xref: /freebsd/sys/dev/hwpmc/hwpmc_powerpc.c (revision 38a52bd3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011,2013 Justin Hibbits
5  * Copyright (c) 2005, Joseph Koshy
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/pmc.h>
36 #include <sys/pmckern.h>
37 #include <sys/sysent.h>
38 #include <sys/syslog.h>
39 #include <sys/systm.h>
40 
41 #include <machine/pmc_mdep.h>
42 #include <machine/spr.h>
43 #include <machine/pte.h>
44 #include <machine/sr.h>
45 #include <machine/cpu.h>
46 #include <machine/stack.h>
47 
48 #include "hwpmc_powerpc.h"
49 
50 #ifdef __powerpc64__
51 #define OFFSET 4 /* Account for the TOC reload slot */
52 #else
53 #define OFFSET 0
54 #endif
55 
56 struct powerpc_cpu **powerpc_pcpu;
57 struct pmc_ppc_event *ppc_event_codes;
58 size_t ppc_event_codes_size;
59 int ppc_event_first;
60 int ppc_event_last;
61 int ppc_max_pmcs;
62 enum pmc_class ppc_class;
63 
64 void (*powerpc_set_pmc)(int cpu, int ri, int config);
65 pmc_value_t (*powerpc_pmcn_read)(unsigned int pmc);
66 void (*powerpc_pmcn_write)(unsigned int pmc, uint32_t val);
67 void (*powerpc_resume_pmc)(bool ie);
68 
69 
70 int
71 pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
72     struct trapframe *tf)
73 {
74 	uintptr_t *osp, *sp;
75 	uintptr_t pc;
76 	int frames = 0;
77 
78 	cc[frames++] = PMC_TRAPFRAME_TO_PC(tf);
79 	sp = (uintptr_t *)PMC_TRAPFRAME_TO_FP(tf);
80 	osp = (uintptr_t *)PAGE_SIZE;
81 
82 	for (; frames < maxsamples; frames++) {
83 		if (sp <= osp)
84 			break;
85 	    #ifdef __powerpc64__
86 		pc = sp[2];
87 	    #else
88 		pc = sp[1];
89 	    #endif
90 		if ((pc & 3) || (pc < 0x100))
91 			break;
92 
93 		/*
94 		 * trapexit() and asttrapexit() are sentinels
95 		 * for kernel stack tracing.
96 		 * */
97 		if (pc + OFFSET == (uintptr_t) &trapexit ||
98 		    pc + OFFSET == (uintptr_t) &asttrapexit)
99 			break;
100 
101 		cc[frames] = pc;
102 		osp = sp;
103 		sp = (uintptr_t *)*sp;
104 	}
105 	return (frames);
106 }
107 
108 static int
109 powerpc_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
110 {
111 
112 	return (0);
113 }
114 
115 static int
116 powerpc_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
117 {
118 
119 	return (0);
120 }
121 
122 int
123 powerpc_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
124 {
125 	int error;
126 	struct pmc_hw *phw;
127 	char powerpc_name[PMC_NAME_MAX];
128 
129 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
130 	    ("[powerpc,%d], illegal CPU %d", __LINE__, cpu));
131 
132 	phw = &powerpc_pcpu[cpu]->pc_ppcpmcs[ri];
133 	snprintf(powerpc_name, sizeof(powerpc_name), "POWERPC-%d", ri);
134 	if ((error = copystr(powerpc_name, pi->pm_name, PMC_NAME_MAX,
135 	    NULL)) != 0)
136 		return error;
137 	pi->pm_class = powerpc_pcpu[cpu]->pc_class;
138 	if (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) {
