2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
15 * Copyright (C) 2012 ARM Limited
17 * Author: Will Deacon <will.deacon@arm.com>
19 #define pr_fmt(fmt) "CPU PMU: " fmt
21 #include <linux/bitmap.h>
22 #include <linux/export.h>
23 #include <linux/kernel.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/irq.h>
29 #include <linux/irqdesc.h>
31 #include <asm/cputype.h>
32 #include <asm/irq_regs.h>
35 /* Set at runtime when we know what CPU type we are. */
36 static struct arm_pmu *cpu_pmu;
39 * Despite the names, these two functions are CPU-specific and are used
40 * by the OProfile/perf code.
42 const char *perf_pmu_name(void)
49 EXPORT_SYMBOL_GPL(perf_pmu_name);
51 int perf_num_counters(void)
56 max_events = cpu_pmu->num_events;
60 EXPORT_SYMBOL_GPL(perf_num_counters);
62 /* Include the PMU-specific implementations. */
63 #include "perf_event_xscale.c"
64 #include "perf_event_v6.c"
65 #include "perf_event_v7.c"
67 static void cpu_pmu_enable_percpu_irq(void *data)
69 int irq = *(int *)data;
71 enable_percpu_irq(irq, IRQ_TYPE_NONE);
74 static void cpu_pmu_disable_percpu_irq(void *data)
76 int irq = *(int *)data;
78 disable_percpu_irq(irq);
81 static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
84 struct platform_device *pmu_device = cpu_pmu->plat_device;
85 struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
87 irqs = min(pmu_device->num_resources, num_possible_cpus());
89 irq = platform_get_irq(pmu_device, 0);
90 if (irq >= 0 && irq_is_percpu(irq)) {
91 on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1);
92 free_percpu_irq(irq, &hw_events->percpu_pmu);
94 for (i = 0; i < irqs; ++i) {
95 if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs))
97 irq = platform_get_irq(pmu_device, i);
99 free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, i));
104 static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
106 int i, err, irq, irqs;
107 struct platform_device *pmu_device = cpu_pmu->plat_device;
108 struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
113 irqs = min(pmu_device->num_resources, num_possible_cpus());
115 pr_warn_once("perf/ARM: No irqs for PMU defined, sampling events not supported\n");
119 irq = platform_get_irq(pmu_device, 0);
120 if (irq >= 0 && irq_is_percpu(irq)) {
121 err = request_percpu_irq(irq, handler, "arm-pmu",
122 &hw_events->percpu_pmu);
124 pr_err("unable to request IRQ%d for ARM PMU counters\n",
128 on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);
130 for (i = 0; i < irqs; ++i) {
132 irq = platform_get_irq(pmu_device, i);
137 * If we have a single PMU interrupt that we can't shift,
138 * assume that we're running on a uniprocessor machine and
139 * continue. Otherwise, continue without this interrupt.
141 if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) {
142 pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n",
147 err = request_irq(irq, handler,
148 IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
149 per_cpu_ptr(&hw_events->percpu_pmu, i));
151 pr_err("unable to request IRQ%d for ARM PMU counters\n",
156 cpumask_set_cpu(i, &cpu_pmu->active_irqs);
164 * PMU hardware loses all context when a CPU goes offline.
165 * When a CPU is hotplugged back in, since some hardware registers are
166 * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
167 * junk values out of them.
169 static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
172 struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb);
174 if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
185 static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
189 struct pmu_hw_events __percpu *cpu_hw_events;
191 cpu_hw_events = alloc_percpu(struct pmu_hw_events);
195 cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify;
196 err = register_cpu_notifier(&cpu_pmu->hotplug_nb);
200 for_each_possible_cpu(cpu) {
201 struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu);
202 raw_spin_lock_init(&events->pmu_lock);
203 events->percpu_pmu = cpu_pmu;
206 cpu_pmu->hw_events = cpu_hw_events;
207 cpu_pmu->request_irq = cpu_pmu_request_irq;
208 cpu_pmu->free_irq = cpu_pmu_free_irq;
210 /* Ensure the PMU has sane values out of reset. */
212 on_each_cpu(cpu_pmu->reset, cpu_pmu, 1);
214 /* If no interrupts available, set the corresponding capability flag */
215 if (!platform_get_irq(cpu_pmu->plat_device, 0))
216 cpu_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
221 free_percpu(cpu_hw_events);
225 static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
227 unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
228 free_percpu(cpu_pmu->hw_events);
232 * PMU platform driver and devicetree bindings.
