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: releng/11.2/sys/amd64/amd64/prof_machdep.c 331722 2018-03-29 02:50:57Z eadler $");
29
30 #ifdef GUPROF
31 #if 0
32 #include "opt_i586_guprof.h"
33 #include "opt_perfmon.h"
34 #endif
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/cpu.h>
40 #include <sys/eventhandler.h>
41 #include <sys/gmon.h>
42 #include <sys/kernel.h>
43 #include <sys/smp.h>
44 #include <sys/sysctl.h>
45
46 #include <machine/clock.h>
47 #if 0
48 #include <machine/perfmon.h>
49 #endif
50 #include <machine/timerreg.h>
51
52 #define CPUTIME_CLOCK_UNINITIALIZED 0
53 #define CPUTIME_CLOCK_I8254 1
54 #define CPUTIME_CLOCK_TSC 2
55 #define CPUTIME_CLOCK_I586_PMC 3
56 #define CPUTIME_CLOCK_I8254_SHIFT 7
57
58 int cputime_bias = 1; /* initialize for locality of reference */
59
60 static int cputime_clock = CPUTIME_CLOCK_UNINITIALIZED;
61 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
62 static u_int cputime_clock_pmc_conf = I586_PMC_GUPROF;
63 static int cputime_clock_pmc_init;
64 static struct gmonparam saved_gmp;
65 #endif
66 static int cputime_prof_active;
67 #endif /* GUPROF */
68
69 #ifdef __GNUCLIKE_ASM
70 __asm(" \n\
71 GM_STATE = 0 \n\
72 GMON_PROF_OFF = 3 \n\
73 \n\
74 .text \n\
75 .p2align 4,0x90 \n\
76 .globl __mcount \n\
77 .type __mcount,@function \n\
78 __mcount: \n\
79 # \n\
80 # Check that we are profiling. Do it early for speed. \n\
81 # \n\
82 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
83 je .mcount_exit \n\
84 # \n\
85 # __mcount is the same as [.]mcount except the caller \n\
86 # hasn't changed the stack except to call here, so the \n\
87 # caller's raddr is above our raddr. \n\
88 # \n\
89 pushq %rax \n\
90 pushq %rdx \n\
91 pushq %rcx \n\
92 pushq %rsi \n\
93 pushq %rdi \n\
94 pushq %r8 \n\
95 pushq %r9 \n\
96 movq 7*8+8(%rsp),%rdi \n\
97 jmp .got_frompc \n\
98 \n\
99 .p2align 4,0x90 \n\
100 .globl .mcount \n\
101 .mcount: \n\
102 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
103 je .mcount_exit \n\
104 # \n\
105 # The caller's stack frame has already been built, so \n\
106 # %rbp is the caller's frame pointer. The caller's \n\
107 # raddr is in the caller's frame following the caller's \n\
108 # caller's frame pointer. \n\
109 # \n\
110 pushq %rax \n\
111 pushq %rdx \n\
112 pushq %rcx \n\
113 pushq %rsi \n\
114 pushq %rdi \n\
115 pushq %r8 \n\
116 pushq %r9 \n\
117 movq 8(%rbp),%rdi \n\
118 .got_frompc: \n\
119 # \n\
120 # Our raddr is the caller's pc. \n\
121 # \n\
122 movq 7*8(%rsp),%rsi \n\
123 \n\
124 pushfq \n\
125 cli \n\
126 call mcount \n\
127 popfq \n\
128 popq %r9 \n\
129 popq %r8 \n\
130 popq %rdi \n\
131 popq %rsi \n\
132 popq %rcx \n\
133 popq %rdx \n\
134 popq %rax \n\
135 .mcount_exit: \n\
136 ret $0 \n\
137 ");
138 #else /* !__GNUCLIKE_ASM */
139 #error "this file needs to be ported to your compiler"
140 #endif /* __GNUCLIKE_ASM */
141
142 #ifdef GUPROF
143 /*
144 * [.]mexitcount saves the return register(s), loads selfpc and calls
145 * mexitcount(selfpc) to do the work. Someday it should be in a machine
146 * dependent file together with cputime(), __mcount and [.]mcount. cputime()
147 * can't just be put in machdep.c because it has to be compiled without -pg.
