xref: /freebsd/sys/dev/hwpmc/hwpmc_tsc.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #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 __diagused, int ri __diagused, struct pmc *pm __unused,
72     const struct pmc_op_pmcallocate *a)
73 {
74 
75 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
76 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
77 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
78 	    ("[tsc,%d] illegal row index %d", __LINE__, ri));
79 
80 	if (a->pm_class != PMC_CLASS_TSC)
81 		return (EINVAL);
82 
83 	if (a->pm_ev != PMC_EV_TSC_TSC ||
84 	    a->pm_mode != PMC_MODE_SC)
85 		return (EINVAL);
86 
87 	return (0);
88 }
89 
90 static int
91 tsc_config_pmc(int cpu, int ri, struct pmc *pm)
92 {
93 	struct pmc_hw *phw;
94 
95 	PMCDBG3(MDP,CFG,1, "cpu=%d ri=%d pm=%p", cpu, ri, pm);
96 
97 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
98 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
99 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
100 
101 	phw = &tsc_pcpu[cpu]->tc_hw;
102 
103 	KASSERT(pm == NULL || phw->phw_pmc == NULL,
104 	    ("[tsc,%d] pm=%p phw->pm=%p hwpmc not unconfigured", __LINE__,
105 	    pm, phw->phw_pmc));
106 
107 	phw->phw_pmc = pm;
108 
109 	return (0);
110 }
111 
112 static int
113 tsc_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
114 {
115 	const struct tsc_descr *pd;
116 	struct pmc_hw *phw;
117 
118 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
119 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
120 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
121 
122 	phw = &tsc_pcpu[cpu]->tc_hw;
123 	pd  = &tsc_pmcdesc[ri];
124 
125 	strlcpy(pi->pm_name, pd->pm_descr.pd_name, sizeof(pi->pm_name));
126 	pi->pm_class = pd->pm_descr.pd_class;
127 
128 	if (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) {
129 		pi->pm_enabled = TRUE;
130 		*ppmc          = phw->phw_pmc;
131 	} else {
132 		pi->pm_enabled = FALSE;
133 		*ppmc          = NULL;
134 	}
135 
136 	return (0);
137 }
138 
139 static int
140 tsc_get_config(int cpu, int ri __diagused, struct pmc **ppm)
141 {
142 
143 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
144 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
145 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
146 
147 	*ppm = tsc_pcpu[cpu]->tc_hw.phw_pmc;
148 
149 	return (0);
150 }
151 
152 static int
153 tsc_get_msr(int ri __diagused, uint32_t *msr)
154 {
155 
156 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
157 	    ("[tsc,%d] ri %d out of range", __LINE__, ri));
158 
159 	*msr = MSR_TSC;
160 
161 	return (0);
162 }
163 
164 static int
165 tsc_pcpu_fini(struct pmc_mdep *md, int cpu)
166 {
167 	int ri;
168 	struct pmc_cpu *pc;
169 
170 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
171 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
172 	KASSERT(tsc_pcpu[cpu] != NULL, ("[tsc,%d] null pcpu", __LINE__));
173 
174 	free(tsc_pcpu[cpu], M_PMC);
175 	tsc_pcpu[cpu] = NULL;
176 
177 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
178 
179 	pc = pmc_pcpu[cpu];
180 	pc->pc_hwpmcs[ri] = NULL;
181 
182 	return (0);
183 }
184 
185 static int
186 tsc_pcpu_init(struct pmc_mdep *md, int cpu)
187 {
188 	int ri;
189 	struct pmc_cpu *pc;
190 	struct tsc_cpu *tsc_pc;
191 
192 
193 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
194 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
195 	KASSERT(tsc_pcpu, ("[tsc,%d] null pcpu", __LINE__));
196 	KASSERT(tsc_pcpu[cpu] == NULL, ("[tsc,%d] non-null per-cpu",
197 	    __LINE__));
198 
199 	tsc_pc = malloc(sizeof(struct tsc_cpu), M_PMC, M_WAITOK|M_ZERO);
200 
201 	tsc_pc->tc_hw.phw_state = PMC_PHW_FLAG_IS_ENABLED |
202 	    PMC_PHW_CPU_TO_STATE(cpu) | PMC_PHW_INDEX_TO_STATE(0) |
203 	    PMC_PHW_FLAG_IS_SHAREABLE;
204 
205 	tsc_pcpu[cpu] = tsc_pc;
206 
207 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
208 
209 	KASSERT(pmc_pcpu, ("[tsc,%d] null generic pcpu", __LINE__));
210 
211 	pc = pmc_pcpu[cpu];
212 
