summaryrefslogtreecommitdiffstats
path: root/drivers/xen/biomerge.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/xen/biomerge.c')
-rw-r--r--drivers/xen/biomerge.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/xen/biomerge.c b/drivers/xen/biomerge.c
new file mode 100644
index 00000000000..ba6eda4b514
--- /dev/null
+++ b/drivers/xen/biomerge.c
@@ -0,0 +1,13 @@
+#include <linux/bio.h>
+#include <linux/io.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));
+}