xref: /linux/arch/x86/events/msr.c (revision e78f70bad29c5ae1e1076698b690b15794e9b81e)
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 
82 	case INTEL_ATOM_GOLDMONT:
83 	case INTEL_ATOM_GOLDMONT_D:
84 	case INTEL_ATOM_GOLDMONT_PLUS:
85 	case INTEL_ATOM_TREMONT_D:
86 	case INTEL_ATOM_TREMONT:
87 	case INTEL_ATOM_TREMONT_L:
88 
89 	case INTEL_XEON_PHI_KNL:
90 	case INTEL_XEON_PHI_KNM:
91 		if (idx == PERF_MSR_SMI)
92 			return true;
93 		break;
94 
95 	case INTEL_SKYLAKE_L:
96 	case INTEL_SKYLAKE:
97 	case INTEL_SKYLAKE_X:
98 	case INTEL_KABYLAKE_L:
99 	case INTEL_KABYLAKE:
100 	case INTEL_COMETLAKE_L:
101 	case INTEL_COMETLAKE:
102 	case INTEL_ICELAKE_L:
103 	case INTEL_ICELAKE:
104 	case INTEL_ICELAKE_X:
105 	case INTEL_ICELAKE_D:
106 	case INTEL_TIGERLAKE_L:
107 	case INTEL_TIGERLAKE:
108 	case INTEL_ROCKETLAKE:
109 	case INTEL_ALDERLAKE:
110 	case INTEL_ALDERLAKE_L:
111 	case INTEL_ATOM_GRACEMONT:
112 	case INTEL_RAPTORLAKE:
113 	case INTEL_RAPTORLAKE_P:
114 	case INTEL_RAPTORLAKE_S:
115 	case INTEL_METEORLAKE:
116 	case INTEL_METEORLAKE_L:
117 		if (idx == PERF_MSR_SMI || idx == PERF_MSR_PPERF)
118 			return true;
119 		break;
120 	}
121 
122 	return false;
123 }
124 
125 PMU_EVENT_ATTR_STRING(tsc,				attr_tsc,		"event=0x00"	);
126 PMU_EVENT_ATTR_STRING(aperf,				attr_aperf,		"event=0x01"	);
127 PMU_EVENT_ATTR_STRING(mperf,				attr_mperf,		"event=0x02"	);
128 PMU_EVENT_ATTR_STRING(pperf,				attr_pperf,		"event=0x03"	);
129 PMU_EVENT_ATTR_STRING(smi,				attr_smi,		"event=0x04"	);
130 PMU_EVENT_ATTR_STRING(ptsc,				attr_ptsc,		"event=0x05"	);
131 PMU_EVENT_ATTR_STRING(irperf,				attr_irperf,		"event=0x06"	);
132 PMU_EVENT_ATTR_STRING(cpu_thermal_margin,		attr_therm,		"event=0x07"	);
133 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.snapshot,	attr_therm_snap,	"1"		);
134 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.unit,		attr_therm_unit,	"C"		);
135 
136 static unsigned long msr_mask;
137 
138 PMU_EVENT_GROUP(events, aperf);
139 PMU_EVENT_GROUP(events, mperf);
140 PMU_EVENT_GROUP(events, pperf);
141 PMU_EVENT_GROUP(events, smi);
142 PMU_EVENT_GROUP(events, ptsc);
143 PMU_EVENT_GROUP(events, irperf);
144 
145 static struct attribute *attrs_therm[] = {
146 	&attr_therm.attr.attr,
147 	&attr_therm_snap.attr.attr,
148 	&attr_therm_unit.attr.attr,
149 	NULL,
150 };
151 
152 static struct attribute_group group_therm = {
153 	.name  = "events",
154 	.attrs = attrs_therm,
155 };
156 
157 static struct perf_msr msr[] = {
158 	[PERF_MSR_TSC]		= { .no_check = true,								},
159 	[PERF_MSR_APERF]	= { MSR_IA32_APERF,		&group_aperf,		test_aperfmperf,	},
160 	[PERF_MSR_MPERF]	= { MSR_IA32_MPERF,		&group_mperf,		test_aperfmperf,	},
161 	[PERF_MSR_PPERF]	= { MSR_PPERF,			&group_pperf,		test_intel,		},
162 	[PERF_MSR_SMI]		= { MSR_SMI_COUNT,		&group_smi,		test_intel,		},
163 	[PERF_MSR_PTSC]		= { MSR_F15H_PTSC,		&group_ptsc,		test_ptsc,		},
164 	[PERF_MSR_IRPERF]	= { MSR_F17H_IRPERF,		&group_irperf,		test_irperf,		},
165 	[PERF_MSR_THERM]	= { MSR_IA32_THERM_STATUS,	&group_therm,		test_therm_status,	},
166 };
167 
168 static struct attribute *events_attrs[] = {
169 	&attr_tsc.attr.attr,
170 	NULL,
171 };
172 
173 static struct attribute_group events_attr_group = {
174 	.name = "events",
175 	.attrs = events_attrs,
176 };
177 
178 PMU_FORMAT_ATTR(event, "config:0-63");
179 static struct attribute *format_attrs[] = {
180 	&format_attr_event.attr,
181 	NULL,
182 };
183 static struct attribute_group format_attr_group = {
