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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OF helpers for IOMMU
4 *
5 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
6 */
7
8#include <linux/export.h>
9#include <linux/iommu.h>
10#include <linux/limits.h>
11#include <linux/module.h>
12#include <linux/msi.h>
13#include <linux/of.h>
14#include <linux/of_iommu.h>
15#include <linux/of_pci.h>
16#include <linux/pci.h>
17#include <linux/slab.h>
18#include <linux/fsl/mc.h>
19
20#define NO_IOMMU 1
21
22/**
23 * of_get_dma_window - Parse *dma-window property and returns 0 if found.
24 *
25 * @dn: device node
26 * @prefix: prefix for property name if any
27 * @index: index to start to parse
28 * @busno: Returns busno if supported. Otherwise pass NULL
29 * @addr: Returns address that DMA starts
30 * @size: Returns the range that DMA can handle
31 *
32 * This supports different formats flexibly. "prefix" can be
33 * configured if any. "busno" and "index" are optionally
34 * specified. Set 0(or NULL) if not used.
35 */
36int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
37 unsigned long *busno, dma_addr_t *addr, size_t *size)
38{
39 const __be32 *dma_window, *end;
40 int bytes, cur_index = 0;
41 char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
42
43 if (!dn || !addr || !size)
44 return -EINVAL;
45
46 if (!prefix)
47 prefix = "";
48
49 snprintf(propname, sizeof(propname), "%sdma-window", prefix);
50 snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
51 snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
52
53 dma_window = of_get_property(dn, propname, &bytes);
54 if (!dma_window)
55 return -ENODEV;
56 end = dma_window + bytes / sizeof(*dma_window);
57
58 while (dma_window < end) {
59 u32 cells;
60 const void *prop;
61
62 /* busno is one cell if supported */
63 if (busno)
64 *busno = be32_to_cpup(dma_window++);
65
66 prop = of_get_property(dn, addrname, NULL);
67 if (!prop)
68 prop = of_get_property(dn, "#address-cells", NULL);
69
70 cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
71 if (!cells)
72 return -EINVAL;
73 *addr = of_read_number(dma_window, cells);
74 dma_window += cells;
75
76 prop = of_get_property(dn, sizename, NULL);
77 cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
78 if (!cells)
79 return -EINVAL;
80 *size = of_read_number(dma_window, cells);
81 dma_window += cells;
82
83 if (cur_index++ == index)
84 break;
85 }
86 return 0;
87}
88EXPORT_SYMBOL_GPL(of_get_dma_window);
89
90static int of_iommu_xlate(struct device *dev,
91 struct of_phandle_args *iommu_spec)
92{
93 const struct iommu_ops *ops;
94 struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
95 int ret;
96
97 ops = iommu_ops_from_fwnode(fwnode);
98 if ((ops && !ops->of_xlate) ||
99 !of_device_is_available(iommu_spec->np))
100 return NO_IOMMU;
101
102 ret = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
103 if (ret)
104 return ret;
105 /*
106 * The otherwise-empty fwspec handily serves to indicate the specific
107 * IOMMU device we're waiting for, which will be useful if we ever get
108 * a proper probe-ordering dependency mechanism in future.
109 */
110 if (!ops)
111 return driver_deferred_probe_check_state(dev);
112
113 if (!try_module_get(ops->owner))
114 return -ENODEV;
115
116 ret = ops->of_xlate(dev, iommu_spec);
117 module_put(ops->owner);
118 return ret;
119}
120
121static int of_iommu_configure_dev_id(struct device_node *master_np,
122 struct device *dev,
123 const u32 *id)
124{
125 struct of_phandle_args iommu_spec = { .args_count = 1 };
126 int err;
127
128 err = of_map_id(master_np, *id, "iommu-map",
129 "iommu-map-mask", &iommu_spec.np,
130 iommu_spec.args);
131 if (err)
132 return err == -ENODEV ? NO_IOMMU : err;
133
134 err = of_iommu_xlate(dev, &iommu_spec);
135 of_node_put(iommu_spec.np);
136 return err;
137}
138
139static int of_iommu_configure_dev(struct device_node *master_np,
140 struct device *dev)
141{
142 struct of_phandle_args iommu_spec;
143 int err = NO_IOMMU, idx = 0;
144
145 while (!of_parse_phandle_with_args(master_np, "iommus",
146 "#iommu-cells",
147 idx, &iommu_spec)) {
148 err = of_iommu_xlate(dev, &iommu_spec);
149 of_node_put(iommu_spec.np);
150 idx++;
151 if (err)
152 break;
153 }
154
155 return err;
156}
157
158struct of_pci_iommu_alias_info {
159 struct device *dev;
160 struct device_node *np;
161};
162
163static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
164{
165 struct of_pci_iommu_alias_info *info = data;
166 u32 input_id = alias;
167
168 return of_iommu_configure_dev_id(info->np, info->dev, &input_id);
169}
170
171static int of_iommu_configure_device(struct device_node *master_np,
172 struct device *dev, const u32 *id)
173{
174 return (id) ? of_iommu_configure_dev_id(master_np, dev, id) :
175 of_iommu_configure_dev(master_np, dev);
176}
177
178const struct iommu_ops *of_iommu_configure(struct device *dev,
179 struct device_node *master_np,
180 const u32 *id)
181{
182 const struct iommu_ops *ops = NULL;
183 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
184 int err = NO_IOMMU;
185
186 if (!master_np)
187 return NULL;
188
189 if (fwspec) {
190 if (fwspec->ops)
191 return fwspec->ops;
192
193 /* In the deferred case, start again from scratch */
194 iommu_fwspec_free(dev);
195 }
196
197 /*
198 * We don't currently walk up the tree looking for a parent IOMMU.
