xref: /openbmc/linux/arch/s390/include/asm/vdso.h (revision 6c33a6f4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __S390_VDSO_H__
3 #define __S390_VDSO_H__
4 
5 /* Default link addresses for the vDSOs */
6 #define VDSO32_LBASE	0
7 #define VDSO64_LBASE	0
8 
9 #define VDSO_VERSION_STRING	LINUX_2.6.29
10 
11 #ifndef __ASSEMBLY__
12 
13 /*
14  * Note about the vdso_data and vdso_per_cpu_data structures:
15  *
16  * NEVER USE THEM IN USERSPACE CODE DIRECTLY. The layout of the
17  * structure is supposed to be known only to the function in the vdso
18  * itself and may change without notice.
19  */
20 
21 struct vdso_data {
22 	__u64 tb_update_count;		/* Timebase atomicity ctr	0x00 */
23 	__u64 xtime_tod_stamp;		/* TOD clock for xtime		0x08 */
24 	__u64 xtime_clock_sec;		/* Kernel time			0x10 */
25 	__u64 xtime_clock_nsec;		/*				0x18 */
26 	__u64 xtime_coarse_sec;		/* Coarse kernel time		0x20 */
27 	__u64 xtime_coarse_nsec;	/*				0x28 */
28 	__u64 wtom_clock_sec;		/* Wall to monotonic clock	0x30 */
29 	__u64 wtom_clock_nsec;		/*				0x38 */
30 	__u64 wtom_coarse_sec;		/* Coarse wall to monotonic	0x40 */
31 	__u64 wtom_coarse_nsec;		/*				0x48 */
32 	__u32 tz_minuteswest;		/* Minutes west of Greenwich	0x50 */
33 	__u32 tz_dsttime;		/* Type of dst correction	0x54 */
34 	__u32 ectg_available;		/* ECTG instruction present	0x58 */
35 	__u32 tk_mult;			/* Mult. used for xtime_nsec	0x5c */
36 	__u32 tk_shift;			/* Shift used for xtime_nsec	0x60 */
37 	__u32 ts_dir;			/* TOD steering direction	0x64 */
38 	__u64 ts_end;			/* TOD steering end		0x68 */
39 };
40 
41 struct vdso_per_cpu_data {
42 	__u64 ectg_timer_base;
43 	__u64 ectg_user_time;
44 	/*
45 	 * Note: node_id and cpu_nr must be at adjacent memory locations.
46 	 * VDSO userspace must read both values with a single instruction.
47 	 */
48 	union {
49 		__u64 getcpu_val;
50 		struct {
51 			__u32 node_id;
52 			__u32 cpu_nr;
53 		};
54 	};
55 };
56 
57 extern struct vdso_data *vdso_data;
58 extern struct vdso_data boot_vdso_data;
59 
60 void vdso_alloc_boot_cpu(struct lowcore *lowcore);
61 int vdso_alloc_per_cpu(struct lowcore *lowcore);
62 void vdso_free_per_cpu(struct lowcore *lowcore);
63 
64 #endif /* __ASSEMBLY__ */
65 #endif /* __S390_VDSO_H__ */
66