Cregit: Linux 5.3: biomerge.c

Contributors: 8
Author	Tokens	Token Proportion	Commits	Commit Proportion
Jeremy Fitzhardinge	50	58.14%	1	11.11%
Julien Grall	17	19.77%	2	22.22%
Roger Pau Monné	9	10.47%	1	11.11%
Ming Lei	4	4.65%	1	11.11%
Christoph Hellwig	2	2.33%	1	11.11%
Stephen Rothwell	2	2.33%	1	11.11%
Gustavo A. R. Silva	1	1.16%	1	11.11%
Greg Kroah-Hartman	1	1.16%	1	11.11%
Total	86		9

// 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
}