1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bio.h>
3 #include <linux/export.h>
4 #include <xen/xen.h>
5 #include <xen/page.h>
6 
7 /* check if @page can be merged with 'vec1' */
xen_biovec_phys_mergeable(const struct bio_vec * vec1,const struct page * page)8 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
9 			       const struct page *page)
10 {
11 #if XEN_PAGE_SIZE == PAGE_SIZE
12 	unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
13 	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(page));
14 
15 	return bfn1 + PFN_DOWN(vec1->bv_offset + vec1->bv_len) == bfn2;
16 #else
17 	/*
18 	 * XXX: Add support for merging bio_vec when using different page
19 	 * size in Xen and Linux.
20 	 */
21 	return false;
22 #endif
23 }
24