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kernel/linux-rt-4.4.41/drivers/xen/biomerge.c 609 Bytes
5113f6f70   김현기   kernel add
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  #include <linux/bio.h>
  #include <linux/io.h>
  #include <linux/export.h>
  #include <xen/page.h>
  
  bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
  			       const struct bio_vec *vec2)
  {
  #if XEN_PAGE_SIZE == PAGE_SIZE
  	unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
  	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(vec2->bv_page));
  
  	return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
  		((bfn1 == bfn2) || ((bfn1+1) == bfn2));
  #else
  	/*
  	 * XXX: Add support for merging bio_vec when using different page
  	 * size in Xen and Linux.
  	 */
  	return 0;
  #endif
  }
  EXPORT_SYMBOL(xen_biovec_phys_mergeable);