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 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, ¤t_status))) 203 return -ENODEV; 204 /* 205 * Check for device status. Device should be 206 * present/enabled/functioning. 207 */ 208 if (!((current_status & ACPI_MEMORY_STA_PRESENT) 209 && (current_status & ACPI_MEMORY_STA_ENABLED) 210 && (current_status & ACPI_MEMORY_STA_FUNCTIONAL))) 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, ¤t_status); 286 if (ACPI_FAILURE(status)) 287 return -ENODEV; 288 289 /* Check for device status. Device should be disabled */ 290 if (current_status & ACPI_MEMORY_STA_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 = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL); 399 if (!mem_device) 400 return -ENOMEM; 401 memset(mem_device, 0, sizeof(struct acpi_memory_device)); 402 403 INIT_LIST_HEAD(&mem_device->res_list); 404 mem_device->device = device; 405 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); 406 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); 407 acpi_driver_data(device) = mem_device; 408 409 /* Get the range from the _CRS */ 410 result = acpi_memory_get_device_resources(mem_device); 411 if (result) { 412 kfree(mem_device); 413 return result; 414 } 415 416 /* Set the device state */ 417 mem_device->state = MEMORY_POWER_ON_STATE; 418 419 printk(KERN_DEBUG "%s \n", acpi_device_name(device)); 420 421 return result; 422 } 423 424 static int acpi_memory_device_remove(struct acpi_device *device, int type) 425 { 426 struct acpi_memory_device *mem_device = NULL; 427 428 429 if (!device || !acpi_driver_data(device)) 430 return -EINVAL; 431 432 mem_device = (struct acpi_memory_device *)acpi_driver_data(device); 433 kfree(mem_device); 434 435 return 0; 436 } 437 438 static int acpi_memory_device_start (struct acpi_device *device) 439 { 440 struct acpi_memory_device *mem_device; 441 int result = 0; 442 443 /* 444 * Early boot code has recognized memory area by EFI/E820. 445 * If DSDT shows these memory devices on boot, hotplug is not necessary 446 * for them. So, it just returns until completion of this driver's 447 * start up. 448 */ 449 if (!acpi_hotmem_initialized) 450 return 0; 451 452 mem_device = acpi_driver_data(device); 453 454 if (!acpi_memory_check_device(mem_device)) { 455 /* call add_memory func */ 456 result = acpi_memory_enable_device(mem_device); 457 if (result) 458 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 459 "Error in acpi_memory_enable_device\n")); 460 } 461 return result; 462 } 463 464 /* 465 * Helper function to check for memory device 466 */ 467 static acpi_status is_memory_device(acpi_handle handle) 468 { 469 char *hardware_id; 470 acpi_status status; 471 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 472 struct acpi_device_info *info; 473 474 475 status = acpi_get_object_info(handle, &buffer); 476 if (ACPI_FAILURE(status)) 477 return status; 478 479 info = buffer.pointer; 480 if (!(info->valid & ACPI_VALID_HID)) { 481 kfree(buffer.pointer); 482 return AE_ERROR; 483 } 484 485 hardware_id = info->hardware_id.value; 486 if ((hardware_id == NULL) || 487 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID))) 488 status = AE_ERROR; 489 490 kfree(buffer.pointer); 491 return status; 492 } 493 494 static acpi_status 495 acpi_memory_register_notify_handler(acpi_handle handle, 496 u32 level, void *ctxt, void **retv) 497 { 498 acpi_status status; 499 500 501 status = is_memory_device(handle); 502 if (ACPI_FAILURE(status)) 503 return AE_OK; /* continue */ 504 505 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY, 506 acpi_memory_device_notify, NULL); 507 /* continue */ 508 return AE_OK; 509 } 510 511 static acpi_status 512 acpi_memory_deregister_notify_handler(acpi_handle handle, 513 u32 level, void *ctxt, void **retv) 514 { 515 acpi_status status; 516 517 518 status = is_memory_device(handle); 519 if (ACPI_FAILURE(status)) 520 return AE_OK; /* continue */ 521 522 status = acpi_remove_notify_handler(handle, 523 ACPI_SYSTEM_NOTIFY, 524 acpi_memory_device_notify); 525 526 return AE_OK; /* continue */ 527 } 528 529 static int __init acpi_memory_device_init(void) 530 { 531 int result; 532 acpi_status status; 533 534 535 result = acpi_bus_register_driver(&acpi_memory_device_driver); 536 537 if (result < 0) 538 return -ENODEV; 539 540 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 541 ACPI_UINT32_MAX, 542 acpi_memory_register_notify_handler, 543 NULL, NULL); 544 545 if (ACPI_FAILURE(status)) { 546 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed")); 547 acpi_bus_unregister_driver(&acpi_memory_device_driver); 548 return -ENODEV; 549 } 550 551 acpi_hotmem_initialized = 1; 552 return 0; 553 } 554 555 static void __exit acpi_memory_device_exit(void) 556 { 557 acpi_status status; 558 559 560 /* 561 * Adding this to un-install notification handlers for all the device 562 * handles. 563 */ 564 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 565 ACPI_UINT32_MAX, 566 acpi_memory_deregister_notify_handler, 567 NULL, NULL); 568 569 if (ACPI_FAILURE(status)) 570 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed")); 571 572 acpi_bus_unregister_driver(&acpi_memory_device_driver); 573 574 return; 575 } 576 577 module_init(acpi_memory_device_init); 578 module_exit(acpi_memory_device_exit); 579