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 firmware 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 <linux/slab.h>
  34 #include <acpi/acpi_drivers.h>
  35
  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 #undef PREFIX
  43 #define         PREFIX          "ACPI:memory_hp:"
  44
  45 ACPI_MODULE_NAME("acpi_memhotplug");
  46 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
  47 MODULE_DESCRIPTION("Hotplug Mem Driver");
  48 MODULE_LICENSE("GPL");
  49
  50 /* Memory Device States */
  51 #define MEMORY_INVALID_STATE    0
  52 #define MEMORY_POWER_ON_STATE   1
  53 #define MEMORY_POWER_OFF_STATE  2
  54
  55 static int acpi_memory_device_add(struct acpi_device *device);
  56 static int acpi_memory_device_remove(struct acpi_device *device, int type);
  57
  58 static const struct acpi_device_id memory_device_ids[] = {
  59         {ACPI_MEMORY_DEVICE_HID, 0},
  60         {"", 0},
  61 };
  62 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
  63
  64 static struct acpi_driver acpi_memory_device_driver = {
  65         .name = "acpi_memhotplug",
  66         .class = ACPI_MEMORY_DEVICE_CLASS,
  67         .ids = memory_device_ids,
  68         .ops = {
  69                 .add = acpi_memory_device_add,
  70                 .remove = acpi_memory_device_remove,
  71                 },
  72 };
  73
  74 struct acpi_memory_info {
  75         struct list_head list;
  76         u64 start_addr;         /* Memory Range start physical addr */
  77         u64 length;             /* Memory Range length */
  78         unsigned short caching; /* memory cache attribute */
  79         unsigned short write_protect;   /* memory read/write attribute */
  80         unsigned int enabled:1;
  81 };
  82
  83 struct acpi_memory_device {
  84         struct acpi_device * device;
  85         unsigned int state;     /* State of the memory device */
  86         struct list_head res_list;
  87 };
  88
  89 static int acpi_hotmem_initialized;
  90
  91 static acpi_status
  92 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  93 {
  94         struct acpi_memory_device *mem_device = context;
  95         struct acpi_resource_address64 address64;
  96         struct acpi_memory_info *info, *new;
  97         acpi_status status;
  98
  99         status = acpi_resource_to_address64(resource, &address64);
 100         if (ACPI_FAILURE(status) ||
 101             (address64.resource_type != ACPI_MEMORY_RANGE))
 102                 return AE_OK;
 103
 104         list_for_each_entry(info, &mem_device->res_list, list) {
 105                 /* Can we combine the resource range information? */
 106                 if ((info->caching == address64.info.mem.caching) &&
 107                     (info->write_protect == address64.info.mem.write_protect) &&
 108                     (info->start_addr + info->length == address64.minimum)) {
 109                         info->length += address64.address_length;
 110                         return AE_OK;
 111                 }
 112         }
 113
 114         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 115         if (!new)
 116                 return AE_ERROR;
 117
 118         INIT_LIST_HEAD(&new->list);
 119         new->caching = address64.info.mem.caching;
 120         new->write_protect = address64.info.mem.write_protect;
 121         new->start_addr = address64.minimum;
 122         new->length = address64.address_length;
 123         list_add_tail(&new->list, &mem_device->res_list);
 124
 125         return AE_OK;
 126 }
 127
 128 static int
 129 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 130 {
 131         acpi_status status;
 132         struct acpi_memory_info *info, *n;
 133
 134
 135         if (!list_empty(&mem_device->res_list))
 136                 return 0;
 137
 138         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 139                                      acpi_memory_get_resource, mem_device);
 140         if (ACPI_FAILURE(status)) {
 141                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 142                         kfree(info);
 143                 INIT_LIST_HEAD(&mem_device->res_list);
 144                 return -EINVAL;
 145         }
 146
 147         return 0;
 148 }
 149
 150 static int
 151 acpi_memory_get_device(acpi_handle handle,
 152                        struct acpi_memory_device **mem_device)
 153 {
 154         acpi_status status;
 155         acpi_handle phandle;
 156         struct acpi_device *device = NULL;
 157         struct acpi_device *pdevice = NULL;
 158         int result;
 159
 160
 161         if (!acpi_bus_get_device(handle, &device) && device)
 162                 goto end;
 163
 164         status = acpi_get_parent(handle, &phandle);
 165         if (ACPI_FAILURE(status)) {
 166                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 167                 return -EINVAL;
 168         }
 169
 170         /* Get the parent device */
 171         result = acpi_bus_get_device(phandle, &pdevice);
 172         if (result) {
 173                 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
 174                 return -EINVAL;
 175         }
 176
 177         /*
 178          * Now add the notified device.  This creates the acpi_device
 179          * and invokes .add function
 180          */
 181         result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 182         if (result) {
 183                 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
 184                 return -EINVAL;
 185         }
 186
 187       end:
 188         *mem_device = acpi_driver_data(device);
 189         if (!(*mem_device)) {
 190                 printk(KERN_ERR "\n driver data not found");
 191                 return -ENODEV;
 192         }
 193
 194         return 0;
 195 }
 196
 197 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 198 {
 199         unsigned long long current_status;
 200
 201         /* Get device present/absent information from the _STA */
 202         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 203                                                NULL, &current_status)))
 204                 return -ENODEV;
 205         /*
 206          * Check for device status. Device should be
 207          * present/enabled/functioning.
