kernel-fxtec-pro1x/arch/sh/include/asm/barrier.h
Peter Zijlstra 93ea02bb84 arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h
We're going to be adding a few new barrier primitives, and in order to
avoid endless duplication make more agressive use of
asm-generic/barrier.h.

Change the asm-generic/barrier.h such that it allows partial barrier
definitions and fills out the rest with defaults.

There are a few architectures (m32r, m68k) that could probably
do away with their barrier.h file entirely but are kept for now due to
their unconventional nop() implementation.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131213150640.846368594@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-12 10:37:15 +01:00

39 lines
1.2 KiB
C

/*
* Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
* Copyright (C) 2002 Paul Mundt
*/
#ifndef __ASM_SH_BARRIER_H
#define __ASM_SH_BARRIER_H
#if defined(CONFIG_CPU_SH4A) || defined(CONFIG_CPU_SH5)
#include <asm/cache_insns.h>
#endif
/*
* A brief note on ctrl_barrier(), the control register write barrier.
*
* Legacy SH cores typically require a sequence of 8 nops after
* modification of a control register in order for the changes to take
* effect. On newer cores (like the sh4a and sh5) this is accomplished
* with icbi.
*
* Also note that on sh4a in the icbi case we can forego a synco for the
* write barrier, as it's not necessary for control registers.
*
* Historically we have only done this type of barrier for the MMUCR, but
* it's also necessary for the CCR, so we make it generic here instead.
*/
#if defined(CONFIG_CPU_SH4A) || defined(CONFIG_CPU_SH5)
#define mb() __asm__ __volatile__ ("synco": : :"memory")
#define rmb() mb()
#define wmb() mb()
#define ctrl_barrier() __icbi(PAGE_OFFSET)
#else
#define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
#endif
#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
#include <asm-generic/barrier.h>
#endif /* __ASM_SH_BARRIER_H */