acpi_memhotplug.c 14 KB

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  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 firmware for memory add
  24. * and remove operations and alerts the VM of the affected memory
  25. * ranges.
  26. */
  27. #include <linux/kernel.h>
  28. #include <linux/module.h>
  29. #include <linux/init.h>
  30. #include <linux/types.h>
  31. #include <linux/memory_hotplug.h>
  32. #include <linux/slab.h>
  33. #include <linux/acpi.h>
  34. #include <acpi/acpi_drivers.h>
  35. #define ACPI_MEMORY_DEVICE_CLASS "memory"
  36. #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
  37. #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
  38. #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
  39. #undef PREFIX
  40. #define PREFIX "ACPI:memory_hp:"
  41. ACPI_MODULE_NAME("acpi_memhotplug");
  42. MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
  43. MODULE_DESCRIPTION("Hotplug Mem Driver");
  44. MODULE_LICENSE("GPL");
  45. /* Memory Device States */
  46. #define MEMORY_INVALID_STATE 0
  47. #define MEMORY_POWER_ON_STATE 1
  48. #define MEMORY_POWER_OFF_STATE 2
  49. static int acpi_memory_device_add(struct acpi_device *device);
  50. static int acpi_memory_device_remove(struct acpi_device *device);
  51. static const struct acpi_device_id memory_device_ids[] = {
  52. {ACPI_MEMORY_DEVICE_HID, 0},
  53. {"", 0},
  54. };
  55. MODULE_DEVICE_TABLE(acpi, memory_device_ids);
  56. static struct acpi_driver acpi_memory_device_driver = {
  57. .name = "acpi_memhotplug",
  58. .class = ACPI_MEMORY_DEVICE_CLASS,
  59. .ids = memory_device_ids,
  60. .ops = {
  61. .add = acpi_memory_device_add,
  62. .remove = acpi_memory_device_remove,
  63. },
  64. };
  65. struct acpi_memory_info {
  66. struct list_head list;
  67. u64 start_addr; /* Memory Range start physical addr */
  68. u64 length; /* Memory Range length */
  69. unsigned short caching; /* memory cache attribute */
  70. unsigned short write_protect; /* memory read/write attribute */
  71. unsigned int enabled:1;
  72. unsigned int failed:1;
  73. };
  74. struct acpi_memory_device {
  75. struct acpi_device * device;
  76. unsigned int state; /* State of the memory device */
  77. struct list_head res_list;
  78. };
  79. static acpi_status
  80. acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  81. {
  82. struct acpi_memory_device *mem_device = context;
  83. struct acpi_resource_address64 address64;
  84. struct acpi_memory_info *info, *new;
  85. acpi_status status;
  86. status = acpi_resource_to_address64(resource, &address64);
  87. if (ACPI_FAILURE(status) ||
  88. (address64.resource_type != ACPI_MEMORY_RANGE))
  89. return AE_OK;
  90. list_for_each_entry(info, &mem_device->res_list, list) {
  91. /* Can we combine the resource range information? */
  92. if ((info->caching == address64.info.mem.caching) &&
  93. (info->write_protect == address64.info.mem.write_protect) &&
  94. (info->start_addr + info->length == address64.minimum)) {
  95. info->length += address64.address_length;
  96. return AE_OK;
  97. }
  98. }
  99. new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
  100. if (!new)
  101. return AE_ERROR;
  102. INIT_LIST_HEAD(&new->list);
  103. new->caching = address64.info.mem.caching;
  104. new->write_protect = address64.info.mem.write_protect;
  105. new->start_addr = address64.minimum;
  106. new->length = address64.address_length;
  107. list_add_tail(&new->list, &mem_device->res_list);
  108. return AE_OK;
  109. }
  110. static void
  111. acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
  112. {
  113. struct acpi_memory_info *info, *n;
  114. list_for_each_entry_safe(info, n, &mem_device->res_list, list)
  115. kfree(info);
  116. INIT_LIST_HEAD(&mem_device->res_list);
  117. }
  118. static int
  119. acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
  120. {
  121. acpi_status status;
  122. if (!list_empty(&mem_device->res_list))
  123. return 0;
  124. status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
  125. acpi_memory_get_resource, mem_device);
  126. if (ACPI_FAILURE(status)) {
  127. acpi_memory_free_device_resources(mem_device);
  128. return -EINVAL;
  129. }
  130. return 0;
  131. }
  132. static int
  133. acpi_memory_get_device(acpi_handle handle,
  134. struct acpi_memory_device **mem_device)
  135. {
  136. struct acpi_device *device = NULL;
  137. int result;
  138. if (!acpi_bus_get_device(handle, &device) && device)
  139. goto end;
  140. /*
  141. * Now add the notified device. This creates the acpi_device
  142. * and invokes .add function
  143. */
  144. result = acpi_bus_scan(handle);
  145. if (result) {
  146. acpi_handle_warn(handle, "Cannot add acpi bus\n");
  147. return -EINVAL;
  148. }
  149. result = acpi_bus_get_device(handle, &device);
  150. if (result) {
  151. acpi_handle_warn(handle, "Missing device object\n");
  152. return -EINVAL;
  153. }
  154. end:
  155. *mem_device = acpi_driver_data(device);
  156. if (!(*mem_device)) {
  157. dev_err(&device->dev, "driver data not found\n");
  158. return -ENODEV;
  159. }
  160. return 0;
  161. }
  162. static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
  163. {
  164. unsigned long long current_status;
  165. /* Get device present/absent information from the _STA */
  166. if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
  167. NULL, &current_status)))
  168. return -ENODEV;
  169. /*
  170. * Check for device status. Device should be
  171. * present/enabled/functioning.
