1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
8 #include <linux/export.h>
9 #include <linux/iommu.h>
10 #include <linux/limits.h>
11 #include <linux/pci.h>
12 #include <linux/msi.h>
14 #include <linux/of_iommu.h>
15 #include <linux/of_pci.h>
16 #include <linux/slab.h>
17 #include <linux/fsl/mc.h>
22 * of_get_dma_window - Parse *dma-window property and returns 0 if found.
25 * @prefix: prefix for property name if any
26 * @index: index to start to parse
27 * @busno: Returns busno if supported. Otherwise pass NULL
28 * @addr: Returns address that DMA starts
29 * @size: Returns the range that DMA can handle
31 * This supports different formats flexibly. "prefix" can be
32 * configured if any. "busno" and "index" are optionally
33 * specified. Set 0(or NULL) if not used.
35 int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
36 unsigned long *busno, dma_addr_t *addr, size_t *size)
38 const __be32 *dma_window, *end;
39 int bytes, cur_index = 0;
40 char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
42 if (!dn || !addr || !size)
48 snprintf(propname, sizeof(propname), "%sdma-window", prefix);
49 snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
50 snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
52 dma_window = of_get_property(dn, propname, &bytes);
55 end = dma_window + bytes / sizeof(*dma_window);
57 while (dma_window < end) {
61 /* busno is one cell if supported */
63 *busno = be32_to_cpup(dma_window++);
65 prop = of_get_property(dn, addrname, NULL);
67 prop = of_get_property(dn, "#address-cells", NULL);
69 cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
72 *addr = of_read_number(dma_window, cells);
75 prop = of_get_property(dn, sizename, NULL);
76 cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
79 *size = of_read_number(dma_window, cells);
82 if (cur_index++ == index)
87 EXPORT_SYMBOL_GPL(of_get_dma_window);
89 static int of_iommu_xlate(struct device *dev,
90 struct of_phandle_args *iommu_spec)
92 const struct iommu_ops *ops;
93 struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
96 ops = iommu_ops_from_fwnode(fwnode);
97 if ((ops && !ops->of_xlate) ||
98 !of_device_is_available(iommu_spec->np))
101 err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
105 * The otherwise-empty fwspec handily serves to indicate the specific
106 * IOMMU device we're waiting for, which will be useful if we ever get
107 * a proper probe-ordering dependency mechanism in future.
110 return driver_deferred_probe_check_state(dev);
112 return ops->of_xlate(dev, iommu_spec);
115 struct of_pci_iommu_alias_info {
117 struct device_node *np;
120 static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
122 struct of_pci_iommu_alias_info *info = data;
123 struct of_phandle_args iommu_spec = { .args_count = 1 };
126 err = of_map_rid(info->np, alias, "iommu-map", "iommu-map-mask",
127 &iommu_spec.np, iommu_spec.args);
129 return err == -ENODEV ? NO_IOMMU : err;
131 err = of_iommu_xlate(info->dev, &iommu_spec);
132 of_node_put(iommu_spec.np);
136 static int of_fsl_mc_iommu_init(struct fsl_mc_device *mc_dev,
137 struct device_node *master_np)
139 struct of_phandle_args iommu_spec = { .args_count = 1 };
142 err = of_map_rid(master_np, mc_dev->icid, "iommu-map",
143 "iommu-map-mask", &iommu_spec.np,
146 return err == -ENODEV ? NO_IOMMU : err;
148 err = of_iommu_xlate(&mc_dev->dev, &iommu_spec);
149 of_node_put(iommu_spec.np);
153 const struct iommu_ops *of_iommu_configure(struct device *dev,
154 struct device_node *master_np)
156 const struct iommu_ops *ops = NULL;
157 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
167 /* In the deferred case, start again from scratch */
168 iommu_fwspec_free(dev);
172 * We don't currently walk up the tree looking for a parent IOMMU.
173 * See the `Notes:' section of
174 * Documentation/devicetree/bindings/iommu/iommu.txt
176 if (dev_is_pci(dev)) {
177 struct of_pci_iommu_alias_info info = {
182 err = pci_for_each_dma_alias(to_pci_dev(dev),
183 of_pci_iommu_init, &info);
184 } else if (dev_is_fsl_mc(dev)) {
185 err = of_fsl_mc_iommu_init(to_fsl_mc_device(dev), master_np);
187 struct of_phandle_args iommu_spec;
190 while (!of_parse_phandle_with_args(master_np, "iommus",
193 err = of_iommu_xlate(dev, &iommu_spec);
194 of_node_put(iommu_spec.np);
203 * Two success conditions can be represented by non-negative err here:
204 * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
205 * 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
206 * <0 : any actual error
209 /* The fwspec pointer changed, read it again */
210 fwspec = dev_iommu_fwspec_get(dev);
214 * If we have reason to believe the IOMMU driver missed the initial
215 * probe for dev, replay it to get things in order.
217 if (!err && dev->bus && !device_iommu_mapped(dev))
218 err = iommu_probe_device(dev);
220 /* Ignore all other errors apart from EPROBE_DEFER */
221 if (err == -EPROBE_DEFER) {
223 } else if (err < 0) {
224 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);