[linux-2.6-block.git] / drivers / xen / biomerge.c

#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);
Commit	Line	Data
d8e04206 JF	1	#include <linux/bio.h>
d8e04206 JF	2	#include <linux/io.h>
9ef9b20b	3	#include <linux/export.h>
d8e04206 JF	4	#include <xen/page.h>
	5
	6	bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
	7	const struct bio_vec *vec2)
	8	{
36f8abd3	9	#if XEN_PAGE_SIZE == PAGE_SIZE
32e09870 JG	10	unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
32e09870 JG	11	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(vec2->bv_page));
d8e04206 JF	12
d8e04206 JF	13	return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
32e09870	14	((bfn1 == bfn2) \|\| ((bfn1+1) == bfn2));
36f8abd3 JG	15	#else
	16	/*
	17	* XXX: Add support for merging bio_vec when using different page
	18	* size in Xen and Linux.
	19	*/
	20	return 0;
	21	#endif
d8e04206	22	}
0b934ccd	23	EXPORT_SYMBOL(xen_biovec_phys_mergeable);