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