[PATCH v9 07/13] xen: add a dma_addr_t dev_addr argument to xen_dma_map_page

Stefano Stabellini
2014-11-12T11:42:50Z

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>
---
arch/arm/include/asm/xen/page-coherent.h | 4 ++--
arch/arm64/include/asm/xen/page-coherent.h | 4 ++--
arch/x86/include/asm/xen/page-coherent.h | 4 ++--
drivers/xen/swiotlb-xen.c | 6 ++++--
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 9cfd895..a309f42 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 dde3fc9..d7cd4c2 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 7f02fe4..acd844c 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 ebd8f21..ad2c5eb 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,
--
1.7.10.4