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_NAME                 "Hotplug Mem Device"
  39
  40 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  41
  42 ACPI_MODULE_NAME("acpi_memhotplug");
  43 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
  44 MODULE_DESCRIPTION("Hotplug Mem Driver");
  45 MODULE_LICENSE("GPL");
  46
  47 /* Memory Device States */
  48 #define MEMORY_INVALID_STATE    0
  49 #define MEMORY_POWER_ON_STATE   1
  50 #define MEMORY_POWER_OFF_STATE  2
  51
  52 static int acpi_memory_device_add(struct acpi_device *device);
  53 static int acpi_memory_device_remove(struct acpi_device *device, int type);
  54 static int acpi_memory_device_start(struct acpi_device *device);
  55
  56 static struct acpi_driver acpi_memory_device_driver = {
  57         .name = "acpi_memhotplug",
  58         .class = ACPI_MEMORY_DEVICE_CLASS,
  59         .ids = ACPI_MEMORY_DEVICE_HID,
  60         .ops = {
  61                 .add = acpi_memory_device_add,
  62                 .remove = acpi_memory_device_remove,
  63                 .start = acpi_memory_device_start,
  64                 },
  65 };
  66
  67 struct acpi_memory_info {
  68         struct list_head list;
  69         u64 start_addr;         /* Memory Range start physical addr */
  70         u64 length;             /* Memory Range length */
  71         unsigned short caching; /* memory cache attribute */
  72         unsigned short write_protect;   /* memory read/write attribute */
  73         unsigned int enabled:1;
  74 };
  75
  76 struct acpi_memory_device {
  77         struct acpi_device * device;
  78         unsigned int state;     /* State of the memory device */
  79         struct list_head res_list;
  80 };
  81
  82 static int acpi_hotmem_initialized;
  83
  84 static acpi_status
  85 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  86 {
  87         struct acpi_memory_device *mem_device = context;
  88         struct acpi_resource_address64 address64;
  89         struct acpi_memory_info *info, *new;
  90         acpi_status status;
  91
  92         status = acpi_resource_to_address64(resource, &address64);
  93         if (ACPI_FAILURE(status) ||
  94             (address64.resource_type != ACPI_MEMORY_RANGE))
  95                 return AE_OK;
  96
  97         list_for_each_entry(info, &mem_device->res_list, list) {
  98                 /* Can we combine the resource range information? */
  99                 if ((info->caching == address64.info.mem.caching) &&
 100                     (info->write_protect == address64.info.mem.write_protect) &&
 101                     (info->start_addr + info->length == address64.minimum)) {
 102                         info->length += address64.address_length;
 103                         return AE_OK;
 104                 }
 105         }
 106
 107         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 108         if (!new)
 109                 return AE_ERROR;
 110
 111         INIT_LIST_HEAD(&new->list);
 112         new->caching = address64.info.mem.caching;
 113         new->write_protect = address64.info.mem.write_protect;
 114         new->start_addr = address64.minimum;
 115         new->length = address64.address_length;
 116         list_add_tail(&new->list, &mem_device->res_list);
 117
 118         return AE_OK;
 119 }
 120
 121 static int
 122 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 123 {
 124         acpi_status status;
 125         struct acpi_memory_info *info, *n;
 126
 127
 128         if (!list_empty(&mem_device->res_list))
 129                 return 0;
 130
 131         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 132                                      acpi_memory_get_resource, mem_device);
 133         if (ACPI_FAILURE(status)) {
 134                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 135                         kfree(info);
 136                 INIT_LIST_HEAD(&mem_device->res_list);
 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_STA_DEVICE_PRESENT)
 203               && (current_status & ACPI_STA_DEVICE_ENABLED)
 204               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 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
 238                 if (node < 0)
 239                         node = memory_add_physaddr_to_nid(info->start_addr);
 240
 241                 result = add_memory(node, info->start_addr, info->length);
 242                 if (result)
 243                         continue;
 244                 info->enabled = 1;
 245                 num_enabled++;
 246         }
 247         if (!num_enabled) {
 248                 printk(KERN_ERR PREFIX "add_memory failed\n");
 249                 mem_device->state = MEMORY_INVALID_STATE;
 250                 return -EINVAL;
 251         }
 252
 253         return result;
 254 }
 255
 256 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 257 {
 258         acpi_status status;
 259         struct acpi_object_list arg_list;
 260         union acpi_object arg;
 261         unsigned long current_status;
 262
 263
 264         /* Issue the _EJ0 command */
 265         arg_list.count = 1;
 266         arg_list.pointer = &arg;
 267         arg.type = ACPI_TYPE_INTEGER;
 268         arg.integer.value = 1;
 269         status = acpi_evaluate_object(mem_device->device->handle,
 270                                       "_EJ0", &arg_list, NULL);
 271         /* Return on _EJ0 failure */
 272         if (ACPI_FAILURE(status)) {
 273                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 274                 return -ENODEV;
 275         }
 276
 277         /* Evalute _STA to check if the device is disabled */
 278         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
 279                                        NULL, &current_status);
 280         if (ACPI_FAILURE(status))
 281                 return -ENODEV;
 282
 283         /* Check for device status.  Device should be disabled */
 284         if (current_status & ACPI_STA_DEVICE_ENABLED)
 285                 return -EINVAL;
 286
 287         return 0;
 288 }
 289
 290 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 291 {
 292         int result;
 293         struct acpi_memory_info *info, *n;
 294
 295
 296         /*
 297          * Ask the VM to offline this memory range.
