ARM: perf: probe devicetree in preference to current CPU
authorWill Deacon <will.deacon@arm.com>
Sat, 28 Jul 2012 16:42:22 +0000 (17:42 +0100)
committerWill Deacon <will.deacon@arm.com>
Thu, 23 Aug 2012 10:35:52 +0000 (11:35 +0100)
The CPU PMU is probed using the current cpuid information as part of the
early_initcall initialising the architecture perf backend. For
architectures without NMI (such as ARM), this does not need to be
performed early and can be deferred to the driver probe callback. This
also allows us to probe the devicetree in preference to parsing the
current cpuid, which may be invalid on a big.LITTLE multi-cluster
system.

This patch defers the PMU probing and uses the devicetree information
when available.

Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm/kernel/perf_event.c
arch/arm/kernel/perf_event_v6.c
arch/arm/kernel/perf_event_v7.c
arch/arm/kernel/perf_event_xscale.c

index 22ed5120a6edc2090ac957a54437dbfa33a026c5..7c29914bdcc614c68ca5055ee23d291f352e4ffd 100644 (file)
@@ -16,6 +16,7 @@
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/export.h>
+#include <linux/of.h>
 #include <linux/perf_event.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
@@ -610,9 +611,11 @@ static void __init armpmu_init(struct arm_pmu *armpmu)
        };
 }
 
-int __init armpmu_register(struct arm_pmu *armpmu, char *name, int type)
+int armpmu_register(struct arm_pmu *armpmu, char *name, int type)
 {
        armpmu_init(armpmu);
+       pr_info("enabled with %s PMU driver, %d counters available\n",
+                       armpmu->name, armpmu->num_events);
        return perf_pmu_register(&armpmu->pmu, name, type);
 }
 
@@ -621,74 +624,12 @@ int __init armpmu_register(struct arm_pmu *armpmu, char *name, int type)
 #include "perf_event_v6.c"
 #include "perf_event_v7.c"
 
-/*
- * Ensure the PMU has sane values out of reset.
- * This requires SMP to be available, so exists as a separate initcall.
- */
-static int __init
-cpu_pmu_reset(void)
-{
-       if (cpu_pmu && cpu_pmu->reset)
-               return on_each_cpu(cpu_pmu->reset, NULL, 1);
-       return 0;
-}
-arch_initcall(cpu_pmu_reset);
-
-/*
- * PMU platform driver and devicetree bindings.
- */
-static struct of_device_id armpmu_of_device_ids[] = {
-       {.compatible = "arm,cortex-a15-pmu"},
-       {.compatible = "arm,cortex-a9-pmu"},
-       {.compatible = "arm,cortex-a8-pmu"},
-       {.compatible = "arm,cortex-a7-pmu"},
-       {.compatible = "arm,cortex-a5-pmu"},
-       {.compatible = "arm,arm11mpcore-pmu"},
-       {.compatible = "arm,arm1176-pmu"},
-       {.compatible = "arm,arm1136-pmu"},
-       {},
-};
-
-static struct platform_device_id armpmu_plat_device_ids[] = {
-       {.name = "arm-pmu"},
-       {},
-};
-
-static int __devinit armpmu_device_probe(struct platform_device *pdev)
-{
-       if (!cpu_pmu)
-               return -ENODEV;
-
-       cpu_pmu->plat_device = pdev;
-       return 0;
-}
-
-static const struct dev_pm_ops armpmu_dev_pm_ops = {
-       SET_RUNTIME_PM_OPS(armpmu_runtime_suspend, armpmu_runtime_resume, NULL)
-};
-
-static struct platform_driver armpmu_driver = {
-       .driver         = {
-               .name   = "arm-pmu",
-               .pm     = &armpmu_dev_pm_ops,
-               .of_match_table = armpmu_of_device_ids,
-       },
-       .probe          = armpmu_device_probe,
-       .id_table       = armpmu_plat_device_ids,
-};
-
-static int __init register_pmu_driver(void)
-{
-       return platform_driver_register(&armpmu_driver);
-}
-device_initcall(register_pmu_driver);
-
 static struct pmu_hw_events *armpmu_get_cpu_events(void)
 {
        return &__get_cpu_var(cpu_hw_events);
 }
 
