2 * Copyright (c) 2001 Jake Burkholder.
3 * Copyright (c) 2005, 2008 Marius Strobl <marius@FreeBSD.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
36 #include <sys/sched.h>
38 #include <sys/sysctl.h>
39 #include <sys/timeet.h>
40 #include <sys/timetc.h>
42 #include <dev/ofw/openfirm.h>
47 #include <machine/frame.h>
48 #include <machine/intr_machdep.h>
49 #include <machine/smp.h>
50 #include <machine/tick.h>
51 #include <machine/ver.h>
53 #define TICK_QUALITY_MP 10
54 #define TICK_QUALITY_UP 1000
56 static SYSCTL_NODE(_machdep, OID_AUTO, tick, CTLFLAG_RD, 0, "tick statistics");
58 static int adjust_edges = 0;
59 SYSCTL_INT(_machdep_tick, OID_AUTO, adjust_edges, CTLFLAG_RD, &adjust_edges,
60 0, "total number of times tick interrupts got more than 12.5% behind");
62 static int adjust_excess = 0;
63 SYSCTL_INT(_machdep_tick, OID_AUTO, adjust_excess, CTLFLAG_RD, &adjust_excess,
64 0, "total number of ignored tick interrupts");
66 static int adjust_missed = 0;
67 SYSCTL_INT(_machdep_tick, OID_AUTO, adjust_missed, CTLFLAG_RD, &adjust_missed,
68 0, "total number of missed tick interrupts");
70 static int adjust_ticks = 0;
71 SYSCTL_INT(_machdep_tick, OID_AUTO, adjust_ticks, CTLFLAG_RD, &adjust_ticks,
72 0, "total number of tick interrupts with adjustment");
74 u_int tick_et_use_stick = 0;
75 SYSCTL_INT(_machdep_tick, OID_AUTO, tick_et_use_stick, CTLFLAG_RD,
76 &tick_et_use_stick, 0, "tick event timer uses STICK instead of TICK");
78 typedef uint64_t rd_tick_t(void);
79 static rd_tick_t *rd_tick;
80 typedef void wr_tick_cmpr_t(uint64_t);
81 static wr_tick_cmpr_t *wr_tick_cmpr;
83 static struct timecounter stick_tc;
84 static struct eventtimer tick_et;
85 static struct timecounter tick_tc;
88 static timecounter_get_t stick_get_timecount_mp;
90 static timecounter_get_t stick_get_timecount_up;
91 static rd_tick_t stick_rd;
92 static wr_tick_cmpr_t stick_wr_cmpr;
93 static int tick_et_start(struct eventtimer *et, sbintime_t first,
95 static int tick_et_stop(struct eventtimer *et);
97 static timecounter_get_t tick_get_timecount_mp;
99 static timecounter_get_t tick_get_timecount_up;
100 static void tick_intr(struct trapframe *tf);
101 static inline void tick_process(struct trapframe *tf);
102 static rd_tick_t tick_rd;
103 static wr_tick_cmpr_t tick_wr_cmpr;
104 static wr_tick_cmpr_t tick_wr_cmpr_bbwar;
105 static uint64_t tick_cputicks(void);
115 stick_wr_cmpr(uint64_t tick)
118 wrstickcmpr(tick, 0);
129 tick_wr_cmpr(uint64_t tick_cmpr)
132 wrtickcmpr(tick_cmpr, 0);
136 tick_wr_cmpr_bbwar(uint64_t tick_cmpr)
139 wrtickcmpr_bbwar(tick_cmpr, 0);
152 uint32_t clock, sclock;
154 clock = PCPU_GET(clock);
156 if (PCPU_GET(impl) == CPU_IMPL_SPARC64V ||
157 PCPU_GET(impl) >= CPU_IMPL_ULTRASPARCIII) {
158 if (OF_getprop(OF_peer(0), "stick-frequency", &sclock,
159 sizeof(sclock)) == -1) {
160 panic("%s: could not determine STICK frequency",
165 * Given that the STICK timers typically are driven at rather low
166 * frequencies they shouldn't be used except when really necessary.
168 if (tick_et_use_stick != 0) {
170 wr_tick_cmpr = stick_wr_cmpr;
172 * We don't provide a CPU ticker as long as the frequency
173 * supplied isn't actually used per-CPU.
177 if (PCPU_GET(impl) >= CPU_IMPL_ULTRASPARCI &&
178 PCPU_GET(impl) < CPU_IMPL_ULTRASPARCIII)
179 wr_tick_cmpr = tick_wr_cmpr_bbwar;
181 wr_tick_cmpr = tick_wr_cmpr;
182 set_cputicker(tick_cputicks, clock, 0);
184 intr_setup(PIL_TICK, tick_intr, -1, NULL, NULL);
187 * Initialize the (S)TICK-based timecounter(s).