 208          */
 209         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 210               && (current_status & ACPI_STA_DEVICE_ENABLED)
 211               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 212                 return -ENODEV;
 213
 214         return 0;
 215 }
 216
 217 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 218 {
 219         int result, num_enabled = 0;
 220         struct acpi_memory_info *info;
 221         int node;
 222
 223
 224         /* Get the range from the _CRS */
 225         result = acpi_memory_get_device_resources(mem_device);
 226         if (result) {
 227                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
 228                 mem_device->state = MEMORY_INVALID_STATE;
 229                 return result;
 230         }
 231
 232         node = acpi_get_node(mem_device->device->handle);
 233         /*
 234          * Tell the VM there is more memory here...
 235          * Note: Assume that this function returns zero on success
 236          * We don't have memory-hot-add rollback function,now.
 237          * (i.e. memory-hot-remove function)
 238          */
 239         list_for_each_entry(info, &mem_device->res_list, list) {
 240                 if (info->enabled) { /* just sanity check...*/
 241                         num_enabled++;
 242                         continue;
 243                 }
 244                 /*
 245                  * If the memory block size is zero, please ignore it.
 246                  * Don't try to do the following memory hotplug flowchart.
 247                  */
 248                 if (!info->length)
 249                         continue;
 250                 if (node < 0)
 251                         node = memory_add_physaddr_to_nid(info->start_addr);
 252
 253                 result = add_memory(node, info->start_addr, info->length);
 254                 if (result)
 255                         continue;
 256                 info->enabled = 1;
 257                 num_enabled++;
 258         }
 259         if (!num_enabled) {
 260                 printk(KERN_ERR PREFIX "add_memory failed\n");
 261                 mem_device->state = MEMORY_INVALID_STATE;
 262                 return -EINVAL;
 263         }
 264         /*
 265          * Sometimes the memory device will contain several memory blocks.
 266          * When one memory block is hot-added to the system memory, it will
 267          * be regarded as a success.
 268          * Otherwise if the last memory block can't be hot-added to the system
 269          * memory, it will be failure and the memory device can't be bound with
 270          * driver.
 271          */
 272         return 0;
 273 }
 274
 275 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 276 {
 277         acpi_status status;
 278         struct acpi_object_list arg_list;
 279         union acpi_object arg;
 280         unsigned long long current_status;
 281
 282
 283         /* Issue the _EJ0 command */
 284         arg_list.count = 1;
 285         arg_list.pointer = &arg;
 286         arg.type = ACPI_TYPE_INTEGER;
 287         arg.integer.value = 1;
 288         status = acpi_evaluate_object(mem_device->device->handle,
 289                                       "_EJ0", &arg_list, NULL);
 290         /* Return on _EJ0 failure */
 291         if (ACPI_FAILURE(status)) {
 292                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 293                 return -ENODEV;
 294         }
 295
 296         /* Evalute _STA to check if the device is disabled */
 297         status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
 298                                        NULL, &current_status);
 299         if (ACPI_FAILURE(status))
 300                 return -ENODEV;
 301
 302         /* Check for device status.  Device should be disabled */
 303         if (current_status & ACPI_STA_DEVICE_ENABLED)
 304                 return -EINVAL;
 305
 306         return 0;
 307 }
 308
 309 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 310 {
 311         int result;
 312         struct acpi_memory_info *info, *n;
 313
 314
 315         /*
 316          * Ask the VM to offline this memory range.
