Liu Jinsong | ef92e7c | 2013-01-24 20:19:47 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2012 Intel Corporation |
| 3 | * Author: Liu Jinsong <jinsong.liu@intel.com> |
| 4 | * Author: Jiang Yunhong <yunhong.jiang@intel.com> |
| 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 | |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/types.h> |
| 22 | #include <linux/acpi.h> |
| 23 | #include <acpi/acpi_drivers.h> |
| 24 | #include <xen/acpi.h> |
| 25 | #include <xen/interface/platform.h> |
| 26 | #include <asm/xen/hypercall.h> |
| 27 | |
| 28 | #define PREFIX "ACPI:xen_memory_hotplug:" |
| 29 | |
| 30 | struct acpi_memory_info { |
| 31 | struct list_head list; |
| 32 | u64 start_addr; /* Memory Range start physical addr */ |
| 33 | u64 length; /* Memory Range length */ |
| 34 | unsigned short caching; /* memory cache attribute */ |
| 35 | unsigned short write_protect; /* memory read/write attribute */ |
| 36 | /* copied from buffer getting from _CRS */ |
| 37 | unsigned int enabled:1; |
| 38 | }; |
| 39 | |
| 40 | struct acpi_memory_device { |
| 41 | struct acpi_device *device; |
| 42 | struct list_head res_list; |
| 43 | }; |
| 44 | |
| 45 | static bool acpi_hotmem_initialized __read_mostly; |
| 46 | |
| 47 | static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info) |
| 48 | { |
| 49 | int rc; |
| 50 | struct xen_platform_op op; |
| 51 | |
| 52 | op.cmd = XENPF_mem_hotadd; |
| 53 | op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT; |
| 54 | op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT; |
| 55 | op.u.mem_add.pxm = pxm; |
| 56 | |
| 57 | rc = HYPERVISOR_dom0_op(&op); |
| 58 | if (rc) |
| 59 | pr_err(PREFIX "Xen Hotplug Memory Add failed on " |
| 60 | "0x%lx -> 0x%lx, _PXM: %d, error: %d\n", |
| 61 | (unsigned long)info->start_addr, |
| 62 | (unsigned long)(info->start_addr + info->length), |
| 63 | pxm, rc); |
| 64 | |
| 65 | return rc; |
| 66 | } |
| 67 | |
| 68 | static int xen_acpi_get_pxm(acpi_handle h) |
| 69 | { |
| 70 | unsigned long long pxm; |
| 71 | acpi_status status; |
| 72 | acpi_handle handle; |
| 73 | acpi_handle phandle = h; |
| 74 | |
| 75 | do { |
| 76 | handle = phandle; |
| 77 | status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm); |
| 78 | if (ACPI_SUCCESS(status)) |
| 79 | return pxm; |
| 80 | status = acpi_get_parent(handle, &phandle); |
| 81 | } while (ACPI_SUCCESS(status)); |
| 82 | |
| 83 | return -ENXIO; |
| 84 | } |
| 85 | |
| 86 | static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device) |
| 87 | { |
| 88 | int pxm, result; |
| 89 | int num_enabled = 0; |
| 90 | struct acpi_memory_info *info; |
| 91 | |
| 92 | if (!mem_device) |
| 93 | return -EINVAL; |
| 94 | |
| 95 | pxm = xen_acpi_get_pxm(mem_device->device->handle); |
| 96 | if (pxm < 0) |
| 97 | return pxm; |
| 98 | |
| 99 | list_for_each_entry(info, &mem_device->res_list, list) { |
| 100 | if (info->enabled) { /* just sanity check...*/ |
| 101 | num_enabled++; |
| 102 | continue; |
| 103 | } |
| 104 | |
| 105 | if (!info->length) |
| 106 | continue; |
| 107 | |
| 108 | result = xen_hotadd_memory(pxm, info); |
| 109 | if (result) |
| 110 | continue; |
| 111 | info->enabled = 1; |
| 112 | num_enabled++; |
