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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2014-11-21 14:07:39 +0300
committerDavid Vrabel <david.vrabel@citrix.com>2014-12-04 15:41:54 +0300
commita4dba130891271084344c12537731542ec77cb85 (patch)
treed7ff4310aadcb0e8d6fc46abb5452727fd56bd17 /arch/arm/xen
parent5121872afe0e6470bc6b41637b258fa6e314be4f (diff)
downloadlinux-a4dba130891271084344c12537731542ec77cb85.tar.xz
xen/arm/arm64: introduce xen_arch_need_swiotlb
Introduce an arch specific function to find out whether a particular dma mapping operation needs to bounce on the swiotlb buffer. On ARM and ARM64, if the page involved is a foreign page and the device is not coherent, we need to bounce because at unmap time we cannot execute any required cache maintenance operations (we don't know how to find the pfn from the mfn). No change of behaviour for x86. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/arm/xen')
-rw-r--r--arch/arm/xen/mm.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index ab700e1e5922..28ebf3ecee4e 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -100,6 +100,13 @@ void __xen_dma_sync_single_for_device(struct device *hwdev,
__xen_dma_page_cpu_to_dev(hwdev, handle, size, dir);
}
+bool xen_arch_need_swiotlb(struct device *dev,
+ unsigned long pfn,
+ unsigned long mfn)
+{
+ return ((pfn != mfn) && !is_device_dma_coherent(dev));
+}
+
int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
unsigned int address_bits,
dma_addr_t *dma_handle)