Messages in this thread | | | From | Segher Boessenkool <> | Subject | Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures | Date | Tue, 21 Aug 2007 01:02:01 +0200 |
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>> And no, RMW on MMIO isn't "problematic" at all, either. >> >> An RMW op is a read op, a modify op, and a write op, all rolled >> into one opcode. But three actual operations. > > Maybe for some CPUs, but not all. ARM for instance can't use the > load exclusive and store exclusive instructions to MMIO space.
Sure, your CPU doesn't have RMW instructions -- how to emulate those if you don't have them is a totally different thing.
Segher
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