1 /*-
2 * Copyright (c) 1996 Bruce D. Evans.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #ifdef GUPROF
31 #include "opt_i586_guprof.h"
32 #include "opt_perfmon.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/cpu.h>
38 #include <sys/eventhandler.h>
39 #include <sys/gmon.h>
40 #include <sys/kernel.h>
41 #include <sys/smp.h>
42 #include <sys/sysctl.h>
43
44 #include <machine/clock.h>
45 #include <machine/perfmon.h>
46 #include <machine/timerreg.h>
47
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
53
54 int cputime_bias = 1; /* initialize for locality of reference */
55
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;
61 #endif
62 #if defined(I586_CPU) || defined(I686_CPU)
63 static int cputime_prof_active;
64 #endif
65 #endif /* GUPROF */
66
67 #ifdef __GNUCLIKE_ASM
68 __asm(" \n\
69 GM_STATE = 0 \n\
70 GMON_PROF_OFF = 3 \n\
71 \n\
72 .text \n\
73 .p2align 4,0x90 \n\
74 .globl __mcount \n\
75 .type __mcount,@function \n\
76 __mcount: \n\
77 # \n\
78 # Check that we are profiling. Do it early for speed. \n\
79 # \n\
80 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
81 je .mcount_exit \n\
82 # \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\
86 # \n\
87 movl 4(%esp),%edx \n\
88 jmp .got_frompc \n\
89 \n\
90 .p2align 4,0x90 \n\
91 .globl .mcount \n\
92 .mcount: \n\
93 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
94 je .mcount_exit \n\
95 # \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\
100 # \n\
101 movl 4(%ebp),%edx \n\
102 .got_frompc: \n\
103 # \n\
104 # Our raddr is the caller's pc. \n\
105 # \n\
106 movl (%esp),%eax \n\
107 \n\
108 pushfl \n\
109 pushl %eax \n\
110 pushl %edx \n\
111 cli \n\
112 call mcount \n\
113 addl $8,%esp \n\
114 popfl \n\
115 .mcount_exit: \n\
116 ret $0 \n\
117 ");
118 #else /* !__GNUCLIKE_ASM */
119 #error "this file needs to be ported to your compiler"
120 #endif /* __GNUCLIKE_ASM */
121
122 #ifdef GUPROF
123 /*
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.
128 */
129 #ifdef __GNUCLIKE_ASM
130 __asm(" \n\
131 .text \n\
132 # \n\
133 # Dummy label to be seen when gprof -u hides [.]mexitcount. \n\
134 # \n\
135 .p2align 4,0x90 \n\
136 .globl __mexitcount \n\
137 .type __mexitcount,@function \n\
138 __mexitcount: \n\
139 nop \n\
140 \n\
141 GMON_PROF_HIRES = 4 \n\
142 \n\
143 .p2align 4,0x90 \n\
144 .globl .mexitcount \n\
145 .mexitcount: \n\
146 cmpl $GMON_PROF_HIRES,_gmonparam+GM_STATE \n\
147 jne .mexitcount_exit \n\
148 pushl %edx \n\
149 pushl %eax \n\
150 movl 8(%esp),%eax \n\
151 pushfl \n\
152 pushl %eax \n\
153 cli \n\
154 call mexitcount \n\
155 addl $4,%esp \n\
156 popfl \n\
157 popl %eax \n\
158 popl %edx \n\
159 .mexitcount_exit: \n\
160 ret $0 \n\
161 ");
162 #endif /* __GNUCLIKE_ASM */
163
164 /*
165 * Return the time elapsed since the last call. The units are machine-
166 * dependent.
167 */
168 int
cputime()169 cputime()
170 {
171 u_int count;
172 int delta;
173 #if (defined(I586_CPU) || defined(I686_CPU)) && \
174 defined(PERFMON) && defined(I586_PMC_GUPROF) && !defined(SMP)
175 u_quad_t event_count;
176 #endif
177 u_char high, low;
178 static u_int prev_count;
179
180 #if defined(I586_CPU) || defined(I686_CPU)
181 if (cputime_clock == CPUTIME_CLOCK_TSC) {
182 /*
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
187 * of precision.
188 */
189 count = (u_int)rdtsc() & ~1u;
190 delta = (int)(count - prev_count) >> 1;
191 prev_count = count;
192 return (delta);
193 }
194 #if defined(PERFMON) && defined(I586_PMC_GUPROF) && !defined(SMP)
195 if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
196 /*
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.
200 */
201 perfmon_read(0, &event_count);
202
203 count = (u_int)event_count;
204 delta = (int)(count - prev_count);
205 prev_count = count;
206 return (delta);
207 }
208 #endif /* PERFMON && I586_PMC_GUPROF && !SMP */
209 #endif /* I586_CPU || I686_CPU */
210
211 /*
212 * Read the current value of the 8254 timer counter 0.
213 */
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;
218
219 /*
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().
