xref: /kernel/linux/linux-5.10/arch/x86/events/msr.c (revision 8c2ecf20)
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
8enum 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
20static bool test_aperfmperf(int idx, void *data)
21{
22	return boot_cpu_has(X86_FEATURE_APERFMPERF);
23}
24
25static bool test_ptsc(int idx, void *data)
26{
27	return boot_cpu_has(X86_FEATURE_PTSC);
28}
29
30static bool test_irperf(int idx, void *data)
31{
32	return boot_cpu_has(X86_FEATURE_IRPERF);
33}
34
35static bool test_therm_status(int idx, void *data)
36{
37	return boot_cpu_has(X86_FEATURE_DTHERM);
38}
39
40static 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		if (idx == PERF_MSR_SMI || idx == PERF_MSR_PPERF)
104			return true;
105		break;
106	}
107
108	return false;
109}
110
111PMU_EVENT_ATTR_STRING(tsc,				attr_tsc,		"event=0x00"	);
112PMU_EVENT_ATTR_STRING(aperf,				attr_aperf,		"event=0x01"	);
113PMU_EVENT_ATTR_STRING(mperf,				attr_mperf,		"event=0x02"	);
114PMU_EVENT_ATTR_STRING(pperf,				attr_pperf,		"event=0x03"	);
115PMU_EVENT_ATTR_STRING(smi,				attr_smi,		"event=0x04"	);
116PMU_EVENT_ATTR_STRING(ptsc,				attr_ptsc,		"event=0x05"	);
117PMU_EVENT_ATTR_STRING(irperf,				attr_irperf,		"event=0x06"	);
118PMU_EVENT_ATTR_STRING(cpu_thermal_margin,		attr_therm,		"event=0x07"	);
119PMU_EVENT_ATTR_STRING(cpu_thermal_margin.snapshot,	attr_therm_snap,	"1"		);
120PMU_EVENT_ATTR_STRING(cpu_thermal_margin.unit,		attr_therm_unit,	"C"		);
121
122static unsigned long msr_mask;
123
124PMU_EVENT_GROUP(events, aperf);
125PMU_EVENT_GROUP(events, mperf);
126PMU_EVENT_GROUP(events, pperf);
127PMU_EVENT_GROUP(events, smi);
128PMU_EVENT_GROUP(events, ptsc);
129PMU_EVENT_GROUP(events, irperf);
130
131static struct attribute *attrs_therm[] = {
132	&attr_therm.attr.attr,
133	&attr_therm_snap.attr.attr,
134	&attr_therm_unit.attr.attr,
135	NULL,
136};
137
138static struct attribute_group group_therm = {
139	.name  = "events",
140	.attrs = attrs_therm,
141};
142
143static struct perf_msr msr[] = {
144	[PERF_MSR_TSC]		= { .no_check = true,								},
145	[PERF_MSR_APERF]	= { MSR_IA32_APERF,		&group_aperf,		test_aperfmperf,	},
146	[PERF_MSR_MPERF]	= { MSR_IA32_MPERF,		&group_mperf,		test_aperfmperf,	},
147	[PERF_MSR_PPERF]	= { MSR_PPERF,			&group_pperf,		test_intel,		},
148	[PERF_MSR_SMI]		= { MSR_SMI_COUNT,		&group_smi,		test_intel,		},
149	[PERF_MSR_PTSC]		= { MSR_F15H_PTSC,		&group_ptsc,		test_ptsc,		},
150	[PERF_MSR_IRPERF]	= { MSR_F17H_IRPERF,		&group_irperf,		test_irperf,		},
151	[PERF_MSR_THERM]	= { MSR_IA32_THERM_STATUS,	&group_therm,		test_therm_status,	},
152};
153
154static struct attribute *events_attrs[] = {
155	&attr_tsc.attr.attr,
156	NULL,
157};
158
159static struct attribute_group events_attr_group = {
160	.name = "events",
161	.attrs = events_attrs,
162};
163
164PMU_FORMAT_ATTR(event, "config:0-63");
165static struct attribute *format_attrs[] = {
166	&format_attr_event.attr,
167	NULL,
168};
169static struct attribute_group format_attr_group = {
170	.name = "format",
171	.attrs = format_attrs,
172};
173
174static const struct attribute_group *attr_groups[] = {
175	&events_attr_group,
176	&format_attr_group,