| 113 | } |
| 114 | |
| 115 | if (!num_enabled) |
| 116 | return -ENODEV; |
| 117 | |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | static acpi_status |
| 122 | acpi_memory_get_resource(struct acpi_resource *resource, void *context) |
| 123 | { |
| 124 | struct acpi_memory_device *mem_device = context; |
| 125 | struct acpi_resource_address64 address64; |
| 126 | struct acpi_memory_info *info, *new; |
| 127 | acpi_status status; |
| 128 | |
| 129 | status = acpi_resource_to_address64(resource, &address64); |
| 130 | if (ACPI_FAILURE(status) || |
| 131 | (address64.resource_type != ACPI_MEMORY_RANGE)) |
| 132 | return AE_OK; |
| 133 | |
| 134 | list_for_each_entry(info, &mem_device->res_list, list) { |
| 135 | if ((info->caching == address64.info.mem.caching) && |
| 136 | (info->write_protect == address64.info.mem.write_protect) && |
| 137 | (info->start_addr + info->length == address64.minimum)) { |
| 138 | info->length += address64.address_length; |
| 139 | return AE_OK; |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL); |
| 144 | if (!new) |
| 145 | return AE_ERROR; |
| 146 | |
| 147 | INIT_LIST_HEAD(&new->list); |
| 148 | new->caching = address64.info.mem.caching; |
| 149 | new->write_protect = address64.info.mem.write_protect; |
| 150 | new->start_addr = address64.minimum; |
| 151 | new->length = address64.address_length; |
| 152 | list_add_tail(&new->list, &mem_device->res_list); |
| 153 | |
| 154 | return AE_OK; |
| 155 | } |
| 156 | |
| 157 | static int |
| 158 | acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) |
| 159 | { |
| 160 | acpi_status status; |
| 161 | struct acpi_memory_info *info, *n; |
| 162 | |
| 163 | if (!list_empty(&mem_device->res_list)) |
| 164 | return 0; |
| 165 | |
| 166 | status = acpi_walk_resources(mem_device->device->handle, |
| 167 | METHOD_NAME__CRS, acpi_memory_get_resource, mem_device); |
| 168 | |
| 169 | if (ACPI_FAILURE(status)) { |
| 170 | list_for_each_entry_safe(info, n, &mem_device->res_list, list) |
| 171 | kfree(info); |
| 172 | INIT_LIST_HEAD(&mem_device->res_list); |
| 173 | return -EINVAL; |
| 174 | } |
| 175 | |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | static int |
| 180 | acpi_memory_get_device(acpi_handle handle, |
| 181 | struct acpi_memory_device **mem_device) |
| 182 | { |
| 183 | acpi_status status; |
| 184 | acpi_handle phandle; |
| 185 | struct acpi_device *device = NULL; |
| 186 | struct acpi_device *pdevice = NULL; |
| 187 | int result; |
| 188 | |
| 189 | if (!acpi_bus_get_device(handle, &device) && device) |
| 190 | goto end; |
| 191 | |
| 192 | status = acpi_get_parent(handle, &phandle); |
| 193 | if (ACPI_FAILURE(status)) { |
| 194 | pr_warn(PREFIX "Cannot find acpi parent\n"); |
| 195 | return -EINVAL; |
| 196 | } |
| 197 | |
| 198 | /* Get the parent device */ |
| 199 | result = acpi_bus_get_device(phandle, &pdevice); |
| 200 | if (result) { |
| 201 | pr_warn(PREFIX "Cannot get acpi bus device\n"); |
| 202 | return -EINVAL; |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Now add the notified device. This creates the acpi_device |
| 207 | * and invokes .add function |
| 208 | */ |
| 209 | result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE); |
