summaryrefslogtreecommitdiff
path: root/drivers/pci/hotplug/acpiphp_ibm.c
blob: 8d45f6d69540f53a2f8b3ea33cce9f86969872c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
/*
 * ACPI PCI Hot Plug IBM Extension
 *
 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
 * Copyright (C) 2004 IBM Corp.
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <vernux@us.ibm.com>
 *
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <acpi/acpi_bus.h>
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <asm/uaccess.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>

#include "acpiphp.h"
#include "../pci.h"

#define DRIVER_VERSION	"1.0.1"
#define DRIVER_AUTHOR	"Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
#define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver IBM extension"

static bool debug;

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRIVER_VERSION);
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
#define MY_NAME "acpiphp_ibm"

#undef dbg
#define dbg(format, arg...)				\
do {							\
	if (debug)					\
		printk(KERN_DEBUG "%s: " format,	\
				MY_NAME , ## arg);	\
} while (0)

#define FOUND_APCI 0x61504349
/* these are the names for the IBM ACPI pseudo-device */
#define IBM_HARDWARE_ID1 "IBM37D0"
#define IBM_HARDWARE_ID2 "IBM37D4"

#define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun)

/* union apci_descriptor - allows access to the
 * various device descriptors that are embedded in the
 * aPCI table
 */
union apci_descriptor {
	struct {
		char sig[4];
		u8   len;
	} header;
	struct {
		u8  type;
		u8  len;
		u16 slot_id;
		u8  bus_id;
		u8  dev_num;
		u8  slot_num;
		u8  slot_attr[2];
		u8  attn;
		u8  status[2];
		u8  sun;
		u8  res[3];
	} slot;
	struct {
		u8 type;
		u8 len;
	} generic;
};

/* struct notification - keeps info about the device
 * that cause the ACPI notification event
 */
struct notification {
	struct acpi_device *device;
	u8                  event;
};

static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
static int ibm_get_table_from_acpi(char **bufp);
static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
				   struct bin_attribute *bin_attr,
				   char *buffer, loff_t pos, size_t size);
static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
		u32 lvl, void *context, void **rv);
static int __init ibm_acpiphp_init(void);
static void __exit ibm_acpiphp_exit(void);

static acpi_handle ibm_acpi_handle;
static struct notification ibm_note;
static struct bin_attribute ibm_apci_table_attr = {
	    .attr = {
		    .name = "apci_table",
		    .mode = S_IRUGO,
	    },
	    .read = ibm_read_apci_table,
	    .write = NULL,
};
static struct acpiphp_attention_info ibm_attention_info = 
{
	.set_attn = ibm_set_attention_status,
	.get_attn = ibm_get_attention_status,
	.owner = THIS_MODULE,
};

/**
 * ibm_slot_from_id - workaround for bad ibm hardware
 * @id: the slot number that linux refers to the slot by
 *
 * Description: This method returns the aCPI slot descriptor
 * corresponding to the Linux slot number.  This descriptor
 * has info about the aPCI slot id and attention status.
 * This descriptor must be freed using kfree when done.
 */
static union apci_descriptor *ibm_slot_from_id(int id)
{
	int ind = 0, size;
	union apci_descriptor *ret = NULL, *des;
	char *table;

	size = ibm_get_table_from_acpi(&table);
	des = (union apci_descriptor *)table;
	if (memcmp(des->header.sig, "aPCI", 4) != 0)
		goto ibm_slot_done;

	des = (union apci_descriptor *)&table[ind += des->header.len];
	while (ind < size && (des->generic.type != 0x82 ||
			des->slot.slot_num != id)) {
		des = (union apci_descriptor *)&table[ind += des->generic.len];
	}

	if (ind < size && des->slot.slot_num == id)
		ret = des;

ibm_slot_done:
	if (ret) {
		ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
		memcpy(ret, des, sizeof(union apci_descriptor));
	}
	kfree(table);
	return ret;
}

/**
 * ibm_set_attention_status - callback method to set the attention LED
 * @slot: the hotplug_slot to work with
 * @status: what to set the LED to (0 or 1)
 *
 * Description: This method is registered with the acpiphp module as a
 * callback to do the device specific task of setting the LED status.
 */
static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
{
	union acpi_object args[2]; 
	struct acpi_object_list params = { .pointer = args, .count = 2 };
	acpi_status stat; 
	unsigned long long rc;
	union apci_descriptor *ibm_slot;

	ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));

	dbg("%s: set slot %d (%d) attention status to %d\n", __func__,
			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
			(status ? 1 : 0));

	args[0].type = ACPI_TYPE_INTEGER;
	args[0].integer.value = ibm_slot->slot.slot_id;
	args[1].type = ACPI_TYPE_INTEGER;
	args[1].integer.value = (status) ? 1 : 0;

	kfree(ibm_slot);

	stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
	if (ACPI_FAILURE(stat)) {
		err("APLS evaluation failed:  0x%08x\n", stat);
		return -ENODEV;
	} else if (!rc) {
		err("APLS method failed:  0x%08llx\n", rc);
		return -ERANGE;
	}
	return 0;
}

/**
 * ibm_get_attention_status - callback method to get attention LED status
 * @slot: the hotplug_slot to work with
 * @status: returns what the LED is set to (0 or 1)
 *
 * Description: This method is registered with the acpiphp module as a
 * callback to do the device specific task of getting the LED status.
 * 
 * Because there is no direct method of getting the LED status directly
 * from an ACPI call, we read the aPCI table and parse out our
 * slot descriptor to read the status from that.
 */
static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
{
	union apci_descriptor *ibm_slot;

	ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));

	if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
		*status = 1;
	else
		*status = 0;

	dbg("%s: get slot %d (%d) attention status is %d\n", __func__,
			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
			*status);

	kfree(ibm_slot);
	return 0;
}

/**
 * ibm_handle_events - listens for ACPI events for the IBM37D0 device
 * @handle: an ACPI handle to the device that caused the event
 * @event: the event info (device specific)
 * @context: passed context (our notification struct)
 *
 * Description: This method is registered as a callback with the ACPI
 * subsystem it is called when this device has an event to notify the OS of.
 *
 * The events actually come from the device as two events that get
 * synthesized into one event with data by this function.  The event
 * ID comes first and then the slot number that caused it.  We report
 * this as one event to the OS.
 *
 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
 * only re-enable the interrupt that causes this event AFTER this method
 * has returned, thereby enforcing serial access for the notification struct.
 */
static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
{
	u8 detail = event & 0x0f;
	u8 subevent = event & 0xf0;
	struct notification *note = context;

	dbg("%s: Received notification %02x\n", __func__, event);

	if (subevent == 0x80) {
		dbg("%s: generationg bus event\n", __func__);
		acpi_bus_generate_proc_event(note->device, note->event, detail);
		acpi_bus_generate_netlink_event(note->device->pnp.device_class,
						  dev_name(&note->device->dev),
						  note->event, detail);
	} else
		note->event = event;
}

/**
 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
 * @bufp: address to pointer to allocate for the table
 *
 * Description: This method reads the APLS buffer in from ACPI and
 * stores the "stripped" table into a single buffer
 * it allocates and passes the address back in bufp.
 *
 * If NULL is passed in as buffer, this method only calculates
 * the size of the table and returns that without filling
 * in the buffer.
 *
 * Returns < 0 on error or the size of the table on success.
 */
static int ibm_get_table_from_acpi(char **bufp)
{
	union acpi_object *package;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	acpi_status status;
	char *lbuf = NULL;
	int i, size = -EIO;

	status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
	if (ACPI_FAILURE(status)) {
		err("%s:  APCI evaluation failed\n", __func__);
		return -ENODEV;
	}

	package = (union acpi_object *) buffer.pointer;
	if (!(package) ||
			(package->type != ACPI_TYPE_PACKAGE) ||
			!(package->package.elements)) {
		err("%s:  Invalid APCI object\n", __func__);
		goto read_table_done;
	}

	for(size = 0, i = 0; i < package->package.count; i++) {
		if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
			err("%s:  Invalid APCI element %d\n", __func__, i);
			goto read_table_done;
		}
		size += package->package.elements[i].buffer.length;
	}

	if (bufp == NULL)
		goto read_table_done;

	lbuf = kzalloc(size, GFP_KERNEL);
	dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
			__func__, package->package.count, size, lbuf);

	if (lbuf) {
		*bufp = lbuf;
	} else {
		size = -ENOMEM;
		goto read_table_done;
	}

	size = 0;
	for (i=0; i<package->package.count; i++) {
		memcpy(&lbuf[size],
				package->package.elements[i].buffer.pointer,
				package->package.elements[i].buffer.length);
		size += package->package.elements[i].buffer.length;
	}

