Our uses of inline asm constraints for atomic operations are fairly
wild and varied. We basically need to guarantee the following:
1. Any instructions with barrier implications
(load-acquire/store-release) have a "memory" clobber
2. When performing exclusive accesses, the addresing mode is generated
using the "Q" constraint
3. Atomic blocks which use the condition flags, have a "cc" clobber
This patch addresses these concerns which, as well as fixing the
semantics of the code, stops GCC complaining about impossible asm
constraints.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch introduces the atomic, mutex and futex operations. Many
atomic operations use the load-acquire and store-release operations
which imply barriers, avoiding the need for explicit DMB.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
