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authorWill Deacon <will.deacon@arm.com>2010-04-29 17:13:24 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-05-17 11:53:57 +0100
commit49c006b93769a86bec2b32b9234abf016ac0d50e (patch)
tree6784e69f48186c6edc6e9130fc1680a31cec0ce4 /arch/arm/kernel/pmu.c
parentc39e52a793f5599582dbacf4d8f62634a492f79e (diff)
ARM: 6064/1: pmu: register IRQs at runtime
The current PMU infrastructure for ARM requires that the IRQs for the PMU device are fixed at compile time and are selected based on the ARCH_ or MACH_ flags. This has the disadvantage of tying the Kernel down to a particular board as far as profiling is concerned. This patch replaces the compile-time IRQ registration with a runtime mechanism which allows the IRQs to be registered with the framework as a platform_device. A further advantage of this change is that there is scope for registering different types of performance counters in the future by changing the id of the platform_device and attaching different resources to it. Acked-by: Jamie Iles <jamie.iles@picochip.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/pmu.c')
-rw-r--r--arch/arm/kernel/pmu.c127
1 files changed, 83 insertions, 44 deletions
diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c
index a124312e343f..b8af96ea62e6 100644
--- a/arch/arm/kernel/pmu.c
+++ b/arch/arm/kernel/pmu.c
@@ -2,6 +2,7 @@
* 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
@@ -9,65 +10,78 @@
*
*/
+#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>
-/*
- * Define the IRQs for the system. We could use something like a platform
- * device but that seems fairly heavyweight for this. Also, the performance
- * counters can't be removed or hotplugged.
- *
- * Ordering is important: init_pmu() will use the ordering to set the affinity
- * to the corresponding core. e.g. the first interrupt will go to cpu 0, the
- * second goes to cpu 1 etc.
- */
-static const int irqs[] = {
-#if defined(CONFIG_ARCH_OMAP2)
- 3,
-#elif defined(CONFIG_ARCH_BCMRING)
- IRQ_PMUIRQ,
-#elif defined(CONFIG_MACH_REALVIEW_EB)
- IRQ_EB11MP_PMU_CPU0,
- IRQ_EB11MP_PMU_CPU1,
- IRQ_EB11MP_PMU_CPU2,
- IRQ_EB11MP_PMU_CPU3,
-#elif defined(CONFIG_ARCH_OMAP3)
- INT_34XX_BENCH_MPU_EMUL,
-#elif defined(CONFIG_ARCH_IOP32X)
- IRQ_IOP32X_CORE_PMU,
-#elif defined(CONFIG_ARCH_IOP33X)
- IRQ_IOP33X_CORE_PMU,
-#elif defined(CONFIG_ARCH_PXA)
- IRQ_PMU,
-#endif
-};
+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);
-static const struct pmu_irqs pmu_irqs = {
- .irqs = irqs,
- .num_irqs = ARRAY_SIZE(irqs),
+ pmu_devices[pdev->id] = pdev;
+ return 0;
+}
+
+static struct platform_driver pmu_driver = {
+ .driver = {
+ .name = "arm-pmu",
+ },
+ .probe = pmu_device_probe,
};
-static volatile long pmu_lock;
+static int __init register_pmu_driver(void)
+{
+ return platform_driver_register(&pmu_driver);
+}
+device_initcall(register_pmu_driver);
-const struct pmu_irqs *
-reserve_pmu(void)
+struct platform_device *
+reserve_pmu(enum arm_pmu_type device)
{
- return test_and_set_bit_lock(0, &pmu_lock) ? ERR_PTR(-EBUSY) :
- &pmu_irqs;
+ 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(const struct pmu_irqs *irqs)
+release_pmu(struct platform_device *pdev)
{
- if (WARN_ON(irqs != &pmu_irqs))
+ if (WARN_ON(pdev != pmu_devices[pdev->id]))
return -EINVAL;
- clear_bit_unlock(0, &pmu_lock);
+ clear_bit_unlock(pdev->id, &pmu_lock);
return 0;
}
EXPORT_SYMBOL_GPL(release_pmu);
@@ -87,17 +101,42 @@ set_irq_affinity(int irq,
#endif
}
-int
-init_pmu(void)
+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 < pmu_irqs.num_irqs; ++i) {
- err = set_irq_affinity(pmu_irqs.irqs[i], i);
+ 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);