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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
28#include <linux/init.h>
29#include <linux/module.h>
30#include <linux/kernel.h>
31#include <acpi/acpi_bus.h>
32#include <linux/sysfs.h>
33#include <linux/kobject.h>
34#include <asm/uaccess.h>
35#include <linux/moduleparam.h>
36
37#include "acpiphp.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
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
43static int debug;
44
45MODULE_AUTHOR(DRIVER_AUTHOR);
46MODULE_DESCRIPTION(DRIVER_DESC);
47MODULE_LICENSE("GPL");
48MODULE_VERSION(DRIVER_VERSION);
49module_param(debug, bool, 0644);
50MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
51#define MY_NAME "acpiphp_ibm"
52
53#undef dbg
54#define dbg(format, arg...) \
55do { \
56 if (debug) \
57 printk(KERN_DEBUG "%s: " format, \
58 MY_NAME , ## arg); \
59} while (0)
60
61#define FOUND_APCI 0x61504349
62/* these are the names for the IBM ACPI pseudo-device */
63#define IBM_HARDWARE_ID1 "IBM37D0"
64#define IBM_HARDWARE_ID2 "IBM37D4"
65
66#define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun)
67
68/* union apci_descriptor - allows access to the
69 * various device descriptors that are embedded in the
70 * aPCI table
71 */
72union apci_descriptor {
73 struct {
74 char sig[4];
75 u8 len;
76 } header;
77 struct {
78 u8 type;
79 u8 len;
80 u16 slot_id;
81 u8 bus_id;
82 u8 dev_num;
83 u8 slot_num;
84 u8 slot_attr[2];
85 u8 attn;
86 u8 status[2];
87 u8 sun;
88 u8 res[3];
89 } slot;
90 struct {
91 u8 type;
92 u8 len;
93 } generic;
94};
95
96/* struct notification - keeps info about the device
97 * that cause the ACPI notification event
98 */
99struct notification {
100 struct acpi_device *device;
101 u8 event;
102};
103
104static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
105static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
106static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
107static int ibm_get_table_from_acpi(char **bufp);
108static ssize_t ibm_read_apci_table(struct kobject *kobj,
109 char *buffer, loff_t pos, size_t size);
110static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
111 u32 lvl, void *context, void **rv);
112static int __init ibm_acpiphp_init(void);
113static void __exit ibm_acpiphp_exit(void);
114
115static acpi_handle ibm_acpi_handle;
116static struct notification ibm_note;
117static struct bin_attribute ibm_apci_table_attr = {
118 .attr = {
119 .name = "apci_table",
120 .owner = THIS_MODULE,
121 .mode = S_IRUGO,
122 },
123 .read = ibm_read_apci_table,
124 .write = NULL,
125};
126static struct acpiphp_attention_info ibm_attention_info =
127{
128 .set_attn = ibm_set_attention_status,
129 .get_attn = ibm_get_attention_status,
130 .owner = THIS_MODULE,
131};
132
133/**
134 * ibm_slot_from_id - workaround for bad ibm hardware
135 * @id: the slot number that linux refers to the slot by
136 *
137 * Description: this method returns the aCPI slot descriptor
138 * corresponding to the Linux slot number. This descriptor
139 * has info about the aPCI slot id and attention status.
140 * This descriptor must be freed using kfree when done.
141 **/
142static union apci_descriptor *ibm_slot_from_id(int id)
143{
144 int ind = 0, size;
145 union apci_descriptor *ret = NULL, *des;
146 char *table;
147
148 size = ibm_get_table_from_acpi(&table);
149 des = (union apci_descriptor *)table;
150 if (memcmp(des->header.sig, "aPCI", 4) != 0)
151 goto ibm_slot_done;
152
153 des = (union apci_descriptor *)&table[ind += des->header.len];
154 while (ind < size && (des->generic.type != 0x82 ||
155 des->slot.slot_num != id)) {
156 des = (union apci_descriptor *)&table[ind += des->generic.len];
157 }
158
159 if (ind < size && des->slot.slot_num == id)
160 ret = des;
161
162ibm_slot_done:
163 if (ret) {
164 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
165 memcpy(ret, des, sizeof(union apci_descriptor));
166 }
167 kfree(table);
168 return ret;
169}
170
171/**
172 * ibm_set_attention_status - callback method to set the attention LED
173 * @slot: the hotplug_slot to work with
174 * @status: what to set the LED to (0 or 1)
175 *
176 * Description: this method is registered with the acpiphp module as a
177 * callback to do the device specific task of setting the LED status
178 **/
179static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
180{
181 union acpi_object args[2];
182 struct acpi_object_list params = { .pointer = args, .count = 2 };
183 acpi_status stat;
184 unsigned long rc;
185 union apci_descriptor *ibm_slot;
186
187 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
188
189 dbg("%s: set slot %d (%d) attention status to %d\n", __FUNCTION__,
190 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
191 (status ? 1 : 0));
192
193 args[0].type = ACPI_TYPE_INTEGER;
194 args[0].integer.value = ibm_slot->slot.slot_id;
195 args[1].type = ACPI_TYPE_INTEGER;
196 args[1].integer.value = (status) ? 1 : 0;
197
198 kfree(ibm_slot);
199
200 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
201 if (ACPI_FAILURE(stat)) {
202 err("APLS evaluation failed: 0x%08x\n", stat);
203 return -ENODEV;
204 } else if (!rc) {
205 err("APLS method failed: 0x%08lx\n", rc);
206 return -ERANGE;
207 }
208 return 0;
209}
210
211/**
212 * ibm_get_attention_status - callback method to get attention LED status
213 * @slot: the hotplug_slot to work with
214 * @status: returns what the LED is set to (0 or 1)
215 *
216 * Description: this method is registered with the acpiphp module as a
217 * callback to do the device specific task of getting the LED status
218 *
219 * Because there is no direct method of getting the LED status directly
220 * from an ACPI call, we read the aPCI table and parse out our
221 * slot descriptor to read the status from that.
