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 const struct acpi_device_id memory_device_ids[] = {
  57         {ACPI_MEMORY_DEVICE_HID, 0},
  58         {"", 0},
  59 };
  60 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
  61
  62 static struct acpi_driver acpi_memory_device_driver = {
  63         .name = "acpi_memhotplug",
  64         .class = ACPI_MEMORY_DEVICE_CLASS,
  65         .ids = memory_device_ids,
  66         .ops = {
  67                 .add = acpi_memory_device_add,
  68                 .remove = acpi_memory_device_remove,
  69                 .start = acpi_memory_device_start,
  70                 },
  71 };
  72
  73 struct acpi_memory_info {
  74         struct list_head list;
  75         u64 start_addr;         /* Memory Range start physical addr */
  76         u64 length;             /* Memory Range length */
  77         unsigned short caching; /* memory cache attribute */
  78         unsigned short write_protect;   /* memory read/write attribute */
  79         unsigned int enabled:1;
  80 };
  81
  82 struct acpi_memory_device {
  83         struct acpi_device * device;
  84         unsigned int state;     /* State of the memory device */
  85         struct list_head res_list;
  86 };
  87
  88 static int acpi_hotmem_initialized;
  89
  90 static acpi_status
  91 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  92 {
  93         struct acpi_memory_device *mem_device = context;
  94         struct acpi_resource_address64 address64;
  95         struct acpi_memory_info *info, *new;
  96         acpi_status status;
  97
  98         status = acpi_resource_to_address64(resource, &address64);
  99         if (ACPI_FAILURE(status) ||
 100             (address64.resource_type != ACPI_MEMORY_RANGE))
 101                 return AE_OK;
 102
 103         list_for_each_entry(info, &mem_device->res_list, list) {
 104                 /* Can we combine the resource range information? */
 105                 if ((info->caching == address64.info.mem.caching) &&
 106                     (info->write_protect == address64.info.mem.write_protect) &&
 107                     (info->start_addr + info->length == address64.minimum)) {
 108                         info->length += address64.address_length;
 109                         return AE_OK;
 110                 }
 111         }
 112
 113         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 114         if (!new)
 115                 return AE_ERROR;
 116
 117         INIT_LIST_HEAD(&new->list);
 118         new->caching = address64.info.mem.caching;
 119         new->write_protect = address64.info.mem.write_protect;
 120         new->start_addr = address64.minimum;
 121         new->length = address64.address_length;
 122         list_add_tail(&new->list, &mem_device->res_list);
 123
 124         return AE_OK;
 125 }
 126
 127 static int
 128 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 129 {
 130         acpi_status status;
 131         struct acpi_memory_info *info, *n;
 132
 133
 134         if (!list_empty(&mem_device->res_list))
 135                 return 0;
 136
 137         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 138                                      acpi_memory_get_resource, mem_device);
 139         if (ACPI_FAILURE(status)) {
 140                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 141                         kfree(info);
 142                 INIT_LIST_HEAD(&mem_device->res_list);
 143                 return -EINVAL;
 144         }
 145
 146         return 0;
 147 }
 148
 149 static int
 150 acpi_memory_get_device(acpi_handle handle,
 151                        struct acpi_memory_device **mem_device)
 152 {
 153         acpi_status status;
 154         acpi_handle phandle;
 155         struct acpi_device *device = NULL;
 156         struct acpi_device *pdevice = NULL;
 157
 158
 159         if (!acpi_bus_get_device(handle, &device) && device)
 160                 goto end;
 161
 162         status = acpi_get_parent(handle, &phandle);
 163         if (ACPI_FAILURE(status)) {
 164                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 165                 return -EINVAL;
 166         }
 167
 168         /* Get the parent device */
 169         status = acpi_bus_get_device(phandle, &pdevice);
 170         if (ACPI_FAILURE(status)) {
 171                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
 172                 return -EINVAL;
 173         }
 174
 175         /*
 176          * Now add the notified device.  This creates the acpi_device
 177          * and invokes .add function
 178          */
 179         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 180         if (ACPI_FAILURE(status)) {
 181                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
 182                 return -EINVAL;
 183         }
 184
 185       end:
 186         *mem_device = acpi_driver_data(device);
 187         if (!(*mem_device)) {
 188                 printk(KERN_ERR "\n driver data not found");
 189                 return -ENODEV;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 196 {
 197         unsigned long current_status;
 198
 199
 200         /* Get device present/absent information from the _STA */
 201         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 202                                                NULL, &current_status)))
 203                 return -ENODEV;
 204         /*
 205          * Check for device status. Device should be
 206          * present/enabled/functioning.
 207          */
 208         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 209               && (current_status & ACPI_STA_DEVICE_ENABLED)
 210               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 211                 return -ENODEV;
 212
 213         return 0;
 214 }
 215
 216 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 217 {
 218         int result, num_enabled = 0;
 219         struct acpi_memory_info *info;
 220         int node;
 221
 222
 223         /* Get the range from the _CRS */
 224         result = acpi_memory_get_device_resources(mem_device);
 225         if (result) {
 226                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
 227                 mem_device->state = MEMORY_INVALID_STATE;
 228                 return result;
 229         }
 230
 231         node = acpi_get_node(mem_device->device->handle);
 232         /*
 233          * Tell the VM there is more memory here...
