aboutsummaryrefslogtreecommitdiff
path: root/drivers/pci/dmar.c
blob: 91b2dc956be5de68e1ebefe1585e6e79cea62fab (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
/*
 * Copyright (c) 2006, Intel Corporation.
 *
 * 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 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., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * 	Copyright (C) Ashok Raj <ashok.raj@intel.com>
 *	Copyright (C) Shaohua Li <shaohua.li@intel.com>
 *	Copyright (C) Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
 *
 * 	This file implements early detection/parsing of DMA Remapping Devices
 * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
 * tables.
 */

#include <linux/pci.h>
#include <linux/dmar.h>
#include "iova.h"

#undef PREFIX
#define PREFIX "DMAR:"

/* No locks are needed as DMA remapping hardware unit
 * list is constructed at boot time and hotplug of
 * these units are not supported by the architecture.
 */
LIST_HEAD(dmar_drhd_units);
LIST_HEAD(dmar_rmrr_units);

static struct acpi_table_header * __initdata dmar_tbl;

static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
{
	/*
	 * add INCLUDE_ALL at the tail, so scan the list will find it at
	 * the very end.
	 */
	if (drhd->include_all)
		list_add_tail(&drhd->list, &dmar_drhd_units);
	else
		list_add(&drhd->list, &dmar_drhd_units);
}

static void __init dmar_register_rmrr_unit(struct dmar_rmrr_unit *rmrr)
{
	list_add(&rmrr->list, &dmar_rmrr_units);
}

static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
					   struct pci_dev **dev, u16 segment)
{
	struct pci_bus *bus;
	struct pci_dev *pdev = NULL;
	struct acpi_dmar_pci_path *path;
	int count;

	bus = pci_find_bus(segment, scope->bus);
	path = (struct acpi_dmar_pci_path *)(scope + 1);
	count = (scope->length - sizeof(struct acpi_dmar_device_scope))
		/ sizeof(struct acpi_dmar_pci_path);

	while (count) {
		if (pdev)
			pci_dev_put(pdev);
		/*
		 * Some BIOSes list non-exist devices in DMAR table, just
		 * ignore it
		 */
		if (!bus) {
			printk(KERN_WARNING
			PREFIX "Device scope bus [%d] not found\n",
			scope->bus);
			break;
		}
		pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
		if (!pdev) {
			printk(KERN_WARNING PREFIX
			"Device scope device [%04x:%02x:%02x.%02x] not found\n",
				segment, bus->number, path->dev, path->fn);
			break;
		}
		path ++;
		count --;
		bus = pdev->subordinate;
	}
	if (!pdev) {
		printk(KERN_WARNING PREFIX
		"Device scope device [%04x:%02x:%02x.%02x] not found\n",
		segment, scope->bus, path->dev, path->fn);
		*dev = NULL;
		return 0;
	}
	if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && \
			pdev->subordinate) || (scope->entry_type == \
			ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
		pci_dev_put(pdev);
		printk(KERN_WARNING PREFIX
			"Device scope type does not match for %s\n",
			 pci_name(pdev));
		return -EINVAL;
	}
	*dev = pdev;
	return 0;
}

static int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
				       struct pci_dev ***devices, u16 segment)
{
	struct acpi_dmar_device_scope *scope;
	void * tmp = start;
	int index;
	int ret;

	*cnt = 0;
	while (start < end) {
		scope = start;
		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
			(*cnt)++;
		else
			printk(KERN_WARNING PREFIX
				"Unsupported device scope\n");
		start += scope->length;
	}
	if (*cnt == 0)
		return 0;

	*devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
	if (!*devices)
		return -ENOMEM;

	start = tmp;
	index = 0;
	while (start < end) {
		scope = start;
		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
			ret = dmar_parse_one_dev_scope(scope,
				&(*devices)[index], segment);
			if (ret) {
				kfree(*devices);
				return ret;
			}
			index ++;
		}
		start += scope->length;
	}

	return 0;
}

/**
 * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
 * structure which uniquely represent one DMA remapping hardware unit
 * present in the platform
 */
static int __init
dmar_parse_one_drhd(struct acpi_dmar_header *header)
{
	struct acpi_dmar_hardware_unit *drhd;
	struct dmar_drhd_unit *dmaru;
	int ret = 0;
	static int include_all;

	dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
	if (!dmaru)
		return -ENOMEM;

	drhd = (struct acpi_dmar_hardware_unit *)header;
	dmaru->reg_base_addr = drhd->address;
	dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */

