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| author |   Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-11-21 11:05:39 +0000 |
|---|---|---|
| committer |   David Vrabel <david.vrabel@citrix.com> | 2014-12-04 12:41:52 +0000 |
| commit | 3567258d281b5b515d5165ed23851d9f84087e7d (patch) | |
| tree | 69da5f20e5354507e3219eaeb6e72b7e5e93f58d /arch/arm/include/asm/xen/page-coherent.h | |
| parent | xen: add a dma_addr_t dev_addr argument to xen_dma_map_page (diff) | |
| download | linux-dev-3567258d281b5b515d5165ed23851d9f84087e7d.tar.xz linux-dev-3567258d281b5b515d5165ed23851d9f84087e7d.zip | |
xen/arm: use hypercall to flush caches in map_page
In xen_dma_map_page, if the page is a local page, call the native
map_page dma_ops. If the page is foreign, call __xen_dma_map_page that
issues any required cache maintenane operations via hypercall.
The reason for doing this is that the native dma_ops map_page could
allocate buffers than need to be freed. If the page is foreign we don't
call the native unmap_page dma_ops function, resulting in a memory leak.
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/arm/include/asm/xen/page-coherent.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h index a309f42b411c..efd562412850 100644 --- a/arch/arm/include/asm/xen/page-coherent.h +++ b/arch/arm/include/asm/xen/page-coherent.h @@ -5,6 +5,9 @@ #include <linux/dma-attrs.h> #include <linux/dma-mapping.h> +void __xen_dma_map_page(struct device *hwdev, struct page *page, + dma_addr_t dev_addr, unsigned long offset, size_t size, + enum dma_data_direction dir, struct dma_attrs *attrs); void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs); @@ -32,7 +35,15 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page, 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); + bool local = PFN_DOWN(dev_addr) == page_to_pfn(page); + /* Dom0 is mapped 1:1, so if pfn == mfn the page is local otherwise + * is a foreign page grant-mapped in dom0. If the page is local we + * can safely call the native dma_ops function, otherwise we call + * the xen specific function. */ + if (local) + __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs); + else + __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs); } static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, |