139 		pi->pm_enabled = TRUE;
140 		*ppmc          = phw->phw_pmc;
141 	} else {
142 		pi->pm_enabled = FALSE;
143 		*ppmc	       = NULL;
144 	}
145 
146 	return (0);
147 }
148 
149 int
150 powerpc_get_config(int cpu, int ri, struct pmc **ppm)
151 {
152 
153 	*ppm = powerpc_pcpu[cpu]->pc_ppcpmcs[ri].phw_pmc;
154 
155 	return (0);
156 }
157 
158 int
159 powerpc_pcpu_init(struct pmc_mdep *md, int cpu)
160 {
161 	struct pmc_cpu *pc;
162 	struct powerpc_cpu *pac;
163 	struct pmc_hw  *phw;
164 	int first_ri, i;
165 
166 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
167 	    ("[powerpc,%d] wrong cpu number %d", __LINE__, cpu));
168 	PMCDBG1(MDP,INI,1,"powerpc-init cpu=%d", cpu);
169 
170 	powerpc_pcpu[cpu] = pac = malloc(sizeof(struct powerpc_cpu) +
171 	    ppc_max_pmcs * sizeof(struct pmc_hw), M_PMC, M_WAITOK | M_ZERO);
172 	pac->pc_class =
173 	    md->pmd_classdep[PMC_MDEP_CLASS_INDEX_POWERPC].pcd_class;
174 
175 	pc = pmc_pcpu[cpu];
176 	first_ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_POWERPC].pcd_ri;
177 	KASSERT(pc != NULL, ("[powerpc,%d] NULL per-cpu pointer", __LINE__));
178 
179 	for (i = 0, phw = pac->pc_ppcpmcs; i < ppc_max_pmcs; i++, phw++) {
180 		phw->phw_state = PMC_PHW_FLAG_IS_ENABLED |
181 		    PMC_PHW_CPU_TO_STATE(cpu) | PMC_PHW_INDEX_TO_STATE(i);
182 		phw->phw_pmc = NULL;
183 		pc->pc_hwpmcs[i + first_ri] = phw;
184 	}
185 
186 	return (0);
187 }
188 
189 int
190 powerpc_pcpu_fini(struct pmc_mdep *md, int cpu)
191 {
192 	PMCDBG1(MDP,INI,1,"powerpc-fini cpu=%d", cpu);
193 
194 	free(powerpc_pcpu[cpu], M_PMC);
195 	powerpc_pcpu[cpu] = NULL;
196 
197 	return (0);
198 }
199 
200 int
201 powerpc_allocate_pmc(int cpu, int ri, struct pmc *pm,
202     const struct pmc_op_pmcallocate *a)
203 {
204 	enum pmc_event pe;
205 	uint32_t caps, config = 0, counter = 0;
206 	int i;
207 
208 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
209 	    ("[powerpc,%d] illegal CPU value %d", __LINE__, cpu));
210 	KASSERT(ri >= 0 && ri < ppc_max_pmcs,
211 	    ("[powerpc,%d] illegal row index %d", __LINE__, ri));
212 
213 	if (a->pm_class != ppc_class)
214 		return (EINVAL);
215 
216 	caps = a->pm_caps;
217 
218 	pe = a->pm_ev;
219 
220 	if (pe < ppc_event_first || pe > ppc_event_last)
221 		return (EINVAL);
222 
223 	for (i = 0; i < ppc_event_codes_size; i++) {
224 		if (ppc_event_codes[i].pe_event == pe) {
225 			config = ppc_event_codes[i].pe_code;
226 			counter =  ppc_event_codes[i].pe_flags;
227 			break;
228 		}
229 	}
230 	if (i == ppc_event_codes_size)
231 		return (EINVAL);
232 
233 	if ((counter & (1 << ri)) == 0)
234 		return (EINVAL);
235 
236 	if (caps & PMC_CAP_SYSTEM)
237 		config |= POWERPC_PMC_KERNEL_ENABLE;
238 	if (caps & PMC_CAP_USER)
239 		config |= POWERPC_PMC_USER_ENABLE;
240 	if ((caps & (PMC_CAP_USER | PMC_CAP_SYSTEM)) == 0)
