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arm: dma-mapping: plumb our iommu mapping ops into arch_setup_dma_ops 

This patch plumbs the existing ARM IOMMU DMA infrastructure (which isn't
actually called outside of a few drivers) into arch_setup_dma_ops, so
that we can use IOMMUs for DMA transfers in a more generic fashion.

Since this significantly complicates the arch_setup_dma_ops function,
it is moved out of line into dma-mapping.c. If CONFIG_ARM_DMA_USE_IOMMU
is not set, the iommu parameter is ignored and the normal ops are used
instead.

Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Will Deacon 2014-08-27 17:52:44 +01:00
parent af4dda732e
commit 4bb25789ed
2 changed files with 81 additions and 14 deletions
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12
arch/arm/include/asm/dma-mapping.h
View File

@ -121,14 +121,12 @@ static inline unsigned long dma_max_pfn(struct device *dev)
}
#define dma_max_pfn(dev) dma_max_pfn(dev)
static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
u64 size, struct iommu_ops *iommu,
bool coherent)
{
if (coherent)
set_dma_ops(dev, &arm_coherent_dma_ops);
}
#define arch_setup_dma_ops arch_setup_dma_ops
extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu, bool coherent);
#define arch_teardown_dma_ops arch_teardown_dma_ops
extern void arch_teardown_dma_ops(struct device *dev);
static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{

83
arch/arm/mm/dma-mapping.c
View File

@ -1947,9 +1947,8 @@ EXPORT_SYMBOL_GPL(arm_iommu_release_mapping);
* arm_iommu_create_mapping)
*
* Attaches specified io address space mapping to the provided device,
* this replaces the dma operations (dma_map_ops pointer) with the
* IOMMU aware version. More than one client might be attached to
* the same io address space mapping.
* More than one client might be attached to the same io address space
* mapping.
*/
int arm_iommu_attach_device(struct device *dev,
struct dma_iommu_mapping *mapping)
@ -1962,7 +1961,6 @@ int arm_iommu_attach_device(struct device *dev,
kref_get(&mapping->kref);
dev->archdata.mapping = mapping;
set_dma_ops(dev, &iommu_ops);
pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
return 0;
@ -1974,7 +1972,6 @@ EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
* @dev: valid struct device pointer
*
* Detaches the provided device from a previously attached map.
* This voids the dma operations (dma_map_ops pointer)
*/
void arm_iommu_detach_device(struct device *dev)
{
@ -1989,10 +1986,82 @@ void arm_iommu_detach_device(struct device *dev)
iommu_detach_device(mapping->domain, dev);
kref_put(&mapping->kref, release_iommu_mapping);
dev->archdata.mapping = NULL;
set_dma_ops(dev, NULL);
pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
}
EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
#endif
static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
{
return coherent ? &iommu_coherent_ops : &iommu_ops;
}
static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu)
{
struct dma_iommu_mapping *mapping;
if (!iommu)
return false;
mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
if (IS_ERR(mapping)) {
pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
size, dev_name(dev));
return false;
}
if (arm_iommu_attach_device(dev, mapping)) {
pr_warn("Failed to attached device %s to IOMMU_mapping\n",
dev_name(dev));
arm_iommu_release_mapping(mapping);
return false;
}
return true;
}
static void arm_teardown_iommu_dma_ops(struct device *dev)
{
struct dma_iommu_mapping *mapping = dev->archdata.mapping;
arm_iommu_detach_device(dev);
arm_iommu_release_mapping(mapping);
}
#else
static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu)
{
return false;
}
static void arm_teardown_iommu_dma_ops(struct device *dev) { }
#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops
#endif /* CONFIG_ARM_DMA_USE_IOMMU */
static struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
{
return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
}
void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu, bool coherent)
{
struct dma_map_ops *dma_ops;
if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
dma_ops = arm_get_iommu_dma_map_ops(coherent);
else
dma_ops = arm_get_dma_map_ops(coherent);
set_dma_ops(dev, dma_ops);
}
void arch_teardown_dma_ops(struct device *dev)
{
arm_teardown_iommu_dma_ops(dev);
}