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/* SPDX-License-Identifier: GPL-2.0 */ /* * Copied from the kernel sources: * * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima * Copyright (C) 2002 Paul Mundt */ #ifndef __TOOLS_LINUX_ASM_SH_BARRIER_H #define __TOOLS_LINUX_ASM_SH_BARRIER_H /* * 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(__SH4A__) #define mb() __asm__ __volatile__ ("synco": : :"memory") #define rmb() mb() #define wmb() mb() #endif #include <asm-generic/barrier.h> #endif /* __TOOLS_LINUX_ASM_SH_BARRIER_H */ |