acpiphp_ibm.c 14 KB

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  1. /*
  2. * ACPI PCI Hot Plug IBM Extension
  3. *
  4. * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
  5. * Copyright (C) 2004 IBM Corp.
  6. *
  7. * All rights reserved.
  8. *
  9. * This program is free software; you can redistribute it and/or modify
  10. * it under the terms of the GNU General Public License as published by
  11. * the Free Software Foundation; either version 2 of the License, or (at
  12. * your option) any later version.
  13. *
  14. * This program is distributed in the hope that it will be useful, but
  15. * WITHOUT ANY WARRANTY; without even the implied warranty of
  16. * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  17. * NON INFRINGEMENT. See the GNU General Public License for more
  18. * details.
  19. *
  20. * You should have received a copy of the GNU General Public License
  21. * along with this program; if not, write to the Free Software
  22. * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23. *
  24. * Send feedback to <vernux@us.ibm.com>
  25. *
  26. */
  27. #define pr_fmt(fmt) "acpiphp_ibm: " fmt
  28. #include <linux/init.h>
  29. #include <linux/slab.h>
  30. #include <linux/module.h>
  31. #include <linux/kernel.h>
  32. #include <linux/sysfs.h>
  33. #include <linux/kobject.h>
  34. #include <linux/moduleparam.h>
  35. #include <linux/pci.h>
  36. #include <asm/uaccess.h>
  37. #include "acpiphp.h"
  38. #include "../pci.h"
  39. #define DRIVER_VERSION "1.0.1"
  40. #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
  41. #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension"
  42. MODULE_AUTHOR(DRIVER_AUTHOR);
  43. MODULE_DESCRIPTION(DRIVER_DESC);
  44. MODULE_LICENSE("GPL");
  45. MODULE_VERSION(DRIVER_VERSION);
  46. #define FOUND_APCI 0x61504349
  47. /* these are the names for the IBM ACPI pseudo-device */
  48. #define IBM_HARDWARE_ID1 "IBM37D0"
  49. #define IBM_HARDWARE_ID2 "IBM37D4"
  50. #define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun)
  51. /* union apci_descriptor - allows access to the
  52. * various device descriptors that are embedded in the
  53. * aPCI table
  54. */
  55. union apci_descriptor {
  56. struct {
  57. char sig[4];
  58. u8 len;
  59. } header;
  60. struct {
  61. u8 type;
  62. u8 len;
  63. u16 slot_id;
  64. u8 bus_id;
  65. u8 dev_num;
  66. u8 slot_num;
  67. u8 slot_attr[2];
  68. u8 attn;
  69. u8 status[2];
  70. u8 sun;
  71. u8 res[3];
  72. } slot;
  73. struct {
  74. u8 type;
  75. u8 len;
  76. } generic;
  77. };
  78. /* struct notification - keeps info about the device
  79. * that cause the ACPI notification event
  80. */
  81. struct notification {
  82. struct acpi_device *device;
  83. u8 event;
  84. };
  85. static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
  86. static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
  87. static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
  88. static int ibm_get_table_from_acpi(char **bufp);
  89. static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
  90. struct bin_attribute *bin_attr,
  91. char *buffer, loff_t pos, size_t size);
  92. static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
  93. u32 lvl, void *context, void **rv);
  94. static int __init ibm_acpiphp_init(void);
  95. static void __exit ibm_acpiphp_exit(void);
  96. static acpi_handle ibm_acpi_handle;
  97. static struct notification ibm_note;
  98. static struct bin_attribute ibm_apci_table_attr = {
  99. .attr = {
  100. .name = "apci_table",
  101. .mode = S_IRUGO,
  102. },
  103. .read = ibm_read_apci_table,
  104. .write = NULL,
  105. };
  106. static struct acpiphp_attention_info ibm_attention_info =
  107. {
  108. .set_attn = ibm_set_attention_status,
  109. .get_attn = ibm_get_attention_status,
  110. .owner = THIS_MODULE,
  111. };
  112. /**
  113. * ibm_slot_from_id - workaround for bad ibm hardware
  114. * @id: the slot number that linux refers to the slot by
  115. *
  116. * Description: This method returns the aCPI slot descriptor
  117. * corresponding to the Linux slot number. This descriptor
  118. * has info about the aPCI slot id and attention status.
