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v4.17
 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bio.h>
 3#include <linux/io.h>
 4#include <linux/export.h>
 5#include <xen/page.h>
 6
 7bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 8			       const struct bio_vec *vec2)
 9{
10#if XEN_PAGE_SIZE == PAGE_SIZE
11	unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
12	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(vec2->bv_page));
13
14	return bfn1 + PFN_DOWN(vec1->bv_offset + vec1->bv_len) == bfn2;
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
22}
23EXPORT_SYMBOL(xen_biovec_phys_mergeable);
v3.15
 
 1#include <linux/bio.h>
 2#include <linux/io.h>
 3#include <linux/export.h>
 4#include <xen/page.h>
 5
 6bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 7			       const struct bio_vec *vec2)
 8{
 9	unsigned long mfn1 = pfn_to_mfn(page_to_pfn(vec1->bv_page));
10	unsigned long mfn2 = pfn_to_mfn(page_to_pfn(vec2->bv_page));
 
11
12	return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
13		((mfn1 == mfn2) || ((mfn1+1) == mfn2));
 
 
 
 
 
 
14}
15EXPORT_SYMBOL(xen_biovec_phys_mergeable);