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* [PATCH 2/8] kernel: Move arches with efficient unaligned access.
@ 2008-04-10 19:44 Harvey Harrison
  2008-04-10 19:44 ` Harvey Harrison
  0 siblings, 1 reply; 2+ messages in thread
From: Harvey Harrison @ 2008-04-10 19:44 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-arch, Mikael Starvik, Roman Zippel, Geert Uytterhoeven,
	David Howells, Paul Mackerras, Martin Schwidefsky, heiko.carstens,
	Ingo Molnar, H. Peter Anvin, Thomas Gleixner

cris, m68k, mn10300, powerpc, s390, and x86 have efficient unaligned
access.  Change their asm includes.

Signed-off-by: Harvey Harrison <harvey.harrison-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 include/asm-cris/unaligned.h    |    8 +--
 include/asm-m68k/unaligned.h    |    9 +---
 include/asm-mn10300/unaligned.h |  126 +--------------------------------------
 include/asm-powerpc/unaligned.h |    9 +---
 include/asm-s390/unaligned.h    |    9 +---
 include/asm-x86/unaligned.h     |   30 +---------
 6 files changed, 8 insertions(+), 183 deletions(-)

diff --git a/include/asm-cris/unaligned.h b/include/asm-cris/unaligned.h
index 7fbbb39..8bd3555 100644
--- a/include/asm-cris/unaligned.h
+++ b/include/asm-cris/unaligned.h
@@ -3,14 +3,8 @@
 
 /*
  * CRIS can do unaligned accesses itself. 
- *
- * The strange macros are there to make sure these can't
- * be misused in a way that makes them not work on other
- * architectures where unaligned accesses aren't as simple.
  */
 
-#define get_unaligned(ptr) (*(ptr))
-
-#define put_unaligned(val, ptr) ((void)( *(ptr) = (val) ))
+#include <linux/unaligned/access_ok.h>
 
 #endif
diff --git a/include/asm-m68k/unaligned.h b/include/asm-m68k/unaligned.h
index 804cb3f..94b4a77 100644
--- a/include/asm-m68k/unaligned.h
+++ b/include/asm-m68k/unaligned.h
@@ -3,14 +3,7 @@
 
 /*
  * The m68k can do unaligned accesses itself.
- *
- * The strange macros are there to make sure these can't
- * be misused in a way that makes them not work on other
- * architectures where unaligned accesses aren't as simple.
  */
-
-#define get_unaligned(ptr) (*(ptr))
-
-#define put_unaligned(val, ptr) ((void)( *(ptr) = (val) ))
+#include <linux/unaligned/access_ok.h>
 
 #endif
diff --git a/include/asm-mn10300/unaligned.h b/include/asm-mn10300/unaligned.h
index cad3afb..c377ba0 100644
--- a/include/asm-mn10300/unaligned.h
+++ b/include/asm-mn10300/unaligned.h
@@ -8,129 +8,9 @@
  * as published by the Free Software Foundation; either version
  * 2 of the Licence, or (at your option) any later version.
  */
-#ifndef _ASM_UNALIGNED_H
-#define _ASM_UNALIGNED_H
+#ifndef _ASM_MN10300_UNALIGNED_H
+#define _ASM_MN10300_UNALIGNED_H
 
