Messages in this thread | | | Date | Tue, 27 May 2008 15:02:15 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: MMIO and gcc re-ordering issue |
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On Tue, 27 May 2008, Matthew Wilcox wrote:
> On Tue, May 27, 2008 at 10:38:22PM +0100, 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* ? > > Didn't we already define ioread*() to have loose semantics?
They are supposed to have the same semantics as readl/writel.
And yes, it's "loose", but only when compared to inb/outb (which are really very strict, if you want to emulate x86 - an "outb" basically is not only ordered, it doesn't even post the write, and waits until it has hit the bus!)
Linus
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