241 		config |= POWERPC_PMC_ENABLE;
242 
243 	pm->pm_md.pm_powerpc.pm_powerpc_evsel = config;
244 
245 	PMCDBG3(MDP,ALL,1,"powerpc-allocate cpu=%d ri=%d -> config=0x%x",
246 	    cpu, ri, config);
247 	return (0);
248 }
249 
250 int
251 powerpc_release_pmc(int cpu, int ri, struct pmc *pmc)
252 {
253 	struct pmc_hw *phw __diagused;
254 
255 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
256 	    ("[powerpc,%d] illegal CPU value %d", __LINE__, cpu));
257 	KASSERT(ri >= 0 && ri < ppc_max_pmcs,
258 	    ("[powerpc,%d] illegal row-index %d", __LINE__, ri));
259 
260 	phw = &powerpc_pcpu[cpu]->pc_ppcpmcs[ri];
261 	KASSERT(phw->phw_pmc == NULL,
262 	    ("[powerpc,%d] PHW pmc %p non-NULL", __LINE__, phw->phw_pmc));
263 
264 	return (0);
265 }
266 
267 int
268 powerpc_start_pmc(int cpu, int ri)
269 {
270 	struct pmc *pm;
271 
272 	PMCDBG2(MDP,STA,1,"powerpc-start cpu=%d ri=%d", cpu, ri);
273 	pm = powerpc_pcpu[cpu]->pc_ppcpmcs[ri].phw_pmc;
274 	powerpc_set_pmc(cpu, ri, pm->pm_md.pm_powerpc.pm_powerpc_evsel);
275 
276 	return (0);
277 }
278 
279 int
280 powerpc_stop_pmc(int cpu, int ri)
281 {
282 	PMCDBG2(MDP,STO,1, "powerpc-stop cpu=%d ri=%d", cpu, ri);
283 	powerpc_set_pmc(cpu, ri, PMCN_NONE);
284 	return (0);
285 }
286 
287 int
288 powerpc_config_pmc(int cpu, int ri, struct pmc *pm)
289 {
290 	struct pmc_hw *phw;
291 
292 	PMCDBG3(MDP,CFG,1, "powerpc-config cpu=%d ri=%d pm=%p", cpu, ri, pm);
293 
294 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
295 	    ("[powerpc,%d] illegal CPU value %d", __LINE__, cpu));
296 	KASSERT(ri >= 0 && ri < ppc_max_pmcs,
297 	    ("[powerpc,%d] illegal row-index %d", __LINE__, ri));
298 
299 	phw = &powerpc_pcpu[cpu]->pc_ppcpmcs[ri];
300 
301 	KASSERT(pm == NULL || phw->phw_pmc == NULL,
302 	    ("[powerpc,%d] pm=%p phw->pm=%p hwpmc not unconfigured",
303 	    __LINE__, pm, phw->phw_pmc));
304 
305 	phw->phw_pmc = pm;
306 
307 	return (0);
308 }
309 
310 pmc_value_t
311 powerpc_pmcn_read_default(unsigned int pmc)
312 {
313 	pmc_value_t val;
314 
315 	if (pmc > ppc_max_pmcs)
316 		panic("Invalid PMC number: %d\n", pmc);
317 
318 	switch (pmc) {
319 	case 0:
320 		val = mfspr(SPR_PMC1);
321 		break;
322 	case 1:
323 		val = mfspr(SPR_PMC2);
324 		break;
325 	case 2:
326 		val = mfspr(SPR_PMC3);
327 		break;
328 	case 3:
329 		val = mfspr(SPR_PMC4);
330 		break;
331 	case 4:
332 		val = mfspr(SPR_PMC5);
333 		break;
334 	case 5:
335 		val = mfspr(SPR_PMC6);
336 		break;
337 	case 6:
338 		val = mfspr(SPR_PMC7);
339 		break;
340 	case 7:
341 		val = mfspr(SPR_PMC8);
342 		break;
343 	}
344 
345 	return (val);
346 }
347 
348 void
349 powerpc_pmcn_write_default(unsigned int pmc, uint32_t val)
350 {
351 	if (pmc > ppc_max_pmcs)
352 		panic("Invalid PMC number: %d\n", pmc);
353 
354 	switch (pmc) {
355 	case 0:
356 		mtspr(SPR_PMC1, val);
357 		break;
358 	case 1:
