[PATCH 20/33] powerpc/dma: remove the iommu fallback for coherent allocations

Christoph Hellwig
2018-10-09T13:28:30Z

All iommu capable platforms now always use the iommu code with the
internal bypass, so there is not need for this magic anymore.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/powerpc/Kconfig | 4 ---
arch/powerpc/kernel/dma.c | 68 ++-------------------------------------
2 files changed, 2 insertions(+), 70 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 06996df07cad..7097019d8907 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -119,9 +119,6 @@ config GENERIC_HWEIGHT
bool
default y

-config ARCH_HAS_DMA_SET_COHERENT_MASK
- bool
-
config PPC
bool
default y
@@ -129,7 +126,6 @@ config PPC
# Please keep this list sorted alphabetically.
#
select ARCH_HAS_DEVMEM_IS_ALLOWED
- select ARCH_HAS_DMA_SET_COHERENT_MASK
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 78ef4076e15c..bef91b8ad064 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -114,51 +114,6 @@ void __dma_nommu_free_coherent(struct device *dev, size_t size,
}
#endif /* !CONFIG_NOT_COHERENT_CACHE */

-static void *dma_nommu_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flag,
- unsigned long attrs)
-{
- struct iommu_table *iommu;
-
- /* The coherent mask may be smaller than the real mask, check if
- * we can really use the direct ops
- */
- if (dma_nommu_dma_supported(dev, dev->coherent_dma_mask))
- return __dma_nommu_alloc_coherent(dev, size, dma_handle,
- flag, attrs);
-
- /* Ok we can't ... do we have an iommu ? If not, fail */
- iommu = get_iommu_table_base(dev);
- if (!iommu)
- return NULL;
-
- /* Try to use the iommu */
- return iommu_alloc_coherent(dev, iommu, size, dma_handle,
- dev->coherent_dma_mask, flag,
- dev_to_node(dev));
-}
-
-static void dma_nommu_free_coherent(struct device *dev, size_t size,
- void *vaddr, dma_addr_t dma_handle,
- unsigned long attrs)
-{
- struct iommu_table *iommu;
-
- /* See comments in dma_nommu_alloc_coherent() */
- if (dma_nommu_dma_supported(dev, dev->coherent_dma_mask))
- return __dma_nommu_free_coherent(dev, size, vaddr, dma_handle,
- attrs);
- /* Maybe we used an iommu ... */
- iommu = get_iommu_table_base(dev);
-
- /* If we hit that we should have never allocated in the first
- * place so how come we are freeing ?
- */
- if (WARN_ON(!iommu))
- return;
- iommu_free_coherent(iommu, size, vaddr, dma_handle);
-}
-
int dma_nommu_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle, size_t size,
unsigned long attrs)
@@ -228,8 +183,8 @@ static inline void dma_nommu_sync_single(struct device *dev,
#endif

const struct dma_map_ops dma_nommu_ops = {
- .alloc = dma_nommu_alloc_coherent,
- .free = dma_nommu_free_coherent,
+ .alloc = __dma_nommu_alloc_coherent,
+ .free = __dma_nommu_free_coherent,
.mmap = dma_nommu_mmap_coherent,
.map_sg = dma_nommu_map_sg,
.dma_supported = dma_nommu_dma_supported,
@@ -243,25 +198,6 @@ const struct dma_map_ops dma_nommu_ops = {
};
EXPORT_SYMBOL(dma_nommu_ops);

-int dma_set_coherent_mask(struct device *dev, u64 mask)
-{
- if (!dma_supported(dev, mask)) {
- /*
- * We need to special case the direct DMA ops which can
- * support a fallback for coherent allocations. There
- * is no dma_op->set_coherent_mask() so we have to do
- * things the hard way:
- */
- if (get_dma_ops(dev) != &dma_nommu_ops ||
- get_iommu_table_base(dev) == NULL ||
- !dma_iommu_dma_supported(dev, mask))
- return -EIO;
- }
- dev->coherent_dma_mask = mask;
- return 0;
-}
-EXPORT_SYMBOL(dma_set_coherent_mask);
-
int dma_set_mask(struct device *dev, u64 dma_mask)
{
if (ppc_md.dma_set_mask)
--
2.19.0