Messages in this thread | | | Date | Tue, 1 May 2001 14:19:33 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: isa_read/write not available on ppc - solution suggestions ?? |
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On Tue, 1 May 2001, Russell King wrote: > > Talking around this issue, is there any chance of getting the > official use of the first parameter to ioremap documented in > Documentation/IO-mapping.txt please? There appears to be > confusion as to whether it is: > > a) PCI bus address > b) CPU untranslated address
It's neither.
It's a cookie that you can do arithmetic off and pass on to the readx/writex, and nothing more. You cannot make any assumptions at all about what it means.
In particular, you can _not_ assume that it is a PCI bus address ("WHICH bus?") and you can absolutely not assume that it is a CPU address (many CPU's do not "memory map" PCI at all).
Linus
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