path: root/arch/sh/atomic_arch.h
AgeCommit message (Collapse)AuthorLines
2017-08-11fix build failure for sh4a due to missing colon in asm statementThomas Petazzoni-1/+1
Due to a missing ":" in an asm() statement, the "memory" clobber is considered by gcc as an input operand and not a clobber, which causes a build failure.
2016-01-21overhaul sh atomics for new atomics framework, add j-core cas.l backendRich Felker-80/+30
sh needs runtime-selected atomic backends since there are a number of supported models that use non-forwards-compatible (non-smp-compatible) atomic mechanisms. previously, the code paths for this were highly inefficient since they involved C function calls with multiple branches in the callee and heavy spills in the caller. the new code performs calls the runtime-selected asm fragment from inline asm with extremely minimal clobbers, rather than using a function call. for the sh4a case where the atomic mechanism is known and there is no forward-compatibility issue, the movli.l and movco.l instructions are provided as a_ll and a_sc, allowing the new shared atomic.h to generate efficient inline versions of all the basic atomic operations without needing a cas loop.
2016-01-21refactor internal atomic.hRich Felker-0/+96
rather than having each arch provide its own atomic.h, there is a new shared atomic.h in src/internal which pulls arch-specific definitions from arc/$(ARCH)/atomic_arch.h. the latter can be extremely minimal, defining only a_cas or new ll/sc type primitives which the shared atomic.h will use to construct everything else. this commit avoids making heavy changes to the individual archs' atomic implementations. definitions which are identical or near-identical to what the new shared atomic.h would produce have been removed, but otherwise the changes made are just hooking up the arch-specific files to the new infrastructure. major changes to take advantage of the new system will come in subsequent commits.