Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1395216

Re: [PATCH v2 1/8] asm-generic/io.h: allow barriers in io{read,write}{16,32}be

Show all headers | View raw

On Thursday 05 May 2016 18:35:45 Horia Geantă wrote:
> While reviewing the addition of io{read,write}64be accessors, Arnd
> 
> -finds a potential problem:
> "If an architecture overrides readq/writeq to have barriers but does
> not override ioread64be/iowrite64be, this will lack the barriers and
> behave differently from the little-endian version. I think the only
> affected architecture is ARC, since ARM and ARM64 both override the
> big-endian accessors to have the correct barriers, and all others
> don't use barriers at all."
> 
> -suggests a fix for the same problem in existing code (16/32-bit
> accessors); the fix leads "to a double-swap on architectures that
> don't override the io{read,write}{16,32}be accessors, but it will
> work correctly on all architectures without them having to override
> these accessors."
> 
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
> ---

Acked-by: Arnd Bergmann <arnd@arndb.de>

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

Re: [PATCH v2 1/8] asm-generic/io.h: allow barriers in io{read,write}{16,32}be Arnd Bergmann <arnd@arndb.de> - 2016-05-05 18:30 +0200

csiph-web