Messages in this thread | | | Date | Sun, 4 Mar 2001 21:04:42 +0100 (CET) | From | Geert Uytterhoeven <> | Subject | Re: IO issues vs. multiple busses |
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On Sat, 3 Mar 2001, Grant Grundler wrote: > Benjamin Herrenschmidt wrote: > > Additionally, the same problem is true for ISA memory, when it exist > > obviously. > > Really? I expected ISA memory to look like reguler uncacheable memory > and the drivers would simply dereference the address. But I'm not an > expert on how ISA busses work...
Nope, it's like PCI memory, but different. You have to use isa_readb() and friends to access it.
While ISA I/O space and PCI I/O space are the same on many machines with memory mapped I/O (with a size limitation for ISA I/O), ISA memory space and PCI memory space are different. Cfr. on my CHRP LongTrail:
| callisto$ cat /proc/iomem | 00000000-08000000 : RAM | c0000000-f6ffffff : GG2 PCI mem | c0000000-c0000fff : ATI Technologies Inc 3D Rage I/II 215GT [Mach64 GT] | c1000000-c107ffff : Apple Computer Inc. Hydra Mac I/O | c1080000-c108007f : Digital Equipment Corporation DECchip 21041 [Tulip Pass 3] | c1080000-c108007f : eth0 | c2000000-c2ffffff : ATI Technologies Inc 3D Rage I/II 215GT [Mach64 GT] | c2000000-c2ffffff : atyfb | c3000000-c30000ff : Symbios Logic Inc. (formerly NCR) 53c875 | c3001000-c3001fff : Symbios Logic Inc. (formerly NCR) 53c875 | c4000000-c7ffffff : S3 Inc. 86c764/765 [Trio32/64/64V+] | f7000000-f7ffffff : GG2 ISA mem | f70e0000-f70e7fff : NVRAM | f8000000-f8ffffff : GG2 PCI I/O | fec00000-fec7ffff : GG2 PCI cfg | ff000000-ff7fffff : ROM exp | fff80000-ffffffff : Flash ROM | callisto$
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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