177	NULL,
178};
179
180static const struct attribute_group *attr_update[] = {
181	&group_aperf,
182	&group_mperf,
183	&group_pperf,
184	&group_smi,
185	&group_ptsc,
186	&group_irperf,
187	&group_therm,
188	NULL,
189};
190
191static int msr_event_init(struct perf_event *event)
192{
193	u64 cfg = event->attr.config;
194
195	if (event->attr.type != event->pmu->type)
196		return -ENOENT;
197
198	/* unsupported modes and filters */
199	if (event->attr.sample_period) /* no sampling */
200		return -EINVAL;
201
202	if (cfg >= PERF_MSR_EVENT_MAX)
203		return -EINVAL;
204
205	cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX);
206
207	if (!(msr_mask & (1 << cfg)))
208		return -EINVAL;
209
210	event->hw.idx		= -1;
211	event->hw.event_base	= msr[cfg].msr;
212	event->hw.config	= cfg;
213
214	return 0;
215}
216
217static inline u64 msr_read_counter(struct perf_event *event)
218{
219	u64 now;
220
221	if (event->hw.event_base)
222		rdmsrl(event->hw.event_base, now);
223	else
224		now = rdtsc_ordered();
225
226	return now;
227}
228
229static void msr_event_update(struct perf_event *event)
230{
231	u64 prev, now;
232	s64 delta;
233
234	/* Careful, an NMI might modify the previous event value: */
235again:
236	prev = local64_read(&event->hw.prev_count);
237	now = msr_read_counter(event);
238
239	if (local64_cmpxchg(&event->hw.prev_count, prev, now) != prev)
240		goto again;
241
242	delta = now - prev;
243	if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
244		delta = sign_extend64(delta, 31);
245		local64_add(delta, &event->count);
246	} else if (unlikely(event->hw.event_base == MSR_IA32_THERM_STATUS)) {
247		/* If valid, extract digital readout, otherwise set to -1: */
248		now = now & (1ULL << 31) ? (now >> 16) & 0x3f :  -1;
249		local64_set(&event->count, now);
250	} else {
251		local64_add(delta, &event->count);
252	}
253}
254
255static void msr_event_start(struct perf_event *event, int flags)
256{
257	u64 now = msr_read_counter(event);
258
259	local64_set(&event->hw.prev_count, now);
260}
261
262static void msr_event_stop(struct perf_event *event, int flags)
263{
264	msr_event_update(event);
265}
266
267static void msr_event_del(struct perf_event *event, int flags)
268{
269	msr_event_stop(event, PERF_EF_UPDATE);
270}
271
272static int msr_event_add(struct perf_event *event, int flags)
273{
274	if (flags & PERF_EF_START)
275		msr_event_start(event, flags);
276
277	return 0;
278}
279
280static struct pmu pmu_msr = {
281	.task_ctx_nr	= perf_sw_context,
282	.attr_groups	= attr_groups,
283	.event_init	= msr_event_init,
284	.add		= msr_event_add,
285	.del		= msr_event_del,
286	.start		= msr_event_start,
287	.stop		= msr_event_stop,
288	.read		= msr_event_update,
289	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT | PERF_PMU_CAP_NO_EXCLUDE,
290	.attr_update	= attr_update,
291};
292
293static int __init msr_init(void)
294{
295	if (!boot_cpu_has(X86_FEATURE_TSC)) {
296		pr_cont("no MSR PMU driver.\n");
297		return 0;
298	}
299
300	msr_mask = perf_msr_probe(msr, PERF_MSR_EVENT_MAX, true, NULL);
301
302	perf_pmu_register(&pmu_msr, "msr", -1);
303
304	return 0;
305}
306device_initcall(msr_init);
307