include/vdso/page.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __VDSO_PAGE_H
   3 #define __VDSO_PAGE_H
   4
   5 #include <uapi/linux/const.h>
   6
   7 /*
   8  * PAGE_SHIFT determines the page size.
   9  *
  10  * Note: This definition is required because PAGE_SHIFT is used
  11  * in several places throughout the codebase.
  12  */
  13 #define PAGE_SHIFT      CONFIG_PAGE_SHIFT
  14
  15 #define PAGE_SIZE       (_AC(1,UL) << CONFIG_PAGE_SHIFT)
  16
  17 #if !defined(CONFIG_64BIT)
  18 /*
  19  * Applies only to 32-bit architectures.
  20  *
  21  * Subtle: (1 << CONFIG_PAGE_SHIFT) is an int, not an unsigned long.
  22  * So if we assign PAGE_MASK to a larger type it gets extended the
  23  * way we want (i.e. with 1s in the high bits) while masking a
  24  * 64-bit value such as phys_addr_t.
  25  */
  26 #define PAGE_MASK       (~((1 << CONFIG_PAGE_SHIFT) - 1))
  27 #else
  28 #define PAGE_MASK       (~(PAGE_SIZE - 1))
  29 #endif
  30
  31 #endif  /* __VDSO_PAGE_H */