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4e0ee78f HD |
1 | /* |
2 | * OF helpers for IOMMU | |
3 | * | |
4 | * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms and conditions of the GNU General Public License, | |
8 | * version 2, as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope it will be useful, but WITHOUT | |
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
13 | * more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along with | |
16 | * this program; if not, write to the Free Software Foundation, Inc., | |
17 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | |
18 | */ | |
19 | ||
20 | #include <linux/export.h> | |
7eba1d51 | 21 | #include <linux/iommu.h> |
4e0ee78f HD |
22 | #include <linux/limits.h> |
23 | #include <linux/of.h> | |
cbff5634 | 24 | #include <linux/of_iommu.h> |
b996444c | 25 | #include <linux/of_pci.h> |
a42a7a1f | 26 | #include <linux/slab.h> |
4e0ee78f | 27 | |
1cd076bf WD |
28 | static const struct of_device_id __iommu_of_table_sentinel |
29 | __used __section(__iommu_of_table_end); | |
30 | ||
4e0ee78f HD |
31 | /** |
32 | * of_get_dma_window - Parse *dma-window property and returns 0 if found. | |
33 | * | |
34 | * @dn: device node | |
35 | * @prefix: prefix for property name if any | |
36 | * @index: index to start to parse | |
37 | * @busno: Returns busno if supported. Otherwise pass NULL | |
38 | * @addr: Returns address that DMA starts | |
39 | * @size: Returns the range that DMA can handle | |
40 | * | |
41 | * This supports different formats flexibly. "prefix" can be | |
42 | * configured if any. "busno" and "index" are optionally | |
43 | * specified. Set 0(or NULL) if not used. | |
44 | */ | |
45 | int of_get_dma_window(struct device_node *dn, const char *prefix, int index, | |
46 | unsigned long *busno, dma_addr_t *addr, size_t *size) | |
47 | { | |
48 | const __be32 *dma_window, *end; | |
49 | int bytes, cur_index = 0; | |
50 | char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX]; | |
51 | ||
52 | if (!dn || !addr || !size) | |
53 | return -EINVAL; | |
54 | ||
55 | if (!prefix) | |
56 | prefix = ""; | |
57 | ||
58 | snprintf(propname, sizeof(propname), "%sdma-window", prefix); | |
59 | snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix); | |
60 | snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix); | |
61 | ||
62 | dma_window = of_get_property(dn, propname, &bytes); | |
63 | if (!dma_window) | |
64 | return -ENODEV; | |
65 | end = dma_window + bytes / sizeof(*dma_window); | |
66 | ||
67 | while (dma_window < end) { | |
68 | u32 cells; | |
69 | const void *prop; | |
70 | ||
71 | /* busno is one cell if supported */ | |
72 | if (busno) | |
73 | *busno = be32_to_cpup(dma_window++); | |
74 | ||
75 | prop = of_get_property(dn, addrname, NULL); | |
76 | if (!prop) | |
77 | prop = of_get_property(dn, "#address-cells", NULL); | |
78 | ||
79 | cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn); | |
80 | if (!cells) | |
81 | return -EINVAL; | |
82 | *addr = of_read_number(dma_window, cells); | |
83 | dma_window += cells; | |
84 | ||
85 | prop = of_get_property(dn, sizename, NULL); | |
86 | cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn); | |
87 | if (!cells) | |
88 | return -EINVAL; | |
89 | *size = of_read_number(dma_window, cells); | |
90 | dma_window += cells; | |
91 | ||
92 | if (cur_index++ == index) | |
93 | break; | |
94 | } | |
95 | return 0; | |
96 | } | |
97 | EXPORT_SYMBOL_GPL(of_get_dma_window); | |
1cd076bf | 98 | |
d7b05582 RM |
99 | static bool of_iommu_driver_present(struct device_node *np) |
100 | { | |
101 | /* | |
102 | * If the IOMMU still isn't ready by the time we reach init, assume | |
103 | * it never will be. We don't want to defer indefinitely, nor attempt | |
104 | * to dereference __iommu_of_table after it's been freed. | |
105 | */ | |
106 | if (system_state > SYSTEM_BOOTING) | |
107 | return false; | |
108 | ||
109 | return of_match_node(&__iommu_of_table, np); | |
110 | } | |
111 | ||
2a0c5754 RM |
112 | static const struct iommu_ops |
113 | *of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec) | |
114 | { | |
115 | const struct iommu_ops *ops; | |
116 | struct fwnode_handle *fwnode = &iommu_spec->np->fwnode; | |
117 | int err; | |
118 | ||
119 | ops = iommu_ops_from_fwnode(fwnode); | |
d7b05582 | 120 | if ((ops && !ops->of_xlate) || |
573d4175 | 121 | !of_device_is_available(iommu_spec->np) || |
d7b05582 | 122 | (!ops && !of_iommu_driver_present(iommu_spec->np))) |
2a0c5754 RM |
123 | return NULL; |
124 | ||
125 | err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops); | |
126 | if (err) | |
127 | return ERR_PTR(err); | |
d7b05582 RM |
128 | /* |
129 | * The otherwise-empty fwspec handily serves to indicate the specific | |
130 | * IOMMU device we're waiting for, which will be useful if we ever get | |
