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authorBryan O'Sullivan <bos@pathscale.com>2006-02-01 03:05:16 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-01 08:53:13 -0800
commitc27a0d75b33c030965cc97d3d7f571107a673fb4 (patch)
treec4d797b413bb6f8a1b8507213294a291ab5114f8 /lib
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>
Diffstat (limited to 'lib')
-rw-r--r--lib/Makefile2
-rw-r--r--lib/iomap_copy.c42
2 files changed, 43 insertions, 1 deletions
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 \
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 000000000000..a6b1e271d53c
--- /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 <linux/io.h>
+#include <linux/module.h>
+
+/**
+ * __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);

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