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