include/xen/page.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _XEN_PAGE_H
0003 #define _XEN_PAGE_H
0004
0005 #include <asm/page.h>
0006
0007 /* The hypercall interface supports only 4KB page */
0008 #define XEN_PAGE_SHIFT  12
0009 #define XEN_PAGE_SIZE   (_AC(1, UL) << XEN_PAGE_SHIFT)
0010 #define XEN_PAGE_MASK   (~(XEN_PAGE_SIZE-1))
0011 #define xen_offset_in_page(p)   ((unsigned long)(p) & ~XEN_PAGE_MASK)
0012
0013 /*
0014  * We assume that PAGE_SIZE is a multiple of XEN_PAGE_SIZE
0015  * XXX: Add a BUILD_BUG_ON?
0016  */
0017
0018 #define xen_pfn_to_page(xen_pfn)    \
0019     (pfn_to_page((unsigned long)(xen_pfn) >> (PAGE_SHIFT - XEN_PAGE_SHIFT)))
0020 #define page_to_xen_pfn(page)       \
0021     ((page_to_pfn(page)) << (PAGE_SHIFT - XEN_PAGE_SHIFT))
0022
0023 #define XEN_PFN_PER_PAGE    (PAGE_SIZE / XEN_PAGE_SIZE)
0024
0025 #define XEN_PFN_DOWN(x) ((x) >> XEN_PAGE_SHIFT)
0026 #define XEN_PFN_UP(x)   (((x) + XEN_PAGE_SIZE-1) >> XEN_PAGE_SHIFT)
0027
0028 #include <asm/xen/page.h>
0029
0030 /* Return the GFN associated to the first 4KB of the page */
0031 static inline unsigned long xen_page_to_gfn(struct page *page)
0032 {
0033     return pfn_to_gfn(page_to_xen_pfn(page));
0034 }
0035
0036 struct xen_memory_region {
0037     unsigned long start_pfn;
0038     unsigned long n_pfns;
0039 };
0040
0041 #define XEN_EXTRA_MEM_MAX_REGIONS 128 /* == E820_MAX_ENTRIES_ZEROPAGE */
0042
0043 extern __initdata
0044 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS];
0045
0046 extern unsigned long xen_released_pages;
0047
0048 #endif  /* _XEN_PAGE_H */