-static void __init cpu_pmu_init(struct arm_pmu *armpmu)
+static void __devinit cpu_pmu_init(struct arm_pmu *cpu_pmu)
 {
        int cpu;
        for_each_possible_cpu(cpu) {
@@ -697,7 +638,11 @@ static void __init cpu_pmu_init(struct arm_pmu *armpmu)
                events->used_mask = per_cpu(used_mask, cpu);
                raw_spin_lock_init(&events->pmu_lock);
        }
-       armpmu->get_hw_events = armpmu_get_cpu_events;
+       cpu_pmu->get_hw_events = armpmu_get_cpu_events;
+
+       /* Ensure the PMU has sane values out of reset. */
+       if (cpu_pmu && cpu_pmu->reset)
+               on_each_cpu(cpu_pmu->reset, NULL, 1);
 }
 
 /*
@@ -722,41 +667,68 @@ static struct notifier_block __cpuinitdata pmu_cpu_notifier = {
        .notifier_call = pmu_cpu_notify,
 };
 
+static const struct dev_pm_ops armpmu_dev_pm_ops = {
+       SET_RUNTIME_PM_OPS(armpmu_runtime_suspend, armpmu_runtime_resume, NULL)
+};
+
+/*
+ * PMU platform driver and devicetree bindings.
+ */
+static struct of_device_id __devinitdata cpu_pmu_of_device_ids[] = {
+       {.compatible = "arm,cortex-a15-pmu",    .data = armv7_a15_pmu_init},
+       {.compatible = "arm,cortex-a9-pmu",     .data = armv7_a9_pmu_init},
+       {.compatible = "arm,cortex-a8-pmu",     .data = armv7_a8_pmu_init},
+       {.compatible = "arm,cortex-a7-pmu",     .data = armv7_a7_pmu_init},
+       {.compatible = "arm,cortex-a5-pmu",     .data = armv7_a5_pmu_init},
+       {.compatible = "arm,arm11mpcore-pmu",   .data = armv6mpcore_pmu_init},
+       {.compatible = "arm,arm1176-pmu",       .data = armv6pmu_init},
+       {.compatible = "arm,arm1136-pmu",       .data = armv6pmu_init},
+       {},
+};
+
+static struct platform_device_id __devinitdata cpu_pmu_plat_device_ids[] = {
+       {.name = "arm-pmu"},
+       {},
+};
+
 /*
- * CPU PMU identification and registration.
+ * CPU PMU identification and probing.
  */
-static int __init
-init_hw_perf_events(void)
+static struct arm_pmu *__devinit probe_current_pmu(void)
 {
+       struct arm_pmu *pmu = NULL;
+       int cpu = get_cpu();
        unsigned long cpuid = read_cpuid_id();
        unsigned long implementor = (cpuid & 0xFF000000) >> 24;
        unsigned long part_number = (cpuid & 0xFFF0);
 
+       pr_info("probing PMU on CPU %d\n", cpu);
+
        /* ARM Ltd CPUs. */
        if (0x41 == implementor) {
                switch (part_number) {
                case 0xB360:    /* ARM1136 */
                case 0xB560:    /* ARM1156 */
                case 0xB760:    /* ARM1176 */
-                       cpu_pmu = armv6pmu_init();
+                       pmu = armv6pmu_init();
                        break;
                case 0xB020:    /* ARM11mpcore */
-                       cpu_pmu = armv6mpcore_pmu_init();
+                       pmu = armv6mpcore_pmu_init();
                        break;
                case 0xC080:    /* Cortex-A8 */
-                       cpu_pmu = armv7_a8_pmu_init();
+                       pmu = armv7_a8_pmu_init();
                        break;
                case 0xC090:    /* Cortex-A9 */
-                       cpu_pmu = armv7_a9_pmu_init();
+                       pmu = armv7_a9_pmu_init();
                        break;
                case 0xC050:    /* Cortex-A5 */
-                       cpu_pmu = armv7_a5_pmu_init();
+                       pmu = armv7_a5_pmu_init();
                        break;
                case 0xC0F0:    /* Cortex-A15 */
-                       cpu_pmu = armv7_a15_pmu_init();
+                       pmu = armv7_a15_pmu_init();
                        break;
                case 0xC070:    /* Cortex-A7 */
-                       cpu_pmu = armv7_a7_pmu_init();
+                       pmu = armv7_a7_pmu_init();
                        break;
                }
        /* Intel CPUs [xscale]. */
@@ -764,27 +736,62 @@ init_hw_perf_events(void)
                part_number = (cpuid >> 13) & 0x7;
                switch (part_number) {
                case 1:
-                       cpu_pmu = xscale1pmu_init();
+                       pmu = xscale1pmu_init();
                        break;
                case 2:
-                       cpu_pmu = xscale2pmu_init();
+                       pmu = xscale2pmu_init();
                        break;
                }
        }
 
