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Commit f24f0b49 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Greg Kroah-Hartman
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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: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Tested-by: default avatarDexuan Cui <decui@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9988ce68

drivers/hv/ring_buffer.c

+3 −21
Original line number Diff line number Diff line
@@ -172,19 +172,8 @@ 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);





	start_read_offset += destlen;

	start_read_offset %= ring_buffer_size;
@@ -204,14 +193,7 @@ 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);



	start_write_offset += srclen;