From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001
From: root <root@artemis.panaceas.org>
Date: Fri, 25 Dec 2015 04:40:36 +0000
Subject: initial_commit

---
 arch/arm/kernel/pmu.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 arch/arm/kernel/pmu.c

(limited to 'arch/arm/kernel/pmu.c')

diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c
new file mode 100644
index 00000000..2c79eec1
--- /dev/null
+++ b/arch/arm/kernel/pmu.c
@@ -0,0 +1,148 @@
+/*
+ *  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 -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 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);
-- 
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