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authorBryan O'Sullivan <bos@pathscale.com>2006-02-01 06:05:16 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-01 11:53:13 -0500
commitc27a0d75b33c030965cc97d3d7f571107a673fb4 (patch)
treec4d797b413bb6f8a1b8507213294a291ab5114f8
parentf7589f28d7dd4586b4e90ac3b2a180409669053a (diff)
[PATCH] Introduce __iowrite32_copy
This arch-independent routine copies data to a memory-mapped I/O region, using 32-bit accesses. The naming is double-underscored to make it clear that it does not guarantee write ordering, nor does it perform a memory barrier afterwards; the kernel doc also explicitly states this. This style of access is required by some devices. This change also introduces include/linux/io.h, at Andrew's suggestion. It only has one occupant at the moment, but is a logical destination for oft-replicated contents of include/asm-*/{io,iomap}.h to migrate to. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/linux/io.h25
-rw-r--r--lib/Makefile2
-rw-r--r--lib/iomap_copy.c42
3 files changed, 68 insertions, 1 deletions
diff --git a/include/linux/io.h b/include/linux/io.h
new file mode 100644
index 000000000000..85533ec5aaa1
--- /dev/null
+++ b/include/linux/io.h
@@ -0,0 +1,25 @@
1/*
2 * Copyright 2006 PathScale, Inc. All Rights Reserved.
3 *
4 * This file is free software; you can redistribute it and/or modify
5 * it under the terms of version 2 of the GNU General Public License
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software Foundation,
15 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
16 */
17
18#ifndef _LINUX_IO_H
19#define _LINUX_IO_H
20
21#include <asm/io.h>
22
23void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
24
25#endif /* _LINUX_IO_H */
diff --git a/lib/Makefile b/lib/Makefile
index 8535f4d7d1c3..648b2c1242fd 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -9,7 +9,7 @@ lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
9 9
10lib-y += kobject.o kref.o kobject_uevent.o klist.o 10lib-y += kobject.o kref.o kobject_uevent.o klist.o
11 11
12obj-y += sort.o parser.o halfmd4.o 12obj-y += sort.o parser.o halfmd4.o iomap_copy.o
13 13
14ifeq ($(CONFIG_DEBUG_KOBJECT),y) 14ifeq ($(CONFIG_DEBUG_KOBJECT),y)
15CFLAGS_kobject.o += -DDEBUG 15CFLAGS_kobject.o += -DDEBUG
diff --git a/lib/iomap_copy.c b/lib/iomap_copy.c
new file mode 100644
index 000000000000..a6b1e271d53c
--- /dev/null
+++ b/lib/iomap_copy.c
@@ -0,0 +1,42 @@
1/*
2 * Copyright 2006 PathScale, Inc. All Rights Reserved.
3 *
4 * This file is free software; you can redistribute it and/or modify
5 * it under the terms of version 2 of the GNU General Public License
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software Foundation,
15 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
16 */
17
18#include <linux/io.h>
19#include <linux/module.h>
20
21/**
22 * __iowrite32_copy - copy data to MMIO space, in 32-bit units
23 * @to: destination, in MMIO space (must be 32-bit aligned)
24 * @from: source (must be 32-bit aligned)
25 * @count: number of 32-bit quantities to copy
26 *
27 * Copy data from kernel space to MMIO space, in units of 32 bits at a
28 * time. Order of access is not guaranteed, nor is a memory barrier
29 * performed afterwards.
30 */
31void __attribute__((weak)) __iowrite32_copy(void __iomem *to,
32 const void *from,
33 size_t count)
34{
35 u32 __iomem *dst = to;
36 const u32 *src = from;
37 const u32 *end = src + count;
38
39 while (src < end)
40 __raw_writel(*src++, dst++);
41}
42EXPORT_SYMBOL_GPL(__iowrite32_copy);