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 cache_attribute; /* memory cache attribute */ 75 unsigned short read_write_attribute; /* 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->cache_attribute = 101 address64.attribute.memory.cache_attribute; 102 mem_device->read_write_attribute = 103 address64.attribute.memory.read_write_attribute; 104 mem_device->start_addr = address64.min_address_range; 105 mem_device->end_addr = address64.max_address_range; 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 mem_device->read_write_attribute); 205 if (result) { 206 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n")); 207 mem_device->state = MEMORY_INVALID_STATE; 208 return result; 209 } 210 211 return result; 212 } 213 214 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device) 215 { 216 acpi_status status; 217 struct acpi_object_list arg_list; 218 union acpi_object arg; 219 unsigned long current_status; 220 221 ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device"); 222 223 /* Issue the _EJ0 command */ 224 arg_list.count = 1; 225 arg_list.pointer = &arg; 226 arg.type = ACPI_TYPE_INTEGER; 227 arg.integer.value = 1; 228 status = acpi_evaluate_object(mem_device->handle, 229 "_EJ0", &arg_list, NULL); 230 /* Return on _EJ0 failure */ 231 if (ACPI_FAILURE(status)) { 232 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n")); 233 return_VALUE(-ENODEV); 234 } 235 236 /* Evalute _STA to check if the device is disabled */ 237 status = acpi_evaluate_integer(mem_device->handle, "_STA", 238 NULL, ¤t_status); 239 if (ACPI_FAILURE(status)) 240 return_VALUE(-ENODEV); 241 242 /* Check for device status. Device should be disabled */ 243 if (current_status & ACPI_MEMORY_STA_ENABLED) 244 return_VALUE(-EINVAL); 245 246 return_VALUE(0); 247 } 248 249 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) 250 { 251 int result; 252 u64 start = mem_device->start_addr; 253 u64 len = mem_device->end_addr - start + 1; 254 unsigned long attr = mem_device->read_write_attribute; 255 256 ACPI_FUNCTION_TRACE("acpi_memory_disable_device"); 257 258 /* 259 * Ask the VM to offline this memory range. 260 * Note: Assume that this function returns zero on success 261 */ 262 result = remove_memory(start, len, attr); 263 if (result) { 264 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n")); 265 return_VALUE(result); 266 } 267 268 /* Power-off and eject the device */ 269 result = acpi_memory_powerdown_device(mem_device); 270 if (result) { 271 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 272 "Device Power Down failed.\n")); 273 /* Set the status of the device to invalid */ 274 mem_device->state = MEMORY_INVALID_STATE; 275 return result; 276 } 277 278 mem_device->state = MEMORY_POWER_OFF_STATE; 279 return result; 280 } 281 282 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) 283 { 284 struct acpi_memory_device *mem_device; 285 struct acpi_device *device; 286 287 ACPI_FUNCTION_TRACE("acpi_memory_device_notify"); 288 289 switch (event) { 290 case ACPI_NOTIFY_BUS_CHECK: 291 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 292 "\nReceived BUS CHECK notification for device\n")); 293 /* Fall Through */ 294 case ACPI_NOTIFY_DEVICE_CHECK: 295 if (event == ACPI_NOTIFY_DEVICE_CHECK) 296 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 297 "\nReceived DEVICE CHECK notification for device\n")); 298 if (acpi_memory_get_device(handle, &mem_device)) { 299 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 300 "Error in finding driver data\n")); 301 return_VOID; 302 } 303 304 if (!acpi_memory_check_device(mem_device)) { 305 if (acpi_memory_enable_device(mem_device)) 306 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 307 "Error in acpi_memory_enable_device\n")); 308 } 309 break; 310 case ACPI_NOTIFY_EJECT_REQUEST: 311 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 312 "\nReceived EJECT REQUEST notification for device\n")); 313 314 if (acpi_bus_get_device(handle, &device)) { 315 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 316 "Device doesn't exist\n")); 317 break; 318 } 319 mem_device = acpi_driver_data(device); 320 if (!mem_device) { 321 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 322 "Driver Data is NULL\n")); 323 break; 324 } 325 326 /* 327 * Currently disabling memory device from kernel mode 328 * TBD: Can also be disabled from user mode scripts 329 * TBD: Can also be disabled by Callback registration 330 * with generic sysfs driver 331 */ 332 if (acpi_memory_disable_device(mem_device)) 333 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 334 "Error in acpi_memory_disable_device\n")); 335 /* 336 * TBD: Invoke acpi_bus_remove to cleanup data structures 337 */ 338 break; 339 default: 340 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 341 "Unsupported event [0x%x]\n", event)); 342 break; 343 } 344 345 return_VOID; 346 } 347 348 