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Diffstat (limited to 'arch/arm/kernel/pmu.c')
-rw-r--r--arch/arm/kernel/pmu.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c
new file mode 100644
index 000000000000..b8af96ea62e6
--- /dev/null
+++ b/arch/arm/kernel/pmu.c
@@ -0,0 +1,142 @@
+/*
+ * linux/arch/arm/kernel/pmu.c
+ *
+ * Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
+ * Copyright (C) 2010 ARM Ltd, Will Deacon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#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/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_device_probe(struct platform_device *pdev)
+{
+
+ if (pdev->id < 0 || pdev->id >= ARM_NUM_PMU_DEVICES) {
+ pr_warning("received registration request for unknown "
+ "device %d\n", pdev->id);
+ return -EINVAL;
+ }
+
+ if (pmu_devices[pdev->id])
+ pr_warning("registering new PMU device type %d overwrites "
+ "previous registration!\n", pdev->id);
+ else
+ pr_info("registered new PMU device of type %d\n",
+ pdev->id);
+
+ pmu_devices[pdev->id] = pdev;
+ return 0;
+}
+
+static struct platform_driver pmu_driver = {
+ .driver = {
+ .name = "arm-pmu",
+ },
+ .probe = pmu_device_probe,
+};
+
+static int __init register_pmu_driver(void)
+{
+ return platform_driver_register(&pmu_driver);
+}
+device_initcall(register_pmu_driver);
+
+struct platform_device *
+reserve_pmu(enum arm_pmu_type device)
+{
+ struct platform_device *pdev;
+
+ if (test_and_set_bit_lock(device, &pmu_lock)) {
+ pdev = ERR_PTR(-EBUSY);
+ } else if (pmu_devices[device] == NULL) {
+ clear_bit_unlock(device, &pmu_lock);
+ pdev = ERR_PTR(-ENODEV);
+ } else {
+ pdev = pmu_devices[device];
+ }
+
+ return pdev;
+}
+EXPORT_SYMBOL_GPL(reserve_pmu);
+
+int
+release_pmu(struct platform_device *pdev)
+{
+ if (WARN_ON(pdev != pmu_devices[pdev->id]))
+ return -EINVAL;
+ clear_bit_unlock(pdev->id, &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 0;
+#endif
+}
+
+static int
+init_cpu_pmu(void)
+{
+ int i, err = 0;
+ struct platform_device *pdev = pmu_devices[ARM_PMU_DEVICE_CPU];
+
+ if (!pdev) {
+ err = -ENODEV;
+ goto out;
+ }
+
+ for (i = 0; i < pdev->num_resources; ++i) {
+ err = set_irq_affinity(platform_get_irq(pdev, i), i);
+ if (err)
+ break;
+ }
+
+out:
+ return err;
+}
+
+int
+init_pmu(enum arm_pmu_type device)
+{
+ int err = 0;
+
+ switch (device) {
+ case ARM_PMU_DEVICE_CPU:
+ err = init_cpu_pmu();
+ break;
+ default:
+ pr_warning("attempt to initialise unknown device %d\n",
+ device);
+ err = -EINVAL;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(init_pmu);