-#include <asm/types.h>
-
-#if 0
-extern int __bug_unaligned_x(void *ptr);
-
-/*
- * What is the most efficient way of loading/storing an unaligned value?
- *
- * That is the subject of this file.  Efficiency here is defined as
- * minimum code size with minimum register usage for the common cases.
- * It is currently not believed that long longs are common, so we
- * trade efficiency for the chars, shorts and longs against the long
- * longs.
- *
- * Current stats with gcc 2.7.2.2 for these functions:
- *
- *	ptrsize	get:	code	regs	put:	code	regs
- *	1		1	1		1	2
- *	2		3	2		3	2
- *	4		7	3		7	3
- *	8		20	6		16	6
- *
- * gcc 2.95.1 seems to code differently:
- *
- *	ptrsize	get:	code	regs	put:	code	regs
- *	1		1	1		1	2
- *	2		3	2		3	2
- *	4		7	4		7	4
- *	8		19	8		15	6
- *
- * which may or may not be more efficient (depending upon whether
- * you can afford the extra registers).  Hopefully the gcc 2.95
- * is inteligent enough to decide if it is better to use the
- * extra register, but evidence so far seems to suggest otherwise.
- *
- * Unfortunately, gcc is not able to optimise the high word
- * out of long long >> 32, or the low word from long long << 32
- */
-
-#define __get_unaligned_2(__p)					\
-	(__p[0] | __p[1] << 8)
-
-#define __get_unaligned_4(__p)					\
-	(__p[0] | __p[1] << 8 | __p[2] << 16 | __p[3] << 24)
-
-#define get_unaligned(ptr)					\
-({								\
-	unsigned int __v1, __v2;				\
-	__typeof__(*(ptr)) __v;					\
-	__u8 *__p = (__u8 *)(ptr);				\
-								\
-	switch (sizeof(*(ptr))) {				\
-	case 1:	__v = *(ptr);			break;		\
-	case 2: __v = __get_unaligned_2(__p);	break;		\
-	case 4: __v = __get_unaligned_4(__p);	break;		\
-	case 8:							\
-		__v2 = __get_unaligned_4((__p+4));		\
-		__v1 = __get_unaligned_4(__p);			\
-		__v = ((unsigned long long)__v2 << 32 | __v1);	\
-		break;						\
-	default: __v = __bug_unaligned_x(__p);	break;		\
-	}							\
-	__v;							\
-})
-
-
-static inline void __put_unaligned_2(__u32 __v, register __u8 *__p)
-{
-	*__p++ = __v;
-	*__p++ = __v >> 8;
-}
-
-static inline void __put_unaligned_4(__u32 __v, register __u8 *__p)
-{
-	__put_unaligned_2(__v >> 16, __p + 2);
-	__put_unaligned_2(__v, __p);
-}
-
-static inline void __put_unaligned_8(const unsigned long long __v, __u8 *__p)
-{
-	/*
-	 * tradeoff: 8 bytes of stack for all unaligned puts (2
-	 * instructions), or an extra register in the long long
-	 * case - go for the extra register.
-	 */
-	__put_unaligned_4(__v >> 32, __p + 4);
-	__put_unaligned_4(__v, __p);
-}
-
-/*
- * Try to store an unaligned value as efficiently as possible.
- */
-#define put_unaligned(val, ptr)						\
-	({								\
-		switch (sizeof(*(ptr))) {				\
-		case 1:							\
-			*(ptr) = (val);					\
-			break;						\
-		case 2:							\
-			__put_unaligned_2((val), (__u8 *)(ptr));	\
-			break;						\
-		case 4:							\
-			__put_unaligned_4((val), (__u8 *)(ptr));	\
-			break;						\
-		case 8:							\
-			__put_unaligned_8((val), (__u8 *)(ptr));	\
-			break;						\
-		default:						\
-			__bug_unaligned_x(ptr);				\
-			break;						\
-		}							\
-		(void) 0;						\
-	})
-
-
-#else
-
-#define get_unaligned(ptr) (*(ptr))
-#define put_unaligned(val, ptr) ({ *(ptr) = (val); (void) 0; })
-
-#endif
+#include <linux/unaligned/access_ok.h>
 
 #endif
diff --git a/include/asm-powerpc/unaligned.h b/include/asm-powerpc/unaligned.h
index 6c95dfa..59bcc21 100644
--- a/include/asm-powerpc/unaligned.h
+++ b/include/asm-powerpc/unaligned.h
@@ -5,15 +5,8 @@
 
 /*
  * The PowerPC can do unaligned accesses itself in big endian mode.
- *
- * The strange macros are there to make sure these can't
- * be misused in a way that makes them not work on other
- * architectures where unaligned accesses aren't as simple.
  */
-
-#define get_unaligned(ptr) (*(ptr))
-
-#define put_unaligned(val, ptr) ((void)( *(ptr) = (val) ))
+#include <linux/unaligned/access_ok.h>
 
 #endif	/* __KERNEL__ */
 #endif	/* _ASM_POWERPC_UNALIGNED_H */
diff --git a/include/asm-s390/unaligned.h b/include/asm-s390/unaligned.h
index 8ee86db..1d4a684 100644
--- a/include/asm-s390/unaligned.h
+++ b/include/asm-s390/unaligned.h
@@ -11,14 +11,7 @@
 
 /*
  * The S390 can do unaligned accesses itself. 
- *
- * The strange macros are there to make sure these can't
- * be misused in a way that makes them not work on other
- * architectures where unaligned accesses aren't as simple.
  */
-
-#define get_unaligned(ptr) (*(ptr))
-
-#define put_unaligned(val, ptr) ((void)( *(ptr) = (val) ))
+#include <linux/unaligned/access_ok.h>
 
 #endif
diff --git a/include/asm-x86/unaligned.h b/include/asm-x86/unaligned.h
index 913598d..7ba2e1a 100644
--- a/include/asm-x86/unaligned.h
+++ b/include/asm-x86/unaligned.h
@@ -3,35 +3,7 @@
 
 /*
  * The x86 can do unaligned accesses itself.
- *
- * The strange macros are there to make sure these can't
- * be misused in a way that makes them not work on other
- * architectures where unaligned accesses aren't as simple.
  */
-
-/**
- * get_unaligned - get value from possibly mis-aligned location
- * @ptr: pointer to value
- *
- * This macro should be used for accessing values larger in size than
- * single bytes at locations that are expected to be improperly aligned,
- * e.g. retrieving a u16 value from a location not u16-aligned.
- *
- * Note that unaligned accesses can be very expensive on some architectures.
- */
-#define get_unaligned(ptr) (*(ptr))
-
-/**
- * put_unaligned - put value to a possibly mis-aligned location
- * @val: value to place
- * @ptr: pointer to location
- *
- * This macro should be used for placing values larger in size than
- * single bytes at locations that are expected to be improperly aligned,
- * e.g. writing a u16 value to a location not u16-aligned.
- *
- * Note that unaligned accesses can be very expensive on some architectures.
- */
-#define put_unaligned(val, ptr) ((void)( *(ptr) = (val) ))
+#include <linux/unaligned/access_ok.h>
 
 #endif /* _ASM_X86_UNALIGNED_H */
-- 
1.5.5.144.g3e42

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