xref: /freebsd/sys/dev/hwpmc/hwpmc_tsc.c (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008 Joseph Koshy
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/pmc.h>
34 #include <sys/pmckern.h>
35 #include <sys/systm.h>
36 
37 #include <machine/specialreg.h>
38 
39 /*
40  * TSC support.
41  */
42 
43 #define	TSC_CAPS	PMC_CAP_READ
44 
45 struct tsc_descr {
46 	struct pmc_descr pm_descr;  /* "base class" */
47 };
48 
49 static struct tsc_descr tsc_pmcdesc[TSC_NPMCS] =
50 {
51     {
52 	.pm_descr =
53 	{
54 		.pd_name  = "TSC",
55 		.pd_class = PMC_CLASS_TSC,
56 		.pd_caps  = TSC_CAPS,
57 		.pd_width = 64
58 	}
59     }
60 };
61 
62 /*
63  * Per-CPU data structure for TSCs.
64  */
65 
66 struct tsc_cpu {
67 	struct pmc_hw	tc_hw;
68 };
69 
70 static struct tsc_cpu **tsc_pcpu;
71 
72 static int
73 tsc_allocate_pmc(int cpu, int ri, struct pmc *pm,
74     const struct pmc_op_pmcallocate *a)
75 {
76 	(void) cpu;
77 
78 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
79 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
80 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
81 	    ("[tsc,%d] illegal row index %d", __LINE__, ri));
82 
83 	if (a->pm_class != PMC_CLASS_TSC)
84 		return (EINVAL);
85 
86 	if ((pm->pm_caps & TSC_CAPS) == 0)
87 		return (EINVAL);
88 
89 	if ((pm->pm_caps & ~TSC_CAPS) != 0)
90 		return (EPERM);
91 
92 	if (a->pm_ev != PMC_EV_TSC_TSC ||
93 	    a->pm_mode != PMC_MODE_SC)
94 		return (EINVAL);
95 
96 	return (0);
97 }
98 
99 static int
100 tsc_config_pmc(int cpu, int ri, struct pmc *pm)
101 {
102 	struct pmc_hw *phw;
103 
104 	PMCDBG3(MDP,CFG,1, "cpu=%d ri=%d pm=%p", cpu, ri, pm);
105 
106 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
107 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
108 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
109 
110 	phw = &tsc_pcpu[cpu]->tc_hw;
111 
112 	KASSERT(pm == NULL || phw->phw_pmc == NULL,
113 	    ("[tsc,%d] pm=%p phw->pm=%p hwpmc not unconfigured", __LINE__,
114 	    pm, phw->phw_pmc));
115 
116 	phw->phw_pmc = pm;
117 
118 	return (0);
119 }
120 
121 static int
122 tsc_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
123 {
124 	int error;
125 	size_t copied;
126 	const struct tsc_descr *pd;
127 	struct pmc_hw *phw;
128 
129 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
130 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
131 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
132 
133 	phw = &tsc_pcpu[cpu]->tc_hw;
134 	pd  = &tsc_pmcdesc[ri];
135 
136 	if ((error = copystr(pd->pm_descr.pd_name, pi->pm_name,
137 	    PMC_NAME_MAX, &copied)) != 0)
138 		return (error);
139 
140 	pi->pm_class = pd->pm_descr.pd_class;
141 
142 	if (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) {
143 		pi->pm_enabled = TRUE;
144 		*ppmc          = phw->phw_pmc;
145 	} else {
146 		pi->pm_enabled = FALSE;
147 		*ppmc          = NULL;
148 	}
149 
150 	return (0);
151 }
152 
153 static int
154 tsc_get_config(int cpu, int ri, struct pmc **ppm)
155 {
156 	(void) ri;
157 
158 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
159 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
