Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v3 00/17] Cross-architecture definitions of relaxed MMIO accessors | Date | Thu, 25 Sep 2014 21:17:19 +0200 |
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On Thursday 25 September 2014, Daniel Thompson wrote: > > + > > +#ifndef readq_relaxed > > +#define readq_relaxed readq > > +#endif > > Not really sure if it matters but this gives a rather surprising > behaviour to #ifdef readq_relaxed given that readq may not be defined. >
It was intentional. I could have written this as
#if !defined(readq_relaxed) && defined(readq)
but the effect would be almost the same, and the version I picked looks simpler. Note that 32-bit architectures could provide readq, it's just the generic code that doesn't, because most you typically don't get atomic 64-bit accesses from dereferencing a 64-bit pointer as the generic readq() function does.
Arnd
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