148 */
149 #ifdef __GNUCLIKE_ASM
150 __asm(" \n\
151 .text \n\
152 # \n\
153 # Dummy label to be seen when gprof -u hides [.]mexitcount. \n\
154 # \n\
155 .p2align 4,0x90 \n\
156 .globl __mexitcount \n\
157 .type __mexitcount,@function \n\
158 __mexitcount: \n\
159 nop \n\
160 \n\
161 GMON_PROF_HIRES = 4 \n\
162 \n\
163 .p2align 4,0x90 \n\
164 .globl .mexitcount \n\
165 .mexitcount: \n\
166 cmpl $GMON_PROF_HIRES,_gmonparam+GM_STATE \n\
167 jne .mexitcount_exit \n\
168 pushq %rax \n\
169 pushq %rdx \n\
170 pushq %rcx \n\
171 pushq %rsi \n\
172 pushq %rdi \n\
173 pushq %r8 \n\
174 pushq %r9 \n\
175 movq 7*8(%rsp),%rdi \n\
176 pushfq \n\
177 cli \n\
178 call mexitcount \n\
179 popfq \n\
180 popq %r9 \n\
181 popq %r8 \n\
182 popq %rdi \n\
183 popq %rsi \n\
184 popq %rcx \n\
185 popq %rdx \n\
186 popq %rax \n\
187 .mexitcount_exit: \n\
188 ret $0 \n\
189 ");
190 #endif /* __GNUCLIKE_ASM */
191
192 /*
193 * Return the time elapsed since the last call. The units are machine-
194 * dependent.
195 */
196 int
197 cputime()
198 {
199 u_int count;
200 int delta;
201 #if defined(PERFMON) && defined(I586_PMC_GUPROF) && !defined(SMP)
202 u_quad_t event_count;
203 #endif
204 u_char high, low;
205 static u_int prev_count;
206
207 if (cputime_clock == CPUTIME_CLOCK_TSC) {
208 /*
209 * Scale the TSC a little to make cputime()'s frequency
210 * fit in an int, assuming that the TSC frequency fits
211 * in a u_int. Use a fixed scale since dynamic scaling
212 * would be slower and we can't really use the low bit
213 * of precision.
214 */
215 count = (u_int)rdtsc() & ~1u;
216 delta = (int)(count - prev_count) >> 1;
217 prev_count = count;
218 return (delta);
219 }
220 #if defined(PERFMON) && defined(I586_PMC_GUPROF) && !defined(SMP)
221 if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
222 /*
223 * XXX permon_read() should be inlined so that the
224 * perfmon module doesn't need to be compiled with
225 * profiling disabled and so that it is fast.
226 */
227 perfmon_read(0, &event_count);
228
229 count = (u_int)event_count;
230 delta = (int)(count - prev_count);
231 prev_count = count;
232 return (delta);
233 }
234 #endif /* PERFMON && I586_PMC_GUPROF && !SMP */
235
236 /*
237 * Read the current value of the 8254 timer counter 0.
238 */
239 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
240 low = inb(TIMER_CNTR0);
241 high = inb(TIMER_CNTR0);
242 count = ((high << 8) | low) << CPUTIME_CLOCK_I8254_SHIFT;
243
244 /*
245 * The timer counts down from TIMER_CNTR0_MAX to 0 and then resets.
246 * While profiling is enabled, this routine is called at least twice
247 * per timer reset (for mcounting and mexitcounting hardclock()),
248 * so at most one reset has occurred since the last call, and one
249 * has occurred iff the current count is larger than the previous
250 * count. This allows counter underflow to be detected faster
251 * than in microtime().
252 */
253 delta = prev_count - count;
254 prev_count = count;
255 if ((int) delta <= 0)
256 return (delta + (i8254_max_count << CPUTIME_CLOCK_I8254_SHIFT));
257 return (delta);
258 }
259
260 static int
261 sysctl_machdep_cputime_clock(SYSCTL_HANDLER_ARGS)
262 {
263 int clock;
264 int error;
265 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
266 int event;
267 struct pmc pmc;
268 #endif
269
270 clock = cputime_clock;
271 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
272 if (clock == CPUTIME_CLOCK_I586_PMC) {
273 pmc.pmc_val = cputime_clock_pmc_conf;
274 clock += pmc.pmc_event;
275 }
276 #endif
277 error = sysctl_handle_opaque(oidp, &clock, sizeof clock, req);
278 if (error == 0 && req->newptr != NULL) {
279 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
280 if (clock >= CPUTIME_CLOCK_I586_PMC) {
281 event = clock - CPUTIME_CLOCK_I586_PMC;
282 if (event >= 256)
283 return (EINVAL);
284 pmc.pmc_num = 0;
285 pmc.pmc_event = event;
286 pmc.pmc_unit = 0;
287 pmc.pmc_flags = PMCF_E | PMCF_OS | PMCF_USR;
288 pmc.pmc_mask = 0;
289 cputime_clock_pmc_conf = pmc.pmc_val;
290 cputime_clock = CPUTIME_CLOCK_I586_PMC;
291 } else
292 #endif
293 {
294 if (clock < 0 || clock >= CPUTIME_CLOCK_I586_PMC)
295 return (EINVAL);
296 cputime_clock = clock;
297 }
298 }
299 return (error);
300 }
301
302 SYSCTL_PROC(_machdep, OID_AUTO, cputime_clock, CTLTYPE_INT | CTLFLAG_RW,
303 0, sizeof(u_int), sysctl_machdep_cputime_clock, "I", "");
304
305 /*
306 * The start and stop routines need not be here since we turn off profiling
307 * before calling them. They are here for convenience.
308 */
309
310 void
311 startguprof(gp)
312 struct gmonparam *gp;
313 {
314 uint64_t freq;
315
316 freq = atomic_load_acq_64(&tsc_freq);
317 if (cputime_clock == CPUTIME_CLOCK_UNINITIALIZED) {
318 if (freq != 0 && mp_ncpus == 1)
319 cputime_clock = CPUTIME_CLOCK_TSC;
320 else
321 cputime_clock = CPUTIME_CLOCK_I8254;
322 }
323 if (cputime_clock == CPUTIME_CLOCK_TSC) {
324 gp->profrate = freq >> 1;
325 cputime_prof_active = 1;
326 } else
327 gp->profrate = i8254_freq << CPUTIME_CLOCK_I8254_SHIFT;
328 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
329 if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
330 if (perfmon_avail() &&
331 perfmon_setup(0, cputime_clock_pmc_conf) == 0) {
332 if (perfmon_start(0) != 0)
333 perfmon_fini(0);
334 else {
335 /* XXX 1 event == 1 us. */
336 gp->profrate = 1000000;
337
338 saved_gmp = *gp;
339
340 /* Zap overheads. They are invalid. */
341 gp->cputime_overhead = 0;
342 gp->mcount_overhead = 0;
343 gp->mcount_post_overhead = 0;
344 gp->mcount_pre_overhead = 0;
345 gp->mexitcount_overhead = 0;
346 gp->mexitcount_post_overhead = 0;
347 gp->mexitcount_pre_overhead = 0;
348
349 cputime_clock_pmc_init = TRUE;
350 }
351 }
352 }
353 #endif /* PERFMON && I586_PMC_GUPROF */
354 cputime_bias = 0;
355 cputime();
356 }
357
358 void
359 stopguprof(gp)
360 struct gmonparam *gp;
361 {
362 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
363 if (cputime_clock_pmc_init) {
364 *gp = saved_gmp;
365 perfmon_fini(0);
366 cputime_clock_pmc_init = FALSE;
367 }
368 #endif
369 if (cputime_clock == CPUTIME_CLOCK_TSC)
370 cputime_prof_active = 0;
371 }
372
373 /* If the cpu frequency changed while profiling, report a warning. */
374 static void
375 tsc_freq_changed(void *arg, const struct cf_level *level, int status)
376 {
377
378 /*
379 * If there was an error during the transition or
380 * TSC is P-state invariant, don't do anything.
381 */
382 if (status != 0 || tsc_is_invariant)
383 return;
384 if (cputime_prof_active && cputime_clock == CPUTIME_CLOCK_TSC)
385 printf("warning: cpu freq changed while profiling active\n");
386 }
387
388 EVENTHANDLER_DEFINE(cpufreq_post_change, tsc_freq_changed, NULL,
389 EVENTHANDLER_PRI_ANY);
390
391 #endif /* GUPROF */
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