[PATCH RFC 0/2] scatterlist: add I/O variant of sg_pcopy & sg_copy and use them

From: Neil Armstrong
Date: Mon Jun 28 2021 - 08:34:28 EST


A local variant of sg_copy_buffer has been introduced in the meson-gx mmc driver [1] after
a mempcy optimization, fixing the iomem buffer manipulation and the reported system crash [2].

But, the fix is suboptimal in terms of performace/ugliness [3] and a proper I/O variant of
sg_copy_buffer should be added and used instead.

[1] https://lore.kernel.org/r/20210609150230.9291-1-narmstrong@xxxxxxxxxxxx
[2] https://lore.kernel.org/r/acb244ad-0759-5a96-c659-5c23003d3dcd@xxxxxxxxxxx
[3] https://lore.kernel.org/r/CAPDyKFrLSMpPJOgd5e4B1x3Vwfg4q23zgy4ESc8EmFL2MnyK7g@xxxxxxxxxxxxxx

Neil Armstrong (2):
scatterlist: add I/O variant of sg_pcopy & sg_copy
mmc: meson-gx: use sg_copy_to/from_io instead of local version

drivers/mmc/host/meson-gx-mmc.c | 53 +++-----------
include/linux/scatterlist.h | 14 ++++
lib/scatterlist.c | 119 ++++++++++++++++++++++++++++++++
3 files changed, 143 insertions(+), 43 deletions(-)

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2.25.1