drivers/xen/biomerge.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bio.h>
   3 #include <linux/io.h>
   4 #include <linux/export.h>
   5 #include <xen/page.h>
   6
   7 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
   8                                const struct bio_vec *vec2)
   9 {
  10 #if XEN_PAGE_SIZE == PAGE_SIZE
  11         unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
  12         unsigned long bfn2 = pfn_to_bfn(page_to_pfn(vec2->bv_page));
  13
  14         return bfn1 + PFN_DOWN(vec1->bv_offset + vec1->bv_len) == bfn2;
  15 #else
  16         /*
  17          * XXX: Add support for merging bio_vec when using different page
  18          * size in Xen and Linux.
  19          */
  20         return false;
  21 #endif
  22 }
  23 EXPORT_SYMBOL(xen_biovec_phys_mergeable);