xref: /openbmc/linux/arch/x86/events/msr.c (revision c0c45238)
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/intel-family.h>
6 #include "probe.h"
7 
8 enum perf_msr_id {
9 	PERF_MSR_TSC			= 0,
10 	PERF_MSR_APERF			= 1,
11 	PERF_MSR_MPERF			= 2,
12 	PERF_MSR_PPERF			= 3,
13 	PERF_MSR_SMI			= 4,
14 	PERF_MSR_PTSC			= 5,
15 	PERF_MSR_IRPERF			= 6,
16 	PERF_MSR_THERM			= 7,
17 	PERF_MSR_EVENT_MAX,
18 };
19 
20 static bool test_aperfmperf(int idx, void *data)
21 {
22 	return boot_cpu_has(X86_FEATURE_APERFMPERF);
23 }
24 
25 static bool test_ptsc(int idx, void *data)
26 {
27 	return boot_cpu_has(X86_FEATURE_PTSC);
28 }
29 
30 static bool test_irperf(int idx, void *data)
31 {
32 	return boot_cpu_has(X86_FEATURE_IRPERF);
33 }
34 
35 static bool test_therm_status(int idx, void *data)
36 {
37 	return boot_cpu_has(X86_FEATURE_DTHERM);
38 }
39 
40 static bool test_intel(int idx, void *data)
41 {
42 	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
43 	    boot_cpu_data.x86 != 6)
44 		return false;
45 
46 	switch (boot_cpu_data.x86_model) {
47 	case INTEL_FAM6_NEHALEM:
48 	case INTEL_FAM6_NEHALEM_G:
49 	case INTEL_FAM6_NEHALEM_EP:
50 	case INTEL_FAM6_NEHALEM_EX:
51 
52 	case INTEL_FAM6_WESTMERE:
53 	case INTEL_FAM6_WESTMERE_EP:
54 	case INTEL_FAM6_WESTMERE_EX:
55 
56 	case INTEL_FAM6_SANDYBRIDGE:
57 	case INTEL_FAM6_SANDYBRIDGE_X:
58 
59 	case INTEL_FAM6_IVYBRIDGE:
60 	case INTEL_FAM6_IVYBRIDGE_X:
61 
62 	case INTEL_FAM6_HASWELL:
63 	case INTEL_FAM6_HASWELL_X:
64 	case INTEL_FAM6_HASWELL_L:
65 	case INTEL_FAM6_HASWELL_G:
66 
67 	case INTEL_FAM6_BROADWELL:
68 	case INTEL_FAM6_BROADWELL_D:
69 	case INTEL_FAM6_BROADWELL_G:
70 	case INTEL_FAM6_BROADWELL_X:
71 	case INTEL_FAM6_SAPPHIRERAPIDS_X:
72 
73 	case INTEL_FAM6_ATOM_SILVERMONT:
74 	case INTEL_FAM6_ATOM_SILVERMONT_D:
75 	case INTEL_FAM6_ATOM_AIRMONT:
76 
77 	case INTEL_FAM6_ATOM_GOLDMONT:
78 	case INTEL_FAM6_ATOM_GOLDMONT_D:
79 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
80 	case INTEL_FAM6_ATOM_TREMONT_D:
81 	case INTEL_FAM6_ATOM_TREMONT:
82 	case INTEL_FAM6_ATOM_TREMONT_L:
83 
84 	case INTEL_FAM6_XEON_PHI_KNL:
85 	case INTEL_FAM6_XEON_PHI_KNM:
86 		if (idx == PERF_MSR_SMI)
87 			return true;
88 		break;
89 
90 	case INTEL_FAM6_SKYLAKE_L:
91 	case INTEL_FAM6_SKYLAKE:
92 	case INTEL_FAM6_SKYLAKE_X:
93 	case INTEL_FAM6_KABYLAKE_L:
94 	case INTEL_FAM6_KABYLAKE:
95 	case INTEL_FAM6_COMETLAKE_L:
96 	case INTEL_FAM6_COMETLAKE:
97 	case INTEL_FAM6_ICELAKE_L:
98 	case INTEL_FAM6_ICELAKE:
99 	case INTEL_FAM6_ICELAKE_X:
100 	case INTEL_FAM6_ICELAKE_D:
101 	case INTEL_FAM6_TIGERLAKE_L:
102 	case INTEL_FAM6_TIGERLAKE:
103 	case INTEL_FAM6_ROCKETLAKE:
104 	case INTEL_FAM6_ALDERLAKE:
105 	case INTEL_FAM6_ALDERLAKE_L:
106 	case INTEL_FAM6_RAPTORLAKE:
107 		if (idx == PERF_MSR_SMI || idx == PERF_MSR_PPERF)
108 			return true;
109 		break;
110 	}
111 
112 	return false;
113 }
