From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
With wrap around mappings for ring buffers we can always use a single
memcpy() to do the job.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Tested-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
---
drivers/hv/ring_buffer.c | 24 +++---------------------
1 files changed, 3 insertions(+), 21 deletions(-)
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 7e21c2c..08043da 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -172,18 +172,7 @@ static u32 hv_copyfrom_ringbuffer(
void *ring_buffer = hv_get_ring_buffer(ring_info);
u32 ring_buffer_size = hv_get_ring_buffersize(ring_info);
- u32 frag_len;
-
- /* wrap-around detected at the src */
- if (destlen > ring_buffer_size - start_read_offset) {
- frag_len = ring_buffer_size - start_read_offset;
-
- memcpy(dest, ring_buffer + start_read_offset, frag_len);
- memcpy(dest + frag_len, ring_buffer, destlen - frag_len);
- } else
-
- memcpy(dest, ring_buffer + start_read_offset, destlen);
-
+ memcpy(dest, ring_buffer + start_read_offset, destlen);
start_read_offset += destlen;
start_read_offset %= ring_buffer_size;
@@ -204,15 +193,8 @@ static u32 hv_copyto_ringbuffer(
{
void *ring_buffer = hv_get_ring_buffer(ring_info);
u32 ring_buffer_size = hv_get_ring_buffersize(ring_info);
- u32 frag_len;
-
- /* wrap-around detected! */
- if (srclen > ring_buffer_size - start_write_offset) {
- frag_len = ring_buffer_size - start_write_offset;
- memcpy(ring_buffer + start_write_offset, src, frag_len);
- memcpy(ring_buffer, src + frag_len, srclen - frag_len);
- } else
- memcpy(ring_buffer + start_write_offset, src, srclen);
+
+ memcpy(ring_buffer + start_write_offset, src, srclen);
start_write_offset += srclen;
start_write_offset %= ring_buffer_size;
--
1.7.4.1
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
