SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 static int acpi_memory_device_start(struct acpi_device *device);
  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                 .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         acpi_handle handle;
  84         struct acpi_device * device;
  85         unsigned int state;     /* State of the memory device */
  86         struct list_head res_list;
  87 };
  88
  89 static acpi_status
  90 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  91 {
  92         struct acpi_memory_device *mem_device = context;
  93         struct acpi_resource_address64 address64;
  94         struct acpi_memory_info *info, *new;
  95         acpi_status status;
  96
  97         status = acpi_resource_to_address64(resource, &address64);
  98         if (ACPI_FAILURE(status) ||
  99             (address64.resource_type != ACPI_MEMORY_RANGE))
 100                 return AE_OK;
 101
 102         list_for_each_entry(info, &mem_device->res_list, list) {
 103                 /* Can we combine the resource range information? */
 104                 if ((info->caching == address64.info.mem.caching) &&
 105                     (info->write_protect == address64.info.mem.write_protect) &&
 106                     (info->start_addr + info->length == address64.minimum)) {
 107                         info->length += address64.address_length;
 108                         return AE_OK;
 109                 }
 110         }
 111
 112         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 113         if (!new)
 114                 return AE_ERROR;
 115
 116         INIT_LIST_HEAD(&new->list);
 117         new->caching = address64.info.mem.caching;
 118         new->write_protect = address64.info.mem.write_protect;
 119         new->start_addr = address64.minimum;
 120         new->length = address64.address_length;
 121         list_add_tail(&new->list, &mem_device->res_list);
 122
 123         return AE_OK;
 124 }
 125
 126 static int
 127 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 128 {
 129         acpi_status status;
 130         struct acpi_memory_info *info, *n;
 131
 132
 133         status = acpi_walk_resources(mem_device->handle, METHOD_NAME__CRS,
 134                                      acpi_memory_get_resource, mem_device);
 135         if (ACPI_FAILURE(status)) {
 136                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 137                         kfree(info);
 138                 return -EINVAL;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int
 145 acpi_memory_get_device(acpi_handle handle,
 146                        struct acpi_memory_device **mem_device)
 147 {
 148         acpi_status status;
 149         acpi_handle phandle;
 150         struct acpi_device *device = NULL;
 151         struct acpi_device *pdevice = NULL;
 152
 153
 154         if (!acpi_bus_get_device(handle, &device) && device)
 155                 goto end;
 156
 157         status = acpi_get_parent(handle, &phandle);
 158         if (ACPI_FAILURE(status)) {
 159                 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
 160                 return -EINVAL;
 161         }
 162
 163         /* Get the parent device */
 164         status = acpi_bus_get_device(phandle, &pdevice);
 165         if (ACPI_FAILURE(status)) {
 166                 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
 167                 return -EINVAL;
 168         }
 169
 170         /*
 171          * Now add the notified device.  This creates the acpi_device
 172          * and invokes .add function
 173          */
 174         status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 175         if (ACPI_FAILURE(status)) {
 176                 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
 177                 return -EINVAL;
 178         }
 179
 180       end:
 181         *mem_device = acpi_driver_data(device);
 182         if (!(*mem_device)) {
 183                 printk(KERN_ERR "\n driver data not found");
 184                 return -ENODEV;
 185         }
 186
 187         return 0;
 188 }
 189
 190 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 191 {
 192         unsigned long current_status;
 193
 194
 195         /* Get device present/absent information from the _STA */
 196         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
 197                                                NULL, &current_status)))
 198                 return -ENODEV;
 199         /*
 200          * Check for device status. Device should be
 201          * present/enabled/functioning.
 202          */
 203         if (!((current_status & ACPI_MEMORY_STA_PRESENT)
 204               && (current_status & ACPI_MEMORY_STA_ENABLED)
 205               && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
 206                 return -ENODEV;
 207
 208         return 0;
 209 }
 210
 211 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 212 {
 213         int result, num_enabled = 0;
 214         struct acpi_memory_info *info;
 215         int node;
 216
 217
 218         /* Get the range from the _CRS */
 219         result = acpi_memory_get_device_resources(mem_device);
 220         if (result) {
 221                 printk(KERN_ERR PREFIX "get_device_resources failed\n");
 222                 mem_device->state = MEMORY_INVALID_STATE;
 223                 return result;
 224         }
 225
 226         node = acpi_get_node(mem_device->handle);
 227         /*
 228          * Tell the VM there is more memory here...
