On Tue, 21 Dec 2021 11:55:56 +0800, Xiongfeng Wang wrote:

For memory accesses with write-combining attributes (e.g. those returned
by ioremap_wc()), the CPU may wait for prior accesses to be merged with
subsequent ones. But in some situation, such wait is bad for the
performance.

We introduce io_stop_wc() to prevent the merging of write-combining
memory accesses before this macro with those after it.

[...]

Applied to arm64 (for-next/misc), thanks!

[1/1] asm-generic: introduce io_stop_wc() and add implementation for ARM64
      https://git.kernel.org/arm64/c/d5624bb29f49

-- 
Catalin