222 **/
223static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
224{
225 union apci_descriptor *ibm_slot;
226
227 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
228
229 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
230 *status = 1;
231 else
232 *status = 0;
233
234 dbg("%s: get slot %d (%d) attention status is %d\n", __FUNCTION__,
235 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
236 *status);
237
238 kfree(ibm_slot);
239 return 0;
240}
241
242/**
243 * ibm_handle_events - listens for ACPI events for the IBM37D0 device
244 * @handle: an ACPI handle to the device that caused the event
245 * @event: the event info (device specific)
246 * @context: passed context (our notification struct)
247 *
248 * Description: this method is registered as a callback with the ACPI
249 * subsystem it is called when this device has an event to notify the OS of
250 *
251 * The events actually come from the device as two events that get
252 * synthesized into one event with data by this function. The event
253 * ID comes first and then the slot number that caused it. We report
254 * this as one event to the OS.
255 *
256 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
257 * only re-enable the interrupt that causes this event AFTER this method
258 * has returned, thereby enforcing serial access for the notification struct.
259 **/
260static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
261{
262 u8 detail = event & 0x0f;
263 u8 subevent = event & 0xf0;
264 struct notification *note = context;
265
266 dbg("%s: Received notification %02x\n", __FUNCTION__, event);
267
268 if (subevent == 0x80) {
269 dbg("%s: generationg bus event\n", __FUNCTION__);
270 acpi_bus_generate_event(note->device, note->event, detail);
271 } else
272 note->event = event;
273}
274
275/**
276 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
277 * @bufp: address to pointer to allocate for the table
278 *
279 * Description: this method reads the APLS buffer in from ACPI and
280 * stores the "stripped" table into a single buffer
281 * it allocates and passes the address back in bufp
282 *
283 * If NULL is passed in as buffer, this method only calculates
284 * the size of the table and returns that without filling
285 * in the buffer
286 *
287 * returns < 0 on error or the size of the table on success
288 **/
289static int ibm_get_table_from_acpi(char **bufp)
290{
291 union acpi_object *package;
292 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
293 acpi_status status;
294 char *lbuf = NULL;
295 int i, size = -EIO;
296
297 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
298 if (ACPI_FAILURE(status)) {
299 err("%s: APCI evaluation failed\n", __FUNCTION__);
300 return -ENODEV;
301 }
302
303 package = (union acpi_object *) buffer.pointer;
Pavel Machek072888f2006-01-08 20:11:59 +0100304 if (!(package) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 (package->type != ACPI_TYPE_PACKAGE) ||
306 !(package->package.elements)) {
307 err("%s: Invalid APCI object\n", __FUNCTION__);
308 goto read_table_done;
309 }
310
311 for(size = 0, i = 0; i < package->package.count; i++) {
312 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
313 err("%s: Invalid APCI element %d\n", __FUNCTION__, i);
314 goto read_table_done;
315 }
316 size += package->package.elements[i].buffer.length;
317 }
318
319 if (bufp == NULL)
320 goto read_table_done;
321
Burman Yan36bcbec2006-12-19 12:56:11 -0800322 lbuf = kzalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
324 __FUNCTION__, package->package.count, size, lbuf);
325
326 if (lbuf) {
327 *bufp = lbuf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 } else {
329 size = -ENOMEM;
330 goto read_table_done;
331 }
332
333 size = 0;
334 for (i=0; i<package->package.count; i++) {
335 memcpy(&lbuf[size],
336 package->package.elements[i].buffer.pointer,
337 package->package.elements[i].buffer.length);
338 size += package->package.elements[i].buffer.length;
339 }
340
341read_table_done:
342 kfree(buffer.pointer);
343 return size;
344}
345
346/**
347 * ibm_read_apci_table - callback for the sysfs apci_table file
348 * @kobj: the kobject this binary attribute is a part of
349 * @buffer: the kernel space buffer to fill
350 * @pos: the offset into the file
351 * @size: the number of bytes requested
352 *
353 * Description: gets registered with sysfs as the reader callback
354 * to be executed when /sys/bus/pci/slots/apci_table gets read
355 *
356 * Since we don't get notified on open and close for this file,
357 * things get really tricky here...
