Messages in this thread | | | Date | Tue, 27 May 2008 14:59:28 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: MMIO and gcc re-ordering issue |
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On Tue, 27 May 2008, Alan Cox wrote: > > > re-ordering, even though I doubt it will be visible in practice. So if you > > use the "__" versions, you'd better have barriers even on x86! > > Are we also going to have __ioread*/__iowrite* ?
I doubt there is any reason to. Let's just keep them very strictly ordered.
> Also is the sematics of __readl/__writel defined for all architectures - > I used it ages ago in the i2o drivers for speed and it got removed > because it didn't build on some platforms.
Agreed - I'm not sure the __ versions are really worth it. We have them, but the semantics are subtle enough that most drivers will never care enough to really use them.
I would suggest using them mainly for architecture-specific drivers, on architectures where it actually matters (which is not the case on x86).
Linus
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