summaryrefslogtreecommitdiffstats
path: root/drivers/iommu/of_iommu.c
blob: 57f23eaaa2f9a4625874839a598b65c1bfb95090 (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
/*
 * OF helpers for IOMMU
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 *
 * 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.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/export.h>
#include <linux/iommu.h>
#include <linux/limits.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
#include <linux/slab.h>

static const struct of_device_id __iommu_of_table_sentinel
	__used __section(__iommu_of_table_end);

/**
 * of_get_dma_window - Parse *dma-window property and returns 0 if found.
 *
 * @dn: device node
 * @prefix: prefix for property name if any
 * @index: index to start to parse
 * @busno: Returns busno if supported. Otherwise pass NULL
 * @addr: Returns address that DMA starts
 * @size: Returns the range that DMA can handle
 *
 * This supports different formats flexibly. "prefix" can be
 * configured if any. "busno" and "index" are optionally
 * specified. Set 0(or NULL) if not used.
 */
int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
		      unsigned long *busno, dma_addr_t *addr, size_t *size)
{
	const __be32 *dma_window, *end;
	int bytes, cur_index = 0;
	char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];

	if (!dn || !addr || !size)
		return -EINVAL;

	if (!prefix)
		prefix = "";

	snprintf(propname, sizeof(propname), "%sdma-window", prefix);
	snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
	snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);

	dma_window = of_get_property(dn, propname, &bytes);
	if (!dma_window)
		return -ENODEV;
	end = dma_window + bytes / sizeof(*dma_window);

	while (dma_window < end) {
		u32 cells;
		const void *prop;

		/* busno is one cell if supported */
		if (busno)
			*busno = be32_to_cpup(dma_window++);

		prop = of_get_property(dn, addrname, NULL);
		if (!prop)
			prop = of_get_property(dn, "#address-cells", NULL);

		cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
		if (!cells)
			return -EINVAL;
		*addr = of_read_number(dma_window, cells);
		dma_window += cells;

		prop = of_get_property(dn, sizename, NULL);
		cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
		if (!cells)
			return -EINVAL;
		*size = of_read_number(dma_window, cells);
		dma_window += cells;

		if (cur_index++ == index)
			break;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(of_get_dma_window);

struct of_iommu_node {
	struct list_head list;
	struct device_node *np;
	const struct iommu_ops *ops;
};
static LIST_HEAD(of_iommu_list);
static DEFINE_SPINLOCK(of_iommu_lock);

void of_iommu_set_ops(struct device_node *np, const struct iommu_ops *ops)
{
	struct of_iommu_node *iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);

	if (WARN_ON(!iommu))
		return;

	of_node_get(np);
	INIT_LIST_HEAD(&iommu->list);
	iommu->np = np;
	iommu->ops = ops;
	spin_lock(&of_iommu_lock);
	list_add_tail(&iommu->list, &of_iommu_list);
	spin_unlock(&of_iommu_lock);
}

const struct iommu_ops *of_iommu_get_ops(struct device_node *np)
{
	struct of_iommu_node *node;
	const struct iommu_ops *ops = NULL;

	spin_lock(&of_iommu_lock);
	list_for_each_entry(node, &of_iommu_list, list)
		if (node->np == np) {
			ops = node->ops;
			break;
		}
	spin_unlock(&of_iommu_lock);
	return ops;
}

const struct iommu_ops *of_iommu_configure(struct device *dev,
					   struct device_node *master_np)
{
	struct of_phandle_args iommu_spec;
	struct device_node *np;
	const struct iommu_ops *ops = NULL;
	int idx = 0;

	/*
	 * We can't do much for PCI devices without knowing how
	 * device IDs are wired up from the PCI bus to the IOMMU.
	 */
	if (dev_is_pci(dev))
		return NULL;

	/*
	 * We don't currently walk up the tree looking for a parent IOMMU.
	 * See the `Notes:' section of
	 * Documentation/devicetree/bindings/iommu/iommu.txt
	 */
	while (!of_parse_phandle_with_args(master_np, "iommus",
					   "#iommu-cells", idx,
					   &iommu_spec)) {
		np = iommu_spec.np;
		ops = of_iommu_get_ops(np);

		if (!ops || !ops->of_xlate || ops->of_xlate(dev, &iommu_spec))
			goto err_put_node;

		of_node_put(np);
		idx++;
	}

	return ops;

err_put_node:
	of_node_put(np);
	return NULL;
}

static int __init of_iommu_init(void)
{
	struct device_node *np;
	const struct of_device_id *match, *matches = &__iommu_of_table;

	for_each_matching_node_and_match(np, matches, &match) {
		const of_iommu_init_fn init_fn = match->data;

		if (init_fn(np))
			pr_err("Failed to initialise IOMMU %s\n",
				of_node_full_name(np));
	}

	return 0;
}
postcore_initcall_sync(of_iommu_init);
OpenPOWER on IntegriCloud