include/xen/page.h

   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 */
  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 */