xref: /linux/arch/x86/events/msr.c (revision 6f7e6393d1ce636bb7ec77a7fe7b77458fddf701)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/perf_event.h>
3 #include <linux/sysfs.h>
4 #include <linux/nospec.h>
5 #include <asm/cpu_device_id.h>
6 #include <asm/msr.h>
7 
8 #include "probe.h"
9 
10 enum perf_msr_id {
11 	PERF_MSR_TSC			= 0,
12 	PERF_MSR_APERF			= 1,
13 	PERF_MSR_MPERF			= 2,
14 	PERF_MSR_PPERF			= 3,
15 	PERF_MSR_SMI			= 4,
16 	PERF_MSR_PTSC			= 5,
17 	PERF_MSR_IRPERF			= 6,
18 	PERF_MSR_THERM			= 7,
19 	PERF_MSR_EVENT_MAX,
20 };
21 
22 static bool test_aperfmperf(int idx, void *data)
23 {
24 	return boot_cpu_has(X86_FEATURE_APERFMPERF);
25 }
26 
27 static bool test_ptsc(int idx, void *data)
28 {
29 	return boot_cpu_has(X86_FEATURE_PTSC);
30 }
31 
32 static bool test_irperf(int idx, void *data)
33 {
34 	return boot_cpu_has(X86_FEATURE_IRPERF);
35 }
36 
37 static bool test_therm_status(int idx, void *data)
38 {
39 	return boot_cpu_has(X86_FEATURE_DTHERM);
40 }
41 
42 static bool test_intel(int idx, void *data)
43 {
44 	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
45 	    boot_cpu_data.x86 != 6)
46 		return false;
47 
48 	switch (boot_cpu_data.x86_vfm) {
49 	case INTEL_NEHALEM:
50 	case INTEL_NEHALEM_G:
51 	case INTEL_NEHALEM_EP:
52 	case INTEL_NEHALEM_EX:
53 
54 	case INTEL_WESTMERE:
55 	case INTEL_WESTMERE_EP:
56 	case INTEL_WESTMERE_EX:
57 
58 	case INTEL_SANDYBRIDGE:
59 	case INTEL_SANDYBRIDGE_X:
60 
61 	case INTEL_IVYBRIDGE:
62 	case INTEL_IVYBRIDGE_X:
63 
64 	case INTEL_HASWELL:
65 	case INTEL_HASWELL_X:
66 	case INTEL_HASWELL_L:
67 	case INTEL_HASWELL_G:
68 
69 	case INTEL_BROADWELL:
70 	case INTEL_BROADWELL_D:
71 	case INTEL_BROADWELL_G:
72 	case INTEL_BROADWELL_X:
73 	case INTEL_SAPPHIRERAPIDS_X:
74 	case INTEL_EMERALDRAPIDS_X:
75 	case INTEL_GRANITERAPIDS_X:
76 	case INTEL_GRANITERAPIDS_D:
77 
78 	case INTEL_ATOM_SILVERMONT:
79 	case INTEL_ATOM_SILVERMONT_D:
80 	case INTEL_ATOM_AIRMONT:
81 	case INTEL_ATOM_AIRMONT_NP:
82 
83 	case INTEL_ATOM_GOLDMONT:
84 	case INTEL_ATOM_GOLDMONT_D:
85 	case INTEL_ATOM_GOLDMONT_PLUS:
86 	case INTEL_ATOM_TREMONT_D:
87 	case INTEL_ATOM_TREMONT:
88 	case INTEL_ATOM_TREMONT_L:
89 
90 	case INTEL_XEON_PHI_KNL:
91 	case INTEL_XEON_PHI_KNM:
92 		if (idx == PERF_MSR_SMI)
93 			return true;
94 		break;
95 
96 	case INTEL_SKYLAKE_L:
97 	case INTEL_SKYLAKE:
98 	case INTEL_SKYLAKE_X:
99 	case INTEL_KABYLAKE_L:
100 	case INTEL_KABYLAKE:
101 	case INTEL_COMETLAKE_L:
102 	case INTEL_COMETLAKE:
103 	case INTEL_ICELAKE_L:
104 	case INTEL_ICELAKE:
105 	case INTEL_ICELAKE_X:
106 	case INTEL_ICELAKE_D:
107 	case INTEL_TIGERLAKE_L:
108 	case INTEL_TIGERLAKE:
109 	case INTEL_ROCKETLAKE:
110 	case INTEL_ALDERLAKE:
111 	case INTEL_ALDERLAKE_L:
112 	case INTEL_ATOM_GRACEMONT:
113 	case INTEL_RAPTORLAKE:
114 	case INTEL_RAPTORLAKE_P:
115 	case INTEL_RAPTORLAKE_S:
116 	case INTEL_METEORLAKE:
117 	case INTEL_METEORLAKE_L:
