linux/arch/arm64/kernel/io.c
Catalin Marinas fc47897d2c arm64: Device specific operations
This patch adds several definitions for device communication, including
I/O accessors and ioremap(). The __raw_* accessors are implemented as
inline asm to avoid compiler generation of post-indexed accesses (less
efficient to emulate in a virtualised environment).

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
2012-09-17 13:42:04 +01:00

65 lines
1.4 KiB
C

/*
* Based on arch/arm/kernel/io.c
*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/export.h>
#include <linux/types.h>
#include <linux/io.h>
/*
* Copy data from IO memory space to "real" memory space.
*/
void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
{
unsigned char *t = to;
while (count) {
count--;
*t = readb(from);
t++;
from++;
}
}
EXPORT_SYMBOL(__memcpy_fromio);
/*
* Copy data from "real" memory space to IO memory space.
*/
void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
{
const unsigned char *f = from;
while (count) {
count--;
writeb(*f, to);
f++;
to++;
}
}
EXPORT_SYMBOL(__memcpy_toio);
/*
* "memset" on IO memory space.
*/
void __memset_io(volatile void __iomem *dst, int c, size_t count)
{
while (count) {
count--;
writeb(c, dst);
dst++;
}
}
EXPORT_SYMBOL(__memset_io);