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