xref: /openbmc/linux/tools/perf/arch/arm64/util/arm-spe.c (revision 8dda2eac)
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/evsel_config.h"
18 #include "../../../util/evlist.h"
19 #include "../../../util/session.h"
20 #include <internal/lib.h> // page_size
21 #include "../../../util/pmu.h"
22 #include "../../../util/debug.h"
23 #include "../../../util/auxtrace.h"
24 #include "../../../util/record.h"
25 #include "../../../util/arm-spe.h"
26 
27 #define KiB(x) ((x) * 1024)
28 #define MiB(x) ((x) * 1024 * 1024)
29 
30 struct arm_spe_recording {
31 	struct auxtrace_record		itr;
32 	struct perf_pmu			*arm_spe_pmu;
33 	struct evlist		*evlist;
34 };
35 
36 static void arm_spe_set_timestamp(struct auxtrace_record *itr,
37 				  struct evsel *evsel)
38 {
39 	struct arm_spe_recording *ptr;
40 	struct perf_pmu *arm_spe_pmu;
41 	struct evsel_config_term *term = evsel__get_config_term(evsel, CFG_CHG);
42 	u64 user_bits = 0, bit;
43 
44 	ptr = container_of(itr, struct arm_spe_recording, itr);
45 	arm_spe_pmu = ptr->arm_spe_pmu;
46 
47 	if (term)
48 		user_bits = term->val.cfg_chg;
49 
50 	bit = perf_pmu__format_bits(&arm_spe_pmu->format, "ts_enable");
51 
52 	/* Skip if user has set it */
53 	if (bit & user_bits)
54 		return;
55 
56 	evsel->core.attr.config |= bit;
57 }
58 
59 static size_t
60 arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
61 		       struct evlist *evlist __maybe_unused)
62 {
63 	return ARM_SPE_AUXTRACE_PRIV_SIZE;
64 }
65 
66 static int arm_spe_info_fill(struct auxtrace_record *itr,
67 			     struct perf_session *session,
68 			     struct perf_record_auxtrace_info *auxtrace_info,
69 			     size_t priv_size)
70 {
71 	struct arm_spe_recording *sper =
72 			container_of(itr, struct arm_spe_recording, itr);
73 	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
74 
75 	if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
76 		return -EINVAL;
77 
78 	if (!session->evlist->core.nr_mmaps)
79 		return -EINVAL;
80 
81 	auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
82 	auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;
83 
84 	return 0;
85 }
86 
87 static int arm_spe_recording_options(struct auxtrace_record *itr,
88 				     struct evlist *evlist,
89 				     struct record_opts *opts)
90 {
91 	struct arm_spe_recording *sper =
92 			container_of(itr, struct arm_spe_recording, itr);
93 	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
94 	struct evsel *evsel, *arm_spe_evsel = NULL;
95 	struct perf_cpu_map *cpus = evlist->core.cpus;
96 	bool privileged = perf_event_paranoid_check(-1);
97 	struct evsel *tracking_evsel;
98 	int err;
99 
100 	sper->evlist = evlist;
101 
102 	evlist__for_each_entry(evlist, evsel) {
103 		if (evsel->core.attr.type == arm_spe_pmu->type) {
104 			if (arm_spe_evsel) {
105 				pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
106 				return -EINVAL;
107 			}
108 			evsel->core.attr.freq = 0;
109 			evsel->core.attr.sample_period = 1;
110 			arm_spe_evsel = evsel;
111 			opts->full_auxtrace = true;
112 		}
113 	}
114 
115 	if (!opts->full_auxtrace)
116 		return 0;
117 
118 	/* We are in full trace mode but '-m,xyz' wasn't specified */
119 	if (!opts->auxtrace_mmap_pages) {
120 		if (privileged) {
121 			opts->auxtrace_mmap_pages = MiB(4) / page_size;
122 		} else {
123 			opts->auxtrace_mmap_pages = KiB(128) / page_size;
124 			if (opts->mmap_pages == UINT_MAX)
125 				opts->mmap_pages = KiB(256) / page_size;
126 		}
127 	}
128 
129 	/* Validate auxtrace_mmap_pages */
130 	if (opts->auxtrace_mmap_pages) {
131 		size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
132 		size_t min_sz = KiB(8);
133 
134 		if (sz < min_sz || !is_power_of_2(sz)) {
135 			pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
136 			       min_sz / 1024);
137 			return -EINVAL;
138 		}
139 	}
140 
141 
142 	/*
143 	 * To obtain the auxtrace buffer file descriptor, the auxtrace event
144 	 * must come first.