 317          * Note: Assume that this function returns zero on success
 318          */
 319         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 320                 if (info->enabled) {
 321                         result = remove_memory(info->start_addr, info->length);
 322                         if (result)
 323                                 return result;
 324                 }
 325                 kfree(info);
 326         }
 327
 328         /* Power-off and eject the device */
 329         result = acpi_memory_powerdown_device(mem_device);
 330         if (result) {
 331                 /* Set the status of the device to invalid */
 332                 mem_device->state = MEMORY_INVALID_STATE;
 333                 return result;
 334         }
 335
 336         mem_device->state = MEMORY_POWER_OFF_STATE;
 337         return result;
 338 }
 339
 340 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 341 {
 342         struct acpi_memory_device *mem_device;
 343         struct acpi_device *device;
 344         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 345
 346         switch (event) {
 347         case ACPI_NOTIFY_BUS_CHECK:
 348                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                                   "\nReceived BUS CHECK notification for device\n"));
 350                 /* Fall Through */
 351         case ACPI_NOTIFY_DEVICE_CHECK:
 352                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 353                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 354                                           "\nReceived DEVICE CHECK notification for device\n"));
 355                 if (acpi_memory_get_device(handle, &mem_device)) {
 356                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 357                         break;
 358                 }
 359
 360                 if (acpi_memory_check_device(mem_device))
 361                         break;
 362
 363                 if (acpi_memory_enable_device(mem_device)) {
 364                         printk(KERN_ERR PREFIX "Cannot enable memory device\n");
 365                         break;
 366                 }
 367
 368                 ost_code = ACPI_OST_SC_SUCCESS;
 369                 break;
 370
 371         case ACPI_NOTIFY_EJECT_REQUEST:
 372                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 373                                   "\nReceived EJECT REQUEST notification for device\n"));
 374
 375                 if (acpi_bus_get_device(handle, &device)) {
 376                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 377                         break;
 378                 }
 379                 mem_device = acpi_driver_data(device);
 380                 if (!mem_device) {
 381                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 382                         break;
 383                 }
 384
 385                 /*
 386                  * Currently disabling memory device from kernel mode
 387                  * TBD: Can also be disabled from user mode scripts
 388                  * TBD: Can also be disabled by Callback registration
 389                  *      with generic sysfs driver
 390                  */
 391                 if (acpi_memory_disable_device(mem_device)) {
 392                         printk(KERN_ERR PREFIX "Disable memory device\n");
 393                         /*
 394                          * If _EJ0 was called but failed, _OST is not
 395                          * necessary.
 396                          */
 397                         if (mem_device->state == MEMORY_INVALID_STATE)
 398                                 return;
 399
 400                         break;
 401                 }
 402
 403                 /*
 404                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 405                  */
 406
 407                 /* _EJ0 succeeded; _OST is not necessary */
 408                 return;
 409
 410         default:
 411                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 412                                   "Unsupported event [0x%x]\n", event));
 413
 414                 /* non-hotplug event; possibly handled by other handler */
 415                 return;
 416         }
 417
 418         /* Inform firmware that the hotplug operation has completed */
 419         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
 420         return;
 421 }
 422
 423 static int acpi_memory_device_add(struct acpi_device *device)
 424 {
 425         int result;
 426         struct acpi_memory_device *mem_device = NULL;
 427
 428
 429         if (!device)
 430                 return -EINVAL;
 431
 432         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 433         if (!mem_device)
 434                 return -ENOMEM;
 435
 436         INIT_LIST_HEAD(&mem_device->res_list);
 437         mem_device->device = device;
 438         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 439         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 440         device->driver_data = mem_device;
 441
 442         /* Get the range from the _CRS */
 443         result = acpi_memory_get_device_resources(mem_device);
 444         if (result) {
 445                 kfree(mem_device);
 446                 return result;
 447         }
 448
 449         /* Set the device state */
 450         mem_device->state = MEMORY_POWER_ON_STATE;
 451
 452         printk(KERN_DEBUG "%s \n", acpi_device_name(device));
 453
 454         /*
 455          * Early boot code has recognized memory area by EFI/E820.
