1. 根目录:
2. arch
3. x86
4. include
5. asm
6. dma-contiguous.h

#ifndef ASMX86_DMA_CONTIGUOUS_H
#define ASMX86_DMA_CONTIGUOUS_H

#ifdef __KERNEL__

#include <linux/types.h>

static inline void
dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) { }

#endif
#endif