2 * Copyright (c) 1996 Bruce D. Evans.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 #include "opt_i586_guprof.h"
32 #include "opt_perfmon.h"
34 #include <sys/param.h>
35 #include <sys/systm.h>
38 #include <sys/eventhandler.h>
40 #include <sys/kernel.h>
42 #include <sys/sysctl.h>
44 #include <machine/clock.h>
45 #include <machine/perfmon.h>
46 #include <machine/timerreg.h>
48 #define CPUTIME_CLOCK_UNINITIALIZED 0
49 #define CPUTIME_CLOCK_I8254 1
50 #define CPUTIME_CLOCK_TSC 2
51 #define CPUTIME_CLOCK_I586_PMC 3
52 #define CPUTIME_CLOCK_I8254_SHIFT 7
54 int cputime_bias = 1; /* initialize for locality of reference */
56 static int cputime_clock = CPUTIME_CLOCK_UNINITIALIZED;
57 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
58 static u_int cputime_clock_pmc_conf = I586_PMC_GUPROF;
59 static int cputime_clock_pmc_init;
60 static struct gmonparam saved_gmp;
62 #if defined(I586_CPU) || defined(I686_CPU)
63 static int cputime_prof_active;
75 .type __mcount,@function \n\
78 # Check that we are profiling. Do it early for speed. \n\
80 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
83 # __mcount is the same as [.]mcount except the caller \n\
84 # hasn't changed the stack except to call here, so the \n\
85 # caller's raddr is above our raddr. \n\
93 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
96 # The caller's stack frame has already been built, so \n\
97 # %ebp is the caller's frame pointer. The caller's \n\
98 # raddr is in the caller's frame following the caller's \n\
99 # caller's frame pointer. \n\
101 movl 4(%ebp),%edx \n\
104 # Our raddr is the caller's pc. \n\
118 #else /* !__GNUCLIKE_ASM */
119 #error "this file needs to be ported to your compiler"
120 #endif /* __GNUCLIKE_ASM */
124 * [.]mexitcount saves the return register(s), loads selfpc and calls
125 * mexitcount(selfpc) to do the work. Someday it should be in a machine
126 * dependent file together with cputime(), __mcount and [.]mcount. cputime()
127 * can't just be put in machdep.c because it has to be compiled without -pg.
129 #ifdef __GNUCLIKE_ASM
133 # Dummy label to be seen when gprof -u hides [.]mexitcount. \n\
136 .globl __mexitcount \n\
137 .type __mexitcount,@function \n\
141 GMON_PROF_HIRES = 4 \n\
144 .globl .mexitcount \n\
146 cmpl $GMON_PROF_HIRES,_gmonparam+GM_STATE \n\
147 jne .mexitcount_exit \n\
150 movl 8(%esp),%eax \n\
159 .mexitcount_exit: \n\
162 #endif /* __GNUCLIKE_ASM */
165 * Return the time elapsed since the last call. The units are machine-
173 #if (defined(I586_CPU) || defined(I686_CPU)) && !defined(SMP) && \
174 defined(PERFMON) && defined(I586_PMC_GUPROF)
175 u_quad_t event_count;
178 static u_int prev_count;
180 #if defined(I586_CPU) || defined(I686_CPU)
181 if (cputime_clock == CPUTIME_CLOCK_TSC) {
183 * Scale the TSC a little to make cputime()'s frequency
184 * fit in an int, assuming that the TSC frequency fits
185 * in a u_int. Use a fixed scale since dynamic scaling
186 * would be slower and we can't really use the low bit
189 count = (u_int)rdtsc() & ~1u;
190 delta = (int)(count - prev_count) >> 1;
194 #if defined(PERFMON) && defined(I586_PMC_GUPROF) && !defined(SMP)
195 if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
197 * XXX permon_read() should be inlined so that the
198 * perfmon module doesn't need to be compiled with
199 * profiling disabled and so that it is fast.
201 perfmon_read(0, &event_count);
203 count = (u_int)event_count;
204 delta = (int)(count - prev_count);
208 #endif /* PERFMON && I586_PMC_GUPROF && !SMP */
209 #endif /* I586_CPU || I686_CPU */
212 * Read the current value of the 8254 timer counter 0.
214 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
215 low = inb(TIMER_CNTR0);
216 high = inb(TIMER_CNTR0);
217 count = ((high << 8) | low) << CPUTIME_CLOCK_I8254_SHIFT;
220 * The timer counts down from TIMER_CNTR0_MAX to 0 and then resets.
