xref: /openbmc/linux/arch/riscv/include/asm/vdso.h (revision d2574c33)
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 asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
42 
43 #endif /* _ASM_RISCV_VDSO_H */
44