summaryrefslogtreecommitdiffstats
path: root/drivers/perf/arm_pmu_platform.c
blob: 971ff336494a4ac6c4b0d533440d6fab076ebd9f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
// SPDX-License-Identifier: GPL-2.0
/*
 * platform_device probing code for ARM performance counters.
 *
 * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
 * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com>
 */
#define pr_fmt(fmt) "hw perfevents: " fmt

#include <linux/bug.h>
#include <linux/cpumask.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/irq.h>
#include <linux/irqdesc.h>
#include <linux/kconfig.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/percpu.h>
#include <linux/perf/arm_pmu.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/smp.h>

static int probe_current_pmu(struct arm_pmu *pmu,
			     const struct pmu_probe_info *info)
{
	int cpu = get_cpu();
	unsigned int cpuid = read_cpuid_id();
	int ret = -ENODEV;

	pr_info("probing PMU on CPU %d\n", cpu);

	for (; info->init != NULL; info++) {
		if ((cpuid & info->mask) != info->cpuid)
			continue;
		ret = info->init(pmu);
		break;
	}

	put_cpu();
	return ret;
}

static int pmu_parse_percpu_irq(struct arm_pmu *pmu, int irq)
{
	int cpu, ret;
	struct pmu_hw_events __percpu *hw_events = pmu->hw_events;

	ret = irq_get_percpu_devid_partition(irq, &pmu->supported_cpus);
	if (ret)
		return ret;

	for_each_cpu(cpu, &pmu->supported_cpus)
		per_cpu(hw_events->irq, cpu) = irq;

	return 0;
}

static bool pmu_has_irq_affinity(struct device_node *node)
{
	return !!of_find_property(node, "interrupt-affinity", NULL);
}

static int pmu_parse_irq_affinity(struct device_node *node, int i)
{
	struct device_node *dn;
	int cpu;

	/*
	 * If we don't have an interrupt-affinity property, we guess irq
	 * affinity matches our logical CPU order, as we used to assume.
	 * This is fragile, so we'll warn in pmu_parse_irqs().
	 */
	if (!pmu_has_irq_affinity(node))
		return i;

	dn = of_parse_phandle(node, "interrupt-affinity", i);
	if (!dn) {
		pr_warn("failed to parse interrupt-affinity[%d] for %s\n",
			i, node->name);
		return -EINVAL;
	}

	cpu = of_cpu_node_to_id(dn);
	if (cpu < 0) {
		pr_warn("failed to find logical CPU for %s\n", dn->name);
		cpu = nr_cpu_ids;
	}

	of_node_put(dn);

	return cpu;
}

static int pmu_parse_irqs(struct arm_pmu *pmu)
{
	int i = 0, num_irqs;
	struct platform_device *pdev = pmu->plat_device;
	struct pmu_hw_events __percpu *hw_events = pmu->hw_events;

	num_irqs = platform_irq_count(pdev);
	if (num_irqs < 0) {
		pr_err("unable to count PMU IRQs\n");
		return num_irqs;
	}

	/*
	 * In this case we have no idea which CPUs are covered by the PMU.
	 * To match our prior behaviour, we assume all CPUs in this case.
	 */
	if (num_irqs == 0) {
		pr_warn("no irqs for PMU, sampling events not supported\n");
		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
		cpumask_setall(&pmu->supported_cpus);
		return 0;
	}

	if (num_irqs == 1) {
		int irq = platform_get_irq(pdev, 0);
		if (irq && irq_is_percpu_devid(irq))
			return pmu_parse_percpu_irq(pmu, irq);
	}

	if (nr_cpu_ids != 1 && !pmu_has_irq_affinity(pdev->dev.of_node)) {
		pr_warn("no interrupt-affinity property for %pOF, guessing.\n",
			pdev->dev.of_node);
	}

	for (i = 0; i < num_irqs; i++) {
		int cpu, irq;

		irq = platform_get_irq(pdev, i);
		if (WARN_ON(irq <= 0))
			continue;

		if (irq_is_percpu_devid(irq)) {
			pr_warn("multiple PPIs or mismatched SPI/PPI detected\n");
			return -EINVAL;
		}

		cpu = pmu_parse_irq_affinity(pdev->dev.of_node, i);
		if (cpu < 0)
			return cpu;
		if (cpu >= nr_cpu_ids)
			continue;

		if (per_cpu(hw_events->irq, cpu)) {
			pr_warn("multiple PMU IRQs for the same CPU detected\n");
			return -EINVAL;
		}

		per_cpu(hw_events->irq, cpu) = irq;
		cpumask_set_cpu(cpu, &pmu->supported_cpus);
	}

	return 0;
}

static int armpmu_request_irqs(struct arm_pmu *armpmu)
{
	struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
	int cpu, err;

	for_each_cpu(cpu, &armpmu->supported_cpus) {
		int irq = per_cpu(hw_events->irq, cpu);
		if (!irq)
			continue;

		err = armpmu_request_irq(irq, cpu);
		if (err)
			break;
	}

	return err;
}

static void armpmu_free_irqs(struct arm_pmu *armpmu)
{
	int cpu;
	struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;

	for_each_cpu(cpu, &armpmu->supported_cpus) {
		int irq = per_cpu(hw_events->irq, cpu);

		armpmu_free_irq(irq, cpu);
	}
}

int arm_pmu_device_probe(struct platform_device *pdev,
			 const struct of_device_id *of_table,
			 const struct pmu_probe_info *probe_table)
{
	const struct of_device_id *of_id;
	armpmu_init_fn init_fn;
	struct device_node *node = pdev->dev.of_node;
	struct arm_pmu *pmu;
	int ret = -ENODEV;

	pmu = armpmu_alloc();
	if (!pmu)
		return -ENOMEM;

	pmu->plat_device = pdev;

	ret = pmu_parse_irqs(pmu);
	if (ret)
		goto out_free;

	if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) {
		init_fn = of_id->data;

		pmu->secure_access = of_property_read_bool(pdev->dev.of_node,
							   "secure-reg-access");

		/* arm64 systems boot only as non-secure */
		if (IS_ENABLED(CONFIG_ARM64) && pmu->secure_access) {
			pr_warn("ignoring \"secure-reg-access\" property for arm64\n");
			pmu->secure_access = false;
		}

		ret = init_fn(pmu);
	} else if (probe_table) {
		cpumask_setall(&pmu->supported_cpus);
		ret = probe_current_pmu(pmu, probe_table);
	}

	if (ret) {
		pr_info("%pOF: failed to probe PMU!\n", node);
		goto out_free;
	}

	ret = armpmu_request_irqs(pmu);
	if (ret)
		goto out_free_irqs;

	ret = armpmu_register(pmu);
	if (ret)
		goto out_free;

	return 0;

out_free_irqs:
	armpmu_free_irqs(pmu);
out_free:
	pr_info("%pOF: failed to register PMU devices!\n", node);
	armpmu_free(pmu);
	return ret;
}
OpenPOWER on IntegriCloud