1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 7233c88f01b8..001079287709 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -29,6 +29,30 @@
 
 #include "hyperv_vmbus.h"
 
+void hv_begin_read(struct hv_ring_buffer_info *rbi)
+{
+        rbi->ring_buffer->interrupt_mask = 1;
+        smp_mb();
+}
+
+u32 hv_end_read(struct hv_ring_buffer_info *rbi)
+{
+        u32 read;
+        u32 write;
+
+        rbi->ring_buffer->interrupt_mask = 0;
+        smp_mb();
+
+        /*
+         * Now check to see if the ring buffer is still empty.
+         * If it is not, we raced and we need to process new
+         * incoming messages.
+         */
+        hv_get_ringbuffer_availbytes(rbi, &read, &write);
+
+        return read;
+}
+
 
 /*
  * hv_get_next_write_location()