213 	KASSERT(pc, ("[tsc,%d] null generic per-cpu", __LINE__));
214 
215 	pc->pc_hwpmcs[ri] = &tsc_pc->tc_hw;
216 
217 	return (0);
218 }
219 
220 static int
221 tsc_read_pmc(int cpu, int ri, struct pmc *pm, pmc_value_t *v)
222 {
223 	enum pmc_mode mode __diagused;
224 
225 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
226 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
227 	KASSERT(ri == 0, ("[tsc,%d] illegal ri %d", __LINE__, ri));
228 
229 	mode = PMC_TO_MODE(pm);
230 
231 	KASSERT(mode == PMC_MODE_SC,
232 	    ("[tsc,%d] illegal pmc mode %d", __LINE__, mode));
233 
234 	PMCDBG1(MDP,REA,1,"tsc-read id=%d", ri);
235 
236 	*v = rdtsc();
237 
238 	return (0);
239 }
240 
241 static int
242 tsc_release_pmc(int cpu, int ri __diagused, struct pmc *pmc __unused)
243 {
244 	struct pmc_hw *phw __diagused;
245 
246 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
247 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
248 	KASSERT(ri == 0,
249 	    ("[tsc,%d] illegal row-index %d", __LINE__, ri));
250 
251 	phw = &tsc_pcpu[cpu]->tc_hw;
252 
253 	KASSERT(phw->phw_pmc == NULL,
254 	    ("[tsc,%d] PHW pmc %p non-NULL", __LINE__, phw->phw_pmc));
255 
256 	/*
257 	 * Nothing to do.
258 	 */
259 	return (0);
260 }
261 
262 static int
263 tsc_start_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused)
264 {
265 
266 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
267 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
268 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
269 
270 	return (0);	/* TSCs are always running. */
271 }
272 
273 static int
274 tsc_stop_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused)
275 {
276 
277 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
278 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
279 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
280 
281 	return (0);	/* Cannot actually stop a TSC. */
282 }
283 
284 static int
285 tsc_write_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused,
286     pmc_value_t v __unused)
287 {
288 
289 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
290 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
291 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
292 
293 	/*
294 	 * The TSCs are used as timecounters by the kernel, so even
295 	 * though some i386 CPUs support writeable TSCs, we don't
296 	 * support writing changing TSC values through the HWPMC API.
297 	 */
298 	return (0);
299 }
300 
301 int
302 pmc_tsc_initialize(struct pmc_mdep *md, int maxcpu)
303 {
304 	struct pmc_classdep *pcd;
305 
306 	KASSERT(md != NULL, ("[tsc,%d] md is NULL", __LINE__));
307 	KASSERT(md->pmd_nclass >= 1, ("[tsc,%d] dubious md->nclass %d",
308 	    __LINE__, md->pmd_nclass));
309 
310 	tsc_pcpu = malloc(sizeof(struct tsc_cpu *) * maxcpu, M_PMC,
311 	    M_ZERO|M_WAITOK);
312 
313 	pcd = &md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC];
314 
315 	pcd->pcd_caps	= PMC_CAP_READ;
316 	pcd->pcd_class	= PMC_CLASS_TSC;
317 	pcd->pcd_num	= TSC_NPMCS;
318 	pcd->pcd_ri	= md->pmd_npmc;
319 	pcd->pcd_width	= 64;
320 
321 	pcd->pcd_allocate_pmc = tsc_allocate_pmc;
322 	pcd->pcd_config_pmc   = tsc_config_pmc;
323 	pcd->pcd_describe     = tsc_describe;
324 	pcd->pcd_get_config   = tsc_get_config;
325 	pcd->pcd_get_msr      = tsc_get_msr;
326 	pcd->pcd_pcpu_init    = tsc_pcpu_init;
327 	pcd->pcd_pcpu_fini    = tsc_pcpu_fini;
328 	pcd->pcd_read_pmc     = tsc_read_pmc;
329 	pcd->pcd_release_pmc  = tsc_release_pmc;
330 	pcd->pcd_start_pmc    = tsc_start_pmc;
331 	pcd->pcd_stop_pmc     = tsc_stop_pmc;
332 	pcd->pcd_write_pmc    = tsc_write_pmc;
333 
334 	md->pmd_npmc += TSC_NPMCS;
335 
336 	return (0);
337 }
338 
339 void
340 pmc_tsc_finalize(struct pmc_mdep *md __diagused)
341 {
342 	PMCDBG0(MDP, INI, 1, "tsc-finalize");
343 
344 	for (int i = 0; i < pmc_cpu_max(); i++)
345 		KASSERT(tsc_pcpu[i] == NULL, ("[tsc,%d] non-null pcpu cpu %d",
346 		    __LINE__, i));
347 
348 	free(tsc_pcpu, M_PMC);
349 	tsc_pcpu = NULL;
350 }
351