114 
115 PMU_EVENT_ATTR_STRING(tsc,				attr_tsc,		"event=0x00"	);
116 PMU_EVENT_ATTR_STRING(aperf,				attr_aperf,		"event=0x01"	);
117 PMU_EVENT_ATTR_STRING(mperf,				attr_mperf,		"event=0x02"	);
118 PMU_EVENT_ATTR_STRING(pperf,				attr_pperf,		"event=0x03"	);
119 PMU_EVENT_ATTR_STRING(smi,				attr_smi,		"event=0x04"	);
120 PMU_EVENT_ATTR_STRING(ptsc,				attr_ptsc,		"event=0x05"	);
121 PMU_EVENT_ATTR_STRING(irperf,				attr_irperf,		"event=0x06"	);
122 PMU_EVENT_ATTR_STRING(cpu_thermal_margin,		attr_therm,		"event=0x07"	);
123 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.snapshot,	attr_therm_snap,	"1"		);
124 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.unit,		attr_therm_unit,	"C"		);
125 
126 static unsigned long msr_mask;
127 
128 PMU_EVENT_GROUP(events, aperf);
129 PMU_EVENT_GROUP(events, mperf);
130 PMU_EVENT_GROUP(events, pperf);
131 PMU_EVENT_GROUP(events, smi);
132 PMU_EVENT_GROUP(events, ptsc);
133 PMU_EVENT_GROUP(events, irperf);
134 
135 static struct attribute *attrs_therm[] = {
136 	&attr_therm.attr.attr,
137 	&attr_therm_snap.attr.attr,
138 	&attr_therm_unit.attr.attr,
139 	NULL,
140 };
141 
142 static struct attribute_group group_therm = {
143 	.name  = "events",
144 	.attrs = attrs_therm,
145 };
146 
147 static struct perf_msr msr[] = {
148 	[PERF_MSR_TSC]		= { .no_check = true,								},
149 	[PERF_MSR_APERF]	= { MSR_IA32_APERF,		&group_aperf,		test_aperfmperf,	},
150 	[PERF_MSR_MPERF]	= { MSR_IA32_MPERF,		&group_mperf,		test_aperfmperf,	},
151 	[PERF_MSR_PPERF]	= { MSR_PPERF,			&group_pperf,		test_intel,		},
152 	[PERF_MSR_SMI]		= { MSR_SMI_COUNT,		&group_smi,		test_intel,		},
153 	[PERF_MSR_PTSC]		= { MSR_F15H_PTSC,		&group_ptsc,		test_ptsc,		},
154 	[PERF_MSR_IRPERF]	= { MSR_F17H_IRPERF,		&group_irperf,		test_irperf,		},
155 	[PERF_MSR_THERM]	= { MSR_IA32_THERM_STATUS,	&group_therm,		test_therm_status,	},
156 };
157 
158 static struct attribute *events_attrs[] = {
159 	&attr_tsc.attr.attr,
160 	NULL,
161 };
162 
163 static struct attribute_group events_attr_group = {
164 	.name = "events",
165 	.attrs = events_attrs,
166 };
167 
168 PMU_FORMAT_ATTR(event, "config:0-63");
169 static struct attribute *format_attrs[] = {
170 	&format_attr_event.attr,
171 	NULL,
172 };
173 static struct attribute_group format_attr_group = {
174 	.name = "format",
175 	.attrs = format_attrs,
176 };
177 
178 static const struct attribute_group *attr_groups[] = {
179 	&events_attr_group,
180 	&format_attr_group,
181 	NULL,
182 };
183 
184 static const struct attribute_group *attr_update[] = {
185 	&group_aperf,
186 	&group_mperf,
187 	&group_pperf,
188 	&group_smi,
189 	&group_ptsc,
190 	&group_irperf,
191 	&group_therm,
192 	NULL,
193 };
194 
195 static int msr_event_init(struct perf_event *event)
196 {
197 	u64 cfg = event->attr.config;
198 
199 	if (event->attr.type != event->pmu->type)
200 		return -ENOENT;
