xref: /openbmc/linux/arch/x86/events/msr.c (revision dc6a81c3)
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 
72 	case INTEL_FAM6_ATOM_SILVERMONT:
73 	case INTEL_FAM6_ATOM_SILVERMONT_D:
74 	case INTEL_FAM6_ATOM_AIRMONT:
75 
76 	case INTEL_FAM6_ATOM_GOLDMONT:
77 	case INTEL_FAM6_ATOM_GOLDMONT_D:
78 
79 	case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
80 
81 	case INTEL_FAM6_XEON_PHI_KNL:
82 	case INTEL_FAM6_XEON_PHI_KNM:
83 		if (idx == PERF_MSR_SMI)
84 			return true;
85 		break;
86 
87 	case INTEL_FAM6_SKYLAKE_L:
88 	case INTEL_FAM6_SKYLAKE:
89 	case INTEL_FAM6_SKYLAKE_X:
90 	case INTEL_FAM6_KABYLAKE_L:
91 	case INTEL_FAM6_KABYLAKE:
92 	case INTEL_FAM6_COMETLAKE_L:
93 	case INTEL_FAM6_COMETLAKE:
94 	case INTEL_FAM6_ICELAKE_L:
95 	case INTEL_FAM6_ICELAKE:
96 	case INTEL_FAM6_ICELAKE_X:
97 	case INTEL_FAM6_ICELAKE_D:
98 	case INTEL_FAM6_TIGERLAKE_L:
99 	case INTEL_FAM6_TIGERLAKE:
100 		if (idx == PERF_MSR_SMI || idx == PERF_MSR_PPERF)
101 			return true;
102 		break;
103 	}
104 
105 	return false;
106 }
107 
108 PMU_EVENT_ATTR_STRING(tsc,				attr_tsc,		"event=0x00"	);
109 PMU_EVENT_ATTR_STRING(aperf,				attr_aperf,		"event=0x01"	);
110 PMU_EVENT_ATTR_STRING(mperf,				attr_mperf,		"event=0x02"	);
111 PMU_EVENT_ATTR_STRING(pperf,				attr_pperf,		"event=0x03"	);
112 PMU_EVENT_ATTR_STRING(smi,				attr_smi,		"event=0x04"	);
113 PMU_EVENT_ATTR_STRING(ptsc,				attr_ptsc,		"event=0x05"	);
114 PMU_EVENT_ATTR_STRING(irperf,				attr_irperf,		"event=0x06"	);
115 PMU_EVENT_ATTR_STRING(cpu_thermal_margin,		attr_therm,		"event=0x07"	);
116 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.snapshot,	attr_therm_snap,	"1"		);
117 PMU_EVENT_ATTR_STRING(cpu_thermal_margin.unit,		attr_therm_unit,	"C"		);
118 
119 static unsigned long msr_mask;
120 
121 PMU_EVENT_GROUP(events, aperf);
122 PMU_EVENT_GROUP(events, mperf);
123 PMU_EVENT_GROUP(events, pperf);
124 PMU_EVENT_GROUP(events, smi);
125 PMU_EVENT_GROUP(events, ptsc);
126 PMU_EVENT_GROUP(events, irperf);
127 
128 static struct attribute *attrs_therm[] = {
129 	&attr_therm.attr.attr,
130 	&attr_therm_snap.attr.attr,
131 	&attr_therm_unit.attr.attr,
132 	NULL,
133 };
134 
135 static struct attribute_group group_therm = {
136 	.name  = "events",
137 	.attrs = attrs_therm,
138 };
139 
140 static struct perf_msr msr[] = {
141 	[PERF_MSR_TSC]		= { .no_check = true,								},
142 	[PERF_MSR_APERF]	= { MSR_IA32_APERF,		&group_aperf,		test_aperfmperf,	},
143 	[PERF_MSR_MPERF]	= { MSR_IA32_MPERF,		&group_mperf,		test_aperfmperf,	},
144 	[PERF_MSR_PPERF]	= { MSR_PPERF,			&group_pperf,		test_intel,		},
145 	[PERF_MSR_SMI]		= { MSR_SMI_COUNT,		&group_smi,		test_intel,		},
146 	[PERF_MSR_PTSC]		= { MSR_F15H_PTSC,		&group_ptsc,		test_ptsc,		},
147 	[PERF_MSR_IRPERF]	= { MSR_F17H_IRPERF,		&group_irperf,		test_irperf,		},
148 	[PERF_MSR_THERM]	= { MSR_IA32_THERM_STATUS,	&group_therm,		test_therm_status,	},
149 };
150 
151 static struct attribute *events_attrs[] = {
152 	&attr_tsc.attr.attr,
153 	NULL,
154 };
155 
156 static struct attribute_group events_attr_group = {
157 	.name = "events",
158 	.attrs = events_attrs,
159 };
160 
161 PMU_FORMAT_ATTR(event, "config:0-63");
162 static struct attribute *format_attrs[] = {
163 	&format_attr_event.attr,
164 	NULL,
165 };
166 static struct attribute_group format_attr_group = {
167 	.name = "format",
168 	.attrs = format_attrs,
169 };
170 
