summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/pci_slot.c
blob: b9ab030a52d50843b0319fb25875f7c965b72ce0 (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
/*
 *  pci_slot.c - ACPI PCI Slot Driver
 *
 *  The code here is heavily leveraged from the acpiphp module.
 *  Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance.
 *  Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code
 *  review and fixes.
 *
 *  Copyright (C) 2007 Alex Chiang <achiang@hp.com>
 *  Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms and conditions of the GNU General Public License,
 *  version 2, as published by the Free Software Foundation.
 *
 *  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.  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.,
 *  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

static int debug;
static int check_sta_before_sun;

#define DRIVER_VERSION 	"0.1"
#define DRIVER_AUTHOR	"Alex Chiang <achiang@hp.com>"
#define DRIVER_DESC	"ACPI PCI Slot Detection Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
module_param(debug, bool, 0644);

#define _COMPONENT		ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_slot");

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

#define SLOT_NAME_SIZE 20		/* Inspired by #define in acpiphp.h */

struct acpi_pci_slot {
	acpi_handle root_handle;	/* handle of the root bridge */
	struct pci_slot *pci_slot;	/* corresponding pci_slot */
	struct list_head list;		/* node in the list of slots */
};

static int acpi_pci_slot_add(acpi_handle handle);
static void acpi_pci_slot_remove(acpi_handle handle);

static LIST_HEAD(slot_list);
static DEFINE_MUTEX(slot_list_lock);
static struct acpi_pci_driver acpi_pci_slot_driver = {
	.add = acpi_pci_slot_add,
	.remove = acpi_pci_slot_remove,
};

static int
check_slot(acpi_handle handle, int *device, unsigned long *sun)
{
	int retval = 0;
	unsigned long adr, sta;
	acpi_status status;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
	dbg("Checking slot on path: %s\n", (char *)buffer.pointer);

	if (check_sta_before_sun) {
		/* If SxFy doesn't have _STA, we just assume it's there */
		status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
		if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) {
			retval = -1;
			goto out;
		}
	}

	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
	if (ACPI_FAILURE(status)) {
		dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
		retval = -1;
		goto out;
	}

	*device = (adr >> 16) & 0xffff;

	/* No _SUN == not a slot == bail */
	status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
	if (ACPI_FAILURE(status)) {
		dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
		retval = -1;
		goto out;
	}

out:
	kfree(buffer.pointer);
	return retval;
}

struct callback_args {
	acpi_walk_callback	user_function;	/* only for walk_p2p_bridge */
	struct pci_bus		*pci_bus;
	acpi_handle		root_handle;
};

/*
 * register_slot
 *
 * Called once for each SxFy object in the namespace. Don't worry about
 * calling pci_create_slot multiple times for the same pci_bus:device,
 * since each subsequent call simply bumps the refcount on the pci_slot.
 *
 * The number of calls to pci_destroy_slot from unregister_slot is
 * symmetrical.
 */
static acpi_status
register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	int device;
	unsigned long sun;
	char name[SLOT_NAME_SIZE];
	struct acpi_pci_slot *slot;
	struct pci_slot *pci_slot;
	struct callback_args *parent_context = context;
	struct pci_bus *pci_bus = parent_context->pci_bus;

	if (check_slot(handle, &device, &sun))
		return AE_OK;

	slot = kmalloc(sizeof(*slot), GFP_KERNEL);
	if (!slot) {
		err("%s: cannot allocate memory\n", __func__);
		return AE_OK;
	}

	snprintf(name, sizeof(name), "%u", (u32)sun);
	pci_slot = pci_create_slot(pci_bus, device, name);
	if (IS_ERR(pci_slot)) {
		err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
		kfree(slot);
	}

	slot->root_handle = parent_context->root_handle;
	slot->pci_slot = pci_slot;
	INIT_LIST_HEAD(&slot->list);
	mutex_lock(&slot_list_lock);
	list_add(&slot->list, &slot_list);
	mutex_unlock(&slot_list_lock);

	dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
		pci_slot, pci_bus->number, device, name);

	return AE_OK;
}

/*
 * walk_p2p_bridge - discover and walk p2p bridges
 * @handle: points to an acpi_pci_root
 * @context: p2p_bridge_context pointer
 *
 * Note that when we call ourselves recursively, we pass a different
 * value of pci_bus in the child_context.
 */
static acpi_status
walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	int device, function;
	unsigned long adr;
	acpi_status status;
	acpi_handle dummy_handle;
	acpi_walk_callback user_function;

	struct pci_dev *dev;
	struct pci_bus *pci_bus;
	struct callback_args child_context;
	struct callback_args *parent_context = context;

	pci_bus = parent_context->pci_bus;
	user_function = parent_context->user_function;

	status = acpi_get_handle(handle, "_ADR", &dummy_handle);
	if (ACPI_FAILURE(status))
		return AE_OK;