184 	.name = "format",
185 	.attrs = format_attrs,
186 };
187 
188 static const struct attribute_group *attr_groups[] = {
189 	&events_attr_group,
190 	&format_attr_group,
191 	NULL,
192 };
193 
194 static const struct attribute_group *attr_update[] = {
195 	&group_aperf,
196 	&group_mperf,
197 	&group_pperf,
198 	&group_smi,
199 	&group_ptsc,
200 	&group_irperf,
201 	&group_therm,
202 	NULL,
203 };
204 
205 static int msr_event_init(struct perf_event *event)
206 {
207 	u64 cfg = event->attr.config;
208 
209 	if (event->attr.type != event->pmu->type)
210 		return -ENOENT;
211 
212 	/* unsupported modes and filters */
213 	if (event->attr.sample_period) /* no sampling */
214 		return -EINVAL;
215 
216 	if (cfg >= PERF_MSR_EVENT_MAX)
217 		return -EINVAL;
218 
219 	cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX);
220 
221 	if (!(msr_mask & (1 << cfg)))
222 		return -EINVAL;
223 
224 	event->hw.idx		= -1;
225 	event->hw.event_base	= msr[cfg].msr;
226 	event->hw.config	= cfg;
227 
228 	return 0;
229 }
230 
231 static inline u64 msr_read_counter(struct perf_event *event)
232 {
233 	u64 now;
234 
235 	if (event->hw.event_base)
236 		rdmsrq(event->hw.event_base, now);
237 	else
238 		now = rdtsc_ordered();
239 
240 	return now;
241 }
242 
243 static void msr_event_update(struct perf_event *event)
244 {
245 	u64 prev, now;
246 	s64 delta;
247 
248 	/* Careful, an NMI might modify the previous event value: */
249 	prev = local64_read(&event->hw.prev_count);
250 	do {
251 		now = msr_read_counter(event);
252 	} while (!local64_try_cmpxchg(&event->hw.prev_count, &prev, now));
253 
254 	delta = now - prev;
255 	if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
256 		delta = sign_extend64(delta, 31);
257 		local64_add(delta, &event->count);
258 	} else if (unlikely(event->hw.event_base == MSR_IA32_THERM_STATUS)) {
259 		/* If valid, extract digital readout, otherwise set to -1: */
260 		now = now & (1ULL << 31) ? (now >> 16) & 0x3f :  -1;
261 		local64_set(&event->count, now);
262 	} else {
263 		local64_add(delta, &event->count);
264 	}
265 }
266 
267 static void msr_event_start(struct perf_event *event, int flags)
268 {
269 	u64 now = msr_read_counter(event);
270 
271 	local64_set(&event->hw.prev_count, now);
272 }
273 
274 static void msr_event_stop(struct perf_event *event, int flags)
275 {
276 	msr_event_update(event);
277 }
278 
279 static void msr_event_del(struct perf_event *event, int flags)
280 {
281 	msr_event_stop(event, PERF_EF_UPDATE);
282 }
283 
284 static int msr_event_add(struct perf_event *event, int flags)
285 {
286 	if (flags & PERF_EF_START)
287 		msr_event_start(event, flags);
288 
289 	return 0;
290 }
291 
292 static struct pmu pmu_msr = {
293 	.task_ctx_nr	= perf_sw_context,
294 	.attr_groups	= attr_groups,
295 	.event_init	= msr_event_init,
296 	.add		= msr_event_add,
297 	.del		= msr_event_del,
298 	.start		= msr_event_start,
299 	.stop		= msr_event_stop,
300 	.read		= msr_event_update,
301 	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT | PERF_PMU_CAP_NO_EXCLUDE,
302 	.attr_update	= attr_update,
303 };
304 
305 static int __init msr_init(void)
306 {
307 	if (!boot_cpu_has(X86_FEATURE_TSC)) {
308 		pr_cont("no MSR PMU driver.\n");
309 		return 0;
310 	}
311 
312 	msr_mask = perf_msr_probe(msr, PERF_MSR_EVENT_MAX, true, NULL);
313 
314 	perf_pmu_register(&pmu_msr, "msr", -1);
315 
316 	return 0;
317 }
318 device_initcall(msr_init);
319