Messages in this thread | | | Subject | Re: Specifying properly the PCI driver model on all linux archite | Date | Tue, 2 Nov 1999 16:51:25 +0000 (GMT) | From | Alan Cox <> |
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> It also totally destroys Alan Cox's and other peoples statements in the past > about Linux being faster than something like UDI because it doesn't have to > go through a routine just to access the bus.
It would if it was some kind of klunky mapping. On a sane machine it isnt. On x86 for example:
#define __io_virt(x) ((void *)(x)) #define memcpy_fromio(a,b,c) memcpy((a),__io_virt(b),(c))
so you get no overhead.
What happens on a sparc64 is another guess.
> It is no surprise to me that many of the drivers don't do things correctly, > considering how tough it is to determine what correct is.
You are welcome and encouraged to submit documentation fixes. Bad documentation is a bug.
Alan
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