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authorVitaly Kuznetsov <vkuznets@redhat.com>2016-09-02 05:58:21 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-02 17:22:51 +0200
commitf24f0b495b17df33c03f3b758b1461385e9f0e50 (patch)
tree6c255cd283067f590b4686c35d0eead6673a3235 /drivers/hv/ring_buffer.c
parent9988ce685676cebe0b14dc128f00e1ae9cd1a4fa (diff)
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Drivers: hv: ring_buffer: use wrap around mappings in hv_copy{from, to}_ringbuffer()
With wrap around mappings for ring buffers we can always use a single memcpy() to do the job. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/ring_buffer.c')
-rw-r--r--drivers/hv/ring_buffer.c24
1 files changed, 3 insertions, 21 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 7e21c2c82ad1..08043da1a61c 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;