linux/drivers/iommu/of_iommu.c
Randy Dunlap 4762315d1c iommu/of: mark an unused function as __maybe_unused
When CONFIG_OF_ADDRESS is not set, there is a build warning/error
about an unused function.
Annotate the function to quieten the warning/error.

../drivers/iommu/of_iommu.c:176:29: warning: 'iommu_resv_region_get_type' defined but not used [-Wunused-function]
  176 | static enum iommu_resv_type iommu_resv_region_get_type(struct device *dev, struct resource *phys,
      |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~

Fixes: a5bf3cfce8 ("iommu: Implement of_iommu_get_resv_regions()")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Will Deacon <will@kernel.org>
Cc: iommu@lists.linux.dev
Reviewed-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20230209010359.23831-1-rdunlap@infradead.org
[joro: Improve code formatting]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-02-16 10:17:31 +01:00

270 lines
6.8 KiB
C

// 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>
#define NO_IOMMU 1
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 NO_IOMMU;
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 == -ENODEV ? NO_IOMMU : 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 = NO_IOMMU, 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);
}
const struct iommu_ops *of_iommu_configure(struct device *dev,
struct device_node *master_np,
const u32 *id)
{
const struct iommu_ops *ops = NULL;
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
int err = NO_IOMMU;
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);
}
/*
* 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);
}
/*
* Two success conditions can be represented by non-negative err here:
* >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
* 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
* <0 : any actual error
*/
if (!err) {
/* The fwspec pointer changed, read it again */
fwspec = dev_iommu_fwspec_get(dev);
ops = fwspec->ops;
}
/*
* If we have reason to believe the IOMMU driver missed the initial
* probe for dev, replay it to get things in order.
*/
if (!err && dev->bus && !device_iommu_mapped(dev))
err = iommu_probe_device(dev);
/* Ignore all other errors apart from EPROBE_DEFER */
if (err == -EPROBE_DEFER) {
ops = ERR_PTR(err);
} else if (err < 0) {
dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
ops = NULL;
}
return ops;
}
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;
maps = of_translate_dma_region(np, maps, &iova, &length);
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);