xref: /illumos-gate/usr/src/uts/sun4v/io/hardclk.c (revision 726fad2a65f16c200a03969c29cb5c86c2d427db)
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 #include <sys/hypervisor_api.h>
49 #include <sys/wdt.h>
50 
51 uint_t sys_clock_mhz = 0;
52 uint64_t sys_tick_freq = 0;
53 uint_t cpu_tick_freq = 0;	/* deprecated, tune sys_tick_freq instead */
54 uint_t scaled_clock_mhz = 0;
55 uint_t nsec_per_sys_tick;
56 uint_t sticks_per_usec;
57 char clock_started = 0;
58 
59 void
60 clkstart(void)
61 {
62 	/*
63 	 * Now is a good time to activate hardware watchdog.
64 	 */
65 	watchdog_init();
66 }
67 
68 /*
69  * preset the delay constant for drv_usecwait(). This is done for early
70  * use of the le or scsi drivers in the kernel. The default contant
71  * might be too high early on. We can get a pretty good approximation
72  * of this by setting it as:
73  *
74  * 	sys_clock_mhz = (sys_tick_freq + 500000) / 1000000
75  *
76  * setcpudelay is called twice during the boot process. The first time
77  * is before the TOD driver is loaded so cpu_init_tick_freq cannot
78  * calibrate sys_tick_freq but can only set it to the prom value. The
79  * first call is also before /etc/system is read.
80  *
81  * Only call cpu_init_tick_freq the second time around if sys_tick_freq
82  * has not been tuned via /etc/system.
83  */
84 void
85 setcpudelay(void)
86 {
87 	static uint64_t sys_tick_freq_save = 0;
88 	/*
89 	 * We want to allow cpu_tick_freq to be tunable; we'll only set it
90 	 * if it hasn't been explicitly tuned.
91 	 */
92 	if (cpu_tick_freq != 0) {
93 		cmn_err(CE_WARN, "cpu_tick_freq is no longer a kernel "
94 		    "tunable, use sys_tick_freq instead");
95 		sys_tick_freq = cpu_tick_freq;
96 	}
97 	if (sys_tick_freq == sys_tick_freq_save) {
98 		cpu_init_tick_freq();
99 		sys_tick_freq_save = sys_tick_freq;
100 	}
101 	ASSERT(sys_tick_freq != 0);
102 
103 	/*
104 	 * See the comments in clock.h for a full description of
105 	 * nsec_scale.  The "& ~1" operation below ensures that
106 	 * nsec_scale is always even, so that for *any* value of
107 	 * %tick, multiplying by nsec_scale clears NPT for free.
108 	 */
109 	nsec_scale = (uint_t)(((u_longlong_t)NANOSEC << (32 - nsec_shift)) /
110 	    sys_tick_freq) & ~1;
111 
112 	/*
113 	 * scaled_clock_mhz is a more accurated (ie not rounded-off)
114 	 * version of sys_clock_mhz that we used to program the tick
115 	 * compare register. Just in case sys_tick_freq is like 142.5 Mhz
116 	 * instead of some whole number like 143
117 	 */
118 
119 	scaled_clock_mhz = (sys_tick_freq) / 1000;
120 	sys_clock_mhz = (sys_tick_freq + 500000) / 1000000;
121 
122 	nsec_per_sys_tick = NANOSEC / sys_tick_freq;
123 
124 	/*
125 	 * Pre-calculate number of sticks per usec for drv_usecwait.
126 	 */
127 	sticks_per_usec = MAX((sys_tick_freq + (MICROSEC - 1)) / MICROSEC, 1);
128 
129 	if (sys_clock_mhz <= 0) {
130 		cmn_err(CE_WARN, "invalid system frequency");
131 	}
132 }
133 
134 /*
135  * Hypervisor can return one of two error conditions
136  * for the TOD_GET API call. 1) H_ENOTSUPPORTED 2) H_EWOULDBLOCK
137  *
138  * To handle the H_ENOTSUPPORTED we return 0 seconds and let clkset
139  * set tod_broken.
140  * To handle the H_EWOULDBLOCK we retry for about 500usec and
141  * return hrestime if we can't successfully get a value.
142  */
143 timestruc_t
144 tod_get(void)
145 {
146 	timestruc_t ts;
147 	uint64_t seconds;
148 	int i;
149 	unsigned int spl_old;
150 	uint64_t ret;
151 
152 	/*
153 	 * Make sure we don't get preempted
154 	 * while getting the tod value.
155 	 * getting preempted could mean we always
156 	 * hit the hypervisor during an update
157 	 * and always get EWOULDBLOCK.
158 	 */
159 
160 	spl_old = ddi_enter_critical();
161 	for (i = 0; i <= HV_TOD_RETRY_THRESH; i++) {
162 		ret = hv_tod_get(&seconds);
163 
164 		if (ret != H_EWOULDBLOCK)
165 			break;
166 		drv_usecwait(HV_TOD_WAIT_USEC);
167 	}
168 	ddi_exit_critical(spl_old);
169 
170 	ts.tv_nsec = 0;
171 	if (ret != H_EOK) {
172 
173 		switch (ret) {
174 		default:
175 			cmn_err(CE_WARN,
176 			    "tod_get: unknown error from hv_tod_get, %lx\n",
177 			    ret);
178 			/*FALLTHRU*/
179 		case H_EWOULDBLOCK:
180 			/*
181 			 * We timed out
182 			 */
183 			tod_status_set(TOD_GET_FAILED);
184 			ts.tv_sec = tod_validate(hrestime.tv_sec);
185 			break;
186 
187 		case H_ENOTSUPPORTED:
188 			ts.tv_sec = 0;
189 			break;
190 		};
191 	} else {
192 		ts.tv_sec = tod_validate(seconds);
193 	}
194 
195 	return (ts);
196 }
197 
198 extern void tod_set_prev(timestruc_t);
199 
200 /*ARGSUSED*/
201 void
202 tod_set(timestruc_t ts)
203 {
204 	int i;
205 	uint64_t ret;
206 
207 	/* for tod_validate() */
208 	tod_set_prev(ts);
209 
210 	for (i = 0; i <= HV_TOD_RETRY_THRESH; i++) {
211 		ret = hv_tod_set(ts.tv_sec);
212 		if (ret != H_EWOULDBLOCK)
213 			break;
214 		drv_usecwait(HV_TOD_WAIT_USEC);
215 	}
216 
217 	if (ret != H_EOK && ret != H_ENOTSUPPORTED && ret != H_EWOULDBLOCK)
218 		cmn_err(CE_WARN,
219 		    "tod_set: Unknown error from hv_tod_set, err %lx", ret);
220 	else
221 		/* TOD was modified */
222 		tod_status_set(TOD_SET_DONE);
223 }
224 
225 /*
226  * The following wrappers have been added so that locking
227  * can be exported to platform-independent clock routines
228  * (ie adjtime(), clock_setttime()), via a functional interface.
229  */
230 int
231 hr_clock_lock(void)
232 {
233 	ushort_t s;
234 
235 	CLOCK_LOCK(&s);
236 	return (s);
237 }
238 
239 void
240 hr_clock_unlock(int s)
241 {
242 	CLOCK_UNLOCK(s);
243 }
244 
245 /*
246  * We don't share the trap table with the prom, so we don't need
247  * to enable/disable its clock.
248  */
249 void
250 mon_clock_init(void)
251 {}
252 
253 void
254 mon_clock_start(void)
255 {}
256 
257 void
258 mon_clock_stop(void)
259 {}
260 
261 void
262 mon_clock_share(void)
263 {}
264 
265 void
266 mon_clock_unshare(void)
267 {}
268