#include <linux/interrupt.h>
+/*
+ * Types of PMUs that can be accessed directly and require mutual
+ * exclusion between profiling tools.
+ */
enum arm_pmu_type {
ARM_PMU_DEVICE_CPU = 0,
ARM_NUM_PMU_DEVICES,
* reserve_pmu() - reserve the hardware performance counters
*
* Reserve the hardware performance counters in the system for exclusive use.
- * The platform_device for the system is returned on success, ERR_PTR()
- * encoded error on failure.
+ * Returns 0 on success or -EBUSY if the lock is already held.
*/
-extern struct platform_device *
+extern int
reserve_pmu(enum arm_pmu_type type);
/**
* release_pmu() - Relinquish control of the performance counters
*
* Release the performance counters and allow someone else to use them.
- * Callers must have disabled the counters and released IRQs before calling
- * this. The platform_device returned from reserve_pmu() must be passed as
- * a cookie.
*/
-extern int
+extern void
release_pmu(enum arm_pmu_type type);
/**
#include <linux/err.h>
-static inline struct platform_device *
-reserve_pmu(enum arm_pmu_type type)
-{
- return ERR_PTR(-ENODEV);
-}
-
static inline int
-release_pmu(enum arm_pmu_type type)
+reserve_pmu(enum arm_pmu_type type)
{
return -ENODEV;
}
-static inline int
-init_pmu(enum arm_pmu_type type)
-{
- return -ENODEV;
-}
+static inline void
+release_pmu(enum arm_pmu_type type) { }
#endif /* CONFIG_CPU_HAS_PMU */
{
struct arm_pmu_platdata *plat;
irq_handler_t handle_irq;
- int i, err = -ENODEV, irq;
+ int i, err, irq, irqs;
- pmu_device = reserve_pmu(ARM_PMU_DEVICE_CPU);
- if (IS_ERR(pmu_device)) {
+ err = reserve_pmu(ARM_PMU_DEVICE_CPU);
+ if (err) {
pr_warning("unable to reserve pmu\n");
- return PTR_ERR(pmu_device);
+ return err;
}
- init_pmu(ARM_PMU_DEVICE_CPU);
+ irqs = pmu_device->num_resources;
plat = dev_get_platdata(&pmu_device->dev);
if (plat && plat->handle_irq)
else
handle_irq = armpmu->handle_irq;
- if (pmu_device->num_resources < 1) {
+ if (irqs < 1) {
pr_err("no irqs for PMUs defined\n");
return -ENODEV;
}
- for (i = 0; i < pmu_device->num_resources; ++i) {
+ for (i = 0; i < irqs; ++i) {
irq = platform_get_irq(pmu_device, i);
if (irq < 0)
continue;
+ /*
+ * If we have a single PMU interrupt that we can't shift,
+ * assume that we're running on a uniprocessor machine and
+ * continue.
+ */
+ err = irq_set_affinity(irq, cpumask_of(i));
+ if (err && irqs > 1) {
+ pr_err("unable to set irq affinity (irq=%d, cpu=%u)\n",
+ irq, i);
+ break;
+ }
+
err = request_irq(irq, handle_irq,
IRQF_DISABLED | IRQF_NOBALANCING,
- "armpmu", NULL);
+ "arm-pmu", NULL);
if (err) {
- pr_warning("unable to request IRQ%d for ARM perf "
- "counters\n", irq);
+ pr_err("unable to request IRQ%d for ARM PMU counters\n",
+ irq);
break;
}
}
free_irq(irq, NULL);
}
release_pmu(ARM_PMU_DEVICE_CPU);
- pmu_device = NULL;
}
return err;
armpmu->stop();
release_pmu(ARM_PMU_DEVICE_CPU);
- pmu_device = NULL;
}
static atomic_t active_events = ATOMIC_INIT(0);
}
arch_initcall(armpmu_reset);
+/*
+ * PMU platform driver and devicetree bindings.
+ */
+static struct of_device_id armpmu_of_device_ids[] = {
+ {.compatible = "arm,cortex-a9-pmu"},
+ {.compatible = "arm,cortex-a8-pmu"},
+ {.compatible = "arm,arm1136-pmu"},
+ {.compatible = "arm,arm1176-pmu"},
+ {},
+};
+
+static struct platform_device_id armpmu_plat_device_ids[] = {
+ {.name = "arm-pmu"},
+ {},
+};
+
+static int __devinit armpmu_device_probe(struct platform_device *pdev)
+{
+ pmu_device = pdev;
+ return 0;
+}
+
+static struct platform_driver armpmu_driver = {
+ .driver = {
+ .name = "arm-pmu",
+ .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);
+
+/*
+ * CPU PMU identification and registration.