160 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
161 
162 	*ppm = tsc_pcpu[cpu]->tc_hw.phw_pmc;
163 
164 	return (0);
165 }
166 
167 static int
168 tsc_get_msr(int ri, uint32_t *msr)
169 {
170 	(void) ri;
171 
172 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
173 	    ("[tsc,%d] ri %d out of range", __LINE__, ri));
174 
175 	*msr = MSR_TSC;
176 
177 	return (0);
178 }
179 
180 static int
181 tsc_pcpu_fini(struct pmc_mdep *md, int cpu)
182 {
183 	int ri;
184 	struct pmc_cpu *pc;
185 
186 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
187 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
188 	KASSERT(tsc_pcpu[cpu] != NULL, ("[tsc,%d] null pcpu", __LINE__));
189 
190 	free(tsc_pcpu[cpu], M_PMC);
191 	tsc_pcpu[cpu] = NULL;
192 
193 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
194 
195 	pc = pmc_pcpu[cpu];
196 	pc->pc_hwpmcs[ri] = NULL;
197 
198 	return (0);
199 }
200 
201 static int
202 tsc_pcpu_init(struct pmc_mdep *md, int cpu)
203 {
204 	int ri;
205 	struct pmc_cpu *pc;
206 	struct tsc_cpu *tsc_pc;
207 
208 
209 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
210 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
211 	KASSERT(tsc_pcpu, ("[tsc,%d] null pcpu", __LINE__));
212 	KASSERT(tsc_pcpu[cpu] == NULL, ("[tsc,%d] non-null per-cpu",
213 	    __LINE__));
214 
215 	tsc_pc = malloc(sizeof(struct tsc_cpu), M_PMC, M_WAITOK|M_ZERO);
216 
217 	tsc_pc->tc_hw.phw_state = PMC_PHW_FLAG_IS_ENABLED |
218 	    PMC_PHW_CPU_TO_STATE(cpu) | PMC_PHW_INDEX_TO_STATE(0) |
219 	    PMC_PHW_FLAG_IS_SHAREABLE;
220 
221 	tsc_pcpu[cpu] = tsc_pc;
222 
223 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
224 
225 	KASSERT(pmc_pcpu, ("[tsc,%d] null generic pcpu", __LINE__));
226 
227 	pc = pmc_pcpu[cpu];
228 
229 	KASSERT(pc, ("[tsc,%d] null generic per-cpu", __LINE__));
230 
231 	pc->pc_hwpmcs[ri] = &tsc_pc->tc_hw;
232 
233 	return (0);
234 }
235 
236 static int
237 tsc_read_pmc(int cpu, int ri, pmc_value_t *v)
238 {
239 	struct pmc *pm;
240 	enum pmc_mode mode;
241 	const struct pmc_hw *phw;
242 
243 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
244 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
245 	KASSERT(ri == 0, ("[tsc,%d] illegal ri %d", __LINE__, ri));
246 
247 	phw = &tsc_pcpu[cpu]->tc_hw;
248 	pm  = phw->phw_pmc;
249 
250 	KASSERT(pm != NULL,
251 	    ("[tsc,%d] no owner for PHW [cpu%d,pmc%d]", __LINE__, cpu, ri));
252 
253 	mode = PMC_TO_MODE(pm);
254 
255 	KASSERT(mode == PMC_MODE_SC,
256 	    ("[tsc,%d] illegal pmc mode %d", __LINE__, mode));
257 
258 	PMCDBG1(MDP,REA,1,"tsc-read id=%d", ri);
259 
260 	*v = rdtsc();
261 
262 	return (0);
263 }
264 
265 static int
266 tsc_release_pmc(int cpu, int ri, struct pmc *pmc)
267 {
268 	struct pmc_hw *phw;
269 
270 	(void) pmc;
271 
272 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
273 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
274 	KASSERT(ri == 0,
275 	    ("[tsc,%d] illegal row-index %d", __LINE__, ri));
276 
277 	phw = &tsc_pcpu[cpu]->tc_hw;
278 
279 	KASSERT(phw->phw_pmc == NULL,
280 	    ("[tsc,%d] PHW pmc %p non-NULL", __LINE__, phw->phw_pmc));
281 
282 	/*
283 	 * Nothing to do.