  119. * This descriptor must be freed using kfree when done.
  120. */
  121. static union apci_descriptor *ibm_slot_from_id(int id)
  122. {
  123. int ind = 0, size;
  124. union apci_descriptor *ret = NULL, *des;
  125. char *table;
  126. size = ibm_get_table_from_acpi(&table);
  127. des = (union apci_descriptor *)table;
  128. if (memcmp(des->header.sig, "aPCI", 4) != 0)
  129. goto ibm_slot_done;
  130. des = (union apci_descriptor *)&table[ind += des->header.len];
  131. while (ind < size && (des->generic.type != 0x82 ||
  132. des->slot.slot_num != id)) {
  133. des = (union apci_descriptor *)&table[ind += des->generic.len];
  134. }
  135. if (ind < size && des->slot.slot_num == id)
  136. ret = des;
  137. ibm_slot_done:
  138. if (ret) {
  139. ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
  140. memcpy(ret, des, sizeof(union apci_descriptor));
  141. }
  142. kfree(table);
  143. return ret;
  144. }
  145. /**
  146. * ibm_set_attention_status - callback method to set the attention LED
  147. * @slot: the hotplug_slot to work with
  148. * @status: what to set the LED to (0 or 1)
  149. *
  150. * Description: This method is registered with the acpiphp module as a
  151. * callback to do the device specific task of setting the LED status.
  152. */
  153. static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
  154. {
  155. union acpi_object args[2];
  156. struct acpi_object_list params = { .pointer = args, .count = 2 };
  157. acpi_status stat;
  158. unsigned long long rc;
  159. union apci_descriptor *ibm_slot;
  160. ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
  161. pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__,
  162. ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
  163. (status ? 1 : 0));
  164. args[0].type = ACPI_TYPE_INTEGER;
  165. args[0].integer.value = ibm_slot->slot.slot_id;
  166. args[1].type = ACPI_TYPE_INTEGER;
  167. args[1].integer.value = (status) ? 1 : 0;
  168. kfree(ibm_slot);
  169. stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
  170. if (ACPI_FAILURE(stat)) {
  171. pr_err("APLS evaluation failed: 0x%08x\n", stat);
  172. return -ENODEV;
  173. } else if (!rc) {
  174. pr_err("APLS method failed: 0x%08llx\n", rc);
  175. return -ERANGE;
  176. }
  177. return 0;
  178. }
  179. /**
  180. * ibm_get_attention_status - callback method to get attention LED status
  181. * @slot: the hotplug_slot to work with
  182. * @status: returns what the LED is set to (0 or 1)
  183. *
  184. * Description: This method is registered with the acpiphp module as a
  185. * callback to do the device specific task of getting the LED status.
  186. *
  187. * Because there is no direct method of getting the LED status directly
  188. * from an ACPI call, we read the aPCI table and parse out our
  189. * slot descriptor to read the status from that.
  190. */
  191. static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
  192. {
  193. union apci_descriptor *ibm_slot;
  194. ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
  195. if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
  196. *status = 1;
  197. else
  198. *status = 0;
  199. pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__,
  200. ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
  201. *status);
  202. kfree(ibm_slot);
  203. return 0;
  204. }
  205. /**
  206. * ibm_handle_events - listens for ACPI events for the IBM37D0 device
  207. * @handle: an ACPI handle to the device that caused the event
  208. * @event: the event info (device specific)
  209. * @context: passed context (our notification struct)
  210. *
  211. * Description: This method is registered as a callback with the ACPI
  212. * subsystem it is called when this device has an event to notify the OS of.
  213. *
  214. * The events actually come from the device as two events that get
  215. * synthesized into one event with data by this function. The event
  216. * ID comes first and then the slot number that caused it. We report
  217. * this as one event to the OS.
