From: jamie@jamieiles•com (Jamie Iles)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH 1/6] ARM: pmu: register IRQs at runtime
Date: Thu, 18 Mar 2010 12:20:10 +0000 [thread overview]
Message-ID: <20100318122010.GC4177@wear.picochip.com> (raw)
In-Reply-To: <1268842288-30960-1-git-send-email-will.deacon@arm.com>
On Wed, Mar 17, 2010 at 04:11:27PM +0000, Will Deacon wrote:
> 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.
Hi Will,
This seems like a nice approach to the problem. A couple of pedantic comments
inline!
Jamie
> Cc: Linux ARM Kernel <linux-arm-kernel@lists•infradead.org>
> Signed-off-by: Will Deacon <will.deacon@arm•com>
> ---
> arch/arm/include/asm/pmu.h | 30 +++++-----
> arch/arm/kernel/perf_event.c | 36 +++++++------
> arch/arm/kernel/pmu.c | 121 ++++++++++++++++++++++++++----------------
> 3 files changed, 110 insertions(+), 77 deletions(-)
[snip]
> +static int __devinit pmu_device_probe(struct platform_device *pdev)
> +{
> +
> + if (pdev->id >= ARM_NUM_PMU_DEVICES) {
> + pr_warning("PMU: Received registration request for unknown "
> + "device %d\n", pdev->id);
> + return -EINVAL;
> + }
> +
> + if (pmu_devices[pdev->id])
> + pr_warning("PMU: Registering new PMU device type %d overwrites "
> + "previous registration!\n", pdev->id);
> + else
> + pr_info("PMU: Registered new PMU device of type %d\n",
> + pdev->id);
> +
> + pmu_devices[pdev->id] = pdev;
struct pdev->id is a signed integer so we should check that it's not less than
0 so we don't overrun pmu_devices..
> @@ -79,7 +91,7 @@ set_irq_affinity(int irq,
> #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",
> + pr_warning("PMU: Unable to set irq affinity (irq=%d, cpu=%u)\n",
> irq, cpu);
How about we stick a '#define pr_fmt(fmt) "PMU: " fmt' before the includes so
we get consistent naming if we add more pr_*() statements?
> return err;
> #else
> @@ -87,17 +99,36 @@ 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];
Just to be safe:
if (!pdev)
return -ENODEV;
> - 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;
> }
>
> return err;
> }
next prev parent reply other threads:[~2010-03-18 12:20 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-12 17:29 [RFC PATCH 0/6] ARM: pmu: provide a registration mechanism for IRQs [v2] Will Deacon
2010-03-12 17:29 ` [RFC PATCH 1/6] ARM: pmu: register IRQs at runtime Will Deacon
2010-03-12 17:29 ` [RFC PATCH 2/6] ARM: Realview: register PMU IRQs during board initialisation Will Deacon
2010-03-12 17:29 ` [RFC PATCH 3/6] ARM: OMAP: " Will Deacon
2010-03-12 17:29 ` [RFC PATCH 4/6] ARM: BCMRING: register PMU IRQ " Will Deacon
2010-03-12 17:29 ` [RFC PATCH 5/6] ARM: iop3xx: register PMU IRQs " Will Deacon
2010-03-12 17:29 ` [RFC PATCH 6/6] ARM: pxa: " Will Deacon
2010-03-16 11:41 ` [RFC PATCH 1/6] ARM: pmu: register IRQs at runtime Jamie Iles
2010-03-17 16:06 ` Will Deacon
2010-03-17 16:11 ` Will Deacon
2010-03-17 16:11 ` [RFC PATCH 2/6] ARM: Realview: register PMU IRQs during board initialisation Will Deacon
2010-03-18 12:20 ` Jamie Iles [this message]
2010-03-24 15:50 ` [RFC PATCH 1/6] ARM: pmu: register IRQs at runtime Will Deacon
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