summaryrefslogtreecommitdiffstats
path: root/drivers/xen/biomerge.c
blob: 4da69dbf7dcad7f2e2898dd807a118596f86058a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
#include <linux/bio.h>
#include <linux/io.h>
#include <linux/export.h>
#include <xen/page.h>

bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
			       const struct bio_vec *vec2)
{
#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(vec2->bv_page));

	return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
		((bfn1 == bfn2) || ((bfn1+1) == bfn2));
#else
	/*
	 * XXX: Add support for merging bio_vec when using different page
	 * size in Xen and Linux.
	 */
	return 0;
#endif
}
EXPORT_SYMBOL(xen_biovec_phys_mergeable);
OpenPOWER on IntegriCloud