arch/riscv/include/asm/vdso.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2012 ARM Limited
   4  * Copyright (C) 2014 Regents of the University of California
   5  * Copyright (C) 2017 SiFive
   6  */
   7
   8 #ifndef _ASM_RISCV_VDSO_H
   9 #define _ASM_RISCV_VDSO_H
  10
  11 #include <linux/types.h>
  12
  13 #ifndef CONFIG_GENERIC_TIME_VSYSCALL
  14 struct vdso_data {
  15 };
  16 #endif
  17
  18 /*
  19  * The VDSO symbols are mapped into Linux so we can just use regular symbol
  20  * addressing to get their offsets in userspace.  The symbols are mapped at an
  21  * offset of 0, but since the linker must support setting weak undefined
  22  * symbols to the absolute address 0 it also happens to support other low
  23  * addresses even when the code model suggests those low addresses would not
  24  * otherwise be availiable.
  25  */
  26 #define VDSO_SYMBOL(base, name)                                                 \
  27 ({                                                                              \
  28         extern const char __vdso_##name[];                                      \
  29         (void __user *)((unsigned long)(base) + __vdso_##name);                 \
  30 })
  31
  32 asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
  33
  34 #endif /* _ASM_RISCV_VDSO_H */