Re: [PATCH] isa_{read,write}{w,l} fixed

Philipp Rumpf (prumpf@inwestnet.de)
Fri, 11 Feb 2000 19:50:08 +0100


> I've fixed several drivers that do that. It doesnt work because structure
> padding goes and bites the idiots who do this. Also a struct pointer isnt

I'm pretty sure it's a reasonably safe assumption gcc doesn't reorder members
of structs as long as they are naturally aligned - otherwise I assume structs
used for DMA would need to be fixed, too ?

> capable of representing the entire physical address of some boxes - it can
> hit the full ISA address space sure.

For PCI, what ioremap() returns is a pointer type (it is not necessarily a
valid pointer, of course), so all mapped I/O addresses are representable by
a structure pointer (unless we had a really broken ABI where certain void *
couldn't be cast to struct pointers).

I'm not sure how the physical address space matters for this.

Philipp

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/