  172. */
  173. if (!((current_status & ACPI_STA_DEVICE_PRESENT)
  174. && (current_status & ACPI_STA_DEVICE_ENABLED)
  175. && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
  176. return -ENODEV;
  177. return 0;
  178. }
  179. static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
  180. {
  181. int result, num_enabled = 0;
  182. struct acpi_memory_info *info;
  183. int node;
  184. node = acpi_get_node(mem_device->device->handle);
  185. /*
  186. * Tell the VM there is more memory here...
  187. * Note: Assume that this function returns zero on success
  188. * We don't have memory-hot-add rollback function,now.
  189. * (i.e. memory-hot-remove function)
  190. */
  191. list_for_each_entry(info, &mem_device->res_list, list) {
  192. if (info->enabled) { /* just sanity check...*/
  193. num_enabled++;
  194. continue;
  195. }
  196. /*
  197. * If the memory block size is zero, please ignore it.
  198. * Don't try to do the following memory hotplug flowchart.
  199. */
  200. if (!info->length)
  201. continue;
  202. if (node < 0)
  203. node = memory_add_physaddr_to_nid(info->start_addr);
  204. result = add_memory(node, info->start_addr, info->length);
  205. /*
  206. * If the memory block has been used by the kernel, add_memory()
  207. * returns -EEXIST. If add_memory() returns the other error, it
  208. * means that this memory block is not used by the kernel.
  209. */
  210. if (result && result != -EEXIST) {
  211. info->failed = 1;
  212. continue;
  213. }
  214. if (!result)
  215. info->enabled = 1;
  216. /*
  217. * Add num_enable even if add_memory() returns -EEXIST, so the
  218. * device is bound to this driver.
  219. */
  220. num_enabled++;
  221. }
  222. if (!num_enabled) {
  223. dev_err(&mem_device->device->dev, "add_memory failed\n");
  224. mem_device->state = MEMORY_INVALID_STATE;
  225. return -EINVAL;
  226. }
  227. /*
  228. * Sometimes the memory device will contain several memory blocks.
  229. * When one memory block is hot-added to the system memory, it will
  230. * be regarded as a success.
  231. * Otherwise if the last memory block can't be hot-added to the system
  232. * memory, it will be failure and the memory device can't be bound with
  233. * driver.
  234. */
  235. return 0;
  236. }
  237. static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
  238. {
  239. int result = 0;
  240. struct acpi_memory_info *info, *n;
  241. list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
  242. if (info->failed)
  243. /* The kernel does not use this memory block */
  244. continue;
  245. if (!info->enabled)
  246. /*
  247. * The kernel uses this memory block, but it may be not
  248. * managed by us.
  249. */
  250. return -EBUSY;
  251. result = remove_memory(info->start_addr, info->length);
  252. if (result)
  253. return result;
  254. list_del(&info->list);
  255. kfree(info);
  256. }
  257. return result;
  258. }
  259. static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
  260. {
  261. struct acpi_memory_device *mem_device;
  262. struct acpi_device *device;
  263. struct acpi_eject_event *ej_event = NULL;
  264. u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
  265. switch (event) {
  266. case ACPI_NOTIFY_BUS_CHECK:
  267. ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  268. "\nReceived BUS CHECK notification for device\n"));
  269. /* Fall Through */
  270. case ACPI_NOTIFY_DEVICE_CHECK:
  271. if (event == ACPI_NOTIFY_DEVICE_CHECK)
  272. ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  273. "\nReceived DEVICE CHECK notification for device\n"));
  274. if (acpi_memory_get_device(handle, &mem_device)) {
  275. acpi_handle_err(handle, "Cannot find driver data\n");
  276. break;
  277. }
  278. ost_code = ACPI_OST_SC_SUCCESS;
  279. break;
  280. case ACPI_NOTIFY_EJECT_REQUEST:
  281. ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  282. "\nReceived EJECT REQUEST notification for device\n"));
  283. if (acpi_bus_get_device(handle, &device)) {
  284. acpi_handle_err(handle, "Device doesn't exist\n");
  285. break;
  286. }
  287. mem_device = acpi_driver_data(device);
  288. if (!mem_device) {
  289. acpi_handle_err(handle, "Driver Data is NULL\n");
  290. break;
  291. }
  292. ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
  293. if (!ej_event) {
  294. pr_err(PREFIX "No memory, dropping EJECT\n");
  295. break;
  296. }
  297. ej_event->device = device;
  298. ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
  299. acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
  300. (void *)ej_event);
  301. /* eject is performed asynchronously */
  302. return;
  303. default:
  304. ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  305. "Unsupported event [0x%x]\n", event));
  306. /* non-hotplug event; possibly handled by other handler */
