         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 237                                        NULL, &current_status);
 238         if (ACPI_FAILURE(status))
 239                 return_VALUE(-ENODEV);
 240
 241         /* Check for device status.  Device should be disabled */
 242         if (current_status & ACPI_MEMORY_STA_ENABLED)
 243                 return_VALUE(-EINVAL);
 244
 245         return_VALUE(0);
 246 }
 247
 248 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 249 {
 250         int result;
 251         u64 start = mem_device->start_addr;
 252         u64 len = mem_device->end_addr - start + 1;
 253         unsigned long attr = mem_device->read_write_attribute;
 254
 255         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 256
 257         /*
 258          * Ask the VM to offline this memory range.
 259          * Note: Assume that this function returns zero on success
 260          */
 261         result = remove_memory(start, len);
 262         if (result) {
 263                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n"));
 264                 return_VALUE(result);
 265         }
 266
 267         /* Power-off and eject the device */
 268         result = acpi_memory_powerdown_device(mem_device);
 269         if (result) {
 270                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 271                                   "Device Power Down failed.\n"));
 272                 /* Set the status of the device to invalid */
 273                 mem_device->state = MEMORY_INVALID_STATE;
 274                 return result;
 275         }
 276
 277         mem_device->state = MEMORY_POWER_OFF_STATE;
 278         return result;
 279 }
 280
 281 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 282 {
 283         struct acpi_memory_device *mem_device;
 284         struct acpi_device *device;
 285
 286         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
 287
 288         switch (event) {
 289         case ACPI_NOTIFY_BUS_CHECK:
 290                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 291                                   "\nReceived BUS CHECK notification for device\n"));
 292                 /* Fall Through */
 293         case ACPI_NOTIFY_DEVICE_CHECK:
 294                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 295                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 296                                           "\nReceived DEVICE CHECK notification for device\n"));
 297                 if (acpi_memory_get_device(handle, &mem_device)) {
 298                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 299                                           "Error in finding driver data\n"));
 300                         return_VOID;
 301                 }
 302
 303                 if (!acpi_memory_check_device(mem_device)) {
 304                         if (acpi_memory_enable_device(mem_device))
 305                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 306                                                   "Error in acpi_memory_enable_device\n"));
 307                 }
 308                 break;
 309         case ACPI_NOTIFY_EJECT_REQUEST:
 310                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 311                                   "\nReceived EJECT REQUEST notification for device\n"));
 312
 313                 if (acpi_bus_get_device(handle, &device)) {
 314                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 315                                           "Device doesn't exist\n"));
 316                         break;
 317                 }
 318                 mem_device = acpi_driver_data(device);
 319                 if (!mem_device) {
 320                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 321                                           "Driver Data is NULL\n"));
 322                         break;
 323                 }
 324
 325                 /*
 326                  * Currently disabling memory device from kernel mode
 327                  * TBD: Can also be disabled from user mode scripts
 328                  * TBD: Can also be disabled by Callback registration
 329                  *      with generic sysfs driver
 330                  */
 331                 if (acpi_memory_disable_device(mem_device))
 332                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 333                                           "Error in acpi_memory_disable_device\n"));
 334                 /*
 335                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 336                  */
 337                 break;
 338         default:
 339                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 340                                   "Unsupported event [0x%x]\n", event));
 341                 break;
 342         }
 343
 344         return_VOID;
 345 }
 346
 347 static int acpi_memory_device_add(struct acpi_device *device)
 348 {
 349         int result;
 350         struct acpi_memory_device *mem_device = NULL;
 351
 352         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
 353
 354         if (!device)
 355                 return_VALUE(-EINVAL);
 356
 357         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 358         if (!mem_device)
 359                 return_VALUE(-ENOMEM);
 360         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 361
 362         mem_device->handle = device->handle;
 363         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 364         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 365         acpi_driver_data(device) = mem_device;