read_table_done:
	kfree(buffer.pointer);
	return size;
}

/**
 * ibm_read_apci_table - callback for the sysfs apci_table file
 * @filp: the open sysfs file
 * @kobj: the kobject this binary attribute is a part of
 * @bin_attr: struct bin_attribute for this file
 * @buffer: the kernel space buffer to fill
 * @pos: the offset into the file
 * @size: the number of bytes requested
 *
 * Description: Gets registered with sysfs as the reader callback
 * to be executed when /sys/bus/pci/slots/apci_table gets read.
 *
 * Since we don't get notified on open and close for this file,
 * things get really tricky here...
 * our solution is to only allow reading the table in all at once.
 */
static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
				   struct bin_attribute *bin_attr,
				   char *buffer, loff_t pos, size_t size)
{
	int bytes_read = -EINVAL;
	char *table = NULL;
	
	dbg("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);

	if (pos == 0) {
		bytes_read = ibm_get_table_from_acpi(&table);
		if (bytes_read > 0 && bytes_read <= size)
			memcpy(buffer, table, bytes_read);
		kfree(table);
	}
	return bytes_read;
}

/**
 * ibm_find_acpi_device - callback to find our ACPI device
 * @handle: the ACPI handle of the device we are inspecting
 * @lvl: depth into the namespace tree
 * @context: a pointer to our handle to fill when we find the device
 * @rv: a return value to fill if desired
 *
 * Description: Used as a callback when calling acpi_walk_namespace
 * to find our device.  When this method returns non-zero
 * acpi_walk_namespace quits its search and returns our value.
 */
static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
		u32 lvl, void *context, void **rv)
{
	acpi_handle *phandle = (acpi_handle *)context;
	acpi_status status; 
	struct acpi_device_info *info;
	int retval = 0;

	status = acpi_get_object_info(handle, &info);
	if (ACPI_FAILURE(status)) {
		err("%s:  Failed to get device information status=0x%x\n",
			__func__, status);
		return retval;
	}

	if (info->current_status && (info->valid & ACPI_VALID_HID) &&
			(!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
			 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
		dbg("found hardware: %s, handle: %p\n",
			info->hardware_id.string, handle);
		*phandle = handle;
		/* returning non-zero causes the search to stop
		 * and returns this value to the caller of 
		 * acpi_walk_namespace, but it also causes some warnings
		 * in the acpi debug code to print...
		 */
		retval = FOUND_APCI;
	}
	kfree(info);
	return retval;
}

static int __init ibm_acpiphp_init(void)
{
	int retval = 0;
	acpi_status status;
	struct acpi_device *device;
	struct kobject *sysdir = &pci_slots_kset->kobj;

	dbg("%s\n", __func__);

	if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
			ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
			&ibm_acpi_handle, NULL) != FOUND_APCI) {
		err("%s: acpi_walk_namespace failed\n", __func__);
		retval = -ENODEV;
		goto init_return;
	}
	dbg("%s: found IBM aPCI device\n", __func__);
	if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
		err("%s: acpi_bus_get_device failed\n", __func__);
		retval = -ENODEV;
		goto init_return;
	}
	if (acpiphp_register_attention(&ibm_attention_info)) {
		retval = -ENODEV;
		goto init_return;
	}

	ibm_note.device = device;
	status = acpi_install_notify_handler(ibm_acpi_handle,
			ACPI_DEVICE_NOTIFY, ibm_handle_events,
			&ibm_note);
	if (ACPI_FAILURE(status)) {
		err("%s: Failed to register notification handler\n",
				__func__);
		retval = -EBUSY;
		goto init_cleanup;
	}

	ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
	retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);

	return retval;

init_cleanup:
	acpiphp_unregister_attention(&ibm_attention_info);
init_return:
	return retval;
}

static void __exit ibm_acpiphp_exit(void)
{
	acpi_status status;
	struct kobject *sysdir = &pci_slots_kset->kobj;

	dbg("%s\n", __func__);

	if (acpiphp_unregister_attention(&ibm_attention_info))
		err("%s: attention info deregistration failed", __func__);

	status = acpi_remove_notify_handler(
			   ibm_acpi_handle,
			   ACPI_DEVICE_NOTIFY,
			   ibm_handle_events);
	if (ACPI_FAILURE(status))
		err("%s: Notification handler removal failed\n", __func__);
	/* remove the /sys entries */
	sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
}

module_init(ibm_acpiphp_init);
module_exit(ibm_acpiphp_exit);