258 lines
6.9 KiB
C
258 lines
6.9 KiB
C
/*
|
|
* 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) ||
|
|
(!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);
|
|
}
|
|
|
|
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);
|