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SubjectRe: user space writel() etc. in 2.2.2
On Fri, 5 Mar 1999, Alan Cox wrote:

OK, finally I am enlightened (by Alan and others). The story is that
there is no portable solution for IO memory acces in current Linux. It is
platform dependent in a non-trivial way:
> > On Fri, 5 Mar 1999, Alan Cox wrote:
> There really isnt an easy one
> ARM - no cache coherency
> Alpha - offset PCI mapping. PCI I/O space is mapped in strange ways
> varies by platform
> PMac - PCI bus is endian swapped in hardware
> x86 - Sane (well its the reference bus)
> Sparc64 - Basically sane - again PCI I/O space is mapped as memory
> I think you come down to needing an
> arch_fooplatform.c (or .tcl)

I will try to put a library to that effect, but I don't have
platforms other then i386. I will cut and pasted code from asm/io.h with
proper adjustments (i.e. no virtual to bus translation, just virtual
mmap()-ed memory). I still have some feeling that it is already done in
io.h, but I will yield.

| Linux Media Labs LLC | Vassili Leonov

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