359 		mtspr(SPR_PMC2, val);
360 		break;
361 	case 2:
362 		mtspr(SPR_PMC3, val);
363 		break;
364 	case 3:
365 		mtspr(SPR_PMC4, val);
366 		break;
367 	case 4:
368 		mtspr(SPR_PMC5, val);
369 		break;
370 	case 5:
371 		mtspr(SPR_PMC6, val);
372 		break;
373 	case 6:
374 		mtspr(SPR_PMC7, val);
375 		break;
376 	case 7:
377 		mtspr(SPR_PMC8, val);
378 		break;
379 	}
380 }
381 
382 int
383 powerpc_read_pmc(int cpu, int ri, pmc_value_t *v)
384 {
385 	struct pmc *pm;
386 	pmc_value_t p, r, tmp;
387 
388 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
389 	    ("[powerpc,%d] illegal CPU value %d", __LINE__, cpu));
390 	KASSERT(ri >= 0 && ri < ppc_max_pmcs,
391 	    ("[powerpc,%d] illegal row index %d", __LINE__, ri));
392 
393 	pm  = powerpc_pcpu[cpu]->pc_ppcpmcs[ri].phw_pmc;
394 	KASSERT(pm,
395 	    ("[core,%d] cpu %d ri %d pmc not configured", __LINE__, cpu,
396 		ri));
397 
398 	/*
399 	 * After an interrupt occurs because of a PMC overflow, the PMC value
400 	 * is not always MAX_PMC_VALUE + 1, but may be a little above it.
401 	 * This may mess up calculations and frustrate machine independent
402 	 * layer expectations, such as that no value read should be greater
403 	 * than reload count in sampling mode.
404 	 * To avoid these issues, use MAX_PMC_VALUE as an upper limit.
405 	 */
406 	p = MIN(powerpc_pmcn_read(ri), POWERPC_MAX_PMC_VALUE);
407 	r = pm->pm_sc.pm_reloadcount;
408 
409 	if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
410 		/*
411 		 * Special case 1: r is too big
412 		 * This usually happens when a PMC write fails, the PMC is
413 		 * stopped and then it is read.
414 		 *
415 		 * Special case 2: PMC was reseted or has a value
416 		 * that should not be possible with current r.
417 		 *
418 		 * In the above cases, just return 0 instead of an arbitrary
419 		 * value.
420 		 */
421 		if (r > POWERPC_MAX_PMC_VALUE || p + r <= POWERPC_MAX_PMC_VALUE)
422 			tmp = 0;
423 		else
424 			tmp = POWERPC_PERFCTR_VALUE_TO_RELOAD_COUNT(p);
425 	} else
426 		tmp = p + (POWERPC_MAX_PMC_VALUE + 1) * PPC_OVERFLOWCNT(pm);
427 
428 	PMCDBG5(MDP,REA,1,"ppc-read cpu=%d ri=%d -> %jx (%jx,%jx)",
429 	    cpu, ri, (uintmax_t)tmp, (uintmax_t)PPC_OVERFLOWCNT(pm),
430 	    (uintmax_t)p);
431 	*v = tmp;
432 	return (0);
433 }
434 
435 int
436 powerpc_write_pmc(int cpu, int ri, pmc_value_t v)
437 {
438 	struct pmc *pm;
439 	pmc_value_t vlo;
440 
441 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
442 	    ("[powerpc,%d] illegal CPU value %d", __LINE__, cpu));
443 	KASSERT(ri >= 0 && ri < ppc_max_pmcs,
444 	    ("[powerpc,%d] illegal row-index %d", __LINE__, ri));
445 
446 	pm = powerpc_pcpu[cpu]->pc_ppcpmcs[ri].phw_pmc;
447 
448 	if (PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm))) {
449 		PPC_OVERFLOWCNT(pm) = v / (POWERPC_MAX_PMC_VALUE + 1);