 298          * Note: Assume that this function returns zero on success
 299          */
 300         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 301                 if (info->enabled) {
 302                         result = remove_memory(info->start_addr, info->length);
 303                         if (result)
 304                                 return result;
 305                 }
 306                 kfree(info);
 307         }
 308
 309         /* Power-off and eject the device */
 310         result = acpi_memory_powerdown_device(mem_device);
 311         if (result) {
 312                 /* Set the status of the device to invalid */
 313                 mem_device->state = MEMORY_INVALID_STATE;
 314                 return result;
 315         }
 316
 317         mem_device->state = MEMORY_POWER_OFF_STATE;
 318         return result;
 319 }
 320
 321 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 322 {
 323         struct acpi_memory_device *mem_device;
 324         struct acpi_device *device;
 325
 326
 327         switch (event) {
 328         case ACPI_NOTIFY_BUS_CHECK:
 329                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 330                                   "\nReceived BUS CHECK notification for device\n"));
 331                 /* Fall Through */
 332         case ACPI_NOTIFY_DEVICE_CHECK:
 333                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 334                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 335                                           "\nReceived DEVICE CHECK notification for device\n"));
 336                 if (acpi_memory_get_device(handle, &mem_device)) {
 337                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 338                         return;
 339                 }
 340
 341                 if (!acpi_memory_check_device(mem_device)) {
 342                         if (acpi_memory_enable_device(mem_device))
 343                                 printk(KERN_ERR PREFIX
 344                                             "Cannot enable memory device\n");
 345                 }
 346                 break;
 347         case ACPI_NOTIFY_EJECT_REQUEST:
 348                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                                   "\nReceived EJECT REQUEST notification for device\n"));
 350
 351                 if (acpi_bus_get_device(handle, &device)) {
 352                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 353                         break;
 354                 }
 355                 mem_device = acpi_driver_data(device);
 356                 if (!mem_device) {
 357                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 358                         break;
 359                 }
 360
 361                 /*
 362                  * Currently disabling memory device from kernel mode
 363                  * TBD: Can also be disabled from user mode scripts
 364                  * TBD: Can also be disabled by Callback registration
 365                  *      with generic sysfs driver
 366                  */
 367                 if (acpi_memory_disable_device(mem_device))
 368                         printk(KERN_ERR PREFIX
 369                                     "Disable memory device\n");
 370                 /*
 371                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 372                  */
 373                 break;
 374         default:
 375                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 376                                   "Unsupported event [0x%x]\n", event));
 377                 break;
 378         }
 379
 380         return;
 381 }
 382
 383 static int acpi_memory_device_add(struct acpi_device *device)
 384 {
 385         int result;
 386         struct acpi_memory_device *mem_device = NULL;
 387
 388
 389         if (!device)
 390                 return -EINVAL;
 391
 392         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 393         if (!mem_device)
 394                 return -ENOMEM;
 395
 396         INIT_LIST_HEAD(&mem_device->res_list);
 397         mem_device->device = device;
 398         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 399         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 400         acpi_driver_data(device) = mem_device;
 401
 402         /* Get the range from the _CRS */
 403         result = acpi_memory_get_device_resources(mem_device);
 404         if (result) {
 405                 kfree(mem_device);
 406                 return result;
 407         }
 408
 409         /* Set the device state */
 410         mem_device->state = MEMORY_POWER_ON_STATE;
 411
 412         printk(KERN_DEBUG "%s \n", acpi_device_name(device));
 413
 414         return result;
 415 }
 416
 417 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 418 {
 419         struct acpi_memory_device *mem_device = NULL;
 420
 421
 422         if (!device || !acpi_driver_data(device))
 423                 return -EINVAL;
 424
 425         mem_device = acpi_driver_data(device);
 426         kfree(mem_device);
 427
 428         return 0;
 429 }
 430
 431 static int acpi_memory_device_start (struct acpi_device *device)
 432 {
 433         struct acpi_memory_device *mem_device;
 434         int result = 0;
 435
 436         /*
 437          * Early boot code has recognized memory area by EFI/E820.
