arch/riscv/include/asm/vdso.h

   1 /*
   2  * Copyright (C) 2012 ARM Limited
   3  * Copyright (C) 2014 Regents of the University of California
   4  * Copyright (C) 2017 SiFive
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifndef _ASM_RISCV_VDSO_H
  20 #define _ASM_RISCV_VDSO_H
  21
  22 #include <linux/types.h>
  23
  24 struct vdso_data {
  25 };
  26
  27 /*
  28  * The VDSO symbols are mapped into Linux so we can just use regular symbol
  29  * addressing to get their offsets in userspace.  The symbols are mapped at an
  30  * offset of 0, but since the linker must support setting weak undefined
  31  * symbols to the absolute address 0 it also happens to support other low
  32  * addresses even when the code model suggests those low addresses would not
  33  * otherwise be availiable.
  34  */
  35 #define VDSO_SYMBOL(base, name)                                                 \
  36 ({                                                                              \
  37         extern const char __vdso_##name[];                                      \
  38         (void __user *)((unsigned long)(base) + __vdso_##name);                 \
  39 })
  40
  41 #ifdef CONFIG_SMP
  42 asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
  43 #endif
  44
  45 #endif /* _ASM_RISCV_VDSO_H */