118 		if (idx == PERF_MSR_SMI || idx == PERF_MSR_PPERF)
119 			return true;
120 		break;
121 	}
122 
123 	return false;
124 }
125 
126 PMU_EVENT_ATTR_STRING(tsc,				attr_tsc,		"event=0x00"	);
127 PMU_EVENT_ATTR_STRING(aperf,				attr_aperf,		"event=0x01"	);
128 PMU_EVENT_ATTR_STRING(mperf,				attr_mperf,		"event=0x02"	);
129 PMU_EVENT_ATTR_STRING(pperf,				attr_pperf,		"event=0x03"	);
130 PMU_EVENT_ATTR_STRING(smi,				attr_smi,		"event=0x04"	);
131 PMU_EVENT_ATTR_STRING(ptsc,				attr_ptsc,		"event=0x05"	);
132 PMU_EVENT_ATTR_STRING(irperf,				attr_irperf,		"event=0x06"	);
133 PMU_EVENT_ATTR_STRING(cpu_thermal_margin,		attr_therm,		"event=0x07"	);
134 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.snapshot,	attr_therm_snap,	"1"		);
135 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.unit,		attr_therm_unit,	"C"		);
136 
137 static unsigned long msr_mask;
138 
139 PMU_EVENT_GROUP(events, aperf);
140 PMU_EVENT_GROUP(events, mperf);
141 PMU_EVENT_GROUP(events, pperf);
142 PMU_EVENT_GROUP(events, smi);
143 PMU_EVENT_GROUP(events, ptsc);
144 PMU_EVENT_GROUP(events, irperf);
145 
146 static struct attribute *attrs_therm[] = {
147 	&attr_therm.attr.attr,
148 	&attr_therm_snap.attr.attr,
149 	&attr_therm_unit.attr.attr,
150 	NULL,
151 };
152 
153 static struct attribute_group group_therm = {
154 	.name  = "events",
155 	.attrs = attrs_therm,
156 };
157 
158 static struct perf_msr msr[] = {
159 	[PERF_MSR_TSC]		= { .no_check = true,								},
160 	[PERF_MSR_APERF]	= { MSR_IA32_APERF,		&group_aperf,		test_aperfmperf,	},
161 	[PERF_MSR_MPERF]	= { MSR_IA32_MPERF,		&group_mperf,		test_aperfmperf,	},
162 	[PERF_MSR_PPERF]	= { MSR_PPERF,			&group_pperf,		test_intel,		},
163 	[PERF_MSR_SMI]		= { MSR_SMI_COUNT,		&group_smi,		test_intel,		},
164 	[PERF_MSR_PTSC]		= { MSR_F15H_PTSC,		&group_ptsc,		test_ptsc,		},
165 	[PERF_MSR_IRPERF]	= { MSR_F17H_IRPERF,		&group_irperf,		test_irperf,		},
166 	[PERF_MSR_THERM]	= { MSR_IA32_THERM_STATUS,	&group_therm,		test_therm_status,	},
167 };
168 
169 static struct attribute *events_attrs[] = {
170 	&attr_tsc.attr.attr,
171 	NULL,
172 };
173 
174 static struct attribute_group events_attr_group = {
175 	.name = "events",
176 	.attrs = events_attrs,
177 };
178 
179 PMU_FORMAT_ATTR(event, "config:0-63");
180 static struct attribute *format_attrs[] = {
181 	&format_attr_event.attr,
182 	NULL,
183 };
184 static struct attribute_group format_attr_group = {
185 	.name = "format",
186 	.attrs = format_attrs,
187 };
188 
189 static const struct attribute_group *attr_groups[] = {
190 	&events_attr_group,
191 	&format_attr_group,
192 	NULL,
193 };
194 
195 static const struct attribute_group *attr_update[] = {
196 	&group_aperf,
197 	&group_mperf,
198 	&group_pperf,
199 	&group_smi,
200 	&group_ptsc,
201 	&group_irperf,
202 	&group_therm,
203 	NULL,
204 };
205 
206 static int msr_event_init(struct perf_event *event)
207 {
208 	u64 cfg = event->attr.config;
209 
