From: John Garry <john.garry@huawei.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
chenxiang <chenxiang66@hisilicon.com>
Subject: Re: About irq_create_affinity_masks() for a platform device driver
Date: Mon, 3 Feb 2020 15:00:38 +0000 [thread overview]
Message-ID: <2b381b20-512a-27a5-38d7-2f6a673bb621@huawei.com> (raw)
In-Reply-To: <87ftfvuww7.fsf@nanos.tec.linutronix.de>
Hi Thomas,
>>
>> pirqs = kzalloc(*count * sizeof(int), GFP_KERNEL);
>> if (!pirqs)
>> return -ENOMEM;
>>
>> dev->desc = irq_create_affinity_masks(*count, affd);
>> if (!dev->desc) {
>> kfree(irqs);
>
> pirqs I assume and this also leaks the affinity masks and the pointer in
> dev.
Right
>
>> return -ENOMEM;
>> }
>>
>> for (i = 0; i < *count; i++) {
>> pirqs[i] = platform_get_irq(dev, i);
>> if (irqs[i] < 0) {
>> kfree(dev->desc);
>> kfree(irqs);
>> return -ENOMEM;
>
> That's obviously broken as well :)
Right, again
>
>> }
>> }
>>
>> *irqs = pirqs;
>>
>> return 0;
>> }
>> EXPORT_SYMBOL_GPL(platform_get_irqs_affinity);
[...]
>
> I wouldn't mind to expose a function which allows you to switch the
> allocated interrupts to managed. The reason why we do it in one go in
> the PCI code is that we get automatically the irq descriptors allocated
> on the correct node. So if the node aware allocation is not a
> showstopper
I wouldn't say so for now.
for this then your function would do:
>
> ...
> for (i = 0; i < count; i++) {
> pirqs[i] = platform_get_irq(dev, i);
>
> irq_update_affinity_desc(pirqs[i], affdescs + i);
>
> }
>
> int irq_update_affinity_desc(unsigned int irq, irq_affinity_desc *affinity)
> {
> unsigned long flags;
> struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
>
> if (!desc)
> return -EINVAL;
>
> if (affinity->is_managed) {
> irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
> irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
Are these correct? I assume we want to follow alloc_descs() here.
> }
> cpumask_copy(desc->irq_common_data.affinity, affinity);
> return 0;
> }
I see. So I made a couple of changes and it did work:
int irq_update_affinity_desc(unsigned int irq, struct irq_affinity_desc
*affinity)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return -EINVAL;
if (affinity->is_managed) {
irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
}
cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
irq_put_desc_unlock(desc, flags);
return 0;
}
And if we were to go this way, then we don't need to add the pointer in
struct platform_device to hold affinity mask descriptors as we're using
them immediately. Or even have a single function to do it all in the irq
code (create the masks and update the affinity desc).
And since we're just updating the masks, I figure we shouldn't need to
add acpi_irq_get_count(), which I invented to get the irq count (without
creating the IRQ mapping).
Thanks,
John
next prev parent reply other threads:[~2020-02-03 15:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-22 10:09 About irq_create_affinity_masks() for a platform device driver John Garry
2020-01-22 10:59 ` Thomas Gleixner
2020-01-22 11:27 ` John Garry
2020-01-31 14:25 ` John Garry
2020-01-31 21:41 ` Thomas Gleixner
2020-02-03 15:00 ` John Garry [this message]
2020-02-04 9:20 ` Thomas Gleixner
2020-02-04 9:55 ` John Garry
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