u-boot/arch/sh/include/asm/cache.h

#ifndef __ASM_SH_CACHE_H
#define __ASM_SH_CACHE_H

#if defined(CONFIG_SH4) || defined(CONFIG_SH4A)

int cache_control(unsigned int cmd);

#define L1_CACHE_BYTES 32

struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct *)(x))

void dcache_wback_range(u32 start, u32 end)
{
	u32 v;

	start &= ~(L1_CACHE_BYTES - 1);
	for (v = start; v < end; v += L1_CACHE_BYTES) {
		asm volatile ("ocbwb     %0" :	/* no output */
			      : "m" (__m(v)));
	}
}

void dcache_invalid_range(u32 start, u32 end)
{
	u32 v;

	start &= ~(L1_CACHE_BYTES - 1);
	for (v = start; v < end; v += L1_CACHE_BYTES) {
		asm volatile ("ocbi     %0" :	/* no output */
			      : "m" (__m(v)));
	}
}
#else

/*
 * 32-bytes is the largest L1 data cache line size for SH the architecture.  So
 * it is a safe default for DMA alignment.
 */
#define ARCH_DMA_MINALIGN	32

#endif /* CONFIG_SH4 || CONFIG_SH4A */

/*
 * Use the L1 data cache line size value for the minimum DMA buffer alignment
 * on SH.
 */
#ifndef ARCH_DMA_MINALIGN
#define ARCH_DMA_MINALIGN	L1_CACHE_BYTES
#endif

#endif	/* __ASM_SH_CACHE_H */