  218. *
  219. * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
  220. * only re-enable the interrupt that causes this event AFTER this method
  221. * has returned, thereby enforcing serial access for the notification struct.
  222. */
  223. static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
  224. {
  225. u8 detail = event & 0x0f;
  226. u8 subevent = event & 0xf0;
  227. struct notification *note = context;
  228. pr_debug("%s: Received notification %02x\n", __func__, event);
  229. if (subevent == 0x80) {
  230. pr_debug("%s: generating bus event\n", __func__);
  231. acpi_bus_generate_netlink_event(note->device->pnp.device_class,
  232. dev_name(&note->device->dev),
  233. note->event, detail);
  234. } else
  235. note->event = event;
  236. }
  237. /**
  238. * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
  239. * @bufp: address to pointer to allocate for the table
  240. *
  241. * Description: This method reads the APLS buffer in from ACPI and
  242. * stores the "stripped" table into a single buffer
  243. * it allocates and passes the address back in bufp.
  244. *
  245. * If NULL is passed in as buffer, this method only calculates
  246. * the size of the table and returns that without filling
  247. * in the buffer.
  248. *
  249. * Returns < 0 on error or the size of the table on success.
  250. */
  251. static int ibm_get_table_from_acpi(char **bufp)
  252. {
  253. union acpi_object *package;
  254. struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  255. acpi_status status;
  256. char *lbuf = NULL;
  257. int i, size = -EIO;
  258. status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
  259. if (ACPI_FAILURE(status)) {
  260. pr_err("%s: APCI evaluation failed\n", __func__);
  261. return -ENODEV;
  262. }
  263. package = (union acpi_object *) buffer.pointer;
  264. if (!(package) ||
  265. (package->type != ACPI_TYPE_PACKAGE) ||
  266. !(package->package.elements)) {
  267. pr_err("%s: Invalid APCI object\n", __func__);
  268. goto read_table_done;
  269. }
  270. for (size = 0, i = 0; i < package->package.count; i++) {
  271. if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
  272. pr_err("%s: Invalid APCI element %d\n", __func__, i);
  273. goto read_table_done;
  274. }
  275. size += package->package.elements[i].buffer.length;
  276. }
  277. if (bufp == NULL)
  278. goto read_table_done;
  279. lbuf = kzalloc(size, GFP_KERNEL);
  280. pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
  281. __func__, package->package.count, size, lbuf);
  282. if (lbuf) {
  283. *bufp = lbuf;
  284. } else {
  285. size = -ENOMEM;
  286. goto read_table_done;
  287. }
  288. size = 0;
  289. for (i=0; i<package->package.count; i++) {
  290. memcpy(&lbuf[size],
  291. package->package.elements[i].buffer.pointer,
  292. package->package.elements[i].buffer.length);
  293. size += package->package.elements[i].buffer.length;
  294. }
  295. read_table_done:
  296. kfree(buffer.pointer);
  297. return size;
  298. }
  299. /**
  300. * ibm_read_apci_table - callback for the sysfs apci_table file
  301. * @filp: the open sysfs file
  302. * @kobj: the kobject this binary attribute is a part of
  303. * @bin_attr: struct bin_attribute for this file
  304. * @buffer: the kernel space buffer to fill
  305. * @pos: the offset into the file
  306. * @size: the number of bytes requested
  307. *
  308. * Description: Gets registered with sysfs as the reader callback
  309. * to be executed when /sys/bus/pci/slots/apci_table gets read.
  310. *
  311. * Since we don't get notified on open and close for this file,
  312. * things get really tricky here...
  313. * our solution is to only allow reading the table in all at once.