171 static const struct attribute_group *attr_groups[] = {
172 	&events_attr_group,
173 	&format_attr_group,
174 	NULL,
175 };
176 
177 static const struct attribute_group *attr_update[] = {
178 	&group_aperf,
179 	&group_mperf,
180 	&group_pperf,
181 	&group_smi,
182 	&group_ptsc,
183 	&group_irperf,
184 	&group_therm,
185 	NULL,
186 };
187 
188 static int msr_event_init(struct perf_event *event)
189 {
190 	u64 cfg = event->attr.config;
191 
192 	if (event->attr.type != event->pmu->type)
193 		return -ENOENT;
194 
195 	/* unsupported modes and filters */
196 	if (event->attr.sample_period) /* no sampling */
197 		return -EINVAL;
198 
199 	if (cfg >= PERF_MSR_EVENT_MAX)
200 		return -EINVAL;
201 
202 	cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX);
203 
204 	if (!(msr_mask & (1 << cfg)))
205 		return -EINVAL;
206 
207 	event->hw.idx		= -1;
208 	event->hw.event_base	= msr[cfg].msr;
209 	event->hw.config	= cfg;
210 
211 	return 0;
212 }
213 
214 static inline u64 msr_read_counter(struct perf_event *event)
215 {
216 	u64 now;
217 
218 	if (event->hw.event_base)
219 		rdmsrl(event->hw.event_base, now);
220 	else
221 		now = rdtsc_ordered();
222 
223 	return now;
224 }
225 
226 static void msr_event_update(struct perf_event *event)
227 {
228 	u64 prev, now;
229 	s64 delta;
230 
231 	/* Careful, an NMI might modify the previous event value: */
232 again:
233 	prev = local64_read(&event->hw.prev_count);
234 	now = msr_read_counter(event);
235 
236 	if (local64_cmpxchg(&event->hw.prev_count, prev, now) != prev)
237 		goto again;
238 
239 	delta = now - prev;
240 	if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
241 		delta = sign_extend64(delta, 31);
242 		local64_add(delta, &event->count);
243 	} else if (unlikely(event->hw.event_base == MSR_IA32_THERM_STATUS)) {
244 		/* If valid, extract digital readout, otherwise set to -1: */
245 		now = now & (1ULL << 31) ? (now >> 16) & 0x3f :  -1;
246 		local64_set(&event->count, now);
247 	} else {
248 		local64_add(delta, &event->count);
249 	}
250 }
251 
252 static void msr_event_start(struct perf_event *event, int flags)
253 {
254 	u64 now = msr_read_counter(event);
255 
256 	local64_set(&event->hw.prev_count, now);
257 }
258 
259 static void msr_event_stop(struct perf_event *event, int flags)
260 {
261 	msr_event_update(event);
262 }
263 
264 static void msr_event_del(struct perf_event *event, int flags)
265 {
266 	msr_event_stop(event, PERF_EF_UPDATE);
267 }
268 
269 static int msr_event_add(struct perf_event *event, int flags)
270 {
271 	if (flags & PERF_EF_START)
272 		msr_event_start(event, flags);
273 
274 	return 0;
275 }
276 
277 static struct pmu pmu_msr = {
278 	.task_ctx_nr	= perf_sw_context,
279 	.attr_groups	= attr_groups,
280 	.event_init	= msr_event_init,
281 	.add		= msr_event_add,
282 	.del		= msr_event_del,
283 	.start		= msr_event_start,
284 	.stop		= msr_event_stop,
285 	.read		= msr_event_update,
286 	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT | PERF_PMU_CAP_NO_EXCLUDE,
287 	.attr_update	= attr_update,
288 };
289 
290 static int __init msr_init(void)
291 {
292 	if (!boot_cpu_has(X86_FEATURE_TSC)) {
293 		pr_cont("no MSR PMU driver.\n");
294 		return 0;
295 	}
296 
297 	msr_mask = perf_msr_probe(msr, PERF_MSR_EVENT_MAX, true, NULL);
298 
299 	perf_pmu_register(&pmu_msr, "msr", -1);
300 
301 	return 0;
302 }
303 device_initcall(msr_init);
304