2 * platform_device probing code for ARM performance counters.
4 * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
5 * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com>
7 #define pr_fmt(fmt) "hw perfevents: " fmt
10 #include <linux/cpumask.h>
11 #include <linux/device.h>
12 #include <linux/errno.h>
13 #include <linux/irq.h>
14 #include <linux/irqdesc.h>
15 #include <linux/kconfig.h>
17 #include <linux/of_device.h>
18 #include <linux/percpu.h>
19 #include <linux/perf/arm_pmu.h>
20 #include <linux/platform_device.h>
21 #include <linux/printk.h>
22 #include <linux/smp.h>
24 static int probe_current_pmu(struct arm_pmu
*pmu
,
25 const struct pmu_probe_info
*info
)
28 unsigned int cpuid
= read_cpuid_id();
31 pr_info("probing PMU on CPU %d\n", cpu
);
33 for (; info
->init
!= NULL
; info
++) {
34 if ((cpuid
& info
->mask
) != info
->cpuid
)
36 ret
= info
->init(pmu
);
44 static int pmu_parse_percpu_irq(struct arm_pmu
*pmu
, int irq
)
47 struct pmu_hw_events __percpu
*hw_events
= pmu
->hw_events
;
49 ret
= irq_get_percpu_devid_partition(irq
, &pmu
->supported_cpus
);
53 for_each_cpu(cpu
, &pmu
->supported_cpus
)
54 per_cpu(hw_events
->irq
, cpu
) = irq
;
59 static bool pmu_has_irq_affinity(struct device_node
*node
)
61 return !!of_find_property(node
, "interrupt-affinity", NULL
);
64 static int pmu_parse_irq_affinity(struct device_node
*node
, int i
)
66 struct device_node
*dn
;
70 * If we don't have an interrupt-affinity property, we guess irq
71 * affinity matches our logical CPU order, as we used to assume.
72 * This is fragile, so we'll warn in pmu_parse_irqs().
74 if (!pmu_has_irq_affinity(node
))
77 dn
= of_parse_phandle(node
, "interrupt-affinity", i
);
79 pr_warn("failed to parse interrupt-affinity[%d] for %s\n",
84 /* Now look up the logical CPU number */
85 for_each_possible_cpu(cpu
) {
86 struct device_node
*cpu_dn
;
88 cpu_dn
= of_cpu_device_node_get(cpu
);
95 if (cpu
>= nr_cpu_ids
) {
96 pr_warn("failed to find logical CPU for %s\n", dn
->name
);
104 static int pmu_parse_irqs(struct arm_pmu
*pmu
)
107 struct platform_device
*pdev
= pmu
->plat_device
;
108 struct pmu_hw_events __percpu
*hw_events
= pmu
->hw_events
;
110 num_irqs
= platform_irq_count(pdev
);
112 pr_err("unable to count PMU IRQs\n");
117 * In this case we have no idea which CPUs are covered by the PMU.
118 * To match our prior behaviour, we assume all CPUs in this case.
121 pr_warn("no irqs for PMU, sampling events not supported\n");
122 pmu
->pmu
.capabilities
|= PERF_PMU_CAP_NO_INTERRUPT
;
123 cpumask_setall(&pmu
->supported_cpus
);
128 int irq
= platform_get_irq(pdev
, 0);
129 if (irq
&& irq_is_percpu(irq
))
130 return pmu_parse_percpu_irq(pmu
, irq
);
133 if (!pmu_has_irq_affinity(pdev
->dev
.of_node
)) {
134 pr_warn("no interrupt-affinity property for %pOF, guessing.\n",
139 * Some platforms have all PMU IRQs OR'd into a single IRQ, with a
140 * special platdata function that attempts to demux them.
142 if (dev_get_platdata(&pdev
->dev
))
143 cpumask_setall(&pmu
->supported_cpus
);
145 for (i
= 0; i
< num_irqs
; i
++) {
148 irq
= platform_get_irq(pdev
, i
);
149 if (WARN_ON(irq
<= 0))
152 if (irq_is_percpu(irq
)) {
153 pr_warn("multiple PPIs or mismatched SPI/PPI detected\n");
157 cpu
= pmu_parse_irq_affinity(pdev
->dev
.of_node
, i
);
160 if (cpu
>= nr_cpu_ids
)
163 if (per_cpu(hw_events
->irq
, cpu
)) {
164 pr_warn("multiple PMU IRQs for the same CPU detected\n");
168 per_cpu(hw_events
->irq
, cpu
) = irq
;
169 cpumask_set_cpu(cpu
, &pmu
->supported_cpus
);
175 int arm_pmu_device_probe(struct platform_device
*pdev
,
176 const struct of_device_id
*of_table
,
177 const struct pmu_probe_info
*probe_table
)
179 const struct of_device_id
*of_id
;
180 armpmu_init_fn init_fn
;
181 struct device_node
*node
= pdev
->dev
.of_node
;
185 pmu
= armpmu_alloc();
189 pmu
->plat_device
= pdev
;
191 ret
= pmu_parse_irqs(pmu
);
195 if (node
&& (of_id
= of_match_node(of_table
, pdev
->dev
.of_node
))) {
196 init_fn
= of_id
->data
;
198 pmu
->secure_access
= of_property_read_bool(pdev
->dev
.of_node
,
199 "secure-reg-access");
201 /* arm64 systems boot only as non-secure */
202 if (IS_ENABLED(CONFIG_ARM64
) && pmu
->secure_access
) {
203 pr_warn("ignoring \"secure-reg-access\" property for arm64\n");
204 pmu
->secure_access
= false;
208 } else if (probe_table
) {
209 cpumask_setall(&pmu
->supported_cpus
);
210 ret
= probe_current_pmu(pmu
, probe_table
);
214 pr_info("%pOF: failed to probe PMU!\n", node
);
218 ret
= armpmu_request_irqs(pmu
);
222 ret
= armpmu_register(pmu
);
229 armpmu_free_irqs(pmu
);
231 pr_info("%pOF: failed to register PMU devices!\n", node
);