linux/arch/arm/include
Ezequiel Garcia c5ca95b507 ARM: 7930/1: Introduce atomic MMIO modify
Some SoC have MMIO regions that are shared across orthogonal
subsystems. This commit implements a possible solution for the
thread-safe access of such regions through a spinlock-protected API.

Concurrent access is protected with a single spinlock for the
entire MMIO address space. While this protects shared-registers,
it also serializes access to unrelated/unshared registers.

We add relaxed and non-relaxed variants, by using writel_relaxed and writel,
respectively. The rationale for this is that some users may not require
register write completion but only thread-safe access to a register.

Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-01-28 14:06:25 +00:00
..
asm ARM: 7930/1: Introduce atomic MMIO modify 2014-01-28 14:06:25 +00:00
debug Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2013-11-14 08:51:29 +09:00
uapi/asm Here are the 3.13 KVM changes. There was a lot of work on the PPC 2013-11-15 13:51:36 +09:00