// SPDX-License-Identifier: GPL-2.0

  #include <linux/bio.h>

  #include <linux/export.h>

  #include <xen/xen.h>

  #include <xen/page.h>

  /* check if @page can be merged with 'vec1' */

  bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,

  			       const struct page *page)

  {

  #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(page));

  	return bfn1 + PFN_DOWN(vec1->bv_offset + vec1->bv_len) == bfn2;

  #else
  	/*
  	 * XXX: Add support for merging bio_vec when using different page
  	 * size in Xen and Linux.
  	 */

  	return false;

  #endif

  }