xref: /openbmc/linux/tools/perf/arch/arm64/util/arm-spe.c (revision 3213486f)
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 <time.h>
12 
13 #include "../../util/cpumap.h"
14 #include "../../util/evsel.h"
15 #include "../../util/evlist.h"
16 #include "../../util/session.h"
17 #include "../../util/util.h"
18 #include "../../util/pmu.h"
19 #include "../../util/debug.h"
20 #include "../../util/auxtrace.h"
21 #include "../../util/arm-spe.h"
22 
23 #define KiB(x) ((x) * 1024)
24 #define MiB(x) ((x) * 1024 * 1024)
25 
26 struct arm_spe_recording {
27 	struct auxtrace_record		itr;
28 	struct perf_pmu			*arm_spe_pmu;
29 	struct perf_evlist		*evlist;
30 };
31 
32 static size_t
33 arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
34 		       struct perf_evlist *evlist __maybe_unused)
35 {
36 	return ARM_SPE_AUXTRACE_PRIV_SIZE;
37 }
38 
39 static int arm_spe_info_fill(struct auxtrace_record *itr,
40 			     struct perf_session *session,
41 			     struct auxtrace_info_event *auxtrace_info,
42 			     size_t priv_size)
43 {
44 	struct arm_spe_recording *sper =
45 			container_of(itr, struct arm_spe_recording, itr);
46 	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
47 
48 	if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
49 		return -EINVAL;
50 
51 	if (!session->evlist->nr_mmaps)
52 		return -EINVAL;
53 
54 	auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
55 	auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;
56 
57 	return 0;
58 }
59 
60 static int arm_spe_recording_options(struct auxtrace_record *itr,
61 				     struct perf_evlist *evlist,
62 				     struct record_opts *opts)
63 {
64 	struct arm_spe_recording *sper =
65 			container_of(itr, struct arm_spe_recording, itr);
66 	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
67 	struct perf_evsel *evsel, *arm_spe_evsel = NULL;
68 	bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
69 	struct perf_evsel *tracking_evsel;
70 	int err;
71 
72 	sper->evlist = evlist;
73 
74 	evlist__for_each_entry(evlist, evsel) {
75 		if (evsel->attr.type == arm_spe_pmu->type) {
76 			if (arm_spe_evsel) {
77 				pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
78 				return -EINVAL;
79 			}
80 			evsel->attr.freq = 0;
81 			evsel->attr.sample_period = 1;
82 			arm_spe_evsel = evsel;
83 			opts->full_auxtrace = true;
84 		}
85 	}
86 
87 	if (!opts->full_auxtrace)
88 		return 0;
89 
90 	/* We are in full trace mode but '-m,xyz' wasn't specified */
91 	if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
92 		if (privileged) {
93 			opts->auxtrace_mmap_pages = MiB(4) / page_size;
94 		} else {
95 			opts->auxtrace_mmap_pages = KiB(128) / page_size;
96 			if (opts->mmap_pages == UINT_MAX)
97 				opts->mmap_pages = KiB(256) / page_size;
98 		}
99 	}
100 
101 	/* Validate auxtrace_mmap_pages */
102 	if (opts->auxtrace_mmap_pages) {
103 		size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
104 		size_t min_sz = KiB(8);
105 
106 		if (sz < min_sz || !is_power_of_2(sz)) {
107 			pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
108 			       min_sz / 1024);
109 			return -EINVAL;
110 		}
111 	}
112 
113 
114 	/*
115 	 * To obtain the auxtrace buffer file descriptor, the auxtrace event
116 	 * must come first.
117 	 */
118 	perf_evlist__to_front(evlist, arm_spe_evsel);
119 
120 	perf_evsel__set_sample_bit(arm_spe_evsel, CPU);
121 	perf_evsel__set_sample_bit(arm_spe_evsel, TIME);
122 	perf_evsel__set_sample_bit(arm_spe_evsel, TID);
123 
124 	/* Add dummy event to keep tracking */
125 	err = parse_events(evlist, "dummy:u", NULL);
126 	if (err)
127 		return err;
128 
129 	tracking_evsel = perf_evlist__last(evlist);
130 	perf_evlist__set_tracking_event(evlist, tracking_evsel);
131 
132 	tracking_evsel->attr.freq = 0;
133 	tracking_evsel->attr.sample_period = 1;
134 	perf_evsel__set_sample_bit(tracking_evsel, TIME);
135 	perf_evsel__set_sample_bit(tracking_evsel, CPU);
136 	perf_evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
137 
138 	return 0;
139 }
140 
141 static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
142 {
143 	struct timespec ts;
144 
145 	clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
146 
147 	return ts.tv_sec ^ ts.tv_nsec;
148 }
149 
150 static void arm_spe_recording_free(struct auxtrace_record *itr)
151 {
152 	struct arm_spe_recording *sper =
153 			container_of(itr, struct arm_spe_recording, itr);
154 
155 	free(sper);
156 }
157 
158 static int arm_spe_read_finish(struct auxtrace_record *itr, int idx)
159 {
160 	struct arm_spe_recording *sper =
161 			container_of(itr, struct arm_spe_recording, itr);
162 	struct perf_evsel *evsel;
163 
164 	evlist__for_each_entry(sper->evlist, evsel) {
165 		if (evsel->attr.type == sper->arm_spe_pmu->type)
166 			return perf_evlist__enable_event_idx(sper->evlist,
167 							     evsel, idx);
168 	}
169 	return -EINVAL;
170 }
171 
172 struct auxtrace_record *arm_spe_recording_init(int *err,
173 					       struct perf_pmu *arm_spe_pmu)
174 {
175 	struct arm_spe_recording *sper;
176 
177 	if (!arm_spe_pmu) {
178 		*err = -ENODEV;
179 		return NULL;
180 	}
181 
182 	sper = zalloc(sizeof(struct arm_spe_recording));
183 	if (!sper) {
184 		*err = -ENOMEM;
185 		return NULL;
186 	}
187 
188 	sper->arm_spe_pmu = arm_spe_pmu;
189 	sper->itr.recording_options = arm_spe_recording_options;
190 	sper->itr.info_priv_size = arm_spe_info_priv_size;
191 	sper->itr.info_fill = arm_spe_info_fill;
192 	sper->itr.free = arm_spe_recording_free;
193 	sper->itr.reference = arm_spe_reference;
194 	sper->itr.read_finish = arm_spe_read_finish;
195 	sper->itr.alignment = 0;
196 
197 	*err = 0;
198 	return &sper->itr;
199 }
200 
201 struct perf_event_attr
202 *arm_spe_pmu_default_config(struct perf_pmu *arm_spe_pmu)
203 {
204 	struct perf_event_attr *attr;
205 
206 	attr = zalloc(sizeof(struct perf_event_attr));
207 	if (!attr) {
208 		pr_err("arm_spe default config cannot allocate a perf_event_attr\n");
209 		return NULL;
210 	}
211 
212 	/*
213 	 * If kernel driver doesn't advertise a minimum,
214 	 * use max allowable by PMSIDR_EL1.INTERVAL
215 	 */
216 	if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
217 				  &attr->sample_period) != 1) {
218 		pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
219 		attr->sample_period = 4096;
220 	}
221 
222 	arm_spe_pmu->selectable = true;
223 	arm_spe_pmu->is_uncore = false;
224 
225 	return attr;
226 }
227