234 static struct of_device_id cpu_pmu_of_device_ids[] = {
235 {.compatible = "arm,cortex-a17-pmu", .data = armv7_a17_pmu_init},
236 {.compatible = "arm,cortex-a15-pmu", .data = armv7_a15_pmu_init},
237 {.compatible = "arm,cortex-a12-pmu", .data = armv7_a12_pmu_init},
238 {.compatible = "arm,cortex-a9-pmu", .data = armv7_a9_pmu_init},
239 {.compatible = "arm,cortex-a8-pmu", .data = armv7_a8_pmu_init},
240 {.compatible = "arm,cortex-a7-pmu", .data = armv7_a7_pmu_init},
241 {.compatible = "arm,cortex-a5-pmu", .data = armv7_a5_pmu_init},
242 {.compatible = "arm,arm11mpcore-pmu", .data = armv6mpcore_pmu_init},
243 {.compatible = "arm,arm1176-pmu", .data = armv6_1176_pmu_init},
244 {.compatible = "arm,arm1136-pmu", .data = armv6_1136_pmu_init},
245 {.compatible = "qcom,krait-pmu", .data = krait_pmu_init},
249 static struct platform_device_id cpu_pmu_plat_device_ids[] = {
251 {.name = "armv6-pmu"},
252 {.name = "armv7-pmu"},
253 {.name = "xscale-pmu"},
257 static const struct pmu_probe_info pmu_probe_table[] = {
258 ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
259 ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
260 ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
261 ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
262 ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A8, armv7_a8_pmu_init),
263 ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A9, armv7_a9_pmu_init),
264 XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V1, xscale1pmu_init),
265 XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V2, xscale2pmu_init),
266 { /* sentinel value */ }
270 * CPU PMU identification and probing.
272 static int probe_current_pmu(struct arm_pmu *pmu)
275 unsigned int cpuid = read_cpuid_id();
277 const struct pmu_probe_info *info;
279 pr_info("probing PMU on CPU %d\n", cpu);
281 for (info = pmu_probe_table; info->init != NULL; info++) {
282 if ((cpuid & info->mask) != info->cpuid)
284 ret = info->init(pmu);
292 static int cpu_pmu_device_probe(struct platform_device *pdev)
294 const struct of_device_id *of_id;
295 const int (*init_fn)(struct arm_pmu *);
296 struct device_node *node = pdev->dev.of_node;
301 pr_info("attempt to register multiple PMU devices!\n");
305 pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL);
307 pr_info("failed to allocate PMU device!\n");
312 cpu_pmu->plat_device = pdev;
314 if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
315 init_fn = of_id->data;
318 ret = probe_current_pmu(pmu);
322 pr_info("failed to probe PMU!\n");
326 ret = cpu_pmu_init(cpu_pmu);
330 ret = armpmu_register(cpu_pmu, -1);
337 cpu_pmu_destroy(cpu_pmu);
339 pr_info("failed to register PMU devices!\n");
344 static struct platform_driver cpu_pmu_driver = {
347 .pm = &armpmu_dev_pm_ops,
348 .of_match_table = cpu_pmu_of_device_ids,
350 .probe = cpu_pmu_device_probe,
351 .id_table = cpu_pmu_plat_device_ids,
354 static int __init register_pmu_driver(void)
356 return platform_driver_register(&cpu_pmu_driver);
358 device_initcall(register_pmu_driver);