| 210 | if (result) { |
| 211 | pr_warn(PREFIX "Cannot add acpi bus\n"); |
| 212 | return -EINVAL; |
| 213 | } |
| 214 | |
| 215 | end: |
| 216 | *mem_device = acpi_driver_data(device); |
| 217 | if (!(*mem_device)) { |
| 218 | pr_err(PREFIX "Driver data not found\n"); |
| 219 | return -ENODEV; |
| 220 | } |
| 221 | |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | static int acpi_memory_check_device(struct acpi_memory_device *mem_device) |
| 226 | { |
| 227 | unsigned long long current_status; |
| 228 | |
| 229 | /* Get device present/absent information from the _STA */ |
| 230 | if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, |
| 231 | "_STA", NULL, ¤t_status))) |
| 232 | return -ENODEV; |
| 233 | /* |
| 234 | * Check for device status. Device should be |
| 235 | * present/enabled/functioning. |
| 236 | */ |
| 237 | if (!((current_status & ACPI_STA_DEVICE_PRESENT) |
| 238 | && (current_status & ACPI_STA_DEVICE_ENABLED) |
| 239 | && (current_status & ACPI_STA_DEVICE_FUNCTIONING))) |
| 240 | return -ENODEV; |
| 241 | |
| 242 | return 0; |
| 243 | } |
| 244 | |
| 245 | static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) |
| 246 | { |
| 247 | pr_debug(PREFIX "Xen does not support memory hotremove\n"); |
| 248 | |
| 249 | return -ENOSYS; |
| 250 | } |
| 251 | |
| 252 | static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) |
| 253 | { |
| 254 | struct acpi_memory_device *mem_device; |
| 255 | struct acpi_device *device; |
| 256 | u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ |
| 257 | |
| 258 | switch (event) { |
| 259 | case ACPI_NOTIFY_BUS_CHECK: |
| 260 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
| 261 | "\nReceived BUS CHECK notification for device\n")); |
| 262 | /* Fall Through */ |
| 263 | case ACPI_NOTIFY_DEVICE_CHECK: |
| 264 | if (event == ACPI_NOTIFY_DEVICE_CHECK) |
| 265 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
| 266 | "\nReceived DEVICE CHECK notification for device\n")); |
| 267 | |
| 268 | if (acpi_memory_get_device(handle, &mem_device)) { |
| 269 | pr_err(PREFIX "Cannot find driver data\n"); |
| 270 | break; |
| 271 | } |
| 272 | |
| 273 | ost_code = ACPI_OST_SC_SUCCESS; |
| 274 | break; |
| 275 | |
| 276 | case ACPI_NOTIFY_EJECT_REQUEST: |
| 277 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
| 278 | "\nReceived EJECT REQUEST notification for device\n")); |
| 279 | |
| 280 | if (acpi_bus_get_device(handle, &device)) { |
| 281 | pr_err(PREFIX "Device doesn't exist\n"); |
| 282 | break; |
| 283 | } |
| 284 | mem_device = acpi_driver_data(device); |
| 285 | if (!mem_device) { |
| 286 | pr_err(PREFIX "Driver Data is NULL\n"); |
| 287 | break; |
| 288 | } |
| 289 | |
| 290 | /* |
| 291 | * TBD: implement acpi_memory_disable_device and invoke |
| 292 | * acpi_bus_remove if Xen support hotremove in the future |
| 293 | */ |
| 294 | acpi_memory_disable_device(mem_device); |
| 295 | break; |
| 296 | |
| 297 | default: |
| 298 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
| 299 | "Unsupported event [0x%x]\n", event)); |
| 300 | /* non-hotplug event; possibly handled by other handler */ |
| 301 | return; |
| 302 | } |
| 303 | |
