Re: [PATCH 05/21] dma-iommu: remove the flush_page callback

From: Robin Murphy
Date: Fri Apr 05 2019 - 13:47:01 EST


On 27/03/2019 08:04, Christoph Hellwig wrote:
We now have a arch_dma_prep_coherent architecture hook that is used
for the generic DMA remap allocator, and we should use the same
interface for the dma-iommu code.

Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/arm64/mm/dma-mapping.c | 8 +-------
drivers/iommu/dma-iommu.c | 8 +++-----
include/linux/dma-iommu.h | 3 +--
3 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index e54288921e72..54787a3d4ad9 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -94,12 +94,6 @@ arch_initcall(arm64_dma_init);
#include <linux/platform_device.h>
#include <linux/amba/bus.h>
-/* Thankfully, all cache ops are by VA so we can ignore phys here */
-static void flush_page(struct device *dev, const void *virt, phys_addr_t phys)
-{
- __dma_flush_area(virt, PAGE_SIZE);
-}
-
static void *__iommu_alloc_attrs(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp,
unsigned long attrs)
@@ -176,7 +170,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
struct page **pages;
pages = iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
- handle, flush_page);
+ handle);
if (!pages)
return NULL;
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 77aabe637a60..77d704c8f565 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -22,6 +22,7 @@
#include <linux/acpi_iort.h>
#include <linux/device.h>
#include <linux/dma-iommu.h>
+#include <linux/dma-noncoherent.h>
#include <linux/gfp.h>
#include <linux/huge_mm.h>
#include <linux/iommu.h>
@@ -531,8 +532,6 @@ void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
* @attrs: DMA attributes for this allocation
* @prot: IOMMU mapping flags
* @handle: Out argument for allocated DMA handle
- * @flush_page: Arch callback which must ensure PAGE_SIZE bytes from the
- * given VA/PA are visible to the given non-coherent device.
*
* If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
* but an IOMMU which supports smaller pages might not map the whole thing.
@@ -541,8 +540,7 @@ void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
* or NULL on failure.
*/
struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
- unsigned long attrs, int prot, dma_addr_t *handle,
- void (*flush_page)(struct device *, const void *, phys_addr_t))
+ unsigned long attrs, int prot, dma_addr_t *handle)
{
struct iommu_domain *domain = iommu_get_dma_domain(dev);
struct iommu_dma_cookie *cookie = domain->iova_cookie;
@@ -586,7 +584,7 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
*/
sg_miter_start(&miter, sgt.sgl, sgt.orig_nents, SG_MITER_FROM_SG);
while (sg_miter_next(&miter))
- flush_page(dev, miter.addr, page_to_phys(miter.page));
+ arch_dma_prep_coherent(miter.page, PAGE_SIZE);
sg_miter_stop(&miter);
}
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 3e206f4ee173..10ef708a605c 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -45,8 +45,7 @@ int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
* the arch code to take care of attributes and cache maintenance
*/
struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
- unsigned long attrs, int prot, dma_addr_t *handle,
- void (*flush_page)(struct device *, const void *, phys_addr_t));
+ unsigned long attrs, int prot, dma_addr_t *handle);
void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
dma_addr_t *handle);