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
  36 #define ACPI_MEMORY_DEVICE_COMPONENT            0x08000000UL
  37 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  38 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  39 #define ACPI_MEMORY_DEVICE_DRIVER_NAME          "Hotplug Mem Driver"
  40 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  41
  42 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  43
  44 ACPI_MODULE_NAME                ("acpi_memory")
  45 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
  46 MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
  47 MODULE_LICENSE("GPL");
  48
  49 /* ACPI _STA method values */
  50 #define ACPI_MEMORY_STA_PRESENT         (0x00000001UL)
  51 #define ACPI_MEMORY_STA_ENABLED         (0x00000002UL)
  52 #define ACPI_MEMORY_STA_FUNCTIONAL      (0x00000008UL)
  53
  54 /* Memory Device States */
  55 #define MEMORY_INVALID_STATE    0
  56 #define MEMORY_POWER_ON_STATE   1
  57 #define MEMORY_POWER_OFF_STATE  2
  58
  59 static int acpi_memory_device_add (struct acpi_device *device);
  60 static int acpi_memory_device_remove (struct acpi_device *device, int type);
  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                         },
  70 };
  71
  72 struct acpi_memory_device {
  73         acpi_handle handle;
  74         unsigned int state;             /* State of the memory device */
  75         unsigned short cache_attribute; /* memory cache attribute */
  76         unsigned short read_write_attribute;/* memory read/write attribute */
  77         u64 start_addr; /* Memory Range start physical addr */
  78         u64 end_addr;   /* Memory Range end physical addr */
  79 };
  80
  81
  82 static int
  83 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
  84 {
  85         acpi_status status;
  86         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
  87         struct acpi_resource *resource = NULL;
  88         struct acpi_resource_address64 address64;
  89
  90         ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
  91
  92         /* Get the range from the _CRS */
  93         status = acpi_get_current_resources(mem_device->handle, &buffer);
  94         if (ACPI_FAILURE(status))
  95                 return_VALUE(-EINVAL);
  96
  97         resource = (struct acpi_resource *) buffer.pointer;
  98         status = acpi_resource_to_address64(resource, &address64);
  99         if (ACPI_SUCCESS(status)) {
 100                 if (address64.resource_type == ACPI_MEMORY_RANGE) {
 101                         /* Populate the structure */
 102                         mem_device->cache_attribute =
 103                                 address64.attribute.memory.cache_attribute;
 104                         mem_device->read_write_attribute =
 105                         address64.attribute.memory.read_write_attribute;
 106                         mem_device->start_addr = address64.min_address_range;
 107                         mem_device->end_addr = address64.max_address_range;
 108                 }
 109         }
 110
 111         acpi_os_free(buffer.pointer);
 112         return_VALUE(0);
 113 }
 114
 115 static int
 116 acpi_memory_get_device(acpi_handle handle,
 117         struct acpi_memory_device **mem_device)
 118 {
 119         acpi_status status;
 120         acpi_handle phandle;
 121         struct acpi_device *device = NULL;
 122         struct acpi_device *pdevice = NULL;
 123
 124         ACPI_FUNCTION_TRACE("acpi_memory_get_device");
 125
 126         if (!acpi_bus_get_device(handle, &device) && device)
 127                 goto end;
 128
 129         status = acpi_get_parent(handle, &phandle);
 130         if (ACPI_FAILURE(status)) {
 131                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 132                         "Error in acpi_get_parent\n"));
 133                 return_VALUE(-EINVAL);
 134         }
 135
 136         /* Get the parent device */
 137         status = acpi_bus_get_device(phandle, &pdevice);
 138         if (ACPI_FAILURE(status)) {
 139                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 140                         "Error in acpi_bus_get_device\n"));
 141                 return_VALUE(-EINVAL);
 142         }
 143
 144         /*
 145          * Now add the notified device.  This creates the acpi_device
 146          * and invokes .add function
 147          */
 148         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 149         if (ACPI_FAILURE(status)) {
 150                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 151                         "Error in acpi_bus_add\n"));
 152                 return_VALUE(-EINVAL);
 153         }
 154
 155 end:
 156         *mem_device = acpi_driver_data(device);
 157         if (!(*mem_device)) {
 158                 printk(KERN_ERR "\n driver data not found" );
 159                 return_VALUE(-ENODEV);
 160         }
 161
 162         return_VALUE(0);
 163 }
 164
 165 static int
 166 acpi_memory_check_device(struct acpi_memory_device *mem_device)
 167 {
 168         unsigned long current_status;
 169
 170         ACPI_FUNCTION_TRACE("acpi_memory_check_device");
 171
 172         /* Get device present/absent information from the _STA */
 173         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
 174                 NULL, &current_status)))
 175                 return_VALUE(-ENODEV);
 176         /*
 177          * Check for device status. Device should be
 178          * present/enabled/functioning.