  307. return;
  308. }
  309. /* Inform firmware that the hotplug operation has completed */
  310. (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
  311. return;
  312. }
  313. static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
  314. {
  315. if (!mem_device)
  316. return;
  317. acpi_memory_free_device_resources(mem_device);
  318. kfree(mem_device);
  319. }
  320. static int acpi_memory_device_add(struct acpi_device *device)
  321. {
  322. int result;
  323. struct acpi_memory_device *mem_device = NULL;
  324. if (!device)
  325. return -EINVAL;
  326. mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
  327. if (!mem_device)
  328. return -ENOMEM;
  329. INIT_LIST_HEAD(&mem_device->res_list);
  330. mem_device->device = device;
  331. sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
  332. sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
  333. device->driver_data = mem_device;
  334. /* Get the range from the _CRS */
  335. result = acpi_memory_get_device_resources(mem_device);
  336. if (result) {
  337. kfree(mem_device);
  338. return result;
  339. }
  340. /* Set the device state */
  341. mem_device->state = MEMORY_POWER_ON_STATE;
  342. pr_debug("%s\n", acpi_device_name(device));
  343. if (!acpi_memory_check_device(mem_device)) {
  344. /* call add_memory func */
  345. result = acpi_memory_enable_device(mem_device);
  346. if (result) {
  347. dev_err(&device->dev,
  348. "Error in acpi_memory_enable_device\n");
  349. acpi_memory_device_free(mem_device);
  350. }
  351. }
  352. return result;
  353. }
  354. static int acpi_memory_device_remove(struct acpi_device *device)
  355. {
  356. struct acpi_memory_device *mem_device = NULL;
  357. int result;
  358. if (!device || !acpi_driver_data(device))
  359. return -EINVAL;
  360. mem_device = acpi_driver_data(device);
  361. result = acpi_memory_remove_memory(mem_device);
  362. if (result)
  363. return result;
  364. acpi_memory_device_free(mem_device);
  365. return 0;
  366. }
  367. /*
  368. * Helper function to check for memory device
  369. */
  370. static acpi_status is_memory_device(acpi_handle handle)
  371. {
  372. char *hardware_id;
  373. acpi_status status;
  374. struct acpi_device_info *info;
  375. status = acpi_get_object_info(handle, &info);
  376. if (ACPI_FAILURE(status))
  377. return status;
  378. if (!(info->valid & ACPI_VALID_HID)) {
  379. kfree(info);
  380. return AE_ERROR;
  381. }
  382. hardware_id = info->hardware_id.string;
  383. if ((hardware_id == NULL) ||
  384. (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
  385. status = AE_ERROR;
  386. kfree(info);
  387. return status;
  388. }
  389. static acpi_status
  390. acpi_memory_register_notify_handler(acpi_handle handle,
  391. u32 level, void *ctxt, void **retv)
  392. {
  393. acpi_status status;
  394. status = is_memory_device(handle);
  395. if (ACPI_FAILURE(status))
  396. return AE_OK; /* continue */
  397. status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
  398. acpi_memory_device_notify, NULL);
  399. /* continue */
  400. return AE_OK;
  401. }
  402. static acpi_status
  403. acpi_memory_deregister_notify_handler(acpi_handle handle,
  404. u32 level, void *ctxt, void **retv)
  405. {
  406. acpi_status status;
  407. status = is_memory_device(handle);
  408. if (ACPI_FAILURE(status))
  409. return AE_OK; /* continue */
  410. status = acpi_remove_notify_handler(handle,
  411. ACPI_SYSTEM_NOTIFY,
  412. acpi_memory_device_notify);
  413. return AE_OK; /* continue */
  414. }
  415. static int __init acpi_memory_device_init(void)
  416. {
  417. int result;
  418. acpi_status status;
  419. result = acpi_bus_register_driver(&acpi_memory_device_driver);
  420. if (result < 0)
  421. return -ENODEV;
  422. status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
  423. ACPI_UINT32_MAX,
  424. acpi_memory_register_notify_handler, NULL,
  425. NULL, NULL);
  426. if (ACPI_FAILURE(status)) {
  427. ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
  428. acpi_bus_unregister_driver(&acpi_memory_device_driver);
  429. return -ENODEV;
  430. }
  431. return 0;
  432. }
  433. static void __exit acpi_memory_device_exit(void)
  434. {
  435. acpi_status status;
  436. /*
  437. * Adding this to un-install notification handlers for all the device
  438. * handles.
  439. */
  440. status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
  441. ACPI_UINT32_MAX,
  442. acpi_memory_deregister_notify_handler, NULL,
  443. NULL, NULL);
  444. if (ACPI_FAILURE(status))
  445. ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
  446. acpi_bus_unregister_driver(&acpi_memory_device_driver);
  447. return;
  448. }
  449. module_init(acpi_memory_device_init);
  450. module_exit(acpi_memory_device_exit);