xref: /freebsd/sys/dev/hwpmc/hwpmc_tsc.c (revision 640235e2c2ba32947f7c59d168437ffa1280f1e6)
1 /*-
2  * Copyright (c) 2008 Joseph Koshy
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 #include <sys/param.h>
31 #include <sys/pmc.h>
32 #include <sys/pmckern.h>
33 #include <sys/systm.h>
34 
35 #include <machine/specialreg.h>
36 
37 /*
38  * TSC support.
39  */
40 
41 #define	TSC_CAPS	PMC_CAP_READ
42 
43 struct tsc_descr {
44 	struct pmc_descr pm_descr;  /* "base class" */
45 };
46 
47 static struct tsc_descr tsc_pmcdesc[TSC_NPMCS] =
48 {
49     {
50 	.pm_descr =
51 	{
52 		.pd_name  = "TSC",
53 		.pd_class = PMC_CLASS_TSC,
54 		.pd_caps  = TSC_CAPS,
55 		.pd_width = 64
56 	}
57     }
58 };
59 
60 /*
61  * Per-CPU data structure for TSCs.
62  */
63 
64 struct tsc_cpu {
65 	struct pmc_hw	tc_hw;
66 };
67 
68 static struct tsc_cpu **tsc_pcpu;
69 
70 static int
71 tsc_allocate_pmc(int cpu, int ri, struct pmc *pm,
72     const struct pmc_op_pmcallocate *a)
73 {
74 	(void) cpu;
75 
76 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
77 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
78 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
79 	    ("[tsc,%d] illegal row index %d", __LINE__, ri));
80 
81 	if (a->pm_class != PMC_CLASS_TSC)
82 		return (EINVAL);
83 
84 	if ((pm->pm_caps & TSC_CAPS) == 0)
85 		return (EINVAL);
86 
87 	if ((pm->pm_caps & ~TSC_CAPS) != 0)
88 		return (EPERM);
89 
90 	if (a->pm_ev != PMC_EV_TSC_TSC ||
91 	    a->pm_mode != PMC_MODE_SC)
92 		return (EINVAL);
93 
94 	return (0);
95 }
96 
97 static int
98 tsc_config_pmc(int cpu, int ri, struct pmc *pm)
99 {
100 	struct pmc_hw *phw;
101 
102 	PMCDBG3(MDP,CFG,1, "cpu=%d ri=%d pm=%p", cpu, ri, pm);
103 
104 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
105 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
106 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
107 
108 	phw = &tsc_pcpu[cpu]->tc_hw;
109 
110 	KASSERT(pm == NULL || phw->phw_pmc == NULL,
111 	    ("[tsc,%d] pm=%p phw->pm=%p hwpmc not unconfigured", __LINE__,
112 	    pm, phw->phw_pmc));
113 
114 	phw->phw_pmc = pm;
115 
116 	return (0);
117 }
118 
119 static int
120 tsc_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
121 {
122 	int error;
123 	size_t copied;
124 	const struct tsc_descr *pd;
125 	struct pmc_hw *phw;
126 
127 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
128 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
129 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
130 
131 	phw = &tsc_pcpu[cpu]->tc_hw;
132 	pd  = &tsc_pmcdesc[ri];
133 
134 	if ((error = copystr(pd->pm_descr.pd_name, pi->pm_name,
135 	    PMC_NAME_MAX, &copied)) != 0)
136 		return (error);
137 
138 	pi->pm_class = pd->pm_descr.pd_class;
139 
140 	if (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) {
141 		pi->pm_enabled = TRUE;
142 		*ppmc          = phw->phw_pmc;
143 	} else {
144 		pi->pm_enabled = FALSE;
145 		*ppmc          = NULL;
146 	}
147 
148 	return (0);
149 }
150 
151 static int
152 tsc_get_config(int cpu, int ri, struct pmc **ppm)
153 {
154 	(void) ri;
155 
156 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
157 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
