OpenCloudOS-Kernel/arch/sparc/include/asm/vvar.h

76 lines
1.5 KiB
C

/*
* Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
*/
#ifndef _ASM_SPARC_VVAR_DATA_H
#define _ASM_SPARC_VVAR_DATA_H
#include <asm/clocksource.h>
#include <asm/processor.h>
#include <asm/barrier.h>
#include <linux/time.h>
#include <linux/types.h>
struct vvar_data {
unsigned int seq;
int vclock_mode;
struct { /* extract of a clocksource struct */
u64 cycle_last;
u64 mask;
int mult;
int shift;
} clock;
/* open coded 'struct timespec' */
u64 wall_time_sec;
u64 wall_time_snsec;
u64 monotonic_time_snsec;
u64 monotonic_time_sec;
u64 monotonic_time_coarse_sec;
u64 monotonic_time_coarse_nsec;
u64 wall_time_coarse_sec;
u64 wall_time_coarse_nsec;
int tz_minuteswest;
int tz_dsttime;
};
extern struct vvar_data *vvar_data;
extern int vdso_fix_stick;
static inline unsigned int vvar_read_begin(const struct vvar_data *s)
{
unsigned int ret;
repeat:
ret = READ_ONCE(s->seq);
if (unlikely(ret & 1)) {
cpu_relax();
goto repeat;
}
smp_rmb(); /* Finish all reads before we return seq */
return ret;
}
static inline int vvar_read_retry(const struct vvar_data *s,
unsigned int start)
{
smp_rmb(); /* Finish all reads before checking the value of seq */
return unlikely(s->seq != start);
}
static inline void vvar_write_begin(struct vvar_data *s)
{
++s->seq;
smp_wmb(); /* Makes sure that increment of seq is reflected */
}
static inline void vvar_write_end(struct vvar_data *s)
{
smp_wmb(); /* Makes the value of seq current before we increment */
++s->seq;
}
#endif /* _ASM_SPARC_VVAR_DATA_H */