blob: 719652b608407ad905721d676ff7a0c245e76ee0 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* OF helpers for IOMMU
*
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
*/
#include <linux/export.h>
#include <linux/iommu.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_iommu.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/fsl/mc.h>
static int 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 ret;
ops = iommu_ops_from_fwnode(fwnode);
if ((ops && !ops->of_xlate) ||
!of_device_is_available(iommu_spec->np))
return -ENODEV;
ret = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
if (ret)
return ret;
/*
* 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 driver_deferred_probe_check_state(dev);
if (!try_module_get(ops->owner))
return -ENODEV;
ret = ops->of_xlate(dev, iommu_spec);
module_put(ops->owner);
return ret;
}
static int of_iommu_configure_dev_id(struct device_node *master_np,
struct device *dev,
const u32 *id)
{
struct of_phandle_args iommu_spec = { .args_count = 1 };
int err;
err = of_map_id(master_np, *id, "iommu-map",
"iommu-map-mask", &iommu_spec.np,
iommu_spec.args);
if (err)
return err;
err = of_iommu_xlate(dev, &iommu_spec);
of_node_put(iommu_spec.np);
return err;
}
static int of_iommu_configure_dev(struct device_node *master_np,
struct device *dev)
{
struct of_phandle_args iommu_spec;
int err = -ENODEV, idx = 0;
while (!of_parse_phandle_with_args(master_np, "iommus",
"#iommu-cells",
idx, &iommu_spec)) {
err = of_iommu_xlate(dev, &iommu_spec);
of_node_put(iommu_spec.np);
idx++;
if (err)
break;
}
return err;
}
struct of_pci_iommu_alias_info {
struct device *dev;
struct device_node *np;
};
static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
{
struct of_pci_iommu_alias_info *info = data;
u32 input_id = alias;
return of_iommu_configure_dev_id(info->np, info->dev, &input_id);
}
static int of_iommu_configure_device(struct device_node *master_np,
struct device *dev, const u32 *id)
{
return (id) ? of_iommu_configure_dev_id(master_np, dev, id) :
of_iommu_configure_dev(master_np, dev);
}
/*
* Returns:
* 0 on success, an iommu was configured
* -ENODEV if the device does not have any IOMMU
* -EPROBEDEFER if probing should be tried again
* -errno fatal errors
*/
int of_iommu_configure(struct device *dev, struct device_node *master_np,
const u32 *id)
{
struct iommu_fwspec *fwspec;
int err;
if (!master_np)
return -ENODEV;
/* Serialise to make dev->iommu stable under our potential fwspec */
mutex_lock(&iommu_probe_device_lock);
fwspec = dev_iommu_fwspec_get(dev);
if (fwspec) {
if (fwspec->ops) {
mutex_unlock(&iommu_probe_device_lock);
return 0;
}
/* In the deferred case, start again from scratch */
iommu_fwspec_free(dev);
}
/*
* We don't currently walk up the tree looking for a parent IOMMU.
* See the `Notes:' section of
* Documentation/devicetree/bindings/iommu/iommu.txt
*/
if (dev_is_pci(dev)) {
struct of_pci_iommu_alias_info info = {
.dev = dev,
.np = master_np,
};
pci_request_acs();
err = pci_for_each_dma_alias(to_pci_dev(dev),
of_pci_iommu_init, &info);
} else {
err = of_iommu_configure_device(master_np, dev, id);
}
mutex_unlock(&iommu_probe_device_lock);
if (err == -ENODEV || err == -EPROBE_DEFER)
return err;
if (err)
goto err_log;
err = iommu_probe_device(dev);
if (err)
goto err_log;
return 0;
err_log:
dev_dbg(dev, "Adding to IOMMU failed: %pe\n", ERR_PTR(err));
return err;
}
static enum iommu_resv_type __maybe_unused
iommu_resv_region_get_type(struct device *dev,
struct resource *phys,
phys_addr_t start, size_t length)
{
phys_addr_t end = start + length - 1;
/*
* IOMMU regions without an associated physical region cannot be
* mapped and are simply reservations.
*/
if (phys->start >= phys->end)
return IOMMU_RESV_RESERVED;
/* may be IOMMU_RESV_DIRECT_RELAXABLE for certain cases */
if (start == phys->start && end == phys->end)
return IOMMU_RESV_DIRECT;
dev_warn(dev, "treating non-direct mapping [%pr] -> [%pap-%pap] as reservation\n", phys,
&start, &end);
return IOMMU_RESV_RESERVED;
}
/**
* of_iommu_get_resv_regions - reserved region driver helper for device tree
* @dev: device for which to get reserved regions
* @list: reserved region list
*
* IOMMU drivers can use this to implement their .get_resv_regions() callback
* for memory regions attached to a device tree node. See the reserved-memory
* device tree bindings on how to use these:
*
* Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
*/
void of_iommu_get_resv_regions(struct device *dev, struct list_head *list)
{
#if IS_ENABLED(CONFIG_OF_ADDRESS)
struct of_phandle_iterator it;
int err;
of_for_each_phandle(&it, err, dev->of_node, "memory-region", NULL, 0) {
const __be32 *maps, *end;
struct resource phys;
int size;
memset(&phys, 0, sizeof(phys));
/*
* The "reg" property is optional and can be omitted by reserved-memory regions
* that represent reservations in the IOVA space, which are regions that should
* not be mapped.
*/
if (of_find_property(it.node, "reg", NULL)) {
err = of_address_to_resource(it.node, 0, &phys);
if (err < 0) {
dev_err(dev, "failed to parse memory region %pOF: %d\n",
it.node, err);
continue;
}
}
maps = of_get_property(it.node, "iommu-addresses", &size);
if (!maps)
continue;
end = maps + size / sizeof(__be32);
while (maps < end) {
struct device_node *np;
u32 phandle;
phandle = be32_to_cpup(maps++);
np = of_find_node_by_phandle(phandle);
if (np == dev->of_node) {
int prot = IOMMU_READ | IOMMU_WRITE;
struct iommu_resv_region *region;
enum iommu_resv_type type;
phys_addr_t iova;
size_t length;
if (of_dma_is_coherent(dev->of_node))
prot |= IOMMU_CACHE;
maps = of_translate_dma_region(np, maps, &iova, &length);
if (length == 0) {
dev_warn(dev, "Cannot reserve IOVA region of 0 size\n");
continue;
}
type = iommu_resv_region_get_type(dev, &phys, iova, length);
region = iommu_alloc_resv_region(iova, length, prot, type,
GFP_KERNEL);
if (region)
list_add_tail(&region->list, list);
}
}
}
#endif
}
EXPORT_SYMBOL(of_iommu_get_resv_regions);