221 * While profiling is enabled, this routine is called at least twice
222 * per timer reset (for mcounting and mexitcounting hardclock()),
223 * so at most one reset has occurred since the last call, and one
224 * has occurred iff the current count is larger than the previous
225 * count. This allows counter underflow to be detected faster
226 * than in microtime().
228 delta = prev_count - count;
230 if ((int) delta <= 0)
231 return (delta + (i8254_max_count << CPUTIME_CLOCK_I8254_SHIFT));
236 sysctl_machdep_cputime_clock(SYSCTL_HANDLER_ARGS)
240 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
245 clock = cputime_clock;
246 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
247 if (clock == CPUTIME_CLOCK_I586_PMC) {
248 pmc.pmc_val = cputime_clock_pmc_conf;
249 clock += pmc.pmc_event;
252 error = sysctl_handle_opaque(oidp, &clock, sizeof clock, req);
253 if (error == 0 && req->newptr != NULL) {
254 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
255 if (clock >= CPUTIME_CLOCK_I586_PMC) {
256 event = clock - CPUTIME_CLOCK_I586_PMC;
260 pmc.pmc_event = event;
262 pmc.pmc_flags = PMCF_E | PMCF_OS | PMCF_USR;
264 cputime_clock_pmc_conf = pmc.pmc_val;
265 cputime_clock = CPUTIME_CLOCK_I586_PMC;
269 if (clock < 0 || clock >= CPUTIME_CLOCK_I586_PMC)
271 cputime_clock = clock;
277 SYSCTL_PROC(_machdep, OID_AUTO, cputime_clock, CTLTYPE_INT | CTLFLAG_RW,
278 0, sizeof(u_int), sysctl_machdep_cputime_clock, "I", "");
281 * The start and stop routines need not be here since we turn off profiling
282 * before calling them. They are here for convenience.
287 struct gmonparam *gp;
289 if (cputime_clock == CPUTIME_CLOCK_UNINITIALIZED) {
290 cputime_clock = CPUTIME_CLOCK_I8254;
291 #if defined(I586_CPU) || defined(I686_CPU)
292 if (tsc_freq != 0 && !tsc_is_broken && mp_ncpus == 1)
293 cputime_clock = CPUTIME_CLOCK_TSC;
296 gp->profrate = i8254_freq << CPUTIME_CLOCK_I8254_SHIFT;
297 #if defined(I586_CPU) || defined(I686_CPU)
298 if (cputime_clock == CPUTIME_CLOCK_TSC) {
299 gp->profrate = tsc_freq >> 1;
300 cputime_prof_active = 1;
302 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
303 else if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
304 if (perfmon_avail() &&
305 perfmon_setup(0, cputime_clock_pmc_conf) == 0) {
306 if (perfmon_start(0) != 0)
309 /* XXX 1 event == 1 us. */
310 gp->profrate = 1000000;
314 /* Zap overheads. They are invalid. */
315 gp->cputime_overhead = 0;
316 gp->mcount_overhead = 0;
317 gp->mcount_post_overhead = 0;
318 gp->mcount_pre_overhead = 0;
319 gp->mexitcount_overhead = 0;
320 gp->mexitcount_post_overhead = 0;
321 gp->mexitcount_pre_overhead = 0;
323 cputime_clock_pmc_init = TRUE;
327 #endif /* PERFMON && I586_PMC_GUPROF */
328 #endif /* I586_CPU || I686_CPU */
335 struct gmonparam *gp;
337 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
338 if (cputime_clock_pmc_init) {
341 cputime_clock_pmc_init = FALSE;
344 #if defined(I586_CPU) || defined(I686_CPU)
345 if (cputime_clock == CPUTIME_CLOCK_TSC)
346 cputime_prof_active = 0;
350 #if defined(I586_CPU) || defined(I686_CPU)
351 /* If the cpu frequency changed while profiling, report a warning. */
353 tsc_freq_changed(void *arg, const struct cf_level *level, int status)
357 * If there was an error during the transition or
358 * TSC is P-state invariant, don't do anything.
360 if (status != 0 || tsc_is_invariant)
362 if (cputime_prof_active && cputime_clock == CPUTIME_CLOCK_TSC)
363 printf("warning: cpu freq changed while profiling active\n");
366 EVENTHANDLER_DEFINE(cpufreq_post_change, tsc_freq_changed, NULL,
367 EVENTHANDLER_PRI_ANY);
368 #endif /* I586_CPU || I686_CPU */