linux/arch/sh/kernel/io.c
Magnus Damm e7cc9a7340 sh: trapped io support V2
The idea is that we want to get rid of the in/out/readb/writeb callbacks from
the machvec and replace that with simple inline read and write operations to
memory. Fast and simple for most hardware devices (think pci).

Some devices require special treatment though - like 16-bit only CF devices -
so we need to have some method to hook in callbacks.

This patch makes it possible to add a per-device trap generating filter. This
way we can get maximum performance of sane hardware - which doesn't need this
filter - and crappy hardware works but gets punished by a performance hit.

V2 changes things around a bit and replaces io access callbacks with a
simple minimum_bus_width value. In the future we can add stride as well.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-02-14 14:22:09 +09:00

81 lines
1.8 KiB
C

/*
* linux/arch/sh/kernel/io.c
*
* Copyright (C) 2000 Stuart Menefy
* Copyright (C) 2005 Paul Mundt
*
* Provide real functions which expand to whatever the header file defined.
* Also definitions of machine independent IO functions.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <asm/machvec.h>
#include <asm/io.h>
/*
* Copy data from IO memory space to "real" memory space.
* This needs to be optimized.
*/
void memcpy_fromio(void *to, volatile void __iomem *from, unsigned long count)
{
char *p = to;
while (count) {
count--;
*p = readb((void __iomem *)from);
p++;
from++;
}
}
EXPORT_SYMBOL(memcpy_fromio);
/*
* Copy data from "real" memory space to IO memory space.
* This needs to be optimized.
*/
void memcpy_toio(volatile void __iomem *to, const void *from, unsigned long count)
{
const char *p = from;
while (count) {
count--;
writeb(*p, (void __iomem *)to);
p++;
to++;
}
}
EXPORT_SYMBOL(memcpy_toio);
/*
* "memset" on IO memory space.
* This needs to be optimized.
*/
void memset_io(volatile void __iomem *dst, int c, unsigned long count)
{
while (count) {
count--;
writeb(c, (void __iomem *)dst);
dst++;
}
}
EXPORT_SYMBOL(memset_io);
void __iomem *ioport_map(unsigned long port, unsigned int nr)
{
void __iomem *ret;
ret = __ioport_map_trapped(port, nr);
if (ret)
return ret;
return __ioport_map(port, nr);
}
EXPORT_SYMBOL(ioport_map);
void ioport_unmap(void __iomem *addr)
{
sh_mv.mv_ioport_unmap(addr);
}
EXPORT_SYMBOL(ioport_unmap);