210 	if (event->attr.type != event->pmu->type)
211 		return -ENOENT;
212 
213 	/* unsupported modes and filters */
214 	if (event->attr.sample_period) /* no sampling */
215 		return -EINVAL;
216 
217 	if (cfg >= PERF_MSR_EVENT_MAX)
218 		return -EINVAL;
219 
220 	cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX);
221 
222 	if (!(msr_mask & (1 << cfg)))
223 		return -EINVAL;
224 
225 	event->hw.idx		= -1;
226 	event->hw.event_base	= msr[cfg].msr;
227 	event->hw.config	= cfg;
228 
229 	return 0;
230 }
231 
232 static inline u64 msr_read_counter(struct perf_event *event)
233 {
234 	u64 now;
235 
236 	if (event->hw.event_base)
237 		rdmsrq(event->hw.event_base, now);
238 	else
239 		now = rdtsc_ordered();
240 
241 	return now;
242 }
243 
244 static void msr_event_update(struct perf_event *event)
245 {
246 	u64 prev, now;
247 	s64 delta;
248 
249 	/* Careful, an NMI might modify the previous event value: */
250 	prev = local64_read(&event->hw.prev_count);
251 	do {
252 		now = msr_read_counter(event);
253 	} while (!local64_try_cmpxchg(&event->hw.prev_count, &prev, now));
254 
255 	delta = now - prev;
256 	if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
257 		delta = sign_extend64(delta, 31);
258 		local64_add(delta, &event->count);
259 	} else if (unlikely(event->hw.event_base == MSR_IA32_THERM_STATUS)) {
260 		/* If valid, extract digital readout, otherwise set to -1: */
261 		now = now & (1ULL << 31) ? (now >> 16) & 0x3f :  -1;
262 		local64_set(&event->count, now);
263 	} else {
264 		local64_add(delta, &event->count);
265 	}
266 }
267 
268 static void msr_event_start(struct perf_event *event, int flags)
269 {
270 	u64 now = msr_read_counter(event);
271 
272 	local64_set(&event->hw.prev_count, now);
273 }
274 
275 static void msr_event_stop(struct perf_event *event, int flags)
276 {
277 	msr_event_update(event);
278 }
279 
280 static void msr_event_del(struct perf_event *event, int flags)
281 {
282 	msr_event_stop(event, PERF_EF_UPDATE);
283 }
284 
285 static int msr_event_add(struct perf_event *event, int flags)
286 {
287 	if (flags & PERF_EF_START)
288 		msr_event_start(event, flags);
289 
290 	return 0;
291 }
292 
293 static struct pmu pmu_msr = {
294 	.task_ctx_nr	= perf_sw_context,
295 	.attr_groups	= attr_groups,
296 	.event_init	= msr_event_init,
297 	.add		= msr_event_add,
298 	.del		= msr_event_del,
299 	.start		= msr_event_start,
300 	.stop		= msr_event_stop,
301 	.read		= msr_event_update,
302 	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT | PERF_PMU_CAP_NO_EXCLUDE,
303 	.attr_update	= attr_update,
304 };
305 
306 static int __init msr_init(void)
307 {
308 	if (!boot_cpu_has(X86_FEATURE_TSC)) {
309 		pr_cont("no MSR PMU driver.\n");
310 		return 0;
311 	}
312 
313 	msr_mask = perf_msr_probe(msr, PERF_MSR_EVENT_MAX, true, NULL);
314 
315 	perf_pmu_register(&pmu_msr, "msr", -1);
316 
317 	return 0;
318 }
319 device_initcall(msr_init);
320