static int acpi_memory_device_add(struct acpi_device *device) 349 { 350 int result; 351 struct acpi_memory_device *mem_device = NULL; 352 353 ACPI_FUNCTION_TRACE("acpi_memory_device_add"); 354 355 if (!device) 356 return_VALUE(-EINVAL); 357 358 mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL); 359 if (!mem_device) 360 return_VALUE(-ENOMEM); 361 memset(mem_device, 0, sizeof(struct acpi_memory_device)); 362 363 mem_device->handle = device->handle; 364 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); 365 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); 366 acpi_driver_data(device) = mem_device; 367 368 /* Get the range from the _CRS */ 369 result = acpi_memory_get_device_resources(mem_device); 370 if (result) { 371 kfree(mem_device); 372 return_VALUE(result); 373 } 374 375 /* Set the device state */ 376 mem_device->state = MEMORY_POWER_ON_STATE; 377 378 printk(KERN_INFO "%s \n", acpi_device_name(device)); 379 380 return_VALUE(result); 381 } 382 383 static int acpi_memory_device_remove(struct acpi_device *device, int type) 384 { 385 struct acpi_memory_device *mem_device = NULL; 386 387 ACPI_FUNCTION_TRACE("acpi_memory_device_remove"); 388 389 if (!device || !acpi_driver_data(device)) 390 return_VALUE(-EINVAL); 391 392 mem_device = (struct acpi_memory_device *)acpi_driver_data(device); 393 kfree(mem_device); 394 395 return_VALUE(0); 396 } 397 398 /* 399 * Helper function to check for memory device 400 */ 401 static acpi_status is_memory_device(acpi_handle handle) 402 { 403 char *hardware_id; 404 acpi_status status; 405 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 406 struct acpi_device_info *info; 407 408 ACPI_FUNCTION_TRACE("is_memory_device"); 409 410 status = acpi_get_object_info(handle, &buffer); 411 if (ACPI_FAILURE(status)) 412 return_ACPI_STATUS(AE_ERROR); 413 414 info = buffer.pointer; 415 if (!(info->valid & ACPI_VALID_HID)) { 416 acpi_os_free(buffer.pointer); 417 return_ACPI_STATUS(AE_ERROR); 418 } 419 420 hardware_id = info->hardware_id.value; 421 if ((hardware_id == NULL) || 422 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID))) 423 status = AE_ERROR; 424 425 acpi_os_free(buffer.pointer); 426 return_ACPI_STATUS(status); 427 } 428 429 static acpi_status 430 acpi_memory_register_notify_handler(acpi_handle handle, 431 u32 level, void *ctxt, void **retv) 432 { 433 acpi_status status; 434 435 ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler"); 436 437 status = is_memory_device(handle); 438 if (ACPI_FAILURE(status)) 439 return_ACPI_STATUS(AE_OK); /* continue */ 440 441 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY, 442 acpi_memory_device_notify, NULL); 443 if (ACPI_FAILURE(status)) { 444 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 445 "Error installing notify handler\n")); 446 return_ACPI_STATUS(AE_OK); /* continue */ 447 } 448 449 return_ACPI_STATUS(status); 450 } 451 452 static acpi_status 453 acpi_memory_deregister_notify_handler(acpi_handle handle, 454 u32 level, void *ctxt, void **retv) 455 { 456 acpi_status status; 457 458 ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler"); 459 460 status = is_memory_device(handle); 461 if (ACPI_FAILURE(status)) 462 return_ACPI_STATUS(AE_OK); /* continue */ 463 464 status = acpi_remove_notify_handler(handle, 465 ACPI_SYSTEM_NOTIFY, 466 acpi_memory_device_notify); 467 if (ACPI_FAILURE(status)) { 468 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 469 "Error removing notify handler\n")); 470 return_ACPI_STATUS(AE_OK); /* continue */ 471 } 472 473 return_ACPI_STATUS(status); 474 } 475 476 static int __init acpi_memory_device_init(void) 477 { 478 int result; 479 acpi_status status; 480 481 ACPI_FUNCTION_TRACE("acpi_memory_device_init"); 482 483 result = acpi_bus_register_driver(&acpi_memory_device_driver); 484 485 if (result < 0) 486 return_VALUE(-ENODEV); 487 488 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 489 ACPI_UINT32_MAX, 490 acpi_memory_register_notify_handler, 491 NULL, NULL); 492 493 if (ACPI_FAILURE(status)) { 494 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n")); 495 acpi_bus_unregister_driver(&acpi_memory_device_driver); 496 return_VALUE(-ENODEV); 497 } 498 499 return_VALUE(0); 500 } 501 502 static void __exit acpi_memory_device_exit(void) 503 { 504 acpi_status status; 505 506 ACPI_FUNCTION_TRACE("acpi_memory_device_exit"); 507 508 /* 509 * Adding this to un-install notification handlers for all the device 510 * handles. 511 */ 512 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 513 ACPI_UINT32_MAX, 514 acpi_memory_deregister_notify_handler, 515 NULL, NULL); 516 517 if (ACPI_FAILURE(status)) 518 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n")); 519 520 acpi_bus_unregister_driver(&acpi_memory_device_driver); 521 522 return_VOID; 523 } 524 525 module_init(acpi_memory_device_init); 526 module_exit(acpi_memory_device_exit); 527