227 */
228 delta = prev_count - count;
229 prev_count = count;
230 if ((int) delta <= 0)
231 return (delta + (i8254_max_count << CPUTIME_CLOCK_I8254_SHIFT));
232 return (delta);
233 }
234
235 static int
sysctl_machdep_cputime_clock(SYSCTL_HANDLER_ARGS)236 sysctl_machdep_cputime_clock(SYSCTL_HANDLER_ARGS)
237 {
238 int clock;
239 int error;
240 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
241 int event;
242 struct pmc pmc;
243 #endif
244
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;
250 }
251 #endif
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;
257 if (event >= 256)
258 return (EINVAL);
259 pmc.pmc_num = 0;
260 pmc.pmc_event = event;
261 pmc.pmc_unit = 0;
262 pmc.pmc_flags = PMCF_E | PMCF_OS | PMCF_USR;
263 pmc.pmc_mask = 0;
264 cputime_clock_pmc_conf = pmc.pmc_val;
265 cputime_clock = CPUTIME_CLOCK_I586_PMC;
266 } else
267 #endif
268 {
269 if (clock < 0 || clock >= CPUTIME_CLOCK_I586_PMC)
270 return (EINVAL);
271 cputime_clock = clock;
272 }
273 }
274 return (error);
275 }
276
277 SYSCTL_PROC(_machdep, OID_AUTO, cputime_clock, CTLTYPE_INT | CTLFLAG_RW,
278 0, sizeof(u_int), sysctl_machdep_cputime_clock, "I", "");
279
280 /*
281 * The start and stop routines need not be here since we turn off profiling
282 * before calling them. They are here for convenience.
283 */
284
285 void
startguprof(gp)286 startguprof(gp)
287 struct gmonparam *gp;
288 {
289 #if defined(I586_CPU) || defined(I686_CPU)
290 uint64_t freq;
291
292 freq = atomic_load_acq_64(&tsc_freq);
293 if (cputime_clock == CPUTIME_CLOCK_UNINITIALIZED) {
294 if (freq != 0 && mp_ncpus == 1)
295 cputime_clock = CPUTIME_CLOCK_TSC;
296 else
297 cputime_clock = CPUTIME_CLOCK_I8254;
298 }
299 if (cputime_clock == CPUTIME_CLOCK_TSC) {
300 gp->profrate = freq >> 1;
301 cputime_prof_active = 1;
302 } else
303 gp->profrate = i8254_freq << CPUTIME_CLOCK_I8254_SHIFT;
304 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
305 if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
306 if (perfmon_avail() &&
307 perfmon_setup(0, cputime_clock_pmc_conf) == 0) {
308 if (perfmon_start(0) != 0)
309 perfmon_fini(0);
310 else {
311 /* XXX 1 event == 1 us. */
312 gp->profrate = 1000000;
313
314 saved_gmp = *gp;
315
316 /* Zap overheads. They are invalid. */
317 gp->cputime_overhead = 0;
318 gp->mcount_overhead = 0;
319 gp->mcount_post_overhead = 0;
320 gp->mcount_pre_overhead = 0;
321 gp->mexitcount_overhead = 0;
322 gp->mexitcount_post_overhead = 0;
323 gp->mexitcount_pre_overhead = 0;
324
325 cputime_clock_pmc_init = TRUE;
326 }
327 }
328 }
329 #endif /* PERFMON && I586_PMC_GUPROF */
330 #else /* !(I586_CPU || I686_CPU) */
331 if (cputime_clock == CPUTIME_CLOCK_UNINITIALIZED)
332 cputime_clock = CPUTIME_CLOCK_I8254;
333 gp->profrate = i8254_freq << CPUTIME_CLOCK_I8254_SHIFT;
334 #endif /* I586_CPU || I686_CPU */
335 cputime_bias = 0;
336 cputime();
337 }
338
339 void
stopguprof(gp)340 stopguprof(gp)
341 struct gmonparam *gp;
342 {
343 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
344 if (cputime_clock_pmc_init) {
345 *gp = saved_gmp;
346 perfmon_fini(0);
347 cputime_clock_pmc_init = FALSE;
348 }
349 #endif
350 #if defined(I586_CPU) || defined(I686_CPU)
351 if (cputime_clock == CPUTIME_CLOCK_TSC)
352 cputime_prof_active = 0;
353 #endif
354 }
355
356 #if defined(I586_CPU) || defined(I686_CPU)
357 /* If the cpu frequency changed while profiling, report a warning. */
358 static void
tsc_freq_changed(void * arg,const struct cf_level * level,int status)359 tsc_freq_changed(void *arg, const struct cf_level *level, int status)
360 {
361
362 /*
363 * If there was an error during the transition or
364 * TSC is P-state invariant, don't do anything.
365 */
366 if (status != 0 || tsc_is_invariant)
367 return;
368 if (cputime_prof_active && cputime_clock == CPUTIME_CLOCK_TSC)
369 printf("warning: cpu freq changed while profiling active\n");
370 }
371
372 EVENTHANDLER_DEFINE(cpufreq_post_change, tsc_freq_changed, NULL,
373 EVENTHANDLER_PRI_ANY);
374 #endif /* I586_CPU || I686_CPU */
375
376 #endif /* GUPROF */
377