| 304 | (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL); |
| 305 | return; |
| 306 | } |
| 307 | |
| 308 | static int xen_acpi_memory_device_add(struct acpi_device *device) |
| 309 | { |
| 310 | int result; |
| 311 | struct acpi_memory_device *mem_device = NULL; |
| 312 | |
| 313 | |
| 314 | if (!device) |
| 315 | return -EINVAL; |
| 316 | |
| 317 | mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL); |
| 318 | if (!mem_device) |
| 319 | return -ENOMEM; |
| 320 | |
| 321 | INIT_LIST_HEAD(&mem_device->res_list); |
| 322 | mem_device->device = device; |
| 323 | sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); |
| 324 | sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); |
| 325 | device->driver_data = mem_device; |
| 326 | |
| 327 | /* Get the range from the _CRS */ |
| 328 | result = acpi_memory_get_device_resources(mem_device); |
| 329 | if (result) { |
| 330 | kfree(mem_device); |
| 331 | return result; |
| 332 | } |
| 333 | |
| 334 | /* |
| 335 | * For booting existed memory devices, early boot code has recognized |
| 336 | * memory area by EFI/E820. If DSDT shows these memory devices on boot, |
| 337 | * hotplug is not necessary for them. |
| 338 | * For hot-added memory devices during runtime, it need hypercall to |
| 339 | * Xen hypervisor to add memory. |
| 340 | */ |
| 341 | if (!acpi_hotmem_initialized) |
| 342 | return 0; |
| 343 | |
| 344 | if (!acpi_memory_check_device(mem_device)) |
| 345 | result = xen_acpi_memory_enable_device(mem_device); |
| 346 | |
| 347 | return result; |
| 348 | } |
| 349 | |
| 350 | static int xen_acpi_memory_device_remove(struct acpi_device *device, int type) |
| 351 | { |
| 352 | struct acpi_memory_device *mem_device = NULL; |
| 353 | |
| 354 | if (!device || !acpi_driver_data(device)) |
| 355 | return -EINVAL; |
| 356 | |
| 357 | mem_device = acpi_driver_data(device); |
| 358 | kfree(mem_device); |
| 359 | |
| 360 | return 0; |
| 361 | } |
| 362 | |
| 363 | /* |
| 364 | * Helper function to check for memory device |
| 365 | */ |
| 366 | static acpi_status is_memory_device(acpi_handle handle) |
| 367 | { |
| 368 | char *hardware_id; |
| 369 | acpi_status status; |
| 370 | struct acpi_device_info *info; |
| 371 | |
| 372 | status = acpi_get_object_info(handle, &info); |
| 373 | if (ACPI_FAILURE(status)) |
| 374 | return status; |
| 375 | |
| 376 | if (!(info->valid & ACPI_VALID_HID)) { |
| 377 | kfree(info); |
| 378 | return AE_ERROR; |
| 379 | } |
| 380 | |
| 381 | hardware_id = info->hardware_id.string; |
| 382 | if ((hardware_id == NULL) || |
| 383 | (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID))) |
| 384 | status = AE_ERROR; |
| 385 | |
| 386 | kfree(info); |
| 387 | return status; |
| 388 | } |
| 389 | |
| 390 | static acpi_status |
| 391 | acpi_memory_register_notify_handler(acpi_handle handle, |
| 392 | u32 level, void *ctxt, void **retv) |
| 393 | { |
| 394 | acpi_status status; |
| 395 | |
| 396 | status = is_memory_device(handle); |
| 397 | if (ACPI_FAILURE(status)) |
| 398 | return AE_OK; /* continue */ |
| 399 | |
| 400 | status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY, |
| 401 | acpi_memory_device_notify, NULL); |
| 402 | /* continue */ |