158 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
159 
160 	*ppm = tsc_pcpu[cpu]->tc_hw.phw_pmc;
161 
162 	return (0);
163 }
164 
165 static int
166 tsc_get_msr(int ri, uint32_t *msr)
167 {
168 	(void) ri;
169 
170 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
171 	    ("[tsc,%d] ri %d out of range", __LINE__, ri));
172 
173 	*msr = MSR_TSC;
174 
175 	return (0);
176 }
177 
178 static int
179 tsc_pcpu_fini(struct pmc_mdep *md, int cpu)
180 {
181 	int ri;
182 	struct pmc_cpu *pc;
183 
184 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
185 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
186 	KASSERT(tsc_pcpu[cpu] != NULL, ("[tsc,%d] null pcpu", __LINE__));
187 
188 	free(tsc_pcpu[cpu], M_PMC);
189 	tsc_pcpu[cpu] = NULL;
190 
191 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
192 
193 	pc = pmc_pcpu[cpu];
194 	pc->pc_hwpmcs[ri] = NULL;
195 
196 	return (0);
197 }
198 
199 static int
200 tsc_pcpu_init(struct pmc_mdep *md, int cpu)
201 {
202 	int ri;
203 	struct pmc_cpu *pc;
204 	struct tsc_cpu *tsc_pc;
205 
206 
207 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
208 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
209 	KASSERT(tsc_pcpu, ("[tsc,%d] null pcpu", __LINE__));
210 	KASSERT(tsc_pcpu[cpu] == NULL, ("[tsc,%d] non-null per-cpu",
211 	    __LINE__));
212 
213 	tsc_pc = malloc(sizeof(struct tsc_cpu), M_PMC, M_WAITOK|M_ZERO);
214 
215 	tsc_pc->tc_hw.phw_state = PMC_PHW_FLAG_IS_ENABLED |
216 	    PMC_PHW_CPU_TO_STATE(cpu) | PMC_PHW_INDEX_TO_STATE(0) |
217 	    PMC_PHW_FLAG_IS_SHAREABLE;
218 
219 	tsc_pcpu[cpu] = tsc_pc;
220 
221 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
222 
223 	KASSERT(pmc_pcpu, ("[tsc,%d] null generic pcpu", __LINE__));
224 
225 	pc = pmc_pcpu[cpu];
226 
227 	KASSERT(pc, ("[tsc,%d] null generic per-cpu", __LINE__));
228 
229 	pc->pc_hwpmcs[ri] = &tsc_pc->tc_hw;
230 
231 	return (0);
232 }
233 
234 static int
235 tsc_read_pmc(int cpu, int ri, pmc_value_t *v)
236 {
237 	struct pmc *pm;
238 	enum pmc_mode mode;
239 	const struct pmc_hw *phw;
240 
241 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
242 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
243 	KASSERT(ri == 0, ("[tsc,%d] illegal ri %d", __LINE__, ri));
244 
245 	phw = &tsc_pcpu[cpu]->tc_hw;
246 	pm  = phw->phw_pmc;
247 
248 	KASSERT(pm != NULL,
249 	    ("[tsc,%d] no owner for PHW [cpu%d,pmc%d]", __LINE__, cpu, ri));
250 
251 	mode = PMC_TO_MODE(pm);
252 
253 	KASSERT(mode == PMC_MODE_SC,
254 	    ("[tsc,%d] illegal pmc mode %d", __LINE__, mode));
255 
256 	PMCDBG1(MDP,REA,1,"tsc-read id=%d", ri);
257 
258 	*v = rdtsc();
259 
260 	return (0);
261 }
262 
263 static int
264 tsc_release_pmc(int cpu, int ri, struct pmc *pmc)
265 {
266 	struct pmc_hw *phw;
267 
268 	(void) pmc;
269 
270 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
271 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
272 	KASSERT(ri == 0,
273 	    ("[tsc,%d] illegal row-index %d", __LINE__, ri));
274 
275 	phw = &tsc_pcpu[cpu]->tc_hw;
276 
277 	KASSERT(phw->phw_pmc == NULL,
278 	    ("[tsc,%d] PHW pmc %p non-NULL", __LINE__, phw->phw_pmc));
279 
280 	/*
281 	 * Nothing to do.
