Loading...
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 | /*
* 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/of_pci.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);
static bool of_iommu_driver_present(struct device_node *np)
{
/*
* If the IOMMU still isn't ready by the time we reach init, assume
* it never will be. We don't want to defer indefinitely, nor attempt
* to dereference __iommu_of_table after it's been freed.
*/
if (system_state > SYSTEM_BOOTING)
return false;
return of_match_node(&__iommu_of_table, np);
}
static const struct iommu_ops
*of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec)
{
const struct iommu_ops *ops;
struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
int err;
ops = iommu_ops_from_fwnode(fwnode);
if ((ops && !ops->of_xlate) ||
!of_device_is_available(iommu_spec->np) ||
(!ops && !of_iommu_driver_present(iommu_spec->np)))
return NULL;
err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
if (err)
return ERR_PTR(err);
/*
* The otherwise-empty fwspec handily serves to indicate the specific
* IOMMU device we're waiting for, which will be useful if we ever get
* a proper probe-ordering dependency mechanism in future.
*/
if (!ops)
return ERR_PTR(-EPROBE_DEFER);
err = ops->of_xlate(dev, iommu_spec);
if (err)
return ERR_PTR(err);
return ops;
}
static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
{
struct of_phandle_args *iommu_spec = data;
iommu_spec->args[0] = alias;
return iommu_spec->np == pdev->bus->dev.of_node;
}
static const struct iommu_ops
*of_pci_iommu_init(struct pci_dev *pdev, struct device_node *bridge_np)
{
const struct iommu_ops *ops;
struct of_phandle_args iommu_spec;
int err;
/*
* Start by tracing the RID alias down the PCI topology as
* far as the host bridge whose OF node we have...
* (we're not even attempting to handle multi-alias devices yet)
*/
iommu_spec.args_count = 1;
iommu_spec.np = bridge_np;
pci_for_each_dma_alias(pdev, __get_pci_rid, &iommu_spec);
/*
* ...then find out what that becomes once it escapes the PCI
* bus into the system beyond, and which IOMMU it ends up at.
*/
iommu_spec.np = NULL;
err = of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
"iommu-map-mask", &iommu_spec.np,
iommu_spec.args);
if (err)
return err == -ENODEV ? NULL : ERR_PTR(err);
ops = of_iommu_xlate(&pdev->dev, &iommu_spec);
of_node_put(iommu_spec.np);
return ops;
}
static const struct iommu_ops
*of_platform_iommu_init(struct device *dev, struct device_node *np)
{
struct of_phandle_args iommu_spec;
const struct iommu_ops *ops = NULL;
int idx = 0;
/*
* 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(np, "iommus", "#iommu-cells",
idx, &iommu_spec)) {
ops = of_iommu_xlate(dev, &iommu_spec);
of_node_put(iommu_spec.np);
idx++;
if (IS_ERR_OR_NULL(ops))
break;
}
return ops;
}
const struct iommu_ops *of_iommu_configure(struct device *dev,
struct device_node *master_np)
{
const struct iommu_ops *ops;
struct iommu_fwspec *fwspec = dev->iommu_fwspec;
if (!master_np)
return NULL;
if (fwspec) {
if (fwspec->ops)
return fwspec->ops;
/* In the deferred case, start again from scratch */
iommu_fwspec_free(dev);
}
if (dev_is_pci(dev))
ops = of_pci_iommu_init(to_pci_dev(dev), master_np);
else
ops = of_platform_iommu_init(dev, master_np);
/*
* If we have reason to believe the IOMMU driver missed the initial
* add_device callback for dev, replay it to get things in order.
*/
if (!IS_ERR_OR_NULL(ops) && ops->add_device &&
dev->bus && !dev->iommu_group) {
int err = ops->add_device(dev);
if (err)
ops = ERR_PTR(err);
}
/* Ignore all other errors apart from EPROBE_DEFER */
if (IS_ERR(ops) && (PTR_ERR(ops) != -EPROBE_DEFER)) {
dev_dbg(dev, "Adding to IOMMU failed: %ld\n", PTR_ERR(ops));
ops = NULL;
}
return ops;
}
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 && init_fn(np))
pr_err("Failed to initialise IOMMU %s\n",
of_node_full_name(np));
}
return 0;
}
postcore_initcall_sync(of_iommu_init);
|