199 * See the `Notes:' section of
200 * Documentation/devicetree/bindings/iommu/iommu.txt
201 */
202 if (dev_is_pci(dev)) {
203 struct of_pci_iommu_alias_info info = {
204 .dev = dev,
205 .np = master_np,
206 };
207
208 pci_request_acs();
209 err = pci_for_each_dma_alias(to_pci_dev(dev),
210 of_pci_iommu_init, &info);
211 } else {
212 err = of_iommu_configure_device(master_np, dev, id);
213
214 fwspec = dev_iommu_fwspec_get(dev);
215 if (!err && fwspec)
216 of_property_read_u32(master_np, "pasid-num-bits",
217 &fwspec->num_pasid_bits);
218 }
219
220 /*
221 * Two success conditions can be represented by non-negative err here:
222 * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
223 * 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
224 * <0 : any actual error
225 */
226 if (!err) {
227 /* The fwspec pointer changed, read it again */
228 fwspec = dev_iommu_fwspec_get(dev);
229 ops = fwspec->ops;
230 }
231 /*
232 * If we have reason to believe the IOMMU driver missed the initial
233 * probe for dev, replay it to get things in order.
234 */
235 if (!err && dev->bus && !device_iommu_mapped(dev))
236 err = iommu_probe_device(dev);
237
238 /* Ignore all other errors apart from EPROBE_DEFER */
239 if (err == -EPROBE_DEFER) {
240 ops = ERR_PTR(err);
241 } else if (err < 0) {
242 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
243 ops = NULL;
244 }
245
246 return ops;
247}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OF helpers for IOMMU
4 *
5 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
6 */
7
8#include <linux/export.h>
9#include <linux/iommu.h>
10#include <linux/limits.h>
11#include <linux/of.h>
12#include <linux/of_iommu.h>
13#include <linux/of_pci.h>
14#include <linux/slab.h>
15#include <linux/fsl/mc.h>
16
17#define NO_IOMMU 1
18
19/**
20 * of_get_dma_window - Parse *dma-window property and returns 0 if found.
21 *
22 * @dn: device node
23 * @prefix: prefix for property name if any
24 * @index: index to start to parse
25 * @busno: Returns busno if supported. Otherwise pass NULL
26 * @addr: Returns address that DMA starts
27 * @size: Returns the range that DMA can handle
28 *
29 * This supports different formats flexibly. "prefix" can be
30 * configured if any. "busno" and "index" are optionally
31 * specified. Set 0(or NULL) if not used.
32 */
33int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
34 unsigned long *busno, dma_addr_t *addr, size_t *size)
35{
36 const __be32 *dma_window, *end;
37 int bytes, cur_index = 0;
38 char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
39
40 if (!dn || !addr || !size)
41 return -EINVAL;
42
43 if (!prefix)
44 prefix = "";
45
46 snprintf(propname, sizeof(propname), "%sdma-window", prefix);
47 snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
48 snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
49
50 dma_window = of_get_property(dn, propname, &bytes);
51 if (!dma_window)
52 return -ENODEV;
53 end = dma_window + bytes / sizeof(*dma_window);
54
55 while (dma_window < end) {
56 u32 cells;
57 const void *prop;
58
59 /* busno is one cell if supported */
60 if (busno)
61 *busno = be32_to_cpup(dma_window++);
62
63 prop = of_get_property(dn, addrname, NULL);
64 if (!prop)
65 prop = of_get_property(dn, "#address-cells", NULL);
66
67 cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
68 if (!cells)
69 return -EINVAL;
70 *addr = of_read_number(dma_window, cells);
71 dma_window += cells;
72
73 prop = of_get_property(dn, sizename, NULL);
74 cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
75 if (!cells)
76 return -EINVAL;
77 *size = of_read_number(dma_window, cells);
78 dma_window += cells;
79
80 if (cur_index++ == index)
81 break;
82 }
83 return 0;
84}
85EXPORT_SYMBOL_GPL(of_get_dma_window);
86
87static int of_iommu_xlate(struct device *dev,
88 struct of_phandle_args *iommu_spec)
89{
90 const struct iommu_ops *ops;
91 struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
92 int err;
93
94 ops = iommu_ops_from_fwnode(fwnode);
95 if ((ops && !ops->of_xlate) ||
96 !of_device_is_available(iommu_spec->np))
97 return NO_IOMMU;
98
99 err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
100 if (err)
101 return err;
102 /*
103 * The otherwise-empty fwspec handily serves to indicate the specific
104 * IOMMU device we're waiting for, which will be useful if we ever get
105 * a proper probe-ordering dependency mechanism in future.
