xref: /illumos-gate/usr/src/uts/sun4u/io/hardclk.c (revision f3041bfa)
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  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/param.h>
27 #include <sys/time.h>
28 #include <sys/systm.h>
29 #include <sys/cmn_err.h>
30 #include <sys/debug.h>
31 #include <sys/clock.h>
32 #include <sys/intreg.h>
33 #include <sys/x_call.h>
34 #include <sys/cpuvar.h>
35 #include <sys/promif.h>
36 #include <sys/mman.h>
37 #include <sys/sysmacros.h>
38 #include <sys/lockstat.h>
39 #include <vm/as.h>
40 #include <vm/hat.h>
41 #include <sys/intr.h>
42 #include <sys/ivintr.h>
43 #include <sys/machsystm.h>
44 #include <sys/reboot.h>
45 #include <sys/membar.h>
46 #include <sys/atomic.h>
47 #include <sys/cpu_module.h>
48 
49 uint_t sys_clock_mhz = 0;
50 uint64_t sys_tick_freq = 0;
51 uint_t cpu_tick_freq = 0;	/* deprecated, tune sys_tick_freq instead */
52 uint_t scaled_clock_mhz = 0;
53 uint_t nsec_per_sys_tick;
54 uint_t sticks_per_usec;
55 char clock_started = 0;
56 
57 /*
58  * Hardware watchdog parameters and knobs
59  */
60 int watchdog_enable = 0;		/* user knob */
61 int watchdog_available = 0;		/* system has a watchdog */
62 int watchdog_activated = 0;		/* the watchdog is armed */
63 uint_t watchdog_timeout_seconds = CLK_WATCHDOG_DEFAULT;
64 
65 /*
66  * tod module name and operations
67  */
68 struct tod_ops	tod_ops;
69 char		*tod_module_name;
70 
71 
72 void
73 clkstart(void)
74 {
75 	int ret = 0;
76 
77 	/*
78 	 * Now is a good time to activate hardware watchdog (if one exists).
79 	 */
80 	mutex_enter(&tod_lock);
81 	if (watchdog_enable)
82 		ret = tod_ops.tod_set_watchdog_timer(watchdog_timeout_seconds);
83 	mutex_exit(&tod_lock);
84 	if (ret != 0)
85 		printf("Hardware watchdog enabled\n");
86 }
87 
88 /*
89  * preset the delay constant for drv_usecwait(). This is done for early
90  * use of the le or scsi drivers in the kernel. The default contant
91  * might be too high early on. We can get a pretty good approximation
92  * of this by setting it as:
93  *
94  * 	sys_clock_mhz = (sys_tick_freq + 500000) / 1000000
95  *
96  * setcpudelay is called twice during the boot process. The first time
97  * is before the TOD driver is loaded so cpu_init_tick_freq cannot
98  * calibrate sys_tick_freq but can only set it to the prom value. The
99  * first call is also before /etc/system is read.
100  *
101  * Only call cpu_init_tick_freq the second time around if sys_tick_freq
102  * has not been tuned via /etc/system.
103  */
104 void
105 setcpudelay(void)
106 {
107 	static uint64_t sys_tick_freq_save = 0;
108 	/*
109 	 * We want to allow cpu_tick_freq to be tunable; we'll only set it
110 	 * if it hasn't been explicitly tuned.
111 	 */
112 	if (cpu_tick_freq != 0) {
113 		cmn_err(CE_WARN, "cpu_tick_freq is no longer a kernel "
114 		    "tunable, use sys_tick_freq instead");
115 		sys_tick_freq = cpu_tick_freq;
116 	}
117 	if (sys_tick_freq == sys_tick_freq_save) {
118 		cpu_init_tick_freq();
119 		sys_tick_freq_save = sys_tick_freq;
120 	}
121 	ASSERT(sys_tick_freq != 0);
122 
123 	/*
124 	 * See the comments in clock.h for a full description of
125 	 * nsec_scale.  The "& ~1" operation below ensures that
126 	 * nsec_scale is always even, so that for *any* value of
127 	 * %tick, multiplying by nsec_scale clears NPT for free.
128 	 */
129 	nsec_scale = (uint_t)(((u_longlong_t)NANOSEC << (32 - nsec_shift)) /
130 	    sys_tick_freq) & ~1;
131 
132 	/*
133 	 * scaled_clock_mhz is a more accurated (ie not rounded-off)
134 	 * version of sys_clock_mhz that we used to program the tick
135 	 * compare register. Just in case sys_tick_freq is like 142.5 Mhz
136 	 * instead of some whole number like 143
137 	 */
138 
139 	scaled_clock_mhz = (sys_tick_freq) / 1000;
140 	sys_clock_mhz = (sys_tick_freq + 500000) / 1000000;
141 
142 	nsec_per_sys_tick = NANOSEC / sys_tick_freq;
143 
144 	/*
145 	 * Pre-calculate number of sticks per usec for drv_usecwait.
146 	 */
147 	sticks_per_usec = MAX((sys_tick_freq + (MICROSEC - 1)) / MICROSEC, 1);
148 
149 	if (sys_clock_mhz <= 0) {
150 		cmn_err(CE_WARN, "invalid system frequency");
151 	}
152 }
153 
154 timestruc_t
155 tod_get(void)
156 {
157 	timestruc_t ts = tod_ops.tod_get();
158 	ts.tv_sec = tod_validate(ts.tv_sec);
159 	return (ts);
160 }
161 
162 extern void tod_set_prev(timestruc_t);
163 
164 void
165 tod_set(timestruc_t ts)
166 {
167 	tod_set_prev(ts);		/* for tod_validate() */
168 	tod_ops.tod_set(ts);
169 	tod_status_set(TOD_SET_DONE);	/* TOD was modified */
170 }
171 
172 
173 /*
174  * The following wrappers have been added so that locking
175  * can be exported to platform-independent clock routines
176  * (ie adjtime(), clock_setttime()), via a functional interface.
177  */
178 int
179 hr_clock_lock(void)
180 {
181 	ushort_t s;
182 
183 	CLOCK_LOCK(&s);
184 	return (s);
185 }
186 
187 void
188 hr_clock_unlock(int s)
189 {
190 	CLOCK_UNLOCK(s);
191 }
192 
193 /*
194  * We don't share the trap table with the prom, so we don't need
195  * to enable/disable its clock.
196  */
197 void
198 mon_clock_init(void)
199 {}
200 
201 void
202 mon_clock_start(void)
203 {}
204 
205 void
206 mon_clock_stop(void)
207 {}
208 
209 void
210 mon_clock_share(void)
211 {}
212 
213 void
214 mon_clock_unshare(void)
215 {}
216