1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _XEN_PAGE_H
3#define _XEN_PAGE_H
4
5#include <asm/page.h>
6
7/* The hypercall interface supports only 4KB page */
8#define XEN_PAGE_SHIFT 12
9#define XEN_PAGE_SIZE (_AC(1, UL) << XEN_PAGE_SHIFT)
10#define XEN_PAGE_MASK (~(XEN_PAGE_SIZE-1))
11#define xen_offset_in_page(p) ((unsigned long)(p) & ~XEN_PAGE_MASK)
12
13/*
14 * We assume that PAGE_SIZE is a multiple of XEN_PAGE_SIZE
15 * XXX: Add a BUILD_BUG_ON?
16 */
17
18#define xen_pfn_to_page(xen_pfn) \
19 (pfn_to_page((unsigned long)(xen_pfn) >> (PAGE_SHIFT - XEN_PAGE_SHIFT)))
20#define page_to_xen_pfn(page) \
21 ((page_to_pfn(page)) << (PAGE_SHIFT - XEN_PAGE_SHIFT))
22
23#define XEN_PFN_PER_PAGE (PAGE_SIZE / XEN_PAGE_SIZE)
24
25#define XEN_PFN_DOWN(x) ((x) >> XEN_PAGE_SHIFT)
26#define XEN_PFN_UP(x) (((x) + XEN_PAGE_SIZE-1) >> XEN_PAGE_SHIFT)
27
28#include <asm/xen/page.h>
29
30/* Return the GFN associated to the first 4KB of the page */
31static inline unsigned long xen_page_to_gfn(struct page *page)
32{
33 return pfn_to_gfn(page_to_xen_pfn(page));
34}
35
36struct xen_memory_region {
37 unsigned long start_pfn;
38 unsigned long n_pfns;
39};
40
41#define XEN_EXTRA_MEM_MAX_REGIONS 128 /* == E820_MAX_ENTRIES_ZEROPAGE */
42
43extern __initdata
44struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS];
45
46extern unsigned long xen_released_pages;
47
48#endif /* _XEN_PAGE_H */
49

source code of linux/include/xen/page.h