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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-10-25 10:33:26 +0000
committerStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-10-25 10:33:26 +0000
commit3d1975b57097820c131c692d2e0d075641370369 (patch)
tree92784190b99b6b9e1a665a29dc2f1efb60623ff6 /arch/arm64/include/asm/io.h
parent783d0281043b9a1111d81d11ed0610b83d8857ed (diff)
arm,arm64: do not always merge biovec if we are running on Xen
This is similar to what it is done on X86: biovecs are prevented from merging otherwise every dma requests would be forced to bounce on the swiotlb buffer. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Changes in v7: - remove the extra autotranslate check in biomerge.c.
Diffstat (limited to 'arch/arm64/include/asm/io.h')
-rw-r--r--arch/arm64/include/asm/io.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 1d12f89140ba..c163287b9871 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -22,11 +22,14 @@
#ifdef __KERNEL__
#include <linux/types.h>
+#include <linux/blk_types.h>
#include <asm/byteorder.h>
#include <asm/barrier.h>
#include <asm/pgtable.h>
+#include <xen/xen.h>
+
/*
* Generic IO read/write. These perform native-endian accesses.
*/
@@ -263,5 +266,11 @@ extern int devmem_is_allowed(unsigned long pfn);
*/
#define xlate_dev_kmem_ptr(p) p
+extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
+ const struct bio_vec *vec2);
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
+ (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) && \
+ (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
+
#endif /* __KERNEL__ */
#endif /* __ASM_IO_H */