 179          */
 180         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 181                 && (current_status & ACPI_MEMORY_STA_ENABLED)
 182                 && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 183                 return_VALUE(-ENODEV);
 184
 185         return_VALUE(0);
 186 }
 187
 188 static int
 189 acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 190 {
 191         int result;
 192
 193         ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
 194
 195         /* Get the range from the _CRS */
 196         result = acpi_memory_get_device_resources(mem_device);
 197         if (result) {
 198                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 199                         "\nget_device_resources failed\n"));
 200                 mem_device->state = MEMORY_INVALID_STATE;
 201                 return result;
 202         }
 203
 204         /*
 205          * Tell the VM there is more memory here...
 206          * Note: Assume that this function returns zero on success
 207          */
 208         result = add_memory(mem_device->start_addr,
 209                         (mem_device->end_addr - mem_device->start_addr) + 1,
 210                         mem_device->read_write_attribute);
 211         if (result) {
 212                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 213                         "\nadd_memory failed\n"));
 214                 mem_device->state = MEMORY_INVALID_STATE;
 215                 return result;
 216         }
 217
 218         return result;
 219 }
 220
 221 static int
 222 acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 223 {
 224         acpi_status status;
 225         struct acpi_object_list arg_list;
 226         union acpi_object arg;
 227         unsigned long current_status;
 228
 229         ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
 230
 231         /* Issue the _EJ0 command */
 232         arg_list.count = 1;
 233         arg_list.pointer = &arg;
 234         arg.type = ACPI_TYPE_INTEGER;
 235         arg.integer.value = 1;
 236         status = acpi_evaluate_object(mem_device->handle,
 237                         "_EJ0", &arg_list, NULL);
 238         /* Return on _EJ0 failure */
 239         if (ACPI_FAILURE(status)) {
 240                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"_EJ0 failed.\n"));
 241                 return_VALUE(-ENODEV);
 242         }
 243
 244         /* Evalute _STA to check if the device is disabled */
 245         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 246                 NULL, &current_status);
 247         if (ACPI_FAILURE(status))
 248                 return_VALUE(-ENODEV);
 249
 250         /* Check for device status.  Device should be disabled */
 251         if (current_status & ACPI_MEMORY_STA_ENABLED)
 252                 return_VALUE(-EINVAL);
 253
 254         return_VALUE(0);
 255 }
 256
 257 static int
 258 acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 259 {
 260         int result;
 261         u64 start = mem_device->start_addr;
 262         u64 len = mem_device->end_addr - start + 1;
 263         unsigned long attr = mem_device->read_write_attribute;
 264
 265         ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 266
 267         /*
 268          * Ask the VM to offline this memory range.