 366
 367         /* Get the range from the _CRS */
 368         result = acpi_memory_get_device_resources(mem_device);
 369         if (result) {
 370                 kfree(mem_device);
 371                 return_VALUE(result);
 372         }
 373
 374         /* Set the device state */
 375         mem_device->state = MEMORY_POWER_ON_STATE;
 376
 377         printk(KERN_INFO "%s \n", acpi_device_name(device));
 378
 379         return_VALUE(result);
 380 }
 381
 382 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 383 {
 384         struct acpi_memory_device *mem_device = NULL;
 385
 386         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
 387
 388         if (!device || !acpi_driver_data(device))
 389                 return_VALUE(-EINVAL);
 390
 391         mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
 392         kfree(mem_device);
 393
 394         return_VALUE(0);
 395 }
 396
 397 /*
 398  * Helper function to check for memory device
 399  */
 400 static acpi_status is_memory_device(acpi_handle handle)
 401 {
 402         char *hardware_id;
 403         acpi_status status;
 404         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 405         struct acpi_device_info *info;
 406
 407         ACPI_FUNCTION_TRACE("is_memory_device");
 408
 409         status = acpi_get_object_info(handle, &buffer);
 410         if (ACPI_FAILURE(status))
 411                 return_ACPI_STATUS(AE_ERROR);
 412
 413         info = buffer.pointer;
 414         if (!(info->valid & ACPI_VALID_HID)) {
 415                 acpi_os_free(buffer.pointer);
 416                 return_ACPI_STATUS(AE_ERROR);
 417         }
 418
 419         hardware_id = info->hardware_id.value;
 420         if ((hardware_id == NULL) ||
 421             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 422                 status = AE_ERROR;
 423
 424         acpi_os_free(buffer.pointer);
 425         return_ACPI_STATUS(status);
 426 }
 427
 428 static acpi_status
 429 acpi_memory_register_notify_handler(acpi_handle handle,
 430                                     u32 level, void *ctxt, void **retv)
 431 {
 432         acpi_status status;
 433
 434         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
 435
 436         status = is_memory_device(handle);
 437         if (ACPI_FAILURE(status))
 438                 return_ACPI_STATUS(AE_OK);      /* continue */
 439
 440         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 441                                              acpi_memory_device_notify, NULL);
 442         if (ACPI_FAILURE(status)) {
 443                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 444                                   "Error installing notify handler\n"));
 445                 return_ACPI_STATUS(AE_OK);      /* continue */
 446         }
 447
 448         return_ACPI_STATUS(status);
 449 }
 450
 451 static acpi_status
 452 acpi_memory_deregister_notify_handler(acpi_handle handle,
 453                                       u32 level, void *ctxt, void **retv)
 454 {
 455         acpi_status status;
 456
 457         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
 458
 459         status = is_memory_device(handle);
 460         if (ACPI_FAILURE(status))
 461                 return_ACPI_STATUS(AE_OK);      /* continue */
 462
 463         status = acpi_remove_notify_handler(handle,
 464                                             ACPI_SYSTEM_NOTIFY,
 465                                             acpi_memory_device_notify);
 466         if (ACPI_FAILURE(status)) {
 467                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 468                                   "Error removing notify handler\n"));
 469                 return_ACPI_STATUS(AE_OK);      /* continue */
 470         }
 471
 472         return_ACPI_STATUS(status);
 473 }
 474
 475 static int __init acpi_memory_device_init(void)
 476 {
 477         int result;
 478         acpi_status status;
 479
 480         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
 481
 482         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 483
 484         if (result < 0)
 485                 return_VALUE(-ENODEV);
 486
 487         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 488                                      ACPI_UINT32_MAX,
 489                                      acpi_memory_register_notify_handler,
 490                                      NULL, NULL);
 491
 492         if (ACPI_FAILURE(status)) {
 493                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 494                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 495                 return_VALUE(-ENODEV);
 496         }
 497
 498         return_VALUE(0);
 499 }
 500
 501 static void __exit acpi_memory_device_exit(void)
 502 {
 503         acpi_status status;
 504
 505         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
 506
 507         /*
 508          * Adding this to un-install notification handlers for all the device
 509          * handles.
 510          */
 511         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 512                                      ACPI_UINT32_MAX,
 513                                      acpi_memory_deregister_notify_handler,
 514                                      NULL, NULL);
 515
 516         if (ACPI_FAILURE(status))
 517                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
 518
 519         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 520
 521         return_VOID;
 522 }
 523
 524 module_init(acpi_memory_device_init);
 525 module_exit(acpi_memory_device_exit);