Re: [PATCH] x86: Remove readq()/writeq() on 32-bit
From: Jeff Garzik
Date: Wed May 13 2009 - 18:40:13 EST
H. Peter Anvin wrote:
#include <linux/io64_lh.h>
linux/io64_lh.h would then look like:
#ifndef _LINUX_IO64_LH_H
#define _LINUX_IO64_LH_H
#include <linux/io.h>
#ifndef HAVE_READQ
/* Low-High nonatomic readq() */
#endif
#ifndef HAVE_WRITEQ
/* Low-High nonatomic writeq() */
Judging from this thread and past, I think people will continue to
complain and get confused, even with the above.
How about
1) tree-wide rename: readq -> readq_na, writeq -> writeq_na
2) make all PCI writel-enabled arches provide readq_na and writeq_na
3) 64-bit PCI writel-enabled arches provide readq and HAVE_READQ, ditto
for writeq. 32-bit provides neither readq nor HAVE_READQ.
4) If your hardware has non-standard ordering, handle it the obvious way
in the driver, as you would do with any other special case.
Jeff
P.S. I use "writel-enabled" to note that some platforms do not provide
PCI read*/write* functions at all.
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