Re: [patch] read[bwl] and ioremap problem

Jes Sorensen (Jes.Sorensen@cern.ch)
19 Dec 1999 00:42:01 +0100


>>>>> "Linus" == Linus Torvalds <torvalds@transmeta.com> writes:

Linus> On 18 Dec 1999, Jes Sorensen wrote:
>> This patch is clearly wrong, since the Mac doesn't have IDE on an
>> ISA bus, thus it shouldn't use those macros. However it's not on a
>> PCI bus either so it shouldn't use readb/writeb in the first place
>> ;-)

Linus> readb/writeb do not have to be PCI.

Linus> Any bus that looks from a sw perspective enough like it might
Linus> as well be considered "PCI-like". Some of them may or may not
Linus> need ioremap(). It becomes a problem only if there is a machine
Linus> that has BOTH a real PCI bus _and_ something else, but with an
Linus> old m68k mac that doesn't end up being a problem.

Agreed, however we have m68k boxes that have an ISA bus and another
bus, where the native bus behaves pretty much like PCI in a PC and the
ISA bus requiring special treatment on those machines, with weird byte
order issues, special areas to read from than write from etc. I
therefore prefer to keep the native busses from using the inb/outb and
readb/writeb macros and reserve those macros to to do the magic for
ISA and PCI.

The Macintosh case is not problematic since I don't think there are
m68k based with anything but NUBUS.

Jes

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