+       put_cpu();
+       return pmu;
+}
+
+static int __devinit cpu_pmu_device_probe(struct platform_device *pdev)
+{
+       const struct of_device_id *of_id;
+       struct arm_pmu *(*init_fn)(void);
+       struct device_node *node = pdev->dev.of_node;
+
        if (cpu_pmu) {
-               pr_info("enabled with %s PMU driver, %d counters available\n",
-                       cpu_pmu->name, cpu_pmu->num_events);
-               cpu_pmu_init(cpu_pmu);
-               register_cpu_notifier(&pmu_cpu_notifier);
-               armpmu_register(cpu_pmu, cpu_pmu->name, PERF_TYPE_RAW);
+               pr_info("attempt to register multiple PMU devices!");
+               return -ENOSPC;
+       }
+
+       if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
+               init_fn = of_id->data;
+               cpu_pmu = init_fn();
        } else {
-               pr_info("no hardware support available\n");
+               cpu_pmu = probe_current_pmu();
        }
 
+       if (!cpu_pmu)
+               return -ENODEV;
+
+       cpu_pmu->plat_device = pdev;
+       cpu_pmu_init(cpu_pmu);
+       register_cpu_notifier(&pmu_cpu_notifier);
+       armpmu_register(cpu_pmu, cpu_pmu->name, PERF_TYPE_RAW);
+
        return 0;
 }
-early_initcall(init_hw_perf_events);
+
+static struct platform_driver cpu_pmu_driver = {
+       .driver         = {
+               .name   = "arm-pmu",
+               .pm     = &armpmu_dev_pm_ops,
+               .of_match_table = cpu_pmu_of_device_ids,
+       },
+       .probe          = cpu_pmu_device_probe,
+       .id_table       = cpu_pmu_plat_device_ids,
+};
+
+static int __init register_pmu_driver(void)
+{
+       return platform_driver_register(&cpu_pmu_driver);
+}
+device_initcall(register_pmu_driver);
 
 /*
  * Callchain handling code.
index c90fcb2b69676b1f462c5be0160de35d9b2f1b26..a4328b12eed5e1dfa26e15b0559a5bf55927a951 100644 (file)
@@ -664,7 +664,7 @@ static struct arm_pmu armv6pmu = {
        .max_period             = (1LLU << 32) - 1,
 };
 
-static struct arm_pmu *__init armv6pmu_init(void)
+static struct arm_pmu *__devinit armv6pmu_init(void)
 {
        return &armv6pmu;
 }
@@ -698,17 +698,17 @@ static struct arm_pmu armv6mpcore_pmu = {
        .max_period             = (1LLU << 32) - 1,
 };
 
-static struct arm_pmu *__init armv6mpcore_pmu_init(void)
+static struct arm_pmu *__devinit armv6mpcore_pmu_init(void)
 {
        return &armv6mpcore_pmu;
 }
 #else
-static struct arm_pmu *__init armv6pmu_init(void)
+static struct arm_pmu *__devinit armv6pmu_init(void)
 {
        return NULL;
 }
 
-static struct arm_pmu *__init armv6mpcore_pmu_init(void)
+static struct arm_pmu *__devinit armv6mpcore_pmu_init(void)
 {
        return NULL;
 }
index f04070bd21838dd9146d694066d756d2bb1e753a..d65a1b82e13f99c568d629849702eb90ad0ec7d9 100644 (file)
@@ -1245,7 +1245,7 @@ static struct arm_pmu armv7pmu = {
        .max_period             = (1LLU << 32) - 1,
 };
 