+ */
static int __init
init_hw_perf_events(void)
{
*
*/
-#define pr_fmt(fmt) "PMU: " fmt
-
-#include <linux/cpumask.h>
#include <linux/err.h>
-#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/of_device.h>
-#include <linux/platform_device.h>
#include <asm/pmu.h>
-static volatile long pmu_lock;
-
-static struct platform_device *pmu_devices[ARM_NUM_PMU_DEVICES];
-
-static int __devinit pmu_register(struct platform_device *pdev,
- enum arm_pmu_type type)
-{
- if (type < 0 || type >= ARM_NUM_PMU_DEVICES) {
- pr_warning("received registration request for unknown "
- "PMU device type %d\n", type);
- return -EINVAL;
- }
-
- if (pmu_devices[type]) {
- pr_warning("rejecting duplicate registration of PMU device "
- "type %d.", type);
- return -ENOSPC;
- }
-
- pr_info("registered new PMU device of type %d\n", type);
- pmu_devices[type] = pdev;
- return 0;
-}
-
-#define OF_MATCH_PMU(_name, _type) { \
- .compatible = _name, \
- .data = (void *)_type, \
-}
-
-#define OF_MATCH_CPU(name) OF_MATCH_PMU(name, ARM_PMU_DEVICE_CPU)
-
-static struct of_device_id armpmu_of_device_ids[] = {
- OF_MATCH_CPU("arm,cortex-a9-pmu"),
- OF_MATCH_CPU("arm,cortex-a8-pmu"),
- OF_MATCH_CPU("arm,arm1136-pmu"),
- OF_MATCH_CPU("arm,arm1176-pmu"),
- {},
-};
-
-#define PLAT_MATCH_PMU(_name, _type) { \
- .name = _name, \
- .driver_data = _type, \
-}
-
-#define PLAT_MATCH_CPU(_name) PLAT_MATCH_PMU(_name, ARM_PMU_DEVICE_CPU)
-
-static struct platform_device_id armpmu_plat_device_ids[] = {
- PLAT_MATCH_CPU("arm-pmu"),
- {},
-};
-
-enum arm_pmu_type armpmu_device_type(struct platform_device *pdev)
-{
- const struct of_device_id *of_id;
- const struct platform_device_id *pdev_id;
-
- /* provided by of_device_id table */
- if (pdev->dev.of_node) {
- of_id = of_match_device(armpmu_of_device_ids, &pdev->dev);
- BUG_ON(!of_id);
- return (enum arm_pmu_type)of_id->data;
- }
-
- /* Provided by platform_device_id table */
- pdev_id = platform_get_device_id(pdev);
- BUG_ON(!pdev_id);
- return pdev_id->driver_data;
-}
-
-static int __devinit armpmu_device_probe(struct platform_device *pdev)
-{
- return pmu_register(pdev, armpmu_device_type(pdev));
-}
-
-static struct platform_driver armpmu_driver = {
- .driver = {
- .name = "arm-pmu",
- .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);
+/*
+ * PMU locking to ensure mutual exclusion between different subsystems.
+ */
+static unsigned long pmu_lock[BITS_TO_LONGS(ARM_NUM_PMU_DEVICES)];
-struct platform_device *
+int
reserve_pmu(enum arm_pmu_type type)
{
- struct platform_device *pdev;
-
- if (test_and_set_bit_lock(type, &pmu_lock)) {
- pdev = ERR_PTR(-EBUSY);
- } else if (pmu_devices[type] == NULL) {
- clear_bit_unlock(type, &pmu_lock);
- pdev = ERR_PTR(-ENODEV);
- } else {
- pdev = pmu_devices[type];
- }
-
- return pdev;
+ return test_and_set_bit_lock(type, pmu_lock) ? -EBUSY : 0;
}
EXPORT_SYMBOL_GPL(reserve_pmu);
-int
+void
release_pmu(enum arm_pmu_type type)
{
- if (WARN_ON(!pmu_devices[type]))
- return -EINVAL;
- clear_bit_unlock(type, &pmu_lock);
- return 0;
-}
-EXPORT_SYMBOL_GPL(release_pmu);
-
-static int
-set_irq_affinity(int irq,
- unsigned int cpu)
-{
-#ifdef CONFIG_SMP
- int err = irq_set_affinity(irq, cpumask_of(cpu));
- if (err)
- pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
- irq, cpu);
- return err;
-#else
- return -EINVAL;
-#endif
-}
-
-static int
-init_cpu_pmu(void)
-{
- int i, irqs, err = 0;
- struct platform_device *pdev = pmu_devices[ARM_PMU_DEVICE_CPU];
-
- if (!pdev)
- return -ENODEV;
-
- irqs = pdev->num_resources;
-
- /*
- * If we have a single PMU interrupt that we can't shift, assume that
- * we're running on a uniprocessor machine and continue.
- */
- if (irqs == 1 && !irq_can_set_affinity(platform_get_irq(pdev, 0)))
- return 0;
-
- for (i = 0; i < irqs; ++i) {
- err = set_irq_affinity(platform_get_irq(pdev, i), i);
- if (err)
- break;
- }
-
- return err;
-}
-
-int
-init_pmu(enum arm_pmu_type type)
-{
- int err = 0;
-
- switch (type) {
- case ARM_PMU_DEVICE_CPU:
- err = init_cpu_pmu();
- break;
- default:
- pr_warning("attempt to initialise PMU of unknown "
- "type %d\n", type);
- err = -EINVAL;
- }
-
- return err;
+ clear_bit_unlock(type, pmu_lock);
}
-EXPORT_SYMBOL_GPL(init_pmu);
projects / linux-beck.git / commitdiff