106 */
107 if (!ops)
108 return driver_deferred_probe_check_state(dev);
109
110 return ops->of_xlate(dev, iommu_spec);
111}
112
113struct of_pci_iommu_alias_info {
114 struct device *dev;
115 struct device_node *np;
116};
117
118static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
119{
120 struct of_pci_iommu_alias_info *info = data;
121 struct of_phandle_args iommu_spec = { .args_count = 1 };
122 int err;
123
124 err = of_map_rid(info->np, alias, "iommu-map", "iommu-map-mask",
125 &iommu_spec.np, iommu_spec.args);
126 if (err)
127 return err == -ENODEV ? NO_IOMMU : err;
128
129 err = of_iommu_xlate(info->dev, &iommu_spec);
130 of_node_put(iommu_spec.np);
131 return err;
132}
133
134static int of_fsl_mc_iommu_init(struct fsl_mc_device *mc_dev,
135 struct device_node *master_np)
136{
137 struct of_phandle_args iommu_spec = { .args_count = 1 };
138 int err;
139
140 err = of_map_rid(master_np, mc_dev->icid, "iommu-map",
141 "iommu-map-mask", &iommu_spec.np,
142 iommu_spec.args);
143 if (err)
144 return err == -ENODEV ? NO_IOMMU : err;
145
146 err = of_iommu_xlate(&mc_dev->dev, &iommu_spec);
147 of_node_put(iommu_spec.np);
148 return err;
149}
150
151const struct iommu_ops *of_iommu_configure(struct device *dev,
152 struct device_node *master_np)
153{
154 const struct iommu_ops *ops = NULL;
155 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
156 int err = NO_IOMMU;
157
158 if (!master_np)
159 return NULL;
160
161 if (fwspec) {
162 if (fwspec->ops)
163 return fwspec->ops;
164
165 /* In the deferred case, start again from scratch */
166 iommu_fwspec_free(dev);
167 }
168
169 /*
170 * We don't currently walk up the tree looking for a parent IOMMU.
171 * See the `Notes:' section of
172 * Documentation/devicetree/bindings/iommu/iommu.txt
173 */
174 if (dev_is_pci(dev)) {
175 struct of_pci_iommu_alias_info info = {
176 .dev = dev,
177 .np = master_np,
178 };
179
180 err = pci_for_each_dma_alias(to_pci_dev(dev),
181 of_pci_iommu_init, &info);
182 } else if (dev_is_fsl_mc(dev)) {
183 err = of_fsl_mc_iommu_init(to_fsl_mc_device(dev), master_np);
184 } else {
185 struct of_phandle_args iommu_spec;
186 int idx = 0;
187
188 while (!of_parse_phandle_with_args(master_np, "iommus",
189 "#iommu-cells",
190 idx, &iommu_spec)) {
191 err = of_iommu_xlate(dev, &iommu_spec);
192 of_node_put(iommu_spec.np);
193 idx++;
194 if (err)
195 break;
196 }
197 }
198
199
200 /*
201 * Two success conditions can be represented by non-negative err here:
202 * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
203 * 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
204 * <0 : any actual error
205 */
206 if (!err) {
207 /* The fwspec pointer changed, read it again */
208 fwspec = dev_iommu_fwspec_get(dev);
209 ops = fwspec->ops;
210 }
211 /*
212 * If we have reason to believe the IOMMU driver missed the initial
213 * probe for dev, replay it to get things in order.
214 */
215 if (!err && dev->bus && !device_iommu_mapped(dev))
216 err = iommu_probe_device(dev);
217
218 /* Ignore all other errors apart from EPROBE_DEFER */
219 if (err == -EPROBE_DEFER) {
220 ops = ERR_PTR(err);
221 } else if (err < 0) {
222 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
223 ops = NULL;
224 }
225
226 return ops;
227}