[PATCH v2 0/2] Optimize dma_*_from_contiguous calls

From: Nicolin Chen
Date: Mon May 06 2019 - 18:36:03 EST

[ Per discussion at v1, we decide to add two new functions and start
replacing callers one by one. For this series, it only touches the
dma-direct part. And instead of merging two PATCHes, I still keep
them separate so that we may easily revert PATCH-2 if anything bad
happens as last time -- PATCH-1 is supposed to be a safe cleanup. ]

This series of patches try to optimize dma_*_from_contiguous calls:
PATCH-1 abstracts two new functions and applies to dma-direct.c file.
PATCH-2 saves single pages and reduce fragmentations from CMA area.

Please check their commit messages for detail changelog.

Nicolin Chen (2):
dma-contiguous: Abstract dma_{alloc,free}_contiguous()
dma-contiguous: Use fallback alloc_pages for single pages

include/linux/dma-contiguous.h | 10 ++++++
kernel/dma/contiguous.c | 57 ++++++++++++++++++++++++++++++++++
kernel/dma/direct.c | 24 +++-----------
3 files changed, 71 insertions(+), 20 deletions(-)