358 * our solution is to only allow reading the table in all at once
359 **/
360static ssize_t ibm_read_apci_table(struct kobject *kobj,
361 char *buffer, loff_t pos, size_t size)
362{
363 int bytes_read = -EINVAL;
364 char *table = NULL;
365
366 dbg("%s: pos = %d, size = %zd\n", __FUNCTION__, (int)pos, size);
367
368 if (pos == 0) {
369 bytes_read = ibm_get_table_from_acpi(&table);
370 if (bytes_read > 0 && bytes_read <= size)
371 memcpy(buffer, table, bytes_read);
372 kfree(table);
373 }
374 return bytes_read;
375}
376
377/**
378 * ibm_find_acpi_device - callback to find our ACPI device
379 * @handle: the ACPI handle of the device we are inspecting
380 * @lvl: depth into the namespace tree
381 * @context: a pointer to our handle to fill when we find the device
382 * @rv: a return value to fill if desired
383 *
384 * Description: used as a callback when calling acpi_walk_namespace
385 * to find our device. When this method returns non-zero
386 * acpi_walk_namespace quits its search and returns our value
387 **/
388static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
389 u32 lvl, void *context, void **rv)
390{
391 acpi_handle *phandle = (acpi_handle *)context;
392 acpi_status status;
393 struct acpi_device_info info;
394 struct acpi_buffer info_buffer = {
395 .length = sizeof(struct acpi_device_info),
396 .pointer = &info,
397 };
398
399 status = acpi_get_object_info(handle, &info_buffer);
400 if (ACPI_FAILURE(status)) {
401 err("%s: Failed to get device information", __FUNCTION__);
402 return 0;
403 }
404 info.hardware_id.value[sizeof(info.hardware_id.value) - 1] = '\0';
405
Pavel Machek072888f2006-01-08 20:11:59 +0100406 if (info.current_status && (info.valid & ACPI_VALID_HID) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 (!strcmp(info.hardware_id.value, IBM_HARDWARE_ID1) ||
408 !strcmp(info.hardware_id.value, IBM_HARDWARE_ID2))) {
409 dbg("found hardware: %s, handle: %p\n", info.hardware_id.value,
410 handle);
411 *phandle = handle;
412 /* returning non-zero causes the search to stop
413 * and returns this value to the caller of
414 * acpi_walk_namespace, but it also causes some warnings
415 * in the acpi debug code to print...
416 */
417 return FOUND_APCI;
418 }
419 return 0;
420}
421
422static int __init ibm_acpiphp_init(void)
423{
424 int retval = 0;
425 acpi_status status;
426 struct acpi_device *device;
427 struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj;
428
429 dbg("%s\n", __FUNCTION__);
430
431 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
432 ACPI_UINT32_MAX, ibm_find_acpi_device,
433 &ibm_acpi_handle, NULL) != FOUND_APCI) {
434 err("%s: acpi_walk_namespace failed\n", __FUNCTION__);
435 retval = -ENODEV;
436 goto init_return;
437 }
438 dbg("%s: found IBM aPCI device\n", __FUNCTION__);
439 if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
440 err("%s: acpi_bus_get_device failed\n", __FUNCTION__);
441 retval = -ENODEV;
442 goto init_return;
443 }
444 if (acpiphp_register_attention(&ibm_attention_info)) {
445 retval = -ENODEV;
446 goto init_return;
447 }
448
449 ibm_note.device = device;
Pavel Machek072888f2006-01-08 20:11:59 +0100450 status = acpi_install_notify_handler(ibm_acpi_handle,
451 ACPI_DEVICE_NOTIFY, ibm_handle_events,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 &ibm_note);
453 if (ACPI_FAILURE(status)) {
Pavel Machek072888f2006-01-08 20:11:59 +0100454 err("%s: Failed to register notification handler\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 __FUNCTION__);
456 retval = -EBUSY;
457 goto init_cleanup;
458 }
459
460 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
461 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
462
463 return retval;
464
465init_cleanup:
466 acpiphp_unregister_attention(&ibm_attention_info);
467init_return:
468 return retval;
469}
470
471static void __exit ibm_acpiphp_exit(void)
472{
473 acpi_status status;
474 struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj;
475
476 dbg("%s\n", __FUNCTION__);
477
478 if (acpiphp_unregister_attention(&ibm_attention_info))
479 err("%s: attention info deregistration failed", __FUNCTION__);
480
Pavel Machek072888f2006-01-08 20:11:59 +0100481 status = acpi_remove_notify_handler(
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 ibm_acpi_handle,
483 ACPI_DEVICE_NOTIFY,
484 ibm_handle_events);
Pavel Machek072888f2006-01-08 20:11:59 +0100485 if (ACPI_FAILURE(status))
486 err("%s: Notification handler removal failed\n", __FUNCTION__);
487 /* remove the /sys entries */
Randy.Dunlap995982c2006-07-10 23:05:25 -0700488 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489}
490
491module_init(ibm_acpiphp_init);
492module_exit(ibm_acpiphp_exit);