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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
18bfcfe5 MR |
2 | /* |
3 | * platform_device probing code for ARM performance counters. | |
4 | * | |
5 | * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles | |
6 | * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com> | |
7 | */ | |
8 | #define pr_fmt(fmt) "hw perfevents: " fmt | |
9 | ||
10 | #include <linux/bug.h> | |
11 | #include <linux/cpumask.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/irq.h> | |
15 | #include <linux/irqdesc.h> | |
16 | #include <linux/kconfig.h> | |
17 | #include <linux/of.h> | |
18 | #include <linux/of_device.h> | |
19 | #include <linux/percpu.h> | |
20 | #include <linux/perf/arm_pmu.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/printk.h> | |
23 | #include <linux/smp.h> | |
24 | ||
25 | static int probe_current_pmu(struct arm_pmu *pmu, | |
26 | const struct pmu_probe_info *info) | |
27 | { | |
28 | int cpu = get_cpu(); | |
29 | unsigned int cpuid = read_cpuid_id(); | |
30 | int ret = -ENODEV; | |
31 | ||
32 | pr_info("probing PMU on CPU %d\n", cpu); | |
33 | ||
34 | for (; info->init != NULL; info++) { | |
35 | if ((cpuid & info->mask) != info->cpuid) | |
36 | continue; | |
37 | ret = info->init(pmu); | |
38 | break; | |
39 | } | |
40 | ||
41 | put_cpu(); | |
42 | return ret; | |
43 | } | |
44 | ||
45 | static int pmu_parse_percpu_irq(struct arm_pmu *pmu, int irq) | |
46 | { | |
47 | int cpu, ret; | |
48 | struct pmu_hw_events __percpu *hw_events = pmu->hw_events; | |
49 | ||
50 | ret = irq_get_percpu_devid_partition(irq, &pmu->supported_cpus); | |
51 | if (ret) | |
52 | return ret; | |
53 | ||
54 | for_each_cpu(cpu, &pmu->supported_cpus) | |
55 | per_cpu(hw_events->irq, cpu) = irq; | |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | static bool pmu_has_irq_affinity(struct device_node *node) | |
61 | { | |
62 | return !!of_find_property(node, "interrupt-affinity", NULL); | |
63 | } | |
64 | ||
65 | static int pmu_parse_irq_affinity(struct device_node *node, int i) | |
66 | { | |
67 | struct device_node *dn; | |
68 | int cpu; | |
69 | ||
70 | /* | |
71 | * If we don't have an interrupt-affinity property, we guess irq | |
72 | * affinity matches our logical CPU order, as we used to assume. | |
73 | * This is fragile, so we'll warn in pmu_parse_irqs(). | |
74 | */ | |
75 | if (!pmu_has_irq_affinity(node)) | |
76 | return i; | |
77 | ||
78 | dn = of_parse_phandle(node, "interrupt-affinity", i); | |
79 | if (!dn) { | |
80 | pr_warn("failed to parse interrupt-affinity[%d] for %s\n", | |
81 | i, node->name); | |
82 | return -EINVAL; | |
83 | } | |
84 | ||
85 | /* Now look up the logical CPU number */ | |
86 | for_each_possible_cpu(cpu) { | |
87 | struct device_node *cpu_dn; | |
88 | ||
89 | cpu_dn = of_cpu_device_node_get(cpu); | |
90 | of_node_put(cpu_dn); | |
91 | ||
92 | if (dn == cpu_dn) | |
93 | break; | |
94 | } | |
95 | ||
96 | if (cpu >= nr_cpu_ids) { | |
97 | pr_warn("failed to find logical CPU for %s\n", dn->name); | |
98 | } | |
99 | ||
100 | of_node_put(dn); | |
101 | ||
102 | return cpu; | |
103 | } | |
104 | ||
105 | static int pmu_parse_irqs(struct arm_pmu *pmu) | |
106 | { | |
107 | int i = 0, num_irqs; | |
108 | struct platform_device *pdev = pmu->plat_device; | |
109 | struct pmu_hw_events __percpu *hw_events = pmu->hw_events; | |
110 | ||
111 | num_irqs = platform_irq_count(pdev); | |
112 | if (num_irqs < 0) { | |
113 | pr_err("unable to count PMU IRQs\n"); | |
114 | return num_irqs; | |
115 | } | |
116 | ||
117 | /* | |
118 | * In this case we have no idea which CPUs are covered by the PMU. | |
119 | * To match our prior behaviour, we assume all CPUs in this case. | |
