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 */
xen_page_to_gfn(struct page * page)31 static inline unsigned long xen_page_to_gfn(struct page *page)
32 {
33 	return pfn_to_gfn(page_to_xen_pfn(page));
34 }
35 
36 struct 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 
43 extern __initdata
44 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS];
45 
46 extern unsigned long xen_released_pages;
47 
48 #endif	/* _XEN_PAGE_H */
49