1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26#ifndef	_SYS_CLOCK_IMPL_H
27#define	_SYS_CLOCK_IMPL_H
28
29#ifdef	__cplusplus
30extern "C" {
31#endif
32
33#if (defined(_KERNEL) || defined(_KMEMUSER))
34#include <sys/types.h>
35#include <sys/cpuvar.h>
36#include <sys/cyclic.h>
37#include <sys/time.h>
38
39/*
40 * Default clock rate in Hz.
41 */
42#define	HZ_DEFAULT			(100)
43
44/*
45 * Thresholds over which we switch between event and cyclic driven lbolt. The
46 * current default values were derived experimentally and will keep the
47 * system on event driven mode when idle and respond to activity around the
48 * lbolt DDI functions by switching to cyclic mode.
49 */
50#define	LBOLT_THRESH_CALLS		(75)
51#define	LBOLT_THRESH_INTERVAL		(1)
52
53/*
54 * Both lbolt_cpu_t and lbolt_info_t are cache line sized and aligned,
55 * please take that in consideration if modifying these.
56 */
57typedef struct lbolt_cpu {
58	int64_t lbc_counter;	/* number of calls to the DDI lbolt routines */
59	int64_t lbc_cnt_start;	/* beggining of the cnt interval (in ticks) */
60	char lbc_pad[CPU_CACHE_COHERENCE_SIZE - (2 * sizeof (int64_t))];
61} lbolt_cpu_t;
62
63typedef struct lbolt_info {
64	union {
65		cyclic_id_t lbi_cyclic_id;	/* lbolt's cyclic id */
66		int64_t lbi_id_pad;		/* 64bit padding */
67	} id;
68	int64_t lbi_thresh_calls;	/* max calls per interval */
69	int64_t lbi_thresh_interval;	/* interval window for the # of calls */
70	int64_t lbi_debug_ts;		/* last time we dropped into kmdb */
71	int64_t lbi_debug_time;		/* time spent in the debugger */
72	int64_t lbi_internal;		/* lbolt source when on cyclic mode */
73	uint32_t lbi_token;		/* synchronize cyclic mode switch */
74	boolean_t lbi_cyc_deactivate;	/* lbolt_cyclic self deactivation */
75	int64_t lbi_cyc_deac_start;	/* deactivation interval */
76} lbolt_info_t;
77
78extern int64_t lbolt_bootstrap(void);
79extern int64_t lbolt_event_driven(void);
80extern int64_t lbolt_cyclic_driven(void);
81extern int64_t (*lbolt_hybrid)(void);
82extern uint_t lbolt_ev_to_cyclic(caddr_t, caddr_t);
83
84extern void lbolt_softint_add(void);
85extern void lbolt_softint_post(void);
86
87extern void lbolt_debug_entry(void);
88extern void lbolt_debug_return(void);
89
90extern lbolt_info_t *lb_info;
91
92/*
93 * LBOLT_WAITFREE{,64} provide a non-waiting version of lbolt.
94 */
95#define	LBOLT_WAITFREE64						\
96	(lbolt_hybrid == lbolt_bootstrap ? 0 :				\
97	(lbolt_hybrid == lbolt_event_driven ?                           \
98	    ((gethrtime_waitfree()/nsec_per_tick) -			\
99	    lb_info->lbi_debug_time) :					\
100	    (lb_info->lbi_internal - lb_info->lbi_debug_time)))
101
102#define	LBOLT_WAITFREE		(clock_t)LBOLT_WAITFREE64
103
104/*
105 * LBOLT_FASTPATH{,64} should *only* be used where the cost of calling the
106 * DDI lbolt routines affects performance. This is currently only used by
107 * the TCP/IP code and will be removed once it's no longer required.
108 */
109#define	LBOLT_FASTPATH64						\
110	(lbolt_hybrid == lbolt_cyclic_driven ?				\
111	    (lb_info->lbi_internal - lb_info->lbi_debug_time) :		\
112	    lbolt_event_driven())
113
114#define	LBOLT_FASTPATH		(clock_t)LBOLT_FASTPATH64
115
116/*
117 * LBOLT_NO_ACCOUNT{,64} is used by lbolt consumers who fire at a periodic
118 * rate, such as clock(), for which the lbolt usage statistics are not updated.
119 * This is especially important for consumers whose rate may be modified by
120 * the user, resulting in an unaccounted for increase in activity around the
121 * lbolt routines that could cause a mode switch.
122 */
123#define	LBOLT_NO_ACCOUNT64						\
124	(lbolt_hybrid == lbolt_bootstrap ? 0 :				\
125	(lbolt_hybrid == lbolt_event_driven ?				\
126	    ((gethrtime()/nsec_per_tick) - lb_info->lbi_debug_time) :	\
127	    (lb_info->lbi_internal - lb_info->lbi_debug_time)))
128
129#define	LBOLT_NO_ACCOUNT	(clock_t)LBOLT_NO_ACCOUNT64
130
131#endif	/* _KERNEL || _KMEMUSER */
132
133#ifdef	__cplusplus
134}
135#endif
136
137#endif /* _SYS_CLOCK_IMPL_H */
138