From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v7 1/4] irqchip: gic: Support hierarchy irq domain.
Date: Thu, 20 Nov 2014 10:29:23 +0000 [thread overview]
Message-ID: <87sihe9ncs.fsf@approximate.cambridge.arm.com> (raw)
In-Reply-To: <1416476511.12869.24.camel@mtksdaap41> (Yingjoe Chen's message of "Thu, 20 Nov 2014 09:41:51 +0000")
Hi Joe,
On Thu, Nov 20 2014 at 9:41:51 am GMT, Yingjoe Chen <yingjoe.chen@mediatek•com> wrote:
> Hi Marc,
>
> On Thu, 2014-11-20 at 11:57 +0800, Yingjoe Chen wrote:
>> On Wed, 2014-11-19 at 17:18 +0000, Marc Zyngier wrote:
>> > > +
>> > > + return 0;
>> > > +}
>> > > +
>> > > +static const struct irq_domain_ops gic_irq_domain_hierarchy_ops = {
>> > > + .xlate = gic_irq_domain_xlate,
>> > > + .alloc = gic_irq_domain_alloc,
>> > > + .free = irq_domain_free_irqs_top,
>> >
>> > I'm convinced that irq_domain_free_irqs_top is the wrong function to
>> > call here, because you're calling it from the bottom, not the top-level
>> > (it has no parent).
>>
>> Base on the name, I though this is helper function for top level
>> irq_domain?
>>
>> > I cannot verify this with your code as I don't a working platform with
>> > GICv2m, but if I enable something similar on GICv3, it dies a very
>> > painful way:
>> >
>> > Unable to handle kernel NULL pointer dereference at virtual address 00000018
>> > pgd = ffffffc03d059000
>> > [00000018] *pgd=0000000081356003, *pud=0000000081356003,
>> > *pmd=0000000000000000
>> > Internal error: Oops: 96000006 [#1] SMP
>> > Modules linked in:
>> > CPU: 4 PID: 1052 Comm: sh Not tainted 3.18.0-rc4+ #3311
>> > task: ffffffc03e320000 ti: ffffffc001390000 task.ti: ffffffc001390000
>> > PC is at irq_domain_free_irqs_recursive+0x1c/0x80
>> > LR is at irq_domain_free_irqs_common+0x88/0x9c
>> > pc : [<ffffffc0000ed790>] lr : [<ffffffc0000ede20>] pstate: 60000145
>> > [...]
>> > [<ffffffc0000ed790>] irq_domain_free_irqs_recursive+0x1c/0x80
>> > [<ffffffc0000ede1c>] irq_domain_free_irqs_common+0x84/0x9c
>> > [<ffffffc0000ede98>] irq_domain_free_irqs_top+0x64/0x7c <--
>> > gic_domain.free()
>> > [<ffffffc0000ed798>] irq_domain_free_irqs_recursive+0x24/0x80
>> > [<ffffffc0000ee468>] irq_domain_free_irqs_parent+0x14/0x20
>> > [<ffffffc0003500b8>] its_irq_domain_free+0xc8/0x250
>> > [<ffffffc0000ed798>] irq_domain_free_irqs_recursive+0x24/0x80
>> > [<ffffffc0000ede1c>] irq_domain_free_irqs_common+0x84/0x9c
>> > [<ffffffc0000ede98>] irq_domain_free_irqs_top+0x64/0x7c
>> > [<ffffffc0000ef518>] msi_domain_free+0x70/0x88
>> > [<ffffffc0000ed798>] irq_domain_free_irqs_recursive+0x24/0x80
>> > [<ffffffc0000ee3ac>] irq_domain_free_irqs+0x108/0x17c
>> > [<ffffffc0000efb68>] msi_domain_free_irqs+0x28/0x4c
>> > [<ffffffc000369cac>] free_msi_irqs+0xb4/0x1c0
>> > [<ffffffc00036adec>] pci_disable_msix+0x3c/0x4c
>> > [...]
>> >
>> > and I cannot see how this could work on the standard GIC either.
>>
>> I'm sorry, I just realize my testcase was too simple, irqs are populated
>> by device tree and never got freed. I'll add that and test it again.
>
> On a second thoughts, unlike the MSI cases, gic_irq_domain_hierarchy_ops
> is only used when we use DT, so we probably will never use the free
> function. Is it OK to remove the free support here?
Well, such thing is coming with GICv2m (SPIs are allocated out of
DT). You can drop it if you want, but I will then have to add it back
(which seems like a waste of time).
I'd prefer if you kept it in with the rest of the conversion.
Thanks,
M.
--
Jazz is not dead. It just smells funny.
next prev parent reply other threads:[~2014-11-20 10:29 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-19 14:14 [PATCH v7 0/4] ARM: mediatek: Add support for interrupt polarity Yingjoe Chen
2014-11-19 14:14 ` [PATCH v7 1/4] irqchip: gic: Support hierarchy irq domain Yingjoe Chen
2014-11-19 17:18 ` Marc Zyngier
2014-11-20 3:57 ` Yingjoe Chen
2014-11-20 9:41 ` Yingjoe Chen
2014-11-20 10:29 ` Marc Zyngier [this message]
2014-11-20 4:26 ` Jiang Liu
2014-11-20 10:07 ` Marc Zyngier
2014-11-21 15:51 ` Yingjoe Chen
2014-11-24 19:31 ` Marc Zyngier
2014-11-19 14:14 ` [PATCH v7 2/4] ARM: mediatek: Add sysirq interrupt polarity support Yingjoe Chen
2014-11-19 18:04 ` Mark Rutland
2014-11-21 15:36 ` Yingjoe Chen
2014-11-19 14:14 ` [PATCH v7 3/4] ARM: mediatek: Add sysirq in mt6589/mt8135/mt8127 dtsi Yingjoe Chen
2014-11-19 17:49 ` Marc Zyngier
2014-11-20 3:29 ` Yingjoe Chen
2014-11-19 14:14 ` [PATCH v7 4/4] dt-bindings: add bindings for mediatek sysirq Yingjoe Chen
2014-11-19 18:07 ` Mark Rutland
2014-11-24 15:14 ` Yingjoe Chen
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