 234          * Note: Assume that this function returns zero on success
 235          * We don't have memory-hot-add rollback function,now.
 236          * (i.e. memory-hot-remove function)
 237          */
 238         list_for_each_entry(info, &mem_device->res_list, list) {
 239                 if (info->enabled) { /* just sanity check...*/
 240                         num_enabled++;
 241                         continue;
 242                 }
 243
 244                 if (node < 0)
 245                         node = memory_add_physaddr_to_nid(info->start_addr);
 246
 247                 result = add_memory(node, info->start_addr, info->length);
 248                 if (result)
 249                         continue;
 250                 info->enabled = 1;
 251                 num_enabled++;
 252         }
 253         if (!num_enabled) {
 254                 printk(KERN_ERR PREFIX "add_memory failed\n");
 255                 mem_device->state = MEMORY_INVALID_STATE;
 256                 return -EINVAL;
 257         }
 258
 259         return result;
 260 }
 261
 262 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 263 {
 264         acpi_status status;
 265         struct acpi_object_list arg_list;
 266         union acpi_object arg;
 267         unsigned long current_status;
 268
 269
 270         /* Issue the _EJ0 command */
 271         arg_list.count = 1;
 272         arg_list.pointer = &arg;
 273         arg.type = ACPI_TYPE_INTEGER;
 274         arg.integer.value = 1;
 275         status = acpi_evaluate_object(mem_device->device->handle,
 276                                       "_EJ0", &arg_list, NULL);
 277         /* Return on _EJ0 failure */
 278         if (ACPI_FAILURE(status)) {
 279                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 280                 return -ENODEV;
 281         }
 282
 283         /* Evalute _STA to check if the device is disabled */
 284         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
 285                                        NULL, &current_status);
 286         if (ACPI_FAILURE(status))
 287                 return -ENODEV;
 288
 289         /* Check for device status.  Device should be disabled */
 290         if (current_status & ACPI_STA_DEVICE_ENABLED)
 291                 return -EINVAL;
 292
 293         return 0;
 294 }
 295
 296 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 297 {
 298         int result;
 299         struct acpi_memory_info *info, *n;
 300
 301
 302         /*
 303          * Ask the VM to offline this memory range.
 304          * Note: Assume that this function returns zero on success
 305          */
 306         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 307                 if (info->enabled) {
 308                         result = remove_memory(info->start_addr, info->length);
 309                         if (result)
 310                                 return result;
 311                 }
 312                 kfree(info);
 313         }
 314
 315         /* Power-off and eject the device */
 316         result = acpi_memory_powerdown_device(mem_device);
 317         if (result) {
 318                 /* Set the status of the device to invalid */
 319                 mem_device->state = MEMORY_INVALID_STATE;
 320                 return result;
 321         }
 322
 323         mem_device->state = MEMORY_POWER_OFF_STATE;
 324         return result;
 325 }
 326
 327 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 328 {
 329         struct acpi_memory_device *mem_device;
 330         struct acpi_device *device;
 331
 332
 333         switch (event) {
 334         case ACPI_NOTIFY_BUS_CHECK:
 335                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 336                                   "\nReceived BUS CHECK notification for device\n"));
 337                 /* Fall Through */
 338         case ACPI_NOTIFY_DEVICE_CHECK:
 339                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 340                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 341                                           "\nReceived DEVICE CHECK notification for device\n"));
 342                 if (acpi_memory_get_device(handle, &mem_device)) {
 343                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 344                         return;
 345                 }
 346
 347                 if (!acpi_memory_check_device(mem_device)) {
 348                         if (acpi_memory_enable_device(mem_device))
 349                                 printk(KERN_ERR PREFIX
 350                                             "Cannot enable memory device\n");
 351                 }
 352                 break;
 353         case ACPI_NOTIFY_EJECT_REQUEST:
 354                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 355                                   "\nReceived EJECT REQUEST notification for device\n"));
 356
 357                 if (acpi_bus_get_device(handle, &device)) {
 358                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 359                         break;
 360                 }
 361                 mem_device = acpi_driver_data(device);
 362                 if (!mem_device) {
 363                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 364                         break;
 365                 }
 366
 367                 /*
 368                  * Currently disabling memory device from kernel mode
 369                  * TBD: Can also be disabled from user mode scripts
 370                  * TBD: Can also be disabled by Callback registration
 371                  *      with generic sysfs driver
 372                  */
 373                 if (acpi_memory_disable_device(mem_device))
 374                         printk(KERN_ERR PREFIX
 375                                     "Disable memory device\n");
 376                 /*
 377                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 378                  */
 379                 break;
 380         default:
 381                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 382                                   "Unsupported event [0x%x]\n", event));
 383                 break;
 384         }
 385
 386         return;
 387 }
 388
 389 static int acpi_memory_device_add(struct acpi_device *device)
 390 {
 391         int result;
 392         struct acpi_memory_device *mem_device = NULL;
 393
 394
 395         if (!device)
 396                 return -EINVAL;
 397
 398         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 399         if (!mem_device)
 400                 return -ENOMEM;
 401
 402         INIT_LIST_HEAD(&mem_device->res_list);
 403         mem_device->device = device;
 404         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 405         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 406         acpi_driver_data(device) = mem_device;
 407
 408         /* Get the range from the _CRS */
 409         result = acpi_memory_get_device_resources(mem_device);
 410         if (result) {
 411                 kfree(mem_device);
 412                 return result;
 413         }
 414
 415         /* Set the device state */
 416         mem_device->state = MEMORY_POWER_ON_STATE;
 417
 418         printk(KERN_DEBUG "%s \n", acpi_device_name(device));
 419
 420         return result;
 421 }
 422
 423 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 424 {
 425         struct acpi_memory_device *mem_device = NULL;
 426
 427
 428         if (!device || !acpi_driver_data(device))
 429                 return -EINVAL;
 430
 431         mem_device = acpi_driver_data(device);
 432         kfree(mem_device);
 433
 434         return 0;
 435 }
 436
 437 static int acpi_memory_device_start (struct acpi_device *device)
 438 {
 439         struct acpi_memory_device *mem_device;
 440         int result = 0;
 441
 442         /*
 443          * Early boot code has recognized memory area by EFI/E820.
