[PATCH v2 17/32] arm: define __smp_xxx

Russell King - ARM Linux linux at arm.linux.org.uk
Sat Jan 2 03:24:38 PST 2016


On Thu, Dec 31, 2015 at 09:07:59PM +0200, Michael S. Tsirkin wrote:
> This defines __smp_xxx barriers for arm,
> for use by virtualization.
> 
> smp_xxx barriers are removed as they are
> defined correctly by asm-generic/barriers.h
> 
> This reduces the amount of arch-specific boiler-plate code.
> 
> Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> Acked-by: Arnd Bergmann <arnd at arndb.de>

In combination with patch 14, this looks like it should result in no
change to the resulting code.

Acked-by: Russell King <rmk+kernel at arm.linux.org.uk>

My only concern is that it gives people an additional handle onto a
"new" set of barriers - just because they're prefixed with __*
unfortunately doesn't stop anyone from using it (been there with
other arch stuff before.)

I wonder whether we should consider making the smp memory barriers
inline functions, so these __smp_xxx() variants can be undef'd
afterwards, thereby preventing drivers getting their hands on these
new macros?

-- 
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