120 | */ | |
121 | if (num_irqs == 0) { | |
122 | pr_warn("no irqs for PMU, sampling events not supported\n"); | |
123 | pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; | |
124 | cpumask_setall(&pmu->supported_cpus); | |
125 | return 0; | |
126 | } | |
127 | ||
128 | if (num_irqs == 1) { | |
129 | int irq = platform_get_irq(pdev, 0); | |
611479c7 | 130 | if (irq && irq_is_percpu_devid(irq)) |
18bfcfe5 MR |
131 | return pmu_parse_percpu_irq(pmu, irq); |
132 | } | |
133 | ||
134 | if (!pmu_has_irq_affinity(pdev->dev.of_node)) { | |
5f4216f4 RH |
135 | pr_warn("no interrupt-affinity property for %pOF, guessing.\n", |
136 | pdev->dev.of_node); | |
18bfcfe5 MR |
137 | } |
138 | ||
139 | /* | |
140 | * Some platforms have all PMU IRQs OR'd into a single IRQ, with a | |
141 | * special platdata function that attempts to demux them. | |
142 | */ | |
143 | if (dev_get_platdata(&pdev->dev)) | |
144 | cpumask_setall(&pmu->supported_cpus); | |
145 | ||
146 | for (i = 0; i < num_irqs; i++) { | |
147 | int cpu, irq; | |
148 | ||
149 | irq = platform_get_irq(pdev, i); | |
150 | if (WARN_ON(irq <= 0)) | |
151 | continue; | |
152 | ||
611479c7 | 153 | if (irq_is_percpu_devid(irq)) { |
18bfcfe5 MR |
154 | pr_warn("multiple PPIs or mismatched SPI/PPI detected\n"); |
155 | return -EINVAL; | |
156 | } | |
157 | ||
158 | cpu = pmu_parse_irq_affinity(pdev->dev.of_node, i); | |
159 | if (cpu < 0) | |
160 | return cpu; | |
161 | if (cpu >= nr_cpu_ids) | |
162 | continue; | |
163 | ||
164 | if (per_cpu(hw_events->irq, cpu)) { | |
165 | pr_warn("multiple PMU IRQs for the same CPU detected\n"); | |
166 | return -EINVAL; | |
167 | } | |
168 | ||
169 | per_cpu(hw_events->irq, cpu) = irq; | |
170 | cpumask_set_cpu(cpu, &pmu->supported_cpus); | |
171 | } | |
172 | ||
173 | return 0; | |
174 | } | |
175 | ||
176 | int arm_pmu_device_probe(struct platform_device *pdev, | |
177 | const struct of_device_id *of_table, | |
178 | const struct pmu_probe_info *probe_table) | |
179 | { | |
180 | const struct of_device_id *of_id; | |
181 | armpmu_init_fn init_fn; | |
182 | struct device_node *node = pdev->dev.of_node; | |
183 | struct arm_pmu *pmu; | |
184 | int ret = -ENODEV; | |
185 | ||
186 | pmu = armpmu_alloc(); | |
187 | if (!pmu) | |
188 | return -ENOMEM; | |
189 | ||
190 | pmu->plat_device = pdev; | |
191 | ||
192 | ret = pmu_parse_irqs(pmu); | |
193 | if (ret) | |
194 | goto out_free; | |
195 | ||
196 | if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) { | |
197 | init_fn = of_id->data; | |
198 | ||
199 | pmu->secure_access = of_property_read_bool(pdev->dev.of_node, | |
200 | "secure-reg-access"); | |
201 | ||
202 | /* arm64 systems boot only as non-secure */ | |
203 | if (IS_ENABLED(CONFIG_ARM64) && pmu->secure_access) { | |
204 | pr_warn("ignoring \"secure-reg-access\" property for arm64\n"); | |
205 | pmu->secure_access = false; | |
206 | } | |
207 | ||
208 | ret = init_fn(pmu); | |
209 | } else if (probe_table) { | |
210 | cpumask_setall(&pmu->supported_cpus); | |
211 | ret = probe_current_pmu(pmu, probe_table); | |
212 | } | |
213 | ||
214 | if (ret) { | |
5f4216f4 | 215 | pr_info("%pOF: failed to probe PMU!\n", node); |
18bfcfe5 MR |
216 | goto out_free; |
217 | } | |
218 | ||
219 | ret = armpmu_request_irqs(pmu); | |
220 | if (ret) | |
221 | goto out_free_irqs; | |
222 | ||
223 | ret = armpmu_register(pmu); | |
224 | if (ret) | |
225 | goto out_free; | |
226 | ||
227 | return 0; | |
228 | ||
229 | out_free_irqs: | |
230 | armpmu_free_irqs(pmu); | |
231 | out_free: | |
5f4216f4 | 232 | pr_info("%pOF: failed to register PMU devices!\n", node); |
18bfcfe5 MR |
233 | armpmu_free(pmu); |
234 | return ret; | |
235 | } |