xref: /openbmc/linux/tools/perf/arch/arm64/util/arm-spe.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Arm Statistical Profiling Extensions (SPE) support
4  * Copyright (c) 2017-2018, Arm Ltd.
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/types.h>
9 #include <linux/bitops.h>
10 #include <linux/log2.h>
11 #include <linux/zalloc.h>
12 #include <time.h>
13 
14 #include "../../../util/cpumap.h"
15 #include "../../../util/event.h"
16 #include "../../../util/evsel.h"
17 #include "../../../util/evlist.h"
18 #include "../../../util/session.h"
19 #include <internal/lib.h> // page_size
20 #include "../../../util/pmu.h"
21 #include "../../../util/debug.h"
22 #include "../../../util/auxtrace.h"
23 #include "../../../util/record.h"
24 #include "../../../util/arm-spe.h"
25 
26 #define KiB(x) ((x) * 1024)
27 #define MiB(x) ((x) * 1024 * 1024)
28 
29 struct arm_spe_recording {
30 	struct auxtrace_record		itr;
31 	struct perf_pmu			*arm_spe_pmu;
32 	struct evlist		*evlist;
33 };
34 
35 static size_t
36 arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
37 		       struct evlist *evlist __maybe_unused)
38 {
39 	return ARM_SPE_AUXTRACE_PRIV_SIZE;
40 }
41 
42 static int arm_spe_info_fill(struct auxtrace_record *itr,
43 			     struct perf_session *session,
44 			     struct perf_record_auxtrace_info *auxtrace_info,
45 			     size_t priv_size)
46 {
47 	struct arm_spe_recording *sper =
48 			container_of(itr, struct arm_spe_recording, itr);
49 	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
50 
51 	if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
52 		return -EINVAL;
53 
54 	if (!session->evlist->core.nr_mmaps)
55 		return -EINVAL;
56 
57 	auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
58 	auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;
59 
60 	return 0;
61 }
62 
63 static int arm_spe_recording_options(struct auxtrace_record *itr,
64 				     struct evlist *evlist,
65 				     struct record_opts *opts)
66 {
67 	struct arm_spe_recording *sper =
68 			container_of(itr, struct arm_spe_recording, itr);
69 	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
70 	struct evsel *evsel, *arm_spe_evsel = NULL;
71 	bool privileged = perf_event_paranoid_check(-1);
72 	struct evsel *tracking_evsel;
73 	int err;
74 
75 	sper->evlist = evlist;
76 
77 	evlist__for_each_entry(evlist, evsel) {
78 		if (evsel->core.attr.type == arm_spe_pmu->type) {
79 			if (arm_spe_evsel) {
80 				pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
81 				return -EINVAL;
82 			}
83 			evsel->core.attr.freq = 0;
84 			evsel->core.attr.sample_period = 1;
85 			arm_spe_evsel = evsel;
86 			opts->full_auxtrace = true;
87 		}
88 	}
89 
90 	if (!opts->full_auxtrace)
91 		return 0;
92 
93 	/* We are in full trace mode but '-m,xyz' wasn't specified */
94 	if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
95 		if (privileged) {
96 			opts->auxtrace_mmap_pages = MiB(4) / page_size;
97 		} else {
98 			opts->auxtrace_mmap_pages = KiB(128) / page_size;
99 			if (opts->mmap_pages == UINT_MAX)
100 				opts->mmap_pages = KiB(256) / page_size;
101 		}
102 	}
103 
104 	/* Validate auxtrace_mmap_pages */
105 	if (opts->auxtrace_mmap_pages) {
106 		size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
107 		size_t min_sz = KiB(8);
108 
109 		if (sz < min_sz || !is_power_of_2(sz)) {
110 			pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
111 			       min_sz / 1024);
112 			return -EINVAL;
113 		}
114 	}
115 
116 
117 	/*
118 	 * To obtain the auxtrace buffer file descriptor, the auxtrace event
119 	 * must come first.
120 	 */
121 	perf_evlist__to_front(evlist, arm_spe_evsel);
122 
123 	perf_evsel__set_sample_bit(arm_spe_evsel, CPU);
124 	perf_evsel__set_sample_bit(arm_spe_evsel, TIME);
125 	perf_evsel__set_sample_bit(arm_spe_evsel, TID);
126 
127 	/* Add dummy event to keep tracking */
128 	err = parse_events(evlist, "dummy:u", NULL);
129 	if (err)
130 		return err;
131 
132 	tracking_evsel = evlist__last(evlist);
133 	perf_evlist__set_tracking_event(evlist, tracking_evsel);
134 
135 	tracking_evsel->core.attr.freq = 0;
136 	tracking_evsel->core.attr.sample_period = 1;
137 	perf_evsel__set_sample_bit(tracking_evsel, TIME);
138 	perf_evsel__set_sample_bit(tracking_evsel, CPU);
139 	perf_evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
140 
141 	return 0;
142 }
143 
144 static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
145 {
146 	struct timespec ts;
147 
148 	clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
149 
150 	return ts.tv_sec ^ ts.tv_nsec;
151 }
152 
153 static void arm_spe_recording_free(struct auxtrace_record *itr)
154 {
155 	struct arm_spe_recording *sper =
156 			container_of(itr, struct arm_spe_recording, itr);
157 
158 	free(sper);
159 }
160 
161 struct auxtrace_record *arm_spe_recording_init(int *err,
162 					       struct perf_pmu *arm_spe_pmu)
163 {
164 	struct arm_spe_recording *sper;
165 
166 	if (!arm_spe_pmu) {
167 		*err = -ENODEV;
168 		return NULL;
169 	}
170 
171 	sper = zalloc(sizeof(struct arm_spe_recording));
172 	if (!sper) {
173 		*err = -ENOMEM;
174 		return NULL;
175 	}
176 
177 	sper->arm_spe_pmu = arm_spe_pmu;
178 	sper->itr.pmu = arm_spe_pmu;
179 	sper->itr.recording_options = arm_spe_recording_options;
180 	sper->itr.info_priv_size = arm_spe_info_priv_size;
181 	sper->itr.info_fill = arm_spe_info_fill;
182 	sper->itr.free = arm_spe_recording_free;
183 	sper->itr.reference = arm_spe_reference;
184 	sper->itr.read_finish = auxtrace_record__read_finish;
185 	sper->itr.alignment = 0;
186 
187 	*err = 0;
188 	return &sper->itr;
189 }
190 
191 struct perf_event_attr
192 *arm_spe_pmu_default_config(struct perf_pmu *arm_spe_pmu)
193 {
194 	struct perf_event_attr *attr;
195 
196 	attr = zalloc(sizeof(struct perf_event_attr));
197 	if (!attr) {
198 		pr_err("arm_spe default config cannot allocate a perf_event_attr\n");
199 		return NULL;
200 	}
201 
202 	/*
203 	 * If kernel driver doesn't advertise a minimum,
204 	 * use max allowable by PMSIDR_EL1.INTERVAL
205 	 */
206 	if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
207 				  &attr->sample_period) != 1) {
208 		pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
209 		attr->sample_period = 4096;
210 	}
211 
212 	arm_spe_pmu->selectable = true;
213 	arm_spe_pmu->is_uncore = false;
214 
215 	return attr;
216 }
217