[PATCH 1 of 3] Introduce __raw_memcpy_toio32

From: Bryan O'Sullivan
Date: Wed Jan 11 2006 - 17:40:57 EST


This arch-independent routine copies data to a memory-mapped I/O region,
using 32-bit accesses. It does not guarantee access ordering, nor does
it perform a memory barrier afterwards. This style of access is required
by some devices.

Signed-off-by: Bryan O'Sullivan <bos@xxxxxxxxxxxxx>

diff -r c90267e4a29b -r 05b3d1af27eb lib/Makefile
--- a/lib/Makefile Wed Jan 11 13:31:24 2006 +0800
+++ b/lib/Makefile Wed Jan 11 14:35:45 2006 -0800
@@ -5,7 +5,7 @@
lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
bust_spinlocks.o rbtree.o radix-tree.o dump_stack.o \
idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \
- sha1.o
+ sha1.o raw_memcpy_io.o

lib-y += kobject.o kref.o kobject_uevent.o klist.o

diff -r c90267e4a29b -r 05b3d1af27eb lib/raw_memcpy_io.c
--- /dev/null Thu Jan 1 00:00:00 1970 +0000
+++ b/lib/raw_memcpy_io.c Wed Jan 11 14:35:45 2006 -0800
@@ -0,0 +1,41 @@
+/*
+ * 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 <linux/module.h>
+#include <asm/io.h>
+
+/**
+ * __raw_memcpy_toio32 - 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)) __raw_memcpy_toio32(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(__raw_memcpy_toio32);
-
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