  314. */
  315. static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
  316. struct bin_attribute *bin_attr,
  317. char *buffer, loff_t pos, size_t size)
  318. {
  319. int bytes_read = -EINVAL;
  320. char *table = NULL;
  321. pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);
  322. if (pos == 0) {
  323. bytes_read = ibm_get_table_from_acpi(&table);
  324. if (bytes_read > 0 && bytes_read <= size)
  325. memcpy(buffer, table, bytes_read);
  326. kfree(table);
  327. }
  328. return bytes_read;
  329. }
  330. /**
  331. * ibm_find_acpi_device - callback to find our ACPI device
  332. * @handle: the ACPI handle of the device we are inspecting
  333. * @lvl: depth into the namespace tree
  334. * @context: a pointer to our handle to fill when we find the device
  335. * @rv: a return value to fill if desired
  336. *
  337. * Description: Used as a callback when calling acpi_walk_namespace
  338. * to find our device. When this method returns non-zero
  339. * acpi_walk_namespace quits its search and returns our value.
  340. */
  341. static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
  342. u32 lvl, void *context, void **rv)
  343. {
  344. acpi_handle *phandle = (acpi_handle *)context;
  345. acpi_status status;
  346. struct acpi_device_info *info;
  347. int retval = 0;
  348. status = acpi_get_object_info(handle, &info);
  349. if (ACPI_FAILURE(status)) {
  350. pr_err("%s: Failed to get device information status=0x%x\n",
  351. __func__, status);
  352. return retval;
  353. }
  354. if (info->current_status && (info->valid & ACPI_VALID_HID) &&
  355. (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
  356. !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
  357. pr_debug("found hardware: %s, handle: %p\n",
  358. info->hardware_id.string, handle);
  359. *phandle = handle;
  360. /* returning non-zero causes the search to stop
  361. * and returns this value to the caller of
  362. * acpi_walk_namespace, but it also causes some warnings
  363. * in the acpi debug code to print...
  364. */
  365. retval = FOUND_APCI;
  366. }
  367. kfree(info);
  368. return retval;
  369. }
  370. static int __init ibm_acpiphp_init(void)
  371. {
  372. int retval = 0;
  373. acpi_status status;
  374. struct acpi_device *device;
  375. struct kobject *sysdir = &pci_slots_kset->kobj;
  376. pr_debug("%s\n", __func__);
  377. if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
  378. ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
  379. &ibm_acpi_handle, NULL) != FOUND_APCI) {
  380. pr_err("%s: acpi_walk_namespace failed\n", __func__);
  381. retval = -ENODEV;
  382. goto init_return;
  383. }
  384. pr_debug("%s: found IBM aPCI device\n", __func__);
  385. if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
  386. pr_err("%s: acpi_bus_get_device failed\n", __func__);
  387. retval = -ENODEV;
  388. goto init_return;
  389. }
  390. if (acpiphp_register_attention(&ibm_attention_info)) {
  391. retval = -ENODEV;
  392. goto init_return;
  393. }
  394. ibm_note.device = device;
  395. status = acpi_install_notify_handler(ibm_acpi_handle,
  396. ACPI_DEVICE_NOTIFY, ibm_handle_events,
  397. &ibm_note);
  398. if (ACPI_FAILURE(status)) {
  399. pr_err("%s: Failed to register notification handler\n",
  400. __func__);
  401. retval = -EBUSY;
  402. goto init_cleanup;
  403. }
  404. ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
  405. retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
  406. return retval;
  407. init_cleanup:
  408. acpiphp_unregister_attention(&ibm_attention_info);
  409. init_return:
  410. return retval;
  411. }
  412. static void __exit ibm_acpiphp_exit(void)
  413. {
  414. acpi_status status;
  415. struct kobject *sysdir = &pci_slots_kset->kobj;
  416. pr_debug("%s\n", __func__);
  417. if (acpiphp_unregister_attention(&ibm_attention_info))
  418. pr_err("%s: attention info deregistration failed", __func__);
  419. status = acpi_remove_notify_handler(
  420. ibm_acpi_handle,
  421. ACPI_DEVICE_NOTIFY,
  422. ibm_handle_events);
  423. if (ACPI_FAILURE(status))
  424. pr_err("%s: Notification handler removal failed\n", __func__);
  425. /* remove the /sys entries */
  426. sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
  427. }
  428. module_init(ibm_acpiphp_init);
  429. module_exit(ibm_acpiphp_exit);