	if (!dmaru->include_all)
		ret = dmar_parse_dev_scope((void *)(drhd + 1),
				((void *)drhd) + header->length,
				&dmaru->devices_cnt, &dmaru->devices,
				drhd->segment);
	else {
		/* Only allow one INCLUDE_ALL */
		if (include_all) {
			printk(KERN_WARNING PREFIX "Only one INCLUDE_ALL "
				"device scope is allowed\n");
			ret = -EINVAL;
		}
		include_all = 1;
	}

	if (ret || (dmaru->devices_cnt == 0 && !dmaru->include_all))
		kfree(dmaru);
	else
		dmar_register_drhd_unit(dmaru);
	return ret;
}

static int __init
dmar_parse_one_rmrr(struct acpi_dmar_header *header)
{
	struct acpi_dmar_reserved_memory *rmrr;
	struct dmar_rmrr_unit *rmrru;
	int ret = 0;

	rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
	if (!rmrru)
		return -ENOMEM;

	rmrr = (struct acpi_dmar_reserved_memory *)header;
	rmrru->base_address = rmrr->base_address;
	rmrru->end_address = rmrr->end_address;
	ret = dmar_parse_dev_scope((void *)(rmrr + 1),
		((void *)rmrr) + header->length,
		&rmrru->devices_cnt, &rmrru->devices, rmrr->segment);

	if (ret || (rmrru->devices_cnt == 0))
		kfree(rmrru);
	else
		dmar_register_rmrr_unit(rmrru);
	return ret;
}

static void __init
dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
{
	struct acpi_dmar_hardware_unit *drhd;
	struct acpi_dmar_reserved_memory *rmrr;

	switch (header->type) {
	case ACPI_DMAR_TYPE_HARDWARE_UNIT:
		drhd = (struct acpi_dmar_hardware_unit *)header;
		printk (KERN_INFO PREFIX
			"DRHD (flags: 0x%08x)base: 0x%016Lx\n",
			drhd->flags, drhd->address);
		break;
	case ACPI_DMAR_TYPE_RESERVED_MEMORY:
		rmrr = (struct acpi_dmar_reserved_memory *)header;

		printk (KERN_INFO PREFIX
			"RMRR base: 0x%016Lx end: 0x%016Lx\n",
			rmrr->base_address, rmrr->end_address);
		break;
	}
}

/**
 * parse_dmar_table - parses the DMA reporting table
 */
static int __init
parse_dmar_table(void)
{
	struct acpi_table_dmar *dmar;
	struct acpi_dmar_header *entry_header;
	int ret = 0;

	dmar = (struct acpi_table_dmar *)dmar_tbl;
	if (!dmar)
		return -ENODEV;

	if (dmar->width < PAGE_SHIFT_4K - 1) {
		printk(KERN_WARNING PREFIX "Invalid DMAR haw\n");
		return -EINVAL;
	}

	printk (KERN_INFO PREFIX "Host address width %d\n",
		dmar->width + 1);

	entry_header = (struct acpi_dmar_header *)(dmar + 1);
	while (((unsigned long)entry_header) <
			(((unsigned long)dmar) + dmar_tbl->length)) {
		dmar_table_print_dmar_entry(entry_header);

		switch (entry_header->type) {
		case ACPI_DMAR_TYPE_HARDWARE_UNIT:
			ret = dmar_parse_one_drhd(entry_header);
			break;
		case ACPI_DMAR_TYPE_RESERVED_MEMORY:
			ret = dmar_parse_one_rmrr(entry_header);
			break;
		default:
			printk(KERN_WARNING PREFIX
				"Unknown DMAR structure type\n");
			ret = 0; /* for forward compatibility */
			break;
		}
		if (ret)
			break;

		entry_header = ((void *)entry_header + entry_header->length);
	}
	return ret;
}


int __init dmar_table_init(void)
{

	int ret;

	ret = parse_dmar_table();
	if (ret) {
		printk(KERN_INFO PREFIX "parse DMAR table failure.\n");
		return ret;
	}

	if (list_empty(&dmar_drhd_units)) {
		printk(KERN_INFO PREFIX "No DMAR devices found\n");
		return -ENODEV;
	}

	if (list_empty(&dmar_rmrr_units)) {
		printk(KERN_INFO PREFIX "No RMRR found\n");
		return -ENODEV;
	}

	return 0;
}

/**
 * early_dmar_detect - checks to see if the platform supports DMAR devices
 */
int __init early_dmar_detect(void)
{
	acpi_status status = AE_OK;

	/* if we could find DMAR table, then there are DMAR devices */
	status = acpi_get_table(ACPI_SIG_DMAR, 0,
				(struct acpi_table_header **)&dmar_tbl);

	if (ACPI_SUCCESS(status) && !dmar_tbl) {
		printk (KERN_WARNING PREFIX "Unable to map DMAR\n");
		status = AE_NOT_FOUND;
	}

	return (ACPI_SUCCESS(status) ? 1 : 0);
}