drivers/xen/biomerge.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/bio.h>
0003 #include <linux/export.h>
0004 #include <xen/xen.h>
0005 #include <xen/page.h>
0006
0007 /* check if @page can be merged with 'vec1' */
0008 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
0009                    const struct page *page)
0010 {
0011 #if XEN_PAGE_SIZE == PAGE_SIZE
0012     unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
0013     unsigned long bfn2 = pfn_to_bfn(page_to_pfn(page));
0014
0015     return bfn1 + PFN_DOWN(vec1->bv_offset + vec1->bv_len) == bfn2;
0016 #else
0017     /*
0018      * XXX: Add support for merging bio_vec when using different page
0019      * size in Xen and Linux.
0020      */
0021     return false;
0022 #endif
0023 }