450 		vlo = v % (POWERPC_MAX_PMC_VALUE + 1);
451 	} else if (v > POWERPC_MAX_PMC_VALUE) {
452 		PMCDBG3(MDP,WRI,2,
453 		    "powerpc-write cpu=%d ri=%d: PMC value is too big: %jx",
454 		    cpu, ri, (uintmax_t)v);
455 		return (EINVAL);
456 	} else
457 		vlo = POWERPC_RELOAD_COUNT_TO_PERFCTR_VALUE(v);
458 
459 	PMCDBG5(MDP,WRI,1,"powerpc-write cpu=%d ri=%d -> %jx (%jx,%jx)",
460 	    cpu, ri, (uintmax_t)v, (uintmax_t)PPC_OVERFLOWCNT(pm),
461 	    (uintmax_t)vlo);
462 
463 	powerpc_pmcn_write(ri, vlo);
464 	return (0);
465 }
466 
467 int
468 powerpc_pmc_intr(struct trapframe *tf)
469 {
470 	struct pmc *pm;
471 	struct powerpc_cpu *pc;
472 	int cpu, error, i, retval;
473 
474 	cpu = curcpu;
475 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
476 	    ("[powerpc,%d] out of range CPU %d", __LINE__, cpu));
477 
478 	PMCDBG3(MDP,INT,1, "cpu=%d tf=%p um=%d", cpu, (void *) tf,
479 	    TRAPF_USERMODE(tf));
480 
481 	retval = 0;
482 	pc = powerpc_pcpu[cpu];
483 
484 	/*
485 	 * Look for a running, sampling PMC which has overflowed
486 	 * and which has a valid 'struct pmc' association.
487 	 */
488 	for (i = 0; i < ppc_max_pmcs; i++) {
489 		if (!POWERPC_PMC_HAS_OVERFLOWED(i))
490 			continue;
491 		retval = 1;	/* Found an interrupting PMC. */
492 
493 		/*
494 		 * Always clear the PMC, to make it stop interrupting.
495 		 * If pm is available and in sampling mode, use reload
496 		 * count, to make PMC read after stop correct.
497 		 * Otherwise, just reset the PMC.
498 		 */
499 		if ((pm = pc->pc_ppcpmcs[i].phw_pmc) != NULL &&
500 		    PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
501 			if (pm->pm_state != PMC_STATE_RUNNING) {
502 				powerpc_write_pmc(cpu, i,
503 				    pm->pm_sc.pm_reloadcount);
504 				continue;
505 			}
506 		} else {
507 			if (pm != NULL) { /* !PMC_IS_SAMPLING_MODE */
508 				PPC_OVERFLOWCNT(pm) = (PPC_OVERFLOWCNT(pm) +
509 				    1) % PPC_OVERFLOWCNT_MAX;
510 				PMCDBG3(MDP,INT,2,
511 				    "cpu=%d ri=%d: overflowcnt=%d",
512 				    cpu, i, PPC_OVERFLOWCNT(pm));
513 			}
514 
515 			powerpc_pmcn_write(i, 0);
516 			continue;
517 		}
518 
519 		error = pmc_process_interrupt(PMC_HR, pm, tf);
520 		if (error != 0) {
521 			PMCDBG3(MDP,INT,3,
522 			    "cpu=%d ri=%d: error %d processing interrupt",
523 			    cpu, i, error);
524 			powerpc_stop_pmc(cpu, i);
525 		}
526 
527 		/* Reload sampling count */
528 		powerpc_write_pmc(cpu, i, pm->pm_sc.pm_reloadcount);
529 	}
530 
531 	if (retval)
532 		counter_u64_add(pmc_stats.pm_intr_processed, 1);
533 	else
534 		counter_u64_add(pmc_stats.pm_intr_ignored, 1);
535 
536 	/*
537 	 * Re-enable PERF exceptions if we were able to find the interrupt
538 	 * source and handle it. Otherwise, it's better to disable PERF
539 	 * interrupts, to avoid the risk of processing the same interrupt
540 	 * forever.
