include/xen/foreign_page.h

   1 /******************************************************************************
   2  * foreign_page.h
   3  *
   4  * Provide a "foreign" page type, that is owned by a foreign allocator and
   5  * not the normal buddy allocator in page_alloc.c
   6  *
   7  * Copyright (c) 2004, K A Fraser
   8  */
   9
  10 #ifndef __ASM_XEN_FOREIGN_PAGE_H__
  11 #define __ASM_XEN_FOREIGN_PAGE_H__
  12
  13 #define PG_foreign              PG_arch_1
  14
  15 #define PageForeign(page)       test_bit(PG_foreign, &(page)->flags)
  16
  17 #define SetPageForeign(page, dtor) do {         \
  18         set_bit(PG_foreign, &(page)->flags);    \
  19         (page)->mapping = (void *)dtor;         \
  20 } while (0)
  21
  22 #define ClearPageForeign(page) do {             \
  23         clear_bit(PG_foreign, &(page)->flags);  \
  24         (page)->mapping = NULL;                 \
  25 } while (0)
  26
  27 #define PageForeignDestructor(page)     \
  28         ( (void (*) (struct page *)) (page)->mapping )
  29
  30 #endif /* __ASM_XEN_FOREIGN_PAGE_H__ */