[RFC 06/18] arm: msm: implement proper dmb() for 7x27
Jamie Lokier
jamie at shareable.org
Tue Jan 19 12:16:11 EST 2010
Daniel Walker wrote:
> From: Larry Bassel <lbassel at quicinc.com>
>
> For 7x27 it is necessary to write to strongly
> ordered memory after executing the coprocessor 15
> instruction dmb instruction.
>
> This is only for data barrier dmb().
> Note that the test for 7x27 is done on all MSM platforms
> (even ones such as 7201a whose kernel is distinct from
> that of 7x25/7x27).
How is userspace dealing with this?
Userspace also needs dmb(), in threaded code.
See __kernel_dmb in arch/arm/kernel/entry-armv.S.
-- Jamie
More information about the linux-arm-kernel
mailing list