Messages in this thread Patch in this message | | | Subject | [RFC] [PATCH] Add memcpy32 function | From | Bryan O'Sullivan <> | Date | Thu, 22 Dec 2005 17:35:59 -0800 |
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In response to the comments that followed Roland Dreier posting our InfiniPath driver for review last week, we've been making some cleanups to our driver code.
As our chip requires 32-bit accesses, we need a copy function that guarantees operating in such terms. It was suggested that we make this generic, with arch-specific optimised versions.
This patch introduces the generic copy routine, memcpy32. At Andrew's suggestion, I've put it in a new header file, include/linux/io.h, which I've styled after include/linux/string.h.
Linus made some comments this morning about the manner in which the functions in string.h are provided, but I wanted to float this patch for review in any case, if only to see whether the alternative really is preferred.
If desired, I can introduce instead an include/asm-generic/memcpy32-algo.h header which defines the generic memcpy32 routine, and edit all 20-odd asm-*/io.h files to use it. That seems wasteful, though.
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
diff -r 0a6978881777 lib/Makefile --- a/lib/Makefile Fri Dec 23 01:41:03 2005 +0800 +++ b/lib/Makefile Thu Dec 22 15:45:05 2005 -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 io.o lib-y += kobject.o kref.o kobject_uevent.o klist.o diff -r 0a6978881777 include/linux/io.h --- /dev/null Thu Jan 1 00:00:00 1970 +0000 +++ b/include/linux/io.h Thu Dec 22 15:45:05 2005 -0800 @@ -0,0 +1,32 @@ +#ifndef _LINUX_IO_H_ +#define _LINUX_IO_H_ + +#include <linux/types.h> + +#ifdef __KERNEL__ + +/* + * Include machine specific inline routines. + */ +#include <asm/io.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#ifndef __HAVE_ARCH_MEMCPY32 +/* + * Copy routine that is guaranteed to operate in terms of 32-bit + * quantities. Source and dest must be 32-bit aligned. Count is + * number of 32-bit quantities (NOT bytes) to copy. + */ +void *memcpy32(void *, const void *, __kernel_size_t); +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* __KERNEL__ */ + +#endif /* _LINUX_IO_H_ */ diff -r 0a6978881777 lib/io.c --- /dev/null Thu Jan 1 00:00:00 1970 +0000 +++ b/lib/io.c Thu Dec 22 15:45:05 2005 -0800 @@ -0,0 +1,21 @@ +#include <linux/io.h> + +#ifndef __HAVE_ARCH_MEMCPY32 +/** + * memcpy32 - Copy one area of memory to another, as a series of + * aligned 32-bit values. + * @dest: Where to copy to (must be 32-bit aligned) + * @src: Where to copy from (must be 32-bit aligned) + * @count: The number of 32-bit values to copy + */ +void *memcpy32(void *dest, const void *src, size_t count) +{ + u32 *tmp = dest; + u32 *s = src; + + while (count--) + *tmp++ = *s++; + return dest; +} +EXPORT_SYMBOL_GPL(memcpy32); +#endif
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