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Commit f6dc8c5b authored by Chase Venters's avatar Chase Venters Committed by Linus Torvalds
Browse files

[PATCH] Make cpu_relax() imply barrier() on all arches 



During the recent discussion of taking 'volatile' off of the spinlock, I
noticed that while most arches #define cpu_relax() such that it implies
barrier(), some arches define cpu_relax() to be empty.

This patch changes the definition of cpu_relax() for frv, h8300, m68knommu,
sh, sh64, v850 and xtensa from an empty while(0) to the compiler barrier().

Signed-off-by: default avatarChase Venters <chase.venters@clientec.com>
Acked-by: default avatarArjan van de Ven <arjan@Linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 0f749646

include/asm-frv/processor.h

+2 −1
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
 */

#define current_text_addr() ({ __label__ _l; _l: &&_l;})



#include <linux/compiler.h>

#include <linux/linkage.h>

#include <asm/sections.h>

#include <asm/segment.h>
@@ -139,7 +140,7 @@ unsigned long get_wchan(struct task_struct *p); 
extern struct task_struct *alloc_task_struct(void);

extern void free_task_struct(struct task_struct *p);



#define cpu_relax()    do { } while (0)

#define cpu_relax()    barrier()



/* data cache prefetch */

#define ARCH_HAS_PREFETCH

include/asm-h8300/processor.h

+2 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
 */

#define current_text_addr() ({ __label__ _l; _l: &&_l;})



#include <linux/compiler.h>

#include <asm/segment.h>

#include <asm/fpu.h>

#include <asm/ptrace.h>
@@ -129,6 +130,6 @@ unsigned long get_wchan(struct task_struct *p); 
	eip; })

#define	KSTK_ESP(tsk)	((tsk) == current ? rdusp() : (tsk)->thread.usp)



#define cpu_relax()    do { } while (0)

#define cpu_relax()    barrier()



#endif

include/asm-m68knommu/processor.h

+2 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
 */

#define current_text_addr() ({ __label__ _l; _l: &&_l;})



#include <linux/compiler.h>

#include <linux/threads.h>

#include <asm/types.h>

#include <asm/segment.h>
@@ -137,6 +138,6 @@ unsigned long get_wchan(struct task_struct *p); 
	eip; })

#define	KSTK_ESP(tsk)	((tsk) == current ? rdusp() : (tsk)->thread.usp)



#define cpu_relax()    do { } while (0)

#define cpu_relax()    barrier()



#endif

include/asm-sh/processor.h

+2 −1
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#define __ASM_SH_PROCESSOR_H

#ifdef __KERNEL__



#include <linux/compiler.h>

#include <asm/page.h>

#include <asm/types.h>

#include <asm/cache.h>
@@ -263,7 +264,7 @@ extern unsigned long get_wchan(struct task_struct *p); 
#define KSTK_ESP(tsk)  ((tsk)->thread.sp)



#define cpu_sleep()	__asm__ __volatile__ ("sleep" : : : "memory")

#define cpu_relax()	do { } while (0)

#define cpu_relax()	barrier()



#endif /* __KERNEL__ */

#endif /* __ASM_SH_PROCESSOR_H */

include/asm-sh64/processor.h

+2 −1
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <asm/cache.h>

#include <asm/registers.h>

#include <linux/threads.h>

#include <linux/compiler.h>



/*

 * Default implementation of macro that returns current
@@ -279,7 +280,7 @@ extern unsigned long get_wchan(struct task_struct *p); 
#define KSTK_EIP(tsk)  ((tsk)->thread.pc)

#define KSTK_ESP(tsk)  ((tsk)->thread.sp)



#define cpu_relax()	do { } while (0)

#define cpu_relax()	barrier()



#endif	/* __ASSEMBLY__ */

#endif /* __ASM_SH64_PROCESSOR_H */