[PATCH 0/2] ioremap_wc on arm64
Jayachandran C
jnair at caviumnetworks.com
Mon May 22 00:01:45 PDT 2017
>From its definition, the device "gather" attribute seems to be a better
fit for implementing write combining mapping in ioremap_wc(). And on
ThunderX2, Device GRE mapping has optimizations that makes it much faster
than normal uncached mapping.
I am not sure of the reasoning behind the original decision to make
ioremap_wc use "Normal Non-Cached" attribute, since all the other variants
of ioremap use device attributes, and ioremap_wc looks like an exception.
Comments are very welcome.
Thanks,
JC.
Jayachandran C (2):
arm64: add PROT_DEVICE_GRE for Device GRE mapping
arm64: switch ioremap_wc to use Device GRE
arch/arm64/include/asm/io.h | 2 +-
arch/arm64/include/asm/pgtable-prot.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
--
2.7.4
More information about the linux-arm-kernel
mailing list