188 * Note that we (try to) sync the (S)TICK timers of APs with the BSP
189 * during their startup but not afterwards. The resulting drift can
190 * cause problems when the time is calculated based on (S)TICK values
191 * read on different CPUs. Thus we always read the register on the
192 * BSP (if necessary via an IPI as sched_bind(9) isn't available in
193 * all circumstances) and use a low quality for the otherwise high
194 * quality (S)TICK timers in the MP case.
196 tick_tc.tc_get_timecount = tick_get_timecount_up;
197 tick_tc.tc_counter_mask = ~0u;
198 tick_tc.tc_frequency = clock;
199 tick_tc.tc_name = "tick";
200 tick_tc.tc_quality = TICK_QUALITY_UP;
202 if (cpu_mp_probe()) {
203 tick_tc.tc_get_timecount = tick_get_timecount_mp;
204 tick_tc.tc_quality = TICK_QUALITY_MP;
209 stick_tc.tc_get_timecount = stick_get_timecount_up;
210 stick_tc.tc_counter_mask = ~0u;
211 stick_tc.tc_frequency = sclock;
212 stick_tc.tc_name = "stick";
213 stick_tc.tc_quality = TICK_QUALITY_UP;
215 if (cpu_mp_probe()) {
216 stick_tc.tc_get_timecount = stick_get_timecount_mp;
217 stick_tc.tc_quality = TICK_QUALITY_MP;
222 tick_et.et_name = tick_et_use_stick ? "stick" : "tick";
223 tick_et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT |
225 tick_et.et_quality = 1000;
226 tick_et.et_frequency = tick_et_use_stick ? sclock : clock;
227 tick_et.et_min_period = 0x00010000LLU; /* To be safe. */
228 tick_et.et_max_period = (0xfffffffeLLU << 32) / tick_et.et_frequency;
229 tick_et.et_start = tick_et_start;
230 tick_et.et_stop = tick_et_stop;
231 tick_et.et_priv = NULL;
232 et_register(&tick_et);
234 cpu_initclocks_bsp();
238 tick_process(struct trapframe *tf)
240 struct trapframe *oldframe;
244 td->td_intr_nesting_level++;
246 if (tick_et.et_active) {
247 oldframe = td->td_intr_frame;
248 td->td_intr_frame = tf;
249 tick_et.et_event_cb(&tick_et, tick_et.et_arg);
250 td->td_intr_frame = oldframe;
252 td->td_intr_nesting_level--;
257 tick_intr(struct trapframe *tf)
259 u_long adj, ref, tick, tick_increment;
264 tick_increment = PCPU_GET(tickincrement);
265 if (tick_increment != 0) {
267 * NB: the sequence of reading the (S)TICK register,
268 * calculating the value of the next tick and writing it to
269 * the (S)TICK_COMPARE register must not be interrupted, not
270 * even by an IPI, otherwise a value that is in the past could
271 * be written in the worst case and thus causing the periodic
275 adj = PCPU_GET(tickadj);
277 wr_tick_cmpr(tick + tick_increment - adj);
279 ref = PCPU_GET(tickref);
282 while (delta >= tick_increment) {
284 delta -= tick_increment;
285 ref += tick_increment;
291 adjust_missed += count - 1;
292 if (delta > (tick_increment >> 3)) {
295 adj = tick_increment >> 4;
302 PCPU_SET(tickref, ref);
303 PCPU_SET(tickadj, adj);
309 stick_get_timecount_up(struct timecounter *tc)
312 return ((u_int)rdstick());
316 tick_get_timecount_up(struct timecounter *tc)
319 return ((u_int)rd(tick));
324 stick_get_timecount_mp(struct timecounter *tc)
332 ipi_wait(ipi_rd(0, tl_ipi_stick_rd, &stick));
338 tick_get_timecount_mp(struct timecounter *tc)
346 ipi_wait(ipi_rd(0, tl_ipi_tick_rd, &tick));
353 tick_et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
355 u_long base, div, fdiv;
359 div = (tick_et.et_frequency * period) >> 32;
363 fdiv = (tick_et.et_frequency * first) >> 32;
366 PCPU_SET(tickincrement, div);
369 * Try to make the (S)TICK interrupts as synchronously as possible
370 * on all CPUs to avoid inaccuracies for migrating processes. Leave
371 * out one tick to make sure that it is not missed.
376 PCPU_SET(tickadj, 0);
377 base = roundup(base, div);
379 PCPU_SET(tickref, base);
380 wr_tick_cmpr(base + fdiv);
386 tick_et_stop(struct eventtimer *et)
389 PCPU_SET(tickincrement, 0);
390 tick_stop(PCPU_GET(impl));
395 tick_clear(u_int cpu_impl)
398 if (cpu_impl == CPU_IMPL_SPARC64V ||
399 cpu_impl >= CPU_IMPL_ULTRASPARCIII)
405 tick_stop(u_int cpu_impl)
408 if (cpu_impl == CPU_IMPL_SPARC64V ||
409 cpu_impl >= CPU_IMPL_ULTRASPARCIII)
410 wrstickcmpr(1L << 63, 0);
411 wrtickcmpr(1L << 63, 0);