	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
	if (ACPI_FAILURE(status))
		return AE_OK;

	device = (adr >> 16) & 0xffff;
	function = adr & 0xffff;

	dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
	if (!dev || !dev->subordinate)
		goto out;

	child_context.pci_bus = dev->subordinate;
	child_context.user_function = user_function;
	child_context.root_handle = parent_context->root_handle;

	dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     user_function, &child_context, NULL);
	if (ACPI_FAILURE(status))
		goto out;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     walk_p2p_bridge, &child_context, NULL);
out:
	pci_dev_put(dev);
	return AE_OK;
}

/*
 * walk_root_bridge - generic root bridge walker
 * @handle: points to an acpi_pci_root
 * @user_function: user callback for slot objects
 *
 * Call user_function for all objects underneath this root bridge.
 * Walk p2p bridges underneath us and call user_function on those too.
 */
static int
walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
{
	int seg, bus;
	unsigned long tmp;
	acpi_status status;
	acpi_handle dummy_handle;
	struct pci_bus *pci_bus;
	struct callback_args context;

	/* If the bridge doesn't have _STA, we assume it is always there */
	status = acpi_get_handle(handle, "_STA", &dummy_handle);
	if (ACPI_SUCCESS(status)) {
		status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
		if (ACPI_FAILURE(status)) {
			info("%s: _STA evaluation failure\n", __func__);
			return 0;
		}
		if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0)
			/* don't register this object */
			return 0;
	}

	status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
	seg = ACPI_SUCCESS(status) ? tmp : 0;

	status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
	bus = ACPI_SUCCESS(status) ? tmp : 0;

	pci_bus = pci_find_bus(seg, bus);
	if (!pci_bus)
		return 0;

	context.pci_bus = pci_bus;
	context.user_function = user_function;
	context.root_handle = handle;

	dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     user_function, &context, NULL);
	if (ACPI_FAILURE(status))
		return status;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     walk_p2p_bridge, &context, NULL);
	if (ACPI_FAILURE(status))
		err("%s: walk_p2p_bridge failure - %d\n", __func__, status);

	return status;
}

/*
 * acpi_pci_slot_add
 * @handle: points to an acpi_pci_root
 */
static int
acpi_pci_slot_add(acpi_handle handle)
{
	acpi_status status;

	status = walk_root_bridge(handle, register_slot);
	if (ACPI_FAILURE(status))
		err("%s: register_slot failure - %d\n", __func__, status);

	return status;
}

/*
 * acpi_pci_slot_remove
 * @handle: points to an acpi_pci_root
 */
static void
acpi_pci_slot_remove(acpi_handle handle)
{
	struct acpi_pci_slot *slot, *tmp;

	mutex_lock(&slot_list_lock);
	list_for_each_entry_safe(slot, tmp, &slot_list, list) {
		if (slot->root_handle == handle) {
			list_del(&slot->list);
			pci_destroy_slot(slot->pci_slot);
			kfree(slot);
		}
	}
	mutex_unlock(&slot_list_lock);
}

static int do_sta_before_sun(const struct dmi_system_id *d)
{
	info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
	check_sta_before_sun = 1;
	return 0;
}

static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
	/*
	 * Fujitsu Primequest machines will return 1023 to indicate an
	 * error if the _SUN method is evaluated on SxFy objects that
	 * are not present (as indicated by _STA), so for those machines,
	 * we want to check _STA before evaluating _SUN.
	 */
	{
	 .callback = do_sta_before_sun,
	 .ident = "Fujitsu PRIMEQUEST",
	 .matches = {
		DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
		DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
		},
	},
	{}
};

static int __init
acpi_pci_slot_init(void)
{
	dmi_check_system(acpi_pci_slot_dmi_table);
	acpi_pci_register_driver(&acpi_pci_slot_driver);
	return 0;
}

static void __exit
acpi_pci_slot_exit(void)
{
	acpi_pci_unregister_driver(&acpi_pci_slot_driver);
}

module_init(acpi_pci_slot_init);
module_exit(acpi_pci_slot_exit);
OpenPOWER on IntegriCloud