Re: [PATCH] fix ppc ioremap prototype

Linus Torvalds
2003-09-04T17:18:50Z

On Thu, 4 Sep 2003, David S. Miller wrote:
> > ioremap() is very easy to explain to a mathematician: its "domain" is
> > _exactly_ that which is in the "iomem_resource" tree. The "range" is a
> > virtual address.
>
> A virtual address? On x86 IOMEM resources are stored as physical
> addresses and ioremap() returns a virtual mapping of that physical
> address.
>
> Maybe our wires are just crossed.

No, I'm bad.

The "range" is not a virtual address, it's an offsettable cookie, useful
for read[bwl]() and write[bwl]() and the "memcpy_[to|from]io()" functions.

But the "domain" part was the important thing.

Linus