282 	 */
283 	return (0);
284 }
285 
286 static int
287 tsc_start_pmc(int cpu, int ri)
288 {
289 	(void) cpu;
290 
291 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
292 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
293 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
294 
295 	return (0);	/* TSCs are always running. */
296 }
297 
298 static int
299 tsc_stop_pmc(int cpu, int ri)
300 {
301 	(void) cpu; (void) ri;
302 
303 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
304 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
305 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
306 
307 	return (0);	/* Cannot actually stop a TSC. */
308 }
309 
310 static int
311 tsc_write_pmc(int cpu, int ri, pmc_value_t v)
312 {
313 	(void) cpu; (void) ri; (void) v;
314 
315 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
316 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
317 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
318 
319 	/*
320 	 * The TSCs are used as timecounters by the kernel, so even
321 	 * though some i386 CPUs support writeable TSCs, we don't
322 	 * support writing changing TSC values through the HWPMC API.
323 	 */
324 	return (0);
325 }
326 
327 int
328 pmc_tsc_initialize(struct pmc_mdep *md, int maxcpu)
329 {
330 	struct pmc_classdep *pcd;
331 
332 	KASSERT(md != NULL, ("[tsc,%d] md is NULL", __LINE__));
333 	KASSERT(md->pmd_nclass >= 1, ("[tsc,%d] dubious md->nclass %d",
334 	    __LINE__, md->pmd_nclass));
335 
336 	tsc_pcpu = malloc(sizeof(struct tsc_cpu *) * maxcpu, M_PMC,
337 	    M_ZERO|M_WAITOK);
338 
339 	pcd = &md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC];
340 
341 	pcd->pcd_caps	= PMC_CAP_READ;
342 	pcd->pcd_class	= PMC_CLASS_TSC;
343 	pcd->pcd_num	= TSC_NPMCS;
344 	pcd->pcd_ri	= md->pmd_npmc;
345 	pcd->pcd_width	= 64;
346 
347 	pcd->pcd_allocate_pmc = tsc_allocate_pmc;
348 	pcd->pcd_config_pmc   = tsc_config_pmc;
349 	pcd->pcd_describe     = tsc_describe;
350 	pcd->pcd_get_config   = tsc_get_config;
351 	pcd->pcd_get_msr      = tsc_get_msr;
352 	pcd->pcd_pcpu_init    = tsc_pcpu_init;
353 	pcd->pcd_pcpu_fini    = tsc_pcpu_fini;
354 	pcd->pcd_read_pmc     = tsc_read_pmc;
355 	pcd->pcd_release_pmc  = tsc_release_pmc;
356 	pcd->pcd_start_pmc    = tsc_start_pmc;
357 	pcd->pcd_stop_pmc     = tsc_stop_pmc;
358 	pcd->pcd_write_pmc    = tsc_write_pmc;
359 
360 	md->pmd_npmc += TSC_NPMCS;
361 
362 	return (0);
363 }
364 
365 void
366 pmc_tsc_finalize(struct pmc_mdep *md)
367 {
368 #ifdef	INVARIANTS
369 	int i, ncpus;
370 
371 	ncpus = pmc_cpu_max();
372 	for (i = 0; i < ncpus; i++)
373 		KASSERT(tsc_pcpu[i] == NULL, ("[tsc,%d] non-null pcpu cpu %d",
374 		    __LINE__, i));
375 
376 	KASSERT(md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_class ==
377 	    PMC_CLASS_TSC, ("[tsc,%d] class mismatch", __LINE__));
378 
379 #else
380 	(void) md;
381 #endif
382 
383 	free(tsc_pcpu, M_PMC);
384 	tsc_pcpu = NULL;
385 }
386