xref: /freebsd/sys/dev/hwpmc/hwpmc_tsc.c (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
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/param.h>
30 #include <sys/pmc.h>
31 #include <sys/pmckern.h>
32 #include <sys/systm.h>
33 
34 #include <machine/specialreg.h>
35 
36 /*
37  * TSC support.
38  */
39 
40 #define	TSC_CAPS	PMC_CAP_READ
41 
42 struct tsc_descr {
43 	struct pmc_descr pm_descr;  /* "base class" */
44 };
45 
46 static struct tsc_descr tsc_pmcdesc[TSC_NPMCS] =
47 {
48     {
49 	.pm_descr =
50 	{
51 		.pd_name  = "TSC",
52 		.pd_class = PMC_CLASS_TSC,
53 		.pd_caps  = TSC_CAPS,
54 		.pd_width = 64
55 	}
56     }
57 };
58 
59 /*
60  * Per-CPU data structure for TSCs.
61  */
62 
63 struct tsc_cpu {
64 	struct pmc_hw	tc_hw;
65 };
66 
67 static struct tsc_cpu **tsc_pcpu;
68 
69 static int
70 tsc_allocate_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused,
71     const struct pmc_op_pmcallocate *a)
72 {
73 
74 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
75 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
76 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
77 	    ("[tsc,%d] illegal row index %d", __LINE__, ri));
78 
79 	if (a->pm_class != PMC_CLASS_TSC)
80 		return (EINVAL);
81 
82 	if (a->pm_ev != PMC_EV_TSC_TSC ||
83 	    a->pm_mode != PMC_MODE_SC)
84 		return (EINVAL);
85 
86 	return (0);
87 }
88 
89 static int
90 tsc_config_pmc(int cpu, int ri, struct pmc *pm)
91 {
92 	struct pmc_hw *phw;
93 
94 	PMCDBG3(MDP,CFG,1, "cpu=%d ri=%d pm=%p", cpu, ri, pm);
95 
96 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
97 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
98 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
99 
100 	phw = &tsc_pcpu[cpu]->tc_hw;
101 
102 	KASSERT(pm == NULL || phw->phw_pmc == NULL,
103 	    ("[tsc,%d] pm=%p phw->pm=%p hwpmc not unconfigured", __LINE__,
104 	    pm, phw->phw_pmc));
105 
106 	phw->phw_pmc = pm;
107 
108 	return (0);
109 }
110 
111 static int
112 tsc_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
113 {
114 	const struct tsc_descr *pd;
115 	struct pmc_hw *phw;
116 
117 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
118 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
119 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
120 
121 	phw = &tsc_pcpu[cpu]->tc_hw;
122 	pd  = &tsc_pmcdesc[ri];
123 
124 	strlcpy(pi->pm_name, pd->pm_descr.pd_name, sizeof(pi->pm_name));
125 	pi->pm_class = pd->pm_descr.pd_class;
126 
127 	if (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) {
128 		pi->pm_enabled = TRUE;
129 		*ppmc          = phw->phw_pmc;
130 	} else {
131 		pi->pm_enabled = FALSE;
132 		*ppmc          = NULL;
133 	}
134 
135 	return (0);
136 }
137 
138 static int
139 tsc_get_config(int cpu, int ri __diagused, struct pmc **ppm)
140 {
141 
142 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
143 	    ("[tsc,%d] illegal CPU %d", __LINE__, cpu));
144 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
145 
146 	*ppm = tsc_pcpu[cpu]->tc_hw.phw_pmc;
147 
148 	return (0);
149 }
150 
151 static int
152 tsc_get_msr(int ri __diagused, uint32_t *msr)
153 {
154 
155 	KASSERT(ri >= 0 && ri < TSC_NPMCS,
156 	    ("[tsc,%d] ri %d out of range", __LINE__, ri));
157 
158 	*msr = MSR_TSC;
159 
160 	return (0);
161 }
162 
163 static int
164 tsc_pcpu_fini(struct pmc_mdep *md, int cpu)
165 {
166 	int ri;
167 	struct pmc_cpu *pc;
168 
169 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
170 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
171 	KASSERT(tsc_pcpu[cpu] != NULL, ("[tsc,%d] null pcpu", __LINE__));
172 
173 	free(tsc_pcpu[cpu], M_PMC);
174 	tsc_pcpu[cpu] = NULL;
175 
176 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
177 
178 	pc = pmc_pcpu[cpu];
179 	pc->pc_hwpmcs[ri] = NULL;
180 
181 	return (0);
182 }
183 
184 static int
185 tsc_pcpu_init(struct pmc_mdep *md, int cpu)
186 {
187 	int ri;
188 	struct pmc_cpu *pc;
189 	struct tsc_cpu *tsc_pc;
190 
191 
192 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
193 	    ("[tsc,%d] illegal cpu %d", __LINE__, cpu));
194 	KASSERT(tsc_pcpu, ("[tsc,%d] null pcpu", __LINE__));
195 	KASSERT(tsc_pcpu[cpu] == NULL, ("[tsc,%d] non-null per-cpu",
196 	    __LINE__));
197 
198 	tsc_pc = malloc(sizeof(struct tsc_cpu), M_PMC, M_WAITOK|M_ZERO);
199 
200 	tsc_pc->tc_hw.phw_state = PMC_PHW_FLAG_IS_ENABLED |
