summaryrefslogtreecommitdiffstats
path: root/drivers/xen/biomerge.c
blob: 05a286d24f1482f77ccea9999577b46cb96ee3c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
// 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
}