xref: /openbmc/linux/arch/riscv/include/asm/vdso.h (revision 07d9a767)
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 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 */
35