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