 229          * Note: Assume that this function returns zero on success
 230          * We don't have memory-hot-add rollback function,now.
 231          * (i.e. memory-hot-remove function)
 232          */
 233         list_for_each_entry(info, &mem_device->res_list, list) {
 234                 u64 start_pfn, end_pfn;
 235
 236                 start_pfn = info->start_addr >> PAGE_SHIFT;
 237                 end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
 238
 239                 if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
 240                         /* already enabled. try next area */
 241                         num_enabled++;
 242                         continue;
 243                 }
 244
 245                 result = add_memory(node, info->start_addr, info->length);
 246                 if (result)
 247                         continue;
 248                 info->enabled = 1;
 249                 num_enabled++;
 250         }
 251         if (!num_enabled) {
 252                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 253                 mem_device->state = MEMORY_INVALID_STATE;
 254                 return -EINVAL;
 255         }
 256
 257         return result;
 258 }
 259
 260 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 261 {
 262         acpi_status status;
 263         struct acpi_object_list arg_list;
 264         union acpi_object arg;
 265         unsigned long current_status;
 266
 267
 268         /* Issue the _EJ0 command */
 269         arg_list.count = 1;
 270         arg_list.pointer = &arg;
 271         arg.type = ACPI_TYPE_INTEGER;
 272         arg.integer.value = 1;
 273         status = acpi_evaluate_object(mem_device->handle,
 274                                       "_EJ0", &arg_list, NULL);
 275         /* Return on _EJ0 failure */
 276         if (ACPI_FAILURE(status)) {
 277                 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
 278                 return -ENODEV;
 279         }
 280
 281         /* Evalute _STA to check if the device is disabled */
 282         status = acpi_evaluate_integer(mem_device->handle, "_STA",
 283                                        NULL, &current_status);
 284         if (ACPI_FAILURE(status))
 285                 return -ENODEV;
 286
 287         /* Check for device status.  Device should be disabled */
 288         if (current_status & ACPI_MEMORY_STA_ENABLED)
 289                 return -EINVAL;
 290
 291         return 0;
 292 }
 293
 294 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 295 {
 296         int result;
 297         struct acpi_memory_info *info, *n;
 298
 299
 300         /*
 301          * Ask the VM to offline this memory range.
 302          * Note: Assume that this function returns zero on success
 303          */
 304         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 305                 if (info->enabled) {
 306                         result = remove_memory(info->start_addr, info->length);
 307                         if (result)
 308                                 return result;
 309                 }
 310                 kfree(info);
 311         }
 312
 313         /* Power-off and eject the device */
 314         result = acpi_memory_powerdown_device(mem_device);
 315         if (result) {
 316                 /* Set the status of the device to invalid */
 317                 mem_device->state = MEMORY_INVALID_STATE;
 318                 return result;
 319         }
 320
 321         mem_device->state = MEMORY_POWER_OFF_STATE;
 322         return result;
 323 }
 324
 325 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 326 {
 327         struct acpi_memory_device *mem_device;
 328         struct acpi_device *device;
 329
 330
 331         switch (event) {
 332         case ACPI_NOTIFY_BUS_CHECK:
 333                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 334                                   "\nReceived BUS CHECK notification for device\n"));
 335                 /* Fall Through */
 336         case ACPI_NOTIFY_DEVICE_CHECK:
 337                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 338                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 339                                           "\nReceived DEVICE CHECK notification for device\n"));
 340                 if (acpi_memory_get_device(handle, &mem_device)) {
 341                         printk(KERN_ERR PREFIX "Cannot find driver data\n");
 342                         return;
 343                 }
 344
 345                 if (!acpi_memory_check_device(mem_device)) {
 346                         if (acpi_memory_enable_device(mem_device))
 347                                 printk(KERN_ERR PREFIX
 348                                             "Cannot enable memory device\n");
 349                 }
 350                 break;
 351         case ACPI_NOTIFY_EJECT_REQUEST:
 352                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 353                                   "\nReceived EJECT REQUEST notification for device\n"));
 354
 355                 if (acpi_bus_get_device(handle, &device)) {
 356                         printk(KERN_ERR PREFIX "Device doesn't exist\n");
 357                         break;
 358                 }
 359                 mem_device = acpi_driver_data(device);
 360                 if (!mem_device) {