131 | * a proper probe-ordering dependency mechanism in future. | |
132 | */ | |
133 | if (!ops) | |
134 | return ERR_PTR(-EPROBE_DEFER); | |
2a0c5754 RM |
135 | |
136 | err = ops->of_xlate(dev, iommu_spec); | |
137 | if (err) | |
138 | return ERR_PTR(err); | |
139 | ||
140 | return ops; | |
141 | } | |
142 | ||
b996444c RM |
143 | static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) |
144 | { | |
145 | struct of_phandle_args *iommu_spec = data; | |
146 | ||
147 | iommu_spec->args[0] = alias; | |
148 | return iommu_spec->np == pdev->bus->dev.of_node; | |
149 | } | |
150 | ||
151 | static const struct iommu_ops | |
2a0c5754 | 152 | *of_pci_iommu_init(struct pci_dev *pdev, struct device_node *bridge_np) |
b996444c RM |
153 | { |
154 | const struct iommu_ops *ops; | |
155 | struct of_phandle_args iommu_spec; | |
2a0c5754 | 156 | int err; |
b996444c RM |
157 | |
158 | /* | |
159 | * Start by tracing the RID alias down the PCI topology as | |
160 | * far as the host bridge whose OF node we have... | |
161 | * (we're not even attempting to handle multi-alias devices yet) | |
162 | */ | |
163 | iommu_spec.args_count = 1; | |
164 | iommu_spec.np = bridge_np; | |
165 | pci_for_each_dma_alias(pdev, __get_pci_rid, &iommu_spec); | |
166 | /* | |
167 | * ...then find out what that becomes once it escapes the PCI | |
168 | * bus into the system beyond, and which IOMMU it ends up at. | |
169 | */ | |
170 | iommu_spec.np = NULL; | |
2a0c5754 RM |
171 | err = of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map", |
172 | "iommu-map-mask", &iommu_spec.np, | |
173 | iommu_spec.args); | |
174 | if (err) | |
175 | return err == -ENODEV ? NULL : ERR_PTR(err); | |
b996444c | 176 | |
2a0c5754 | 177 | ops = of_iommu_xlate(&pdev->dev, &iommu_spec); |
b996444c RM |
178 | |
179 | of_node_put(iommu_spec.np); | |
180 | return ops; | |
181 | } | |
182 | ||
2a0c5754 RM |
183 | static const struct iommu_ops |
184 | *of_platform_iommu_init(struct device *dev, struct device_node *np) | |
7eba1d51 WD |
185 | { |
186 | struct of_phandle_args iommu_spec; | |
53c92d79 | 187 | const struct iommu_ops *ops = NULL; |
7eba1d51 WD |
188 | int idx = 0; |
189 | ||
190 | /* | |
191 | * We don't currently walk up the tree looking for a parent IOMMU. | |
192 | * See the `Notes:' section of | |
193 | * Documentation/devicetree/bindings/iommu/iommu.txt | |
194 | */ | |
2a0c5754 RM |
195 | while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", |
196 | idx, &iommu_spec)) { | |
197 | ops = of_iommu_xlate(dev, &iommu_spec); | |
198 | of_node_put(iommu_spec.np); | |
7eba1d51 | 199 | idx++; |
2a0c5754 RM |
200 | if (IS_ERR_OR_NULL(ops)) |
201 | break; | |
7eba1d51 WD |
202 | } |
203 | ||
204 | return ops; | |
2a0c5754 RM |
205 | } |
206 | ||
207 | const struct iommu_ops *of_iommu_configure(struct device *dev, | |
208 | struct device_node *master_np) | |
209 | { | |
210 | const struct iommu_ops *ops; | |
d7b05582 | 211 | struct iommu_fwspec *fwspec = dev->iommu_fwspec; |
2a0c5754 RM |
212 | |
213 | if (!master_np) | |
214 | return NULL; | |
215 | ||
d7b05582 RM |
216 | if (fwspec) { |
217 | if (fwspec->ops) | |
218 | return fwspec->ops; | |
219 | ||
220 | /* In the deferred case, start again from scratch */ | |
221 | iommu_fwspec_free(dev); | |
222 | } | |
223 | ||
2a0c5754 RM |
224 | if (dev_is_pci(dev)) |
225 | ops = of_pci_iommu_init(to_pci_dev(dev), master_np); | |
226 | else | |
227 | ops = of_platform_iommu_init(dev, master_np); | |
d7b05582 RM |
228 | /* |
229 | * If we have reason to believe the IOMMU driver missed the initial | |
230 | * add_device callback for dev, replay it to get things in order. | |
231 | */ | |
232 | if (!IS_ERR_OR_NULL(ops) && ops->add_device && | |
233 | dev->bus && !dev->iommu_group) { | |
234 | int err = ops->add_device(dev); | |
235 | ||
236 | if (err) | |
237 | ops = ERR_PTR(err); | |
238 | } | |
7eba1d51 | 239 | |
a37b19a3 S |
240 | /* Ignore all other errors apart from EPROBE_DEFER */ |
241 | if (IS_ERR(ops) && (PTR_ERR(ops) != -EPROBE_DEFER)) { | |
242 | dev_dbg(dev, "Adding to IOMMU failed: %ld\n", PTR_ERR(ops)); | |
243 | ops = NULL; | |
244 | } | |
245 | ||
7b07cbef | 246 | return ops; |
7eba1d51 WD |
247 | } |
248 | ||
bb8e15d6 | 249 | static int __init of_iommu_init(void) |
1cd076bf WD |
250 | { |
251 | struct device_node *np; | |
252 | const struct of_device_id *match, *matches = &__iommu_of_table; | |
253 | ||
254 | for_each_matching_node_and_match(np, matches, &match) { | |
255 | const of_iommu_init_fn init_fn = match->data; | |
256 | ||
7b07cbef | 257 | if (init_fn && init_fn(np)) |
1cd076bf WD |
258 | pr_err("Failed to initialise IOMMU %s\n", |
259 | of_node_full_name(np)); | |
260 | } | |
bb8e15d6 KW |
261 | |
262 | return 0; | |
1cd076bf | 263 | } |
bb8e15d6 | 264 | postcore_initcall_sync(of_iommu_init); |