201 
202 	/* unsupported modes and filters */
203 	if (event->attr.sample_period) /* no sampling */
204 		return -EINVAL;
205 
206 	if (cfg >= PERF_MSR_EVENT_MAX)
207 		return -EINVAL;
208 
209 	cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX);
210 
211 	if (!(msr_mask & (1 << cfg)))
212 		return -EINVAL;
213 
214 	event->hw.idx		= -1;
215 	event->hw.event_base	= msr[cfg].msr;
216 	event->hw.config	= cfg;
217 
218 	return 0;
219 }
220 
221 static inline u64 msr_read_counter(struct perf_event *event)
222 {
223 	u64 now;
224 
225 	if (event->hw.event_base)
226 		rdmsrl(event->hw.event_base, now);
227 	else
228 		now = rdtsc_ordered();
229 
230 	return now;
231 }
232 
233 static void msr_event_update(struct perf_event *event)
234 {
235 	u64 prev, now;
236 	s64 delta;
237 
238 	/* Careful, an NMI might modify the previous event value: */
239 again:
240 	prev = local64_read(&event->hw.prev_count);
241 	now = msr_read_counter(event);
242 
243 	if (local64_cmpxchg(&event->hw.prev_count, prev, now) != prev)
244 		goto again;
245 
246 	delta = now - prev;
247 	if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
248 		delta = sign_extend64(delta, 31);
249 		local64_add(delta, &event->count);
250 	} else if (unlikely(event->hw.event_base == MSR_IA32_THERM_STATUS)) {
251 		/* If valid, extract digital readout, otherwise set to -1: */
252 		now = now & (1ULL << 31) ? (now >> 16) & 0x3f :  -1;
253 		local64_set(&event->count, now);
254 	} else {
255 		local64_add(delta, &event->count);
256 	}
257 }
258 
259 static void msr_event_start(struct perf_event *event, int flags)
260 {
261 	u64 now = msr_read_counter(event);
262 
263 	local64_set(&event->hw.prev_count, now);
264 }
265 
266 static void msr_event_stop(struct perf_event *event, int flags)
267 {
268 	msr_event_update(event);
269 }
270 
271 static void msr_event_del(struct perf_event *event, int flags)
272 {
273 	msr_event_stop(event, PERF_EF_UPDATE);
274 }
275 
276 static int msr_event_add(struct perf_event *event, int flags)
277 {
278 	if (flags & PERF_EF_START)
279 		msr_event_start(event, flags);
280 
281 	return 0;
282 }
283 
284 static struct pmu pmu_msr = {
285 	.task_ctx_nr	= perf_sw_context,
286 	.attr_groups	= attr_groups,
287 	.event_init	= msr_event_init,
288 	.add		= msr_event_add,
289 	.del		= msr_event_del,
290 	.start		= msr_event_start,
291 	.stop		= msr_event_stop,
292 	.read		= msr_event_update,
293 	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT | PERF_PMU_CAP_NO_EXCLUDE,
294 	.attr_update	= attr_update,
295 };
296 
297 static int __init msr_init(void)
298 {
299 	if (!boot_cpu_has(X86_FEATURE_TSC)) {
300 		pr_cont("no MSR PMU driver.\n");
301 		return 0;
302 	}
303 
304 	msr_mask = perf_msr_probe(msr, PERF_MSR_EVENT_MAX, true, NULL);
305 
306 	perf_pmu_register(&pmu_msr, "msr", -1);
307 
308 	return 0;
309 }
310 device_initcall(msr_init);
311