201 	    PMC_PHW_CPU_TO_STATE(cpu) | PMC_PHW_INDEX_TO_STATE(0) |
202 	    PMC_PHW_FLAG_IS_SHAREABLE;
203 
204 	tsc_pcpu[cpu] = tsc_pc;
205 
206 	ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
207 
208 	KASSERT(pmc_pcpu, ("[tsc,%d] null generic pcpu", __LINE__));
209 
210 	pc = pmc_pcpu[cpu];
211 
212 	KASSERT(pc, ("[tsc,%d] null generic per-cpu", __LINE__));
213 
214 	pc->pc_hwpmcs[ri] = &tsc_pc->tc_hw;
215 
216 	return (0);
217 }
218 
219 static int
220 tsc_read_pmc(int cpu, int ri, struct pmc *pm, pmc_value_t *v)
221 {
222 	enum pmc_mode mode __diagused;
223 
224 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
225 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
226 	KASSERT(ri == 0, ("[tsc,%d] illegal ri %d", __LINE__, ri));
227 
228 	mode = PMC_TO_MODE(pm);
229 
230 	KASSERT(mode == PMC_MODE_SC,
231 	    ("[tsc,%d] illegal pmc mode %d", __LINE__, mode));
232 
233 	PMCDBG1(MDP,REA,1,"tsc-read id=%d", ri);
234 
235 	*v = rdtsc();
236 
237 	return (0);
238 }
239 
240 static int
241 tsc_release_pmc(int cpu, int ri __diagused, struct pmc *pmc __unused)
242 {
243 	struct pmc_hw *phw __diagused;
244 
245 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
246 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
247 	KASSERT(ri == 0,
248 	    ("[tsc,%d] illegal row-index %d", __LINE__, ri));
249 
250 	phw = &tsc_pcpu[cpu]->tc_hw;
251 
252 	KASSERT(phw->phw_pmc == NULL,
253 	    ("[tsc,%d] PHW pmc %p non-NULL", __LINE__, phw->phw_pmc));
254 
255 	/*
256 	 * Nothing to do.
257 	 */
258 	return (0);
259 }
260 
261 static int
262 tsc_start_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused)
263 {
264 
265 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
266 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
267 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
268 
269 	return (0);	/* TSCs are always running. */
270 }
271 
272 static int
273 tsc_stop_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused)
274 {
275 
276 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
277 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
278 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
279 
280 	return (0);	/* Cannot actually stop a TSC. */
281 }
282 
283 static int
284 tsc_write_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused,
285     pmc_value_t v __unused)
286 {
287 
288 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
289 	    ("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
290 	KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
291 
292 	/*
293 	 * The TSCs are used as timecounters by the kernel, so even
294 	 * though some i386 CPUs support writeable TSCs, we don't
295 	 * support writing changing TSC values through the HWPMC API.
296 	 */
297 	return (0);
298 }
299 
300 int
301 pmc_tsc_initialize(struct pmc_mdep *md, int maxcpu)
302 {
303 	struct pmc_classdep *pcd;
304 
305 	KASSERT(md != NULL, ("[tsc,%d] md is NULL", __LINE__));
306 	KASSERT(md->pmd_nclass >= 1, ("[tsc,%d] dubious md->nclass %d",
307 	    __LINE__, md->pmd_nclass));
308 
309 	tsc_pcpu = malloc(sizeof(struct tsc_cpu *) * maxcpu, M_PMC,
310 	    M_ZERO|M_WAITOK);
311 
312 	pcd = &md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC];
313 
314 	pcd->pcd_caps	= PMC_CAP_READ;
315 	pcd->pcd_class	= PMC_CLASS_TSC;
316 	pcd->pcd_num	= TSC_NPMCS;
317 	pcd->pcd_ri	= md->pmd_npmc;
318 	pcd->pcd_width	= 64;
319 
320 	pcd->pcd_allocate_pmc = tsc_allocate_pmc;
321 	pcd->pcd_config_pmc   = tsc_config_pmc;
322 	pcd->pcd_describe     = tsc_describe;
323 	pcd->pcd_get_config   = tsc_get_config;
324 	pcd->pcd_get_msr      = tsc_get_msr;
325 	pcd->pcd_pcpu_init    = tsc_pcpu_init;
326 	pcd->pcd_pcpu_fini    = tsc_pcpu_fini;
327 	pcd->pcd_read_pmc     = tsc_read_pmc;
328 	pcd->pcd_release_pmc  = tsc_release_pmc;
329 	pcd->pcd_start_pmc    = tsc_start_pmc;
330 	pcd->pcd_stop_pmc     = tsc_stop_pmc;
331 	pcd->pcd_write_pmc    = tsc_write_pmc;
332 
333 	md->pmd_npmc += TSC_NPMCS;
334 
335 	return (0);
336 }
337 
338 void
339 pmc_tsc_finalize(struct pmc_mdep *md __diagused)
340 {
341 	PMCDBG0(MDP, INI, 1, "tsc-finalize");
342 
343 	for (int i = 0; i < pmc_cpu_max(); i++)
344 		KASSERT(tsc_pcpu[i] == NULL, ("[tsc,%d] non-null pcpu cpu %d",
345 		    __LINE__, i));
346 
347 	free(tsc_pcpu, M_PMC);
348 	tsc_pcpu = NULL;
349 }
350