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