284 	 */
285 	return (0);
286 }
287 
288 static int
289 tsc_start_pmc(int cpu, int ri)
290 {
291 	(void) cpu;
292 
293 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
294 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
295 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
296 
297 	return (0);	/* TSCs are always running. */
298 }
299 
300 static int
301 tsc_stop_pmc(int cpu, int ri)
302 {
303 	(void) cpu; (void) ri;
304 
305 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
306 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
307 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
308 
309 	return (0);	/* Cannot actually stop a TSC. */
310 }
311 
312 static int
313 tsc_write_pmc(int cpu, int ri, pmc_value_t v)
314 {
315 	(void) cpu; (void) ri; (void) v;
316 
317 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
318 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
319 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
320 
321 	/*
322 	 * The TSCs are used as timecounters by the kernel, so even
323 	 * though some i386 CPUs support writeable TSCs, we don't
324 	 * support writing changing TSC values through the HWPMC API.
325 	 */
326 	return (0);
327 }
328 
329 int
330 pmc_tsc_initialize(struct pmc_mdep *md, int maxcpu)
331 {
332 	struct pmc_classdep *pcd;
333 
334 	KASSERT(md != NULL, ("[tsc,%d] md is NULL", __LINE__));
335 	KASSERT(md->pmd_nclass >= 1, ("[tsc,%d] dubious md->nclass %d",
336 	    __LINE__, md->pmd_nclass));
337 
338 	tsc_pcpu = malloc(sizeof(struct tsc_cpu *) * maxcpu, M_PMC,
339 	    M_ZERO|M_WAITOK);
340 
341 	pcd = &md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC];
342 
343 	pcd->pcd_caps	= PMC_CAP_READ;
344 	pcd->pcd_class	= PMC_CLASS_TSC;
345 	pcd->pcd_num	= TSC_NPMCS;
346 	pcd->pcd_ri	= md->pmd_npmc;
347 	pcd->pcd_width	= 64;
348 
349 	pcd->pcd_allocate_pmc = tsc_allocate_pmc;
350 	pcd->pcd_config_pmc   = tsc_config_pmc;
351 	pcd->pcd_describe     = tsc_describe;
352 	pcd->pcd_get_config   = tsc_get_config;
353 	pcd->pcd_get_msr      = tsc_get_msr;
354 	pcd->pcd_pcpu_init    = tsc_pcpu_init;
355 	pcd->pcd_pcpu_fini    = tsc_pcpu_fini;
356 	pcd->pcd_read_pmc     = tsc_read_pmc;
357 	pcd->pcd_release_pmc  = tsc_release_pmc;
358 	pcd->pcd_start_pmc    = tsc_start_pmc;
359 	pcd->pcd_stop_pmc     = tsc_stop_pmc;
360 	pcd->pcd_write_pmc    = tsc_write_pmc;
361 
362 	md->pmd_npmc += TSC_NPMCS;
363 
364 	return (0);
365 }
366 
367 void
368 pmc_tsc_finalize(struct pmc_mdep *md)
369 {
370 #ifdef	INVARIANTS
371 	int i, ncpus;
372 
373 	ncpus = pmc_cpu_max();
374 	for (i = 0; i < ncpus; i++)
375 		KASSERT(tsc_pcpu[i] == NULL, ("[tsc,%d] non-null pcpu cpu %d",
376 		    __LINE__, i));
377 
378 	KASSERT(md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_class ==
379 	    PMC_CLASS_TSC, ("[tsc,%d] class mismatch", __LINE__));
380 
381 #else
382 	(void) md;
383 #endif
384 
385 	free(tsc_pcpu, M_PMC);
386 	tsc_pcpu = NULL;
387 }
388