From c27a0d75b33c030965cc97d3d7f571107a673fb4 Mon Sep 17 00:00:00 2001 From: Bryan O'Sullivan Date: Wed, 1 Feb 2006 03:05:16 -0800 Subject: [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 Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Makefile | 2 +- lib/iomap_copy.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 1 deletion(-) create mode 100644 lib/iomap_copy.c (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index 8535f4d..648b2c1 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -9,7 +9,7 @@ lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \ lib-y += kobject.o kref.o kobject_uevent.o klist.o -obj-y += sort.o parser.o halfmd4.o +obj-y += sort.o parser.o halfmd4.o iomap_copy.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/iomap_copy.c b/lib/iomap_copy.c new file mode 100644 index 0000000..a6b1e27 --- /dev/null +++ b/lib/iomap_copy.c @@ -0,0 +1,42 @@ +/* + * Copyright 2006 PathScale, Inc. All Rights Reserved. + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License + * 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, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include +#include + +/** + * __iowrite32_copy - copy data to MMIO space, in 32-bit units + * @to: destination, in MMIO space (must be 32-bit aligned) + * @from: source (must be 32-bit aligned) + * @count: number of 32-bit quantities to copy + * + * Copy data from kernel space to MMIO space, in units of 32 bits at a + * time. Order of access is not guaranteed, nor is a memory barrier + * performed afterwards. + */ +void __attribute__((weak)) __iowrite32_copy(void __iomem *to, + const void *from, + size_t count) +{ + u32 __iomem *dst = to; + const u32 *src = from; + const u32 *end = src + count; + + while (src < end) + __raw_writel(*src++, dst++); +} +EXPORT_SYMBOL_GPL(__iowrite32_copy); -- cgit v1.1