 456          * If DSDT shows these memory devices on boot, hotplug is not necessary
 457          * for them. So, it just returns until completion of this driver's
 458          * start up.
 459          */
 460         if (!acpi_hotmem_initialized)
 461                 return 0;
 462
 463         if (!acpi_memory_check_device(mem_device)) {
 464                 /* call add_memory func */
 465                 result = acpi_memory_enable_device(mem_device);
 466                 if (result)
 467                         printk(KERN_ERR PREFIX
 468                                 "Error in acpi_memory_enable_device\n");
 469         }
 470         return result;
 471 }
 472
 473 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 474 {
 475         struct acpi_memory_device *mem_device = NULL;
 476
 477
 478         if (!device || !acpi_driver_data(device))
 479                 return -EINVAL;
 480
 481         mem_device = acpi_driver_data(device);
 482         kfree(mem_device);
 483
 484         return 0;
 485 }
 486
 487 /*
 488  * Helper function to check for memory device
 489  */
 490 static acpi_status is_memory_device(acpi_handle handle)
 491 {
 492         char *hardware_id;
 493         acpi_status status;
 494         struct acpi_device_info *info;
 495
 496         status = acpi_get_object_info(handle, &info);
 497         if (ACPI_FAILURE(status))
 498                 return status;
 499
 500         if (!(info->valid & ACPI_VALID_HID)) {
 501                 kfree(info);
 502                 return AE_ERROR;
 503         }
 504
 505         hardware_id = info->hardware_id.string;
 506         if ((hardware_id == NULL) ||
 507             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 508                 status = AE_ERROR;
 509
 510         kfree(info);
 511         return status;
 512 }
 513
 514 static acpi_status
 515 acpi_memory_register_notify_handler(acpi_handle handle,
 516                                     u32 level, void *ctxt, void **retv)
 517 {
 518         acpi_status status;
 519
 520
 521         status = is_memory_device(handle);
 522         if (ACPI_FAILURE(status))
 523                 return AE_OK;   /* continue */
 524
 525         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 526                                              acpi_memory_device_notify, NULL);
 527         /* continue */
 528         return AE_OK;
 529 }
 530
 531 static acpi_status
 532 acpi_memory_deregister_notify_handler(acpi_handle handle,
 533                                       u32 level, void *ctxt, void **retv)
 534 {
 535         acpi_status status;
 536
 537
 538         status = is_memory_device(handle);
 539         if (ACPI_FAILURE(status))
 540                 return AE_OK;   /* continue */
 541
 542         status = acpi_remove_notify_handler(handle,
 543                                             ACPI_SYSTEM_NOTIFY,
 544                                             acpi_memory_device_notify);
 545
 546         return AE_OK;   /* continue */
 547 }
 548
 549 static int __init acpi_memory_device_init(void)
 550 {
 551         int result;
 552         acpi_status status;
 553
 554
 555         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 556
 557         if (result < 0)
 558                 return -ENODEV;
 559
 560         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 561                                      ACPI_UINT32_MAX,
 562                                      acpi_memory_register_notify_handler, NULL,
 563                                      NULL, NULL);
 564
 565         if (ACPI_FAILURE(status)) {
 566                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 567                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 568                 return -ENODEV;
 569         }
 570
 571         acpi_hotmem_initialized = 1;
 572         return 0;
 573 }
 574
 575 static void __exit acpi_memory_device_exit(void)
 576 {
 577         acpi_status status;
 578
 579
 580         /*
 581          * Adding this to un-install notification handlers for all the device
 582          * handles.
 583          */
 584         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 585                                      ACPI_UINT32_MAX,
 586                                      acpi_memory_deregister_notify_handler, NULL,
 587                                      NULL, NULL);
 588
 589         if (ACPI_FAILURE(status))
 590                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 591
 592         acpi_bus_unregister_driver(&acpi_memory_device_driver);
 593
 594         return;
 595 }
 596
 597 module_init(acpi_memory_device_init);
 598 module_exit(acpi_memory_device_exit);