 269          * Note: Assume that this function returns zero on success
 270          */
 271         result = remove_memory(start, len, attr);
 272         if (result) {
 273                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n"));
 274                 return_VALUE(result);
 275         }
 276
 277         /* Power-off and eject the device */
 278         result = acpi_memory_powerdown_device(mem_device);
 279         if (result) {
 280                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 281                                         "Device Power Down failed.\n"));
 282                 /* Set the status of the device to invalid */
 283                 mem_device->state = MEMORY_INVALID_STATE;
 284                 return result;
 285         }
 286
 287         mem_device->state = MEMORY_POWER_OFF_STATE;
 288         return result;
 289 }
 290
 291 static void
 292 acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 293 {
 294         struct acpi_memory_device *mem_device;
 295         struct acpi_device *device;
 296
 297         ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
 298
 299         switch (event) {
 300         case ACPI_NOTIFY_BUS_CHECK:
 301                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 302                         "\nReceived BUS CHECK notification for device\n"));
 303                 /* Fall Through */
 304         case ACPI_NOTIFY_DEVICE_CHECK:
 305                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 306                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 307                         "\nReceived DEVICE CHECK notification for device\n"));
 308                 if (acpi_memory_get_device(handle, &mem_device)) {
 309                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 310                                 "Error in finding driver data\n"));
 311                         return_VOID;
 312                 }
 313
 314                 if (!acpi_memory_check_device(mem_device)) {
 315                         if (acpi_memory_enable_device(mem_device))
 316                                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 317                                 "Error in acpi_memory_enable_device\n"));
 318                 }
 319                 break;
 320         case ACPI_NOTIFY_EJECT_REQUEST:
 321                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 322                         "\nReceived EJECT REQUEST notification for device\n"));
 323
 324                 if (acpi_bus_get_device(handle, &device)) {
 325                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 326                                         "Device doesn't exist\n"));
 327                         break;
 328                 }
 329                 mem_device = acpi_driver_data(device);
 330                 if (!mem_device) {
 331                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 332                                         "Driver Data is NULL\n"));
 333                         break;
 334                 }
 335
 336                 /*
 337                  * Currently disabling memory device from kernel mode
 338                  * TBD: Can also be disabled from user mode scripts
 339                  * TBD: Can also be disabled by Callback registration
 340                  *      with generic sysfs driver
 341                  */
 342                 if (acpi_memory_disable_device(mem_device))
 343                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 344                                 "Error in acpi_memory_disable_device\n"));
 345                 /*
 346                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 347                  */
 348                 break;
 349         default:
 350                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 351                         "Unsupported event [0x%x]\n", event));
 352                 break;
 353         }
 354
 355         return_VOID;
 356 }
 357
 358 static int
 359 acpi_memory_device_add(struct acpi_device *device)
 360 {
 361         int result;
 362         struct acpi_memory_device *mem_device = NULL;
 363
 364         ACPI_FUNCTION_TRACE("acpi_memory_device_add");
 365
 366         if (!device)
 367                 return_VALUE(-EINVAL);
 368
 369         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 370         if (!mem_device)
 371                 return_VALUE(-ENOMEM);
 372         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 373
 374         mem_device->handle = device->handle;
 375         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 376         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 377         acpi_driver_data(device) = mem_device;
 378
 379         /* Get the range from the _CRS */
 380         result = acpi_memory_get_device_resources(mem_device);
 381         if (result) {
 382                 kfree(mem_device);
 383                 return_VALUE(result);
 384         }
 385
 386         /* Set the device state */
 387         mem_device->state = MEMORY_POWER_ON_STATE;
 388
 389         printk(KERN_INFO "%s \n", acpi_device_name(device));