| 403 | return AE_OK; |
| 404 | } |
| 405 | |
| 406 | static acpi_status |
| 407 | acpi_memory_deregister_notify_handler(acpi_handle handle, |
| 408 | u32 level, void *ctxt, void **retv) |
| 409 | { |
| 410 | acpi_status status; |
| 411 | |
| 412 | status = is_memory_device(handle); |
| 413 | if (ACPI_FAILURE(status)) |
| 414 | return AE_OK; /* continue */ |
| 415 | |
| 416 | status = acpi_remove_notify_handler(handle, |
| 417 | ACPI_SYSTEM_NOTIFY, |
| 418 | acpi_memory_device_notify); |
| 419 | |
| 420 | return AE_OK; /* continue */ |
| 421 | } |
| 422 | |
| 423 | static const struct acpi_device_id memory_device_ids[] = { |
| 424 | {ACPI_MEMORY_DEVICE_HID, 0}, |
| 425 | {"", 0}, |
| 426 | }; |
| 427 | MODULE_DEVICE_TABLE(acpi, memory_device_ids); |
| 428 | |
| 429 | static struct acpi_driver xen_acpi_memory_device_driver = { |
| 430 | .name = "acpi_memhotplug", |
| 431 | .class = ACPI_MEMORY_DEVICE_CLASS, |
| 432 | .ids = memory_device_ids, |
| 433 | .ops = { |
| 434 | .add = xen_acpi_memory_device_add, |
| 435 | .remove = xen_acpi_memory_device_remove, |
| 436 | }, |
| 437 | }; |
| 438 | |
| 439 | static int __init xen_acpi_memory_device_init(void) |
| 440 | { |
| 441 | int result; |
| 442 | acpi_status status; |
| 443 | |
| 444 | if (!xen_initial_domain()) |
| 445 | return -ENODEV; |
| 446 | |
| 447 | /* unregister the stub which only used to reserve driver space */ |
| 448 | xen_stub_memory_device_exit(); |
| 449 | |
| 450 | result = acpi_bus_register_driver(&xen_acpi_memory_device_driver); |
| 451 | if (result < 0) { |
| 452 | xen_stub_memory_device_init(); |
| 453 | return -ENODEV; |
| 454 | } |
| 455 | |
| 456 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, |
| 457 | ACPI_UINT32_MAX, |
| 458 | acpi_memory_register_notify_handler, |
| 459 | NULL, NULL, NULL); |
| 460 | |
| 461 | if (ACPI_FAILURE(status)) { |
| 462 | pr_warn(PREFIX "walk_namespace failed\n"); |
| 463 | acpi_bus_unregister_driver(&xen_acpi_memory_device_driver); |
| 464 | xen_stub_memory_device_init(); |
| 465 | return -ENODEV; |
| 466 | } |
| 467 | |
| 468 | acpi_hotmem_initialized = true; |
| 469 | return 0; |
| 470 | } |
| 471 | |
| 472 | static void __exit xen_acpi_memory_device_exit(void) |
| 473 | { |
| 474 | acpi_status status; |
| 475 | |
| 476 | if (!xen_initial_domain()) |
| 477 | return; |
| 478 | |
| 479 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, |
| 480 | ACPI_UINT32_MAX, |
| 481 | acpi_memory_deregister_notify_handler, |
| 482 | NULL, NULL, NULL); |
| 483 | if (ACPI_FAILURE(status)) |
| 484 | pr_warn(PREFIX "walk_namespace failed\n"); |
| 485 | |
| 486 | acpi_bus_unregister_driver(&xen_acpi_memory_device_driver); |
| 487 | |
| 488 | /* |
| 489 | * stub reserve space again to prevent any chance of native |
| 490 | * driver loading. |
| 491 | */ |
| 492 | xen_stub_memory_device_init(); |
| 493 | return; |
| 494 | } |
| 495 | |
| 496 | module_init(xen_acpi_memory_device_init); |
| 497 | module_exit(xen_acpi_memory_device_exit); |
| 498 | ACPI_MODULE_NAME("xen-acpi-memhotplug"); |
| 499 | MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>"); |
| 500 | MODULE_DESCRIPTION("Xen Hotplug Mem Driver"); |
| 501 | MODULE_LICENSE("GPL"); |