tree 70c6c5944eb978c6eff55eab1e1b1df7049477ec
parent 78b4b05db57b04b3ed17dc71259bf1402c04abfa
author FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> 1205766903 +0900
committer James Bottomley <James.Bottomley@HansenPartnership.com> 1207588545 -0500

[SCSI] block: add sg buffer copy helper functions

This patch adds new three helper functions to copy data between an SG
list and a linear buffer.

- sg_copy_from_buffer copies data from linear buffer to an SG list

- sg_copy_to_buffer copies data from an SG list to a linear buffer

When the APIs copy data from a linear buffer to an SG list,
flush_kernel_dcache_page is called. It's not necessary for everyone
but it's a no-op on most architectures and in general the API is not
used in performance critical path.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>