145 	 */
146 	evlist__to_front(evlist, arm_spe_evsel);
147 
148 	/*
149 	 * In the case of per-cpu mmaps, sample CPU for AUX event;
150 	 * also enable the timestamp tracing for samples correlation.
151 	 */
152 	if (!perf_cpu_map__empty(cpus)) {
153 		evsel__set_sample_bit(arm_spe_evsel, CPU);
154 		arm_spe_set_timestamp(itr, arm_spe_evsel);
155 	}
156 
157 	/* Add dummy event to keep tracking */
158 	err = parse_events(evlist, "dummy:u", NULL);
159 	if (err)
160 		return err;
161 
162 	tracking_evsel = evlist__last(evlist);
163 	evlist__set_tracking_event(evlist, tracking_evsel);
164 
165 	tracking_evsel->core.attr.freq = 0;
166 	tracking_evsel->core.attr.sample_period = 1;
167 
168 	/* In per-cpu case, always need the time of mmap events etc */
169 	if (!perf_cpu_map__empty(cpus))
170 		evsel__set_sample_bit(tracking_evsel, TIME);
171 
172 	return 0;
173 }
174 
175 static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
176 {
177 	struct timespec ts;
178 
179 	clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
180 
181 	return ts.tv_sec ^ ts.tv_nsec;
182 }
183 
184 static void arm_spe_recording_free(struct auxtrace_record *itr)
185 {
186 	struct arm_spe_recording *sper =
187 			container_of(itr, struct arm_spe_recording, itr);
188 
189 	free(sper);
190 }
191 
192 struct auxtrace_record *arm_spe_recording_init(int *err,
193 					       struct perf_pmu *arm_spe_pmu)
194 {
195 	struct arm_spe_recording *sper;
196 
197 	if (!arm_spe_pmu) {
198 		*err = -ENODEV;
199 		return NULL;
200 	}
201 
202 	sper = zalloc(sizeof(struct arm_spe_recording));
203 	if (!sper) {
204 		*err = -ENOMEM;
205 		return NULL;
206 	}
207 
208 	sper->arm_spe_pmu = arm_spe_pmu;
209 	sper->itr.pmu = arm_spe_pmu;
210 	sper->itr.recording_options = arm_spe_recording_options;
211 	sper->itr.info_priv_size = arm_spe_info_priv_size;
212 	sper->itr.info_fill = arm_spe_info_fill;
213 	sper->itr.free = arm_spe_recording_free;
214 	sper->itr.reference = arm_spe_reference;
215 	sper->itr.read_finish = auxtrace_record__read_finish;
216 	sper->itr.alignment = 0;
217 
218 	*err = 0;
219 	return &sper->itr;
220 }
221 
222 struct perf_event_attr
223 *arm_spe_pmu_default_config(struct perf_pmu *arm_spe_pmu)
224 {
225 	struct perf_event_attr *attr;
226 
227 	attr = zalloc(sizeof(struct perf_event_attr));
228 	if (!attr) {
229 		pr_err("arm_spe default config cannot allocate a perf_event_attr\n");
230 		return NULL;
231 	}
232 
233 	/*
234 	 * If kernel driver doesn't advertise a minimum,
235 	 * use max allowable by PMSIDR_EL1.INTERVAL
236 	 */
237 	if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
238 				  &attr->sample_period) != 1) {
239 		pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
240 		attr->sample_period = 4096;
241 	}
242 
243 	arm_spe_pmu->selectable = true;
244 	arm_spe_pmu->is_uncore = false;
245 
246 	return attr;
247 }
248