-static u32 __init armv7_read_num_pmnc_events(void)
+static u32 __devinit armv7_read_num_pmnc_events(void)
 {
        u32 nb_cnt;
 
@@ -1256,7 +1256,7 @@ static u32 __init armv7_read_num_pmnc_events(void)
        return nb_cnt + 1;
 }
 
-static struct arm_pmu *__init armv7_a8_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a8_pmu_init(void)
 {
        armv7pmu.name           = "ARMv7 Cortex-A8";
        armv7pmu.map_event      = armv7_a8_map_event;
@@ -1264,7 +1264,7 @@ static struct arm_pmu *__init armv7_a8_pmu_init(void)
        return &armv7pmu;
 }
 
-static struct arm_pmu *__init armv7_a9_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a9_pmu_init(void)
 {
        armv7pmu.name           = "ARMv7 Cortex-A9";
        armv7pmu.map_event      = armv7_a9_map_event;
@@ -1272,7 +1272,7 @@ static struct arm_pmu *__init armv7_a9_pmu_init(void)
        return &armv7pmu;
 }
 
-static struct arm_pmu *__init armv7_a5_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a5_pmu_init(void)
 {
        armv7pmu.name           = "ARMv7 Cortex-A5";
        armv7pmu.map_event      = armv7_a5_map_event;
@@ -1280,7 +1280,7 @@ static struct arm_pmu *__init armv7_a5_pmu_init(void)
        return &armv7pmu;
 }
 
-static struct arm_pmu *__init armv7_a15_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a15_pmu_init(void)
 {
        armv7pmu.name           = "ARMv7 Cortex-A15";
        armv7pmu.map_event      = armv7_a15_map_event;
@@ -1289,7 +1289,7 @@ static struct arm_pmu *__init armv7_a15_pmu_init(void)
        return &armv7pmu;
 }
 
-static struct arm_pmu *__init armv7_a7_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a7_pmu_init(void)
 {
        armv7pmu.name           = "ARMv7 Cortex-A7";
        armv7pmu.map_event      = armv7_a7_map_event;
@@ -1298,27 +1298,27 @@ static struct arm_pmu *__init armv7_a7_pmu_init(void)
        return &armv7pmu;
 }
 #else
-static struct arm_pmu *__init armv7_a8_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a8_pmu_init(void)
 {
        return NULL;
 }
 
-static struct arm_pmu *__init armv7_a9_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a9_pmu_init(void)
 {
        return NULL;
 }
 
-static struct arm_pmu *__init armv7_a5_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a5_pmu_init(void)
 {
        return NULL;
 }
 
-static struct arm_pmu *__init armv7_a15_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a15_pmu_init(void)
 {
        return NULL;
 }
 
-static struct arm_pmu *__init armv7_a7_pmu_init(void)
+static struct arm_pmu *__devinit armv7_a7_pmu_init(void)
 {
        return NULL;
 }
index f759fe0bab632303b34484001ca2b6a9e91452f1..dcc478c07456ce4388d0d670270ee4fe712055da 100644 (file)
@@ -449,7 +449,7 @@ static struct arm_pmu xscale1pmu = {
        .max_period     = (1LLU << 32) - 1,
 };
 
-static struct arm_pmu *__init xscale1pmu_init(void)
+static struct arm_pmu *__devinit xscale1pmu_init(void)
 {
        return &xscale1pmu;
 }
@@ -816,17 +816,17 @@ static struct arm_pmu xscale2pmu = {
        .max_period     = (1LLU << 32) - 1,
 };
 
-static struct arm_pmu *__init xscale2pmu_init(void)
+static struct arm_pmu *__devinit xscale2pmu_init(void)
 {
        return &xscale2pmu;
 }
 #else
-static struct arm_pmu *__init xscale1pmu_init(void)
+static struct arm_pmu *__devinit xscale1pmu_init(void)
 {
        return NULL;
 }
 
-static struct arm_pmu *__init xscale2pmu_init(void)
+static struct arm_pmu *__devinit xscale2pmu_init(void)
 {
        return NULL;
 }
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