Searched hist:c5ca95b507c8a2a69e49eeda539b41bd76922d7f (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/arch/arm/kernel/ |
| H A D | io.c | diff c5ca95b507c8a2a69e49eeda539b41bd76922d7f Wed Dec 18 16:08:52 CST 2013 Ezequiel Garcia <ezequiel.garcia@free-electrons.com> 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>
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| /openbmc/linux/arch/arm/include/asm/ |
| H A D | io.h | diff c5ca95b507c8a2a69e49eeda539b41bd76922d7f Wed Dec 18 16:08:52 CST 2013 Ezequiel Garcia <ezequiel.garcia@free-electrons.com> 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>
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