xref: /OK3568_Linux_fs/kernel/drivers/xen/biomerge.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/bio.h>
3*4882a593Smuzhiyun #include <linux/export.h>
4*4882a593Smuzhiyun #include <xen/xen.h>
5*4882a593Smuzhiyun #include <xen/page.h>
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun /* check if @page can be merged with 'vec1' */
xen_biovec_phys_mergeable(const struct bio_vec * vec1,const struct page * page)8*4882a593Smuzhiyun bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
9*4882a593Smuzhiyun 			       const struct page *page)
10*4882a593Smuzhiyun {
11*4882a593Smuzhiyun #if XEN_PAGE_SIZE == PAGE_SIZE
12*4882a593Smuzhiyun 	unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
13*4882a593Smuzhiyun 	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(page));
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun 	return bfn1 + PFN_DOWN(vec1->bv_offset + vec1->bv_len) == bfn2;
16*4882a593Smuzhiyun #else
17*4882a593Smuzhiyun 	/*
18*4882a593Smuzhiyun 	 * XXX: Add support for merging bio_vec when using different page
19*4882a593Smuzhiyun 	 * size in Xen and Linux.
20*4882a593Smuzhiyun 	 */
21*4882a593Smuzhiyun 	return false;
22*4882a593Smuzhiyun #endif
23*4882a593Smuzhiyun }
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