Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / xen / biomerge.c

diff --git a/kernel/drivers/xen/biomerge.c b/kernel/drivers/xen/biomerge.c
new file mode 100644 (file)
index 0000000..0edb91c
--- /dev/null
+++ b/kernel/drivers/xen/biomerge.c
@@ -0,0 +1,15 @@
+#include <linux/bio.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <xen/page.h>
+
+bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
+                              const struct bio_vec *vec2)
+{
+       unsigned long mfn1 = pfn_to_mfn(page_to_pfn(vec1->bv_page));
+       unsigned long mfn2 = pfn_to_mfn(page_to_pfn(vec2->bv_page));
+
+       return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
+               ((mfn1 == mfn2) || ((mfn1+1) == mfn2));
+}
+EXPORT_SYMBOL(xen_biovec_phys_mergeable);