 390
 391         return_VALUE(result);
 392 }
 393
 394 static int
 395 acpi_memory_device_remove (struct acpi_device *device, int type)
 396 {
 397         struct acpi_memory_device *mem_device = NULL;
 398
 399         ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
 400
 401         if (!device || !acpi_driver_data(device))
 402                 return_VALUE(-EINVAL);
 403
 404         mem_device = (struct acpi_memory_device *) acpi_driver_data(device);
 405         kfree(mem_device);
 406
 407         return_VALUE(0);
 408 }
 409
 410 /*
 411  * Helper function to check for memory device
 412  */
 413 static acpi_status
 414 is_memory_device(acpi_handle handle)
 415 {
 416         char *hardware_id;
 417         acpi_status status;
 418         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 419         struct acpi_device_info *info;
 420
 421         ACPI_FUNCTION_TRACE("is_memory_device");
 422
 423         status = acpi_get_object_info(handle, &buffer);
 424         if (ACPI_FAILURE(status))
 425                 return_ACPI_STATUS(AE_ERROR);
 426
 427         info = buffer.pointer;
 428         if (!(info->valid & ACPI_VALID_HID)) {
 429                 acpi_os_free(buffer.pointer);
 430                 return_ACPI_STATUS(AE_ERROR);
 431         }
 432
 433         hardware_id = info->hardware_id.value;
 434         if ((hardware_id == NULL) ||
 435                 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 436                 status = AE_ERROR;
 437
 438         acpi_os_free(buffer.pointer);
 439         return_ACPI_STATUS(status);
 440 }
 441
 442 static acpi_status
 443 acpi_memory_register_notify_handler (acpi_handle handle,
 444         u32 level, void *ctxt, void **retv)
 445 {
 446         acpi_status status;
 447
 448         ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
 449
 450         status = is_memory_device(handle);
 451         if (ACPI_FAILURE(status))
 452                 return_ACPI_STATUS(AE_OK);      /* continue */
 453
 454         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 455                         acpi_memory_device_notify, NULL);
 456         if (ACPI_FAILURE(status)) {
 457                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 458                         "Error installing notify handler\n"));
 459                 return_ACPI_STATUS(AE_OK);      /* continue */
 460         }
 461
 462         return_ACPI_STATUS(status);
 463 }
 464
 465 static acpi_status
 466 acpi_memory_deregister_notify_handler (acpi_handle handle,
 467                                u32 level, void *ctxt, void **retv)
 468 {
 469         acpi_status status;
 470
 471         ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
 472
 473         status = is_memory_device(handle);
 474         if (ACPI_FAILURE(status))
 475                 return_ACPI_STATUS(AE_OK);      /* continue */
 476
 477         status = acpi_remove_notify_handler(handle,
 478                         ACPI_SYSTEM_NOTIFY, acpi_memory_device_notify);
 479         if (ACPI_FAILURE(status)) {
 480                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 481                                 "Error removing notify handler\n"));
 482                 return_ACPI_STATUS(AE_OK);      /* continue */
 483         }
 484
 485         return_ACPI_STATUS(status);
 486 }
 487
 488 static int __init
 489 acpi_memory_device_init (void)
 490 {
 491         int result;
 492         acpi_status status;
 493
 494         ACPI_FUNCTION_TRACE("acpi_memory_device_init");
 495
 496         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 497
 498         if (result < 0)
 499                 return_VALUE(-ENODEV);
 500
 501         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 502                                 ACPI_UINT32_MAX,
 503                                 acpi_memory_register_notify_handler,
 504                                 NULL, NULL);
 505
 506         if (ACPI_FAILURE (status)) {
 507                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "walk_namespace failed\n"));
 508                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 509                 return_VALUE(-ENODEV);
 510         }
 511
 512         return_VALUE(0);
 513 }
 514
 515 static void __exit
 516 acpi_memory_device_exit (void)
 517 {
 518         acpi_status status;
 519
 520         ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
 521
 522         /*
 523          * Adding this to un-install notification handlers for all the device
 524          * handles.
 525          */
 526         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 527                         ACPI_UINT32_MAX,
 528                         acpi_memory_deregister_notify_handler,
 529                         NULL, NULL);
 530
 531         if (ACPI_FAILURE (status))
 532                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "walk_namespace failed\n"));
 533
 534         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 535
 536         return_VOID;
 537 }
 538
 539 module_init(acpi_memory_device_init);
 540 module_exit(acpi_memory_device_exit);
 541
 542