 438          * If DSDT shows these memory devices on boot, hotplug is not necessary
 439          * for them. So, it just returns until completion of this driver's
 440          * start up.
 441          */
 442         if (!acpi_hotmem_initialized)
 443                 return 0;
 444
 445         mem_device = acpi_driver_data(device);
 446
 447         if (!acpi_memory_check_device(mem_device)) {
 448                 /* call add_memory func */
 449                 result = acpi_memory_enable_device(mem_device);
 450                 if (result)
 451                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 452                                 "Error in acpi_memory_enable_device\n"));
 453         }
 454         return result;
 455 }
 456
 457 /*
 458  * Helper function to check for memory device
 459  */
 460 static acpi_status is_memory_device(acpi_handle handle)
 461 {
 462         char *hardware_id;
 463         acpi_status status;
 464         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 465         struct acpi_device_info *info;
 466
 467
 468         status = acpi_get_object_info(handle, &buffer);
 469         if (ACPI_FAILURE(status))
 470                 return status;
 471
 472         info = buffer.pointer;
 473         if (!(info->valid & ACPI_VALID_HID)) {
 474                 kfree(buffer.pointer);
 475                 return AE_ERROR;
 476         }
 477
 478         hardware_id = info->hardware_id.value;
 479         if ((hardware_id == NULL) ||
 480             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 481                 status = AE_ERROR;
 482
 483         kfree(buffer.pointer);
 484         return status;
 485 }
 486
 487 static acpi_status
 488 acpi_memory_register_notify_handler(acpi_handle handle,
 489                                     u32 level, void *ctxt, void **retv)
 490 {
 491         acpi_status status;
 492
 493
 494         status = is_memory_device(handle);
 495         if (ACPI_FAILURE(status))
 496                 return AE_OK;   /* continue */
 497
 498         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 499                                              acpi_memory_device_notify, NULL);
 500         /* continue */
 501         return AE_OK;
 502 }
 503
 504 static acpi_status
 505 acpi_memory_deregister_notify_handler(acpi_handle handle,
 506                                       u32 level, void *ctxt, void **retv)
 507 {
 508         acpi_status status;
 509
 510
 511         status = is_memory_device(handle);
 512         if (ACPI_FAILURE(status))
 513                 return AE_OK;   /* continue */
 514
 515         status = acpi_remove_notify_handler(handle,
 516                                             ACPI_SYSTEM_NOTIFY,
 517                                             acpi_memory_device_notify);
 518
 519         return AE_OK;   /* continue */
 520 }
 521
 522 static int __init acpi_memory_device_init(void)
 523 {
 524         int result;
 525         acpi_status status;
 526
 527
 528         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 529
 530         if (result < 0)
 531                 return -ENODEV;
 532
 533         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 534                                      ACPI_UINT32_MAX,
 535                                      acpi_memory_register_notify_handler,
 536                                      NULL, NULL);
 537
 538         if (ACPI_FAILURE(status)) {
 539                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 540                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 541                 return -ENODEV;
 542         }
 543
 544         acpi_hotmem_initialized = 1;
 545         return 0;
 546 }
 547
 548 static void __exit acpi_memory_device_exit(void)
 549 {
 550         acpi_status status;
 551
 552
 553         /*
 554          * Adding this to un-install notification handlers for all the device
 555          * handles.
 556          */
 557         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 558                                      ACPI_UINT32_MAX,
 559                                      acpi_memory_deregister_notify_handler,
 560                                      NULL, NULL);
 561
 562         if (ACPI_FAILURE(status))
 563                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 564
 565         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 566
 567         return;
 568 }
 569
 570 module_init(acpi_memory_device_init);
 571 module_exit(acpi_memory_device_exit);