xen: add a dma_addr_t dev_addr argument to xen_dma_map_page

dev_addr is the machine address of the page.

The new parameter can be used by the ARM and ARM64 implementations of
xen_dma_map_page to find out if the page is a local page (pfn == mfn) or
a foreign page (pfn != mfn).

dev_addr could be retrieved again from the physical address, using
pfn_to_mfn, but it requires accessing an rbtree. Since we already have
the dev_addr in our hands at the call site there is no need to get the
mfn twice.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

4 files changed, 10 insertions, 8 deletions

diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h
index 9cfd895eb4bb..a309f42b411c 100644
--- a/arch/arm/include/asm/xen/page-coherent.h
+++ b/arch/arm/include/asm/xen/page-coherent.h
@@ -29,8 +29,8 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 }
 
 static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
-             unsigned long offset, size_t size, enum dma_data_direction dir,
-             struct dma_attrs *attrs)
+             dma_addr_t dev_addr, unsigned long offset, size_t size,
+             enum dma_data_direction dir, struct dma_attrs *attrs)
 {
         __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
 }
diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h
index dde3fc9c49f0..d7cd4c2b2fd2 100644
--- a/arch/arm64/include/asm/xen/page-coherent.h
+++ b/arch/arm64/include/asm/xen/page-coherent.h
@@ -20,8 +20,8 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 }
 
 static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
-             unsigned long offset, size_t size, enum dma_data_direction dir,
-             struct dma_attrs *attrs)
+             dma_addr_t dev_addr, unsigned long offset, size_t size,
+             enum dma_data_direction dir, struct dma_attrs *attrs)
 {
 }
 
diff --git a/arch/x86/include/asm/xen/page-coherent.h b/arch/x86/include/asm/xen/page-coherent.h
index 7f02fe4e2c7b..acd844c017d3 100644
--- a/arch/x86/include/asm/xen/page-coherent.h
+++ b/arch/x86/include/asm/xen/page-coherent.h
@@ -22,8 +22,8 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 }
 
 static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
-             unsigned long offset, size_t size, enum dma_data_direction dir,
-             struct dma_attrs *attrs) { }
+             dma_addr_t dev_addr, unsigned long offset, size_t size,
+             enum dma_data_direction dir, struct dma_attrs *attrs) { }
 
 static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
                 size_t size, enum dma_data_direction dir,
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index ebd8f218a788..ad2c5eb8a9c7 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -403,7 +403,7 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
                 /* we are not interested in the dma_addr returned by
                  * xen_dma_map_page, only in the potential cache flushes executed
                  * by the function. */
-                xen_dma_map_page(dev, page, offset, size, dir, attrs);
+                xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);
                 return dev_addr;
         }
 
@@ -417,7 +417,7 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
                 return DMA_ERROR_CODE;
 
         xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
-                                        map & ~PAGE_MASK, size, dir, attrs);
+                                        dev_addr, map & ~PAGE_MASK, size, dir, attrs);
         dev_addr = xen_phys_to_bus(map);
 
         /*
@@ -574,6 +574,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
                                 return 0;
                         }
                         xen_dma_map_page(hwdev, pfn_to_page(map >> PAGE_SHIFT),
+                                                dev_addr,
                                                 map & ~PAGE_MASK,
                                                 sg->length,
                                                 dir,
@@ -584,6 +585,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
                          * xen_dma_map_page, only in the potential cache flushes executed
                          * by the function. */
                         xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT),
+                                                dev_addr,
                                                 paddr & ~PAGE_MASK,
                                                 sg->length,
                                                 dir,