541 	 */
542 	powerpc_resume_pmc(retval != 0);
543 	if (retval == 0)
544 		log(LOG_WARNING,
545 		    "pmc_intr: couldn't find interrupting PMC on cpu %d - "
546 		    "disabling PERF interrupts\n", cpu);
547 
548 	return (retval);
549 }
550 
551 struct pmc_mdep *
552 pmc_md_initialize(void)
553 {
554 	struct pmc_mdep *pmc_mdep;
555 	int error;
556 	uint16_t vers;
557 
558 	/*
559 	 * Allocate space for pointers to PMC HW descriptors and for
560 	 * the MDEP structure used by MI code.
561 	 */
562 	powerpc_pcpu = malloc(sizeof(struct powerpc_cpu *) * pmc_cpu_max(), M_PMC,
563 			   M_WAITOK|M_ZERO);
564 
565 	/* Just one class */
566 	pmc_mdep = pmc_mdep_alloc(1);
567 
568 	vers = mfpvr() >> 16;
569 
570 	pmc_mdep->pmd_switch_in  = powerpc_switch_in;
571 	pmc_mdep->pmd_switch_out = powerpc_switch_out;
572 
573 	switch (vers) {
574 	case MPC7447A:
575 	case MPC7448:
576 	case MPC7450:
577 	case MPC7455:
578 	case MPC7457:
579 		error = pmc_mpc7xxx_initialize(pmc_mdep);
580 		break;
581 	case IBM970:
582 	case IBM970FX:
583 	case IBM970MP:
584 		error = pmc_ppc970_initialize(pmc_mdep);
585 		break;
586 	case IBMPOWER8E:
587 	case IBMPOWER8NVL:
588 	case IBMPOWER8:
589 	case IBMPOWER9:
590 		error = pmc_power8_initialize(pmc_mdep);
591 		break;
592 	case FSL_E500v1:
593 	case FSL_E500v2:
594 	case FSL_E500mc:
595 	case FSL_E5500:
596 		error = pmc_e500_initialize(pmc_mdep);
597 		break;
598 	default:
599 		error = -1;
600 		break;
601 	}
602 
603 	if (error != 0) {
604 		pmc_mdep_free(pmc_mdep);
605 		pmc_mdep = NULL;
606 	}
607 
608 	/* Set the value for kern.hwpmc.cpuid */
609 	snprintf(pmc_cpuid, sizeof(pmc_cpuid), "%08x", mfpvr());
610 
611 	return (pmc_mdep);
612 }
613 
614 void
615 pmc_md_finalize(struct pmc_mdep *md)
616 {
617 
618 	free(powerpc_pcpu, M_PMC);
619 	powerpc_pcpu = NULL;
620 }
621 
622 int
623 pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
624     struct trapframe *tf)
625 {
626 	uintptr_t *osp, *sp;
627 	int frames = 0;
628 
629 	cc[frames++] = PMC_TRAPFRAME_TO_PC(tf);
630 	sp = (uintptr_t *)PMC_TRAPFRAME_TO_FP(tf);
631 	osp = NULL;
632 
633 	for (; frames < maxsamples; frames++) {
634 		if (sp <= osp)
635 			break;
636 		osp = sp;
637 #ifdef __powerpc64__
638 		/* Check if 32-bit mode. */
639 		if (!(tf->srr1 & PSL_SF)) {
640 			cc[frames] = fuword32((uint32_t *)sp + 1);
641 			sp = (uintptr_t *)(uintptr_t)fuword32(sp);
642 		} else {
643 			cc[frames] = fuword(sp + 2);
644 			sp = (uintptr_t *)fuword(sp);
645 		}
646 #else
647 		cc[frames] = fuword32((uint32_t *)sp + 1);
648 		sp = (uintptr_t *)fuword32(sp);
649 #endif
650 	}
651 
652 	return (frames);
653 }
654