diff options
Diffstat (limited to 'arch/sparc/include/asm/vvar.h')
-rw-r--r-- | arch/sparc/include/asm/vvar.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/vvar.h b/arch/sparc/include/asm/vvar.h new file mode 100644 index 000000000..6eaf5cfca --- /dev/null +++ b/arch/sparc/include/asm/vvar.h @@ -0,0 +1,75 @@ +/* + * 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 */ |