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authorArnd Bergmann <arnd@arndb.de>2009-06-18 21:48:17 +0200
committerH. Peter Anvin <hpa@zytor.com>2009-06-18 14:39:47 -0700
commit7bfd124d6dae7d394e73753300594a81a022fe7d (patch)
treef6b82b71071a5dcda066f0c2b33739d06b8bab65 /arch/x86/include/asm/shmbuf.h
parent4adc667593f83a18a8e54ce94f250fd166a272ac (diff)
downloadlinux-7bfd124d6dae7d394e73753300594a81a022fe7d.tar.gz
x86: convert trivial headers to asm-generic version
For these nine header files, the asm-generic version should
be semantically identical to what is in x86. Change the
contents to be binary identical, for better review.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <cover.1245354003.git.arnd@arndb.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/shmbuf.h')
-rw-r--r--arch/x86/include/asm/shmbuf.h28
1 files changed, 18 insertions, 10 deletions
diff --git a/arch/x86/include/asm/shmbuf.h b/arch/x86/include/asm/shmbuf.h
index b51413b74971..5768fa60ac82 100644
--- a/arch/x86/include/asm/shmbuf.h
+++ b/arch/x86/include/asm/shmbuf.h
@@ -1,32 +1,40 @@
-#ifndef _ASM_X86_SHMBUF_H
-#define _ASM_X86_SHMBUF_H
+#ifndef __ASM_GENERIC_SHMBUF_H
+#define __ASM_GENERIC_SHMBUF_H
+
+#include <asm/bitsperlong.h>
 
 /*
  * The shmid64_ds structure for x86 architecture.
  * Note extra padding because this structure is passed back and forth
  * between kernel and user space.
  *
- * Pad space on 32 bit is left for:
+ * shmid64_ds was originally meant to be architecture specific, but
+ * everyone just ended up making identical copies without specific
+ * optimizations, so we may just as well all use the same one.
+ *
+ * 64 bit architectures typically define a 64 bit __kernel_time_t,
+ * so they do not need the first two padding words.
+ * On big-endian systems, the padding is in the wrong place.
+ *
+ *
+ * Pad space is left for:
  * - 64-bit time_t to solve y2038 problem
  * - 2 miscellaneous 32-bit values
- *
- * Pad space on 64 bit is left for:
- * - 2 miscellaneous 64-bit values
  */
 
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 	size_t			shm_segsz;	/* size of segment (bytes) */
 	__kernel_time_t		shm_atime;	/* last attach time */
-#ifdef __i386__
+#if __BITS_PER_LONG != 64
 	unsigned long		__unused1;
 #endif
 	__kernel_time_t		shm_dtime;	/* last detach time */
-#ifdef __i386__
+#if __BITS_PER_LONG != 64
 	unsigned long		__unused2;
 #endif
 	__kernel_time_t		shm_ctime;	/* last change time */
-#ifdef __i386__
+#if __BITS_PER_LONG != 64
 	unsigned long		__unused3;
 #endif
 	__kernel_pid_t		shm_cpid;	/* pid of creator */
@@ -48,4 +56,4 @@ struct shminfo64 {
 	unsigned long	__unused4;
 };
 
-#endif /* _ASM_X86_SHMBUF_H */
+#endif /* __ASM_GENERIC_SHMBUF_H */