 361                         printk(KERN_ERR PREFIX "Driver Data is NULL\n");
 362                         break;
 363                 }
 364
 365                 /*
 366                  * Currently disabling memory device from kernel mode
 367                  * TBD: Can also be disabled from user mode scripts
 368                  * TBD: Can also be disabled by Callback registration
 369                  *      with generic sysfs driver
 370                  */
 371                 if (acpi_memory_disable_device(mem_device))
 372                         printk(KERN_ERR PREFIX
 373                                     "Disable memory device\n");
 374                 /*
 375                  * TBD: Invoke acpi_bus_remove to cleanup data structures
 376                  */
 377                 break;
 378         default:
 379                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 380                                   "Unsupported event [0x%x]\n", event));
 381                 break;
 382         }
 383
 384         return;
 385 }
 386
 387 static int acpi_memory_device_add(struct acpi_device *device)
 388 {
 389         int result;
 390         struct acpi_memory_device *mem_device = NULL;
 391
 392
 393         if (!device)
 394                 return -EINVAL;
 395
 396         mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 397         if (!mem_device)
 398                 return -ENOMEM;
 399         memset(mem_device, 0, sizeof(struct acpi_memory_device));
 400
 401         INIT_LIST_HEAD(&mem_device->res_list);
 402         mem_device->handle = device->handle;
 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_INFO "%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 = (struct acpi_memory_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         mem_device = acpi_driver_data(device);
 443
 444         if (!acpi_memory_check_device(mem_device)) {
 445                 /* call add_memory func */
 446                 result = acpi_memory_enable_device(mem_device);
 447                 if (result)
 448                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 449                                 "Error in acpi_memory_enable_device\n"));
 450         }
 451         return result;
 452 }
 453
 454 /*
 455  * Helper function to check for memory device
 456  */
 457 static acpi_status is_memory_device(acpi_handle handle)
 458 {
 459         char *hardware_id;
 460         acpi_status status;
 461         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 462         struct acpi_device_info *info;
 463
 464
 465         status = acpi_get_object_info(handle, &buffer);
 466         if (ACPI_FAILURE(status))
 467                 return status;
 468
 469         info = buffer.pointer;
 470         if (!(info->valid & ACPI_VALID_HID)) {
 471                 acpi_os_free(buffer.pointer);
 472                 return AE_ERROR;
 473         }
 474
 475         hardware_id = info->hardware_id.value;
 476         if ((hardware_id == NULL) ||
 477             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 478                 status = AE_ERROR;
 479
 480         acpi_os_free(buffer.pointer);
 481         return status;
 482 }
 483
 484 static acpi_status
 485 acpi_memory_register_notify_handler(acpi_handle handle,
 486                                     u32 level, void *ctxt, void **retv)
 487 {
 488         acpi_status status;
 489
 490
 491         status = is_memory_device(handle);
 492         if (ACPI_FAILURE(status)){
 493                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
 494                 return AE_OK;   /* continue */
 495         }
 496
 497         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 498                                              acpi_memory_device_notify, NULL);
 499         /* continue */
 500         return AE_OK;
 501 }
 502
 503 static acpi_status
 504 acpi_memory_deregister_notify_handler(acpi_handle handle,
 505                                       u32 level, void *ctxt, void **retv)
 506 {
 507         acpi_status status;
 508
 509
 510         status = is_memory_device(handle);
 511         if (ACPI_FAILURE(status)){
 512                 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
 513                 return AE_OK;   /* continue */
 514         }
 515
 516         status = acpi_remove_notify_handler(handle,
 517                                             ACPI_SYSTEM_NOTIFY,
 518                                             acpi_memory_device_notify);
 519
 520         return AE_OK;   /* continue */
 521 }
 522
 523 static int __init acpi_memory_device_init(void)
 524 {
 525         int result;
 526         acpi_status status;
 527
 528
 529         result = acpi_bus_register_driver(&acpi_memory_device_driver);
 530
 531         if (result < 0)
 532                 return -ENODEV;
 533
 534         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 535                                      ACPI_UINT32_MAX,
 536                                      acpi_memory_register_notify_handler,
 537                                      NULL, NULL);
 538
 539         if (ACPI_FAILURE(status)) {
 540                 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
 541                 acpi_bus_unregister_driver(&acpi_memory_device_driver);
 542                 return -ENODEV;
 543         }
 544
 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);