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authorRussell King <rmk+kernel@arm.linux.org.uk>2013-08-28 18:37:31 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-08-28 18:37:31 +0100
commitcdf0bfb0126bbd8c5424ca01fd59fd70d8ea80f9 (patch)
treee7864d3dacf433b7ccbe17a49b2e72b6a4b3a24c /include/xen/interface/io/ring.h
parentb4f656eea63376da79b0b5a17660c4ce14b71b74 (diff)
parent6af396a6b6c698eb3834184518fc9a59bc22c817 (diff)
Merge branch 'for-rmk/barriers' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable
Diffstat (limited to 'include/xen/interface/io/ring.h')
-rw-r--r--include/xen/interface/io/ring.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h
index 75271b9a8f61..7d28aff605c7 100644
--- a/include/xen/interface/io/ring.h
+++ b/include/xen/interface/io/ring.h
@@ -188,6 +188,11 @@ struct __name##_back_ring { \
#define RING_REQUEST_CONS_OVERFLOW(_r, _cons) \
(((_cons) - (_r)->rsp_prod_pvt) >= RING_SIZE(_r))
+/* Ill-behaved frontend determination: Can there be this many requests? */
+#define RING_REQUEST_PROD_OVERFLOW(_r, _prod) \
+ (((_prod) - (_r)->rsp_prod_pvt) > RING_SIZE(_r))
+
+
#define RING_PUSH_REQUESTS(_r) do { \
wmb(); /* back sees requests /before/ updated producer index */ \
(_r)->sring->req_prod = (_r)->req_prod_pvt; \