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