arch/s390/include/asm/vdso.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __S390_VDSO_H__
#define __S390_VDSO_H__

/* Default link addresses for the vDSOs */
#define VDSO32_LBASE	0
#define VDSO64_LBASE	0

#define VDSO_VERSION_STRING	LINUX_2.6.29

#ifndef __ASSEMBLY__

/*
 * Note about the vdso_data and vdso_per_cpu_data structures:
 *
 * NEVER USE THEM IN USERSPACE CODE DIRECTLY. The layout of the
 * structure is supposed to be known only to the function in the vdso
 * itself and may change without notice.
 */

struct vdso_data {
	__u64 tb_update_count;		/* Timebase atomicity ctr	0x00 */
	__u64 xtime_tod_stamp;		/* TOD clock for xtime		0x08 */
	__u64 xtime_clock_sec;		/* Kernel time			0x10 */
	__u64 xtime_clock_nsec;		/*				0x18 */
	__u64 xtime_coarse_sec;		/* Coarse kernel time		0x20 */
	__u64 xtime_coarse_nsec;	/*				0x28 */
	__u64 wtom_clock_sec;		/* Wall to monotonic clock	0x30 */
	__u64 wtom_clock_nsec;		/*				0x38 */
	__u64 wtom_coarse_sec;		/* Coarse wall to monotonic	0x40 */
	__u64 wtom_coarse_nsec;		/*				0x48 */
	__u32 tz_minuteswest;		/* Minutes west of Greenwich	0x50 */
	__u32 tz_dsttime;		/* Type of dst correction	0x54 */
	__u32 ectg_available;		/* ECTG instruction present	0x58 */
	__u32 tk_mult;			/* Mult. used for xtime_nsec	0x5c */
	__u32 tk_shift;			/* Shift used for xtime_nsec	0x60 */
	__u32 ts_dir;			/* TOD steering direction	0x64 */
	__u64 ts_end;			/* TOD steering end		0x68 */
};

struct vdso_per_cpu_data {
	__u64 ectg_timer_base;
	__u64 ectg_user_time;
	/*
	 * Note: node_id and cpu_nr must be at adjacent memory locations.
	 * VDSO userspace must read both values with a single instruction.
	 */
	union {
		__u64 getcpu_val;
		struct {
			__u32 node_id;
			__u32 cpu_nr;
		};
	};
};

extern struct vdso_data *vdso_data;
extern struct vdso_data boot_vdso_data;

void vdso_alloc_boot_cpu(struct lowcore *lowcore);
int vdso_alloc_per_cpu(struct lowcore *lowcore);
void vdso_free_per_cpu(struct lowcore *lowcore);

#endif /* __ASSEMBLY__ */
#endif /* __S390_VDSO_H__ */