[linux-fbdev] Re: readl() and friends and eieio on PPC

[Paul Mackerras]

Jes Sorensen <Jes.Sorensen at cern.ch> wrote:

> Defininf a C function with the name of a PPC specific assembler
> function is pretty stupid. To the best of my knowledge wmb() is the
> generic name for the thing you are looking for.

Not exactly, in fact iobarrier() is probably better.

The eieio instruction has two separate effects:

1. as a write barrier for writes to cacheable memory (hence wmb)

2. as a read/write barrier for reads and writes to non-cacheable
   memory (hence iobarrier)

Paul.

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