From: ebiederm@xmission•com (Eric W. Biederman)
To: Yinghai Lu <yinghai@kernel•org>
Cc: Jeremy Fitzhardinge <jeremy@goop•org>,
Ian Campbell <Ian.Campbell@citrix•com>,
"x86@kernel•org" <x86@kernel•org>,
"linux-kernel@vger•kernel.org" <linux-kernel@vger•kernel.org>,
"linuxppc-dev@ozlabs•org" <linuxppc-dev@ozlabs•org>,
Ingo Molnar <mingo@redhat•com>, Paul Mackerras <paulus@samba•org>,
"H. Peter Anvin" <hpa@zytor•com>,
Thomas Gleixner <tglx@linutronix•de>
Subject: Re: [PATCH] irq: move some interrupt arch_* functions into struct irq_chip.
Date: Wed, 10 Mar 2010 11:15:58 -0800 [thread overview]
Message-ID: <m1k4tkf0nl.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <4B97EC00.6030300@kernel.org> (Yinghai Lu's message of "Wed\, 10 Mar 2010 10\:59\:12 -0800")
Yinghai Lu <yinghai@kernel•org> writes:
> On 03/10/2010 04:51 AM, Ian Campbell wrote:
>> On Wed, 2010-03-10 at 12:06 +0000, Yinghai Lu wrote:
>>> On Wed, Mar 10, 2010 at 2:55 AM, <ijc@hellion•org.uk> wrote:
>>>> From: Ian Campbell <ian.campbell@citrix•com>
>>>>
>>>> Move arch_init_copy_chip_data and arch_free_chip_data into function
>>>> pointers in struct irq_chip since they operate on irq_desc->chip_data.
>>>>
>>>> arch_init_chip_data cannot be moved into struct irq_chip at this time
>>>> because irq_desc->chip is not known at the time the irq_desc is
>>>> setup. For now rename arch_init_chip_data to arch_init_irq_desc (for
>>>> PowerPC, the only other user, whose usage better matches the new name)
>>>> and on x86 convert arch_init_chip_data to ioapic_init_chip_data and
>>>> call this whenever the IO APIC code allocates a new IRQ.
>>>>
>>>> I've retained the chip_data behaviour for uv_irq although it isn't
>>>> clear to me if these interrupt types support migration or how closely
>>>> related to the APIC modes they really are. If it weren't for this the
>>>> ioapic_{init,copy,free}_chip_data functions could be static to
>>>> io_apic.c.
>>>>
>>>> I've tested by booting on a 64 bit system, but it's not clear to me
>>>> what actions I need to take to actually exercise some of these code
>>>> paths.
>>>>
>>>
>>> can you just add another pointer field in irq_desc?
>>>
>>> some kind of *irq_info etc.
>>
>> I think I don't understand what you are suggesting.
>>
>> There is already a pointer for irq_chip specific use i.e.
>> irq_desc->chip_data. This patchset is just about ensuring that the field
>> really is available to any chip implementation rather than just assuming
>> it is always used for the acpi chip types (on x86 at least).
>>
>> Does adding a second pointer with the same (intended?) semantics as the
>> existing one buy us anything?
>
>
> #ifdef CONFIG_INTR_REMAP
> struct irq_2_iommu *irq_2_iommu;
> #endif
> struct irq_chip *chip;
> struct msi_desc *msi_desc;
>
> we already have that for irq_2_iommu and msi_desc
Those are at different levels of the hierarchy. Adding another pointer
for Xen is like having a different iommu and so adding another pointer
to handle that kind of iommu.
Eric
next prev parent reply other threads:[~2010-03-10 19:16 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1268218524.11737.68547.camel@zakaz.uk.xensource.com>
2010-03-10 10:55 ` [PATCH] irq: move some interrupt arch_* functions into struct irq_chip ijc
2010-03-10 11:00 ` Ian Campbell
2010-03-10 17:18 ` Eric W. Biederman
2010-03-10 17:41 ` Ian Campbell
2010-03-10 18:11 ` Eric W. Biederman
2010-03-10 12:06 ` Yinghai Lu
2010-03-10 12:51 ` Ