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/8.0/sys/amd64/amd64/prof_machdep.c 184102 2008-10-21 00:38:00Z jkim $");
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 #if defined(I586_CPU) || defined(I686_CPU)
67 static int cputime_prof_active;
68 #endif
69 #endif /* GUPROF */
70
71 #ifdef __GNUCLIKE_ASM
72 __asm(" \n\
73 GM_STATE = 0 \n\
74 GMON_PROF_OFF = 3 \n\
75 \n\
76 .text \n\
77 .p2align 4,0x90 \n\
78 .globl __mcount \n\
79 .type __mcount,@function \n\
80 __mcount: \n\
81 # \n\
82 # Check that we are profiling. Do it early for speed. \n\
83 # \n\
84 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
85 je .mcount_exit \n\
86 # \n\
87 # __mcount is the same as [.]mcount except the caller \n\
88 # hasn't changed the stack except to call here, so the \n\
89 # caller's raddr is above our raddr. \n\
90 # \n\
91 pushq %rax \n\
92 pushq %rdx \n\
93 pushq %rcx \n\
94 pushq %rsi \n\
95 pushq %rdi \n\
96 pushq %r8 \n\
97 pushq %r9 \n\
98 movq 7*8+8(%rsp),%rdi \n\
99 jmp .got_frompc \n\
100 \n\
101 .p2align 4,0x90 \n\
102 .globl .mcount \n\
103 .mcount: \n\
104 cmpl $GMON_PROF_OFF,_gmonparam+GM_STATE \n\
105 je .mcount_exit \n\
106 # \n\
107 # The caller's stack frame has already been built, so \n\
108 # %rbp is the caller's frame pointer. The caller's \n\
109 # raddr is in the caller's frame following the caller's \n\
110 # caller's frame pointer. \n\
111 # \n\
112 pushq %rax \n\
113 pushq %rdx \n\
114 pushq %rcx \n\
115 pushq %rsi \n\
116 pushq %rdi \n\
117 pushq %r8 \n\
118 pushq %r9 \n\
119 movq 8(%rbp),%rdi \n\
120 .got_frompc: \n\
121 # \n\
122 # Our raddr is the caller's pc. \n\
123 # \n\
124 movq 7*8(%rsp),%rsi \n\
125 \n\
126 pushfq \n\
127 cli \n\
128 call mcount \n\
129 popfq \n\
130 popq %r9 \n\
131 popq %r8 \n\
132 popq %rdi \n\
133 popq %rsi \n\
134 popq %rcx \n\
135 popq %rdx \n\
136 popq %rax \n\
137 .mcount_exit: \n\
138 ret $0 \n\
139 ");
140 #else /* !__GNUCLIKE_ASM */
141 #error "this file needs to be ported to your compiler"
142 #endif /* __GNUCLIKE_ASM */
143
144 #ifdef GUPROF
145 /*
146 * [.]mexitcount saves the return register(s), loads selfpc and calls
147 * mexitcount(selfpc) to do the work. Someday it should be in a machine
148 * dependent file together with cputime(), __mcount and [.]mcount. cputime()
149 * can't just be put in machdep.c because it has to be compiled without -pg.
150 */
151 #ifdef __GNUCLIKE_ASM
152 __asm(" \n\
153 .text \n\
154 # \n\
155 # Dummy label to be seen when gprof -u hides [.]mexitcount. \n\
156 # \n\
157 .p2align 4,0x90 \n\
158 .globl __mexitcount \n\
159 .type __mexitcount,@function \n\
160 __mexitcount: \n\
161 nop \n\
162 \n\
163 GMON_PROF_HIRES = 4 \n\
164 \n\
165 .p2align 4,0x90 \n\
166 .globl .mexitcount \n\
167 .mexitcount: \n\
168 cmpl $GMON_PROF_HIRES,_gmonparam+GM_STATE \n\
169 jne .mexitcount_exit \n\
170 pushq %rax \n\
171 pushq %rdx \n\
172 pushq %rcx \n\
173 pushq %rsi \n\
174 pushq %rdi \n\
175 pushq %r8 \n\
176 pushq %r9 \n\
177 movq 7*8(%rsp),%rdi \n\
178 pushfq \n\
179 cli \n\
180 call mexitcount \n\
181 popfq \n\
182 popq %r9 \n\
183 popq %r8 \n\
184 popq %rdi \n\
185 popq %rsi \n\
186 popq %rcx \n\
187 popq %rdx \n\
188 popq %rax \n\
189 .mexitcount_exit: \n\
190 ret $0 \n\
191 ");
192 #endif /* __GNUCLIKE_ASM */
193
194 /*
195 * Return the time elapsed since the last call. The units are machine-
196 * dependent.
197 */
198 int
199 cputime()
200 {
201 u_int count;
202 int delta;
203 #if (defined(I586_CPU) || defined(I686_CPU)) && !defined(SMP) && \
204 defined(PERFMON) && defined(I586_PMC_GUPROF)
205 u_quad_t event_count;
206 #endif
207 u_char high, low;
208 static u_int prev_count;
209
210 #if defined(I586_CPU) || defined(I686_CPU)
211 if (cputime_clock == CPUTIME_CLOCK_TSC) {
212 /*
213 * Scale the TSC a little to make cputime()'s frequency
214 * fit in an int, assuming that the TSC frequency fits
215 * in a u_int. Use a fixed scale since dynamic scaling
216 * would be slower and we can't really use the low bit
217 * of precision.
218 */
219 count = (u_int)rdtsc() & ~1u;
220 delta = (int)(count - prev_count) >> 1;
221 prev_count = count;
222 return (delta);
223 }
224 #if defined(PERFMON) && defined(I586_PMC_GUPROF) && !defined(SMP)
225 if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
226 /*
227 * XXX permon_read() should be inlined so that the
228 * perfmon module doesn't need to be compiled with
229 * profiling disabled and so that it is fast.
230 */
231 perfmon_read(0, &event_count);
232
233 count = (u_int)event_count;
234 delta = (int)(count - prev_count);
235 prev_count = count;
236 return (delta);
237 }
238 #endif /* PERFMON && I586_PMC_GUPROF && !SMP */
239 #endif /* I586_CPU || I686_CPU */
240
241 /*
242 * Read the current value of the 8254 timer counter 0.
243 */
244 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
245 low = inb(TIMER_CNTR0);
246 high = inb(TIMER_CNTR0);
247 count = ((high << 8) | low) << CPUTIME_CLOCK_I8254_SHIFT;
248
249 /*
250 * The timer counts down from TIMER_CNTR0_MAX to 0 and then resets.
251 * While profiling is enabled, this routine is called at least twice
252 * per timer reset (for mcounting and mexitcounting hardclock()),
253 * so at most one reset has occurred since the last call, and one
254 * has occurred iff the current count is larger than the previous
255 * count. This allows counter underflow to be detected faster
256 * than in microtime().
257 */
258 delta = prev_count - count;
259 prev_count = count;
260 if ((int) delta <= 0)
261 return (delta + (i8254_max_count << CPUTIME_CLOCK_I8254_SHIFT));
262 return (delta);
263 }
264
265 static int
266 sysctl_machdep_cputime_clock(SYSCTL_HANDLER_ARGS)
267 {
268 int clock;
269 int error;
270 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
271 int event;
272 struct pmc pmc;
273 #endif
274
275 clock = cputime_clock;
276 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
277 if (clock == CPUTIME_CLOCK_I586_PMC) {
278 pmc.pmc_val = cputime_clock_pmc_conf;
279 clock += pmc.pmc_event;
280 }
281 #endif
282 error = sysctl_handle_opaque(oidp, &clock, sizeof clock, req);
283 if (error == 0 && req->newptr != NULL) {
284 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
285 if (clock >= CPUTIME_CLOCK_I586_PMC) {
286 event = clock - CPUTIME_CLOCK_I586_PMC;
287 if (event >= 256)
288 return (EINVAL);
289 pmc.pmc_num = 0;
290 pmc.pmc_event = event;
291 pmc.pmc_unit = 0;
292 pmc.pmc_flags = PMCF_E | PMCF_OS | PMCF_USR;
293 pmc.pmc_mask = 0;
294 cputime_clock_pmc_conf = pmc.pmc_val;
295 cputime_clock = CPUTIME_CLOCK_I586_PMC;
296 } else
297 #endif
298 {
299 if (clock < 0 || clock >= CPUTIME_CLOCK_I586_PMC)
300 return (EINVAL);
301 cputime_clock = clock;
302 }
303 }
304 return (error);
305 }
306
307 SYSCTL_PROC(_machdep, OID_AUTO, cputime_clock, CTLTYPE_INT | CTLFLAG_RW,
308 0, sizeof(u_int), sysctl_machdep_cputime_clock, "I", "");
309
310 /*
311 * The start and stop routines need not be here since we turn off profiling
312 * before calling them. They are here for convenience.
313 */
314
315 void
316 startguprof(gp)
317 struct gmonparam *gp;
318 {
319 if (cputime_clock == CPUTIME_CLOCK_UNINITIALIZED) {
320 cputime_clock = CPUTIME_CLOCK_I8254;
321 #if defined(I586_CPU) || defined(I686_CPU)
322 if (tsc_freq != 0 && !tsc_is_broken && mp_ncpus == 1)
323 cputime_clock = CPUTIME_CLOCK_TSC;
324 #endif
325 }
326 gp->profrate = i8254_freq << CPUTIME_CLOCK_I8254_SHIFT;
327 #if defined(I586_CPU) || defined(I686_CPU)
328 if (cputime_clock == CPUTIME_CLOCK_TSC) {
329 gp->profrate = tsc_freq >> 1;
330 cputime_prof_active = 1;
331 }
332 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
333 else if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
334 if (perfmon_avail() &&
335 perfmon_setup(0, cputime_clock_pmc_conf) == 0) {
336 if (perfmon_start(0) != 0)
337 perfmon_fini(0);
338 else {
339 /* XXX 1 event == 1 us. */
340 gp->profrate = 1000000;
341
342 saved_gmp = *gp;
343
344 /* Zap overheads. They are invalid. */
345 gp->cputime_overhead = 0;
346 gp->mcount_overhead = 0;
347 gp->mcount_post_overhead = 0;
348 gp->mcount_pre_overhead = 0;
349 gp->mexitcount_overhead = 0;
350 gp->mexitcount_post_overhead = 0;
351 gp->mexitcount_pre_overhead = 0;
352
353 cputime_clock_pmc_init = TRUE;
354 }
355 }
356 }
357 #endif /* PERFMON && I586_PMC_GUPROF */
358 #endif /* I586_CPU || I686_CPU */
359 cputime_bias = 0;
360 cputime();
361 }
362
363 void
364 stopguprof(gp)
365 struct gmonparam *gp;
366 {
367 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
368 if (cputime_clock_pmc_init) {
369 *gp = saved_gmp;
370 perfmon_fini(0);
371 cputime_clock_pmc_init = FALSE;
372 }
373 #endif
374 #if defined(I586_CPU) || defined(I686_CPU)
375 if (cputime_clock == CPUTIME_CLOCK_TSC)
376 cputime_prof_active = 0;
377 #endif
378 }
379
380 #if defined(I586_CPU) || defined(I686_CPU)
381 /* If the cpu frequency changed while profiling, report a warning. */
382 static void
383 tsc_freq_changed(void *arg, const struct cf_level *level, int status)
384 {
385
386 /*
387 * If there was an error during the transition or
388 * TSC is P-state invariant, don't do anything.
389 */
390 if (status != 0 || tsc_is_invariant)
391 return;
392 if (cputime_prof_active && cputime_clock == CPUTIME_CLOCK_TSC)
393 printf("warning: cpu freq changed while profiling active\n");
394 }
395
396 EVENTHANDLER_DEFINE(cpufreq_post_change, tsc_freq_changed, NULL,
397 EVENTHANDLER_PRI_ANY);
398 #endif /* I586_CPU || I686_CPU */
399
400 #endif /* GUPROF */
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