 444          * If DSDT shows these memory devices on boot, hotplug is not necessary
 445          * for them. So, it just returns until completion of this driver's
 446          * start up.
 447          */
 448         if (!acpi_hotmem_initialized)
 449                 return 0;
 450
 451         mem_device = acpi_driver_data(device);
 452
 453         if (!acpi_memory_check_device(mem_device)) {
 454                 /* call add_memory func */
 455                 result = acpi_memory_enable_device(mem_device);
 456                 if (result)
 457                         printk(KERN_ERR PREFIX
 458                                 "Error in acpi_memory_enable_device\n");
 459         }
 460         return result;
 461 }
 462
 463 /*
 464  * Helper function to check for memory device
 465  */
 466 static acpi_status is_memory_device(acpi_handle handle)
 467 {
 468         char *hardware_id;
 469         acpi_status status;
 470         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 471         struct acpi_device_info *info;
 472
 473
 474         status = acpi_get_object_info(handle, &buffer);
 475         if (ACPI_FAILURE(status))
 476                 return status;
 477
 478         info = buffer.pointer;
 479         if (!(info->valid & ACPI_VALID_HID)) {
 480                 kfree(buffer.pointer);
 481                 return AE_ERROR;
 482         }
 483
 484         hardware_id = info->hardware_id.value;
 485         if ((hardware_id == NULL) ||
 486             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 487                 status = AE_ERROR;
 488
 489         kfree(buffer.pointer);
 490         return status;
 491 }
 492
 493 static acpi_status
 494 acpi_memory_register_notify_handler(acpi_handle handle,
 495                                     u32 level, void *ctxt, void **retv)
 496 {
 497         acpi_status status;
 498
 499
 500         status = is_memory_device(handle);
 501         if (ACPI_FAILURE(status))
 502                 return AE_OK;   /* continue */
 503
 504         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 505                                              acpi_memory_device_notify, NULL);
 506         /* continue */
 507         return AE_OK;
 508 }
 509
 510 static acpi_status
 511 acpi_memory_deregister_notify_handler(acpi_handle handle,
 512                                       u32 level, void *ctxt, void **retv)
 513 {
 514         acpi_status status;
 515
 516
 517         status = is_memory_device(handle);
 518         if (ACPI_FAILURE(status))
 519                 return AE_OK;   /* continue */
 520
 521         status = acpi_remove_notify_handler(handle,
 522                                             ACPI_SYSTEM_NOTIFY,
 523                                             acpi_memory_device_notify);
 524
 525         return AE_OK;   /* continue */
 526 }
 527
 528 static int __init acpi_memory_device_init(void)
 529 {
 530         int result;
 531         acpi_status status;
 532
 533
 534         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 535
 536         if (result < 0)
 537                 return -ENODEV;
 538
 539         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 540                                      ACPI_UINT32_MAX,
 541                                      acpi_memory_register_notify_handler,
 542                                      NULL, NULL);
 543
 544         if (ACPI_FAILURE(status)) {
 545                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 546                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 547                 return -ENODEV;
 548         }
 549
 550         acpi_hotmem_initialized = 1;
 551         return 0;
 552 }
 553
 554 static void __exit acpi_memory_device_exit(void)
 555 {
 556         acpi_status status;
 557
 558
 559         /*
 560          * Adding this to un-install notification handlers for all the device
 561          * handles.
 562          */
 563         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 564                                      ACPI_UINT32_MAX,
 565                                      acpi_memory_deregister_notify_handler,
 566                                      NULL, NULL);
 567
 568         if (ACPI_FAILURE(status))
 569                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 570
 571         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 572
 573         return;
 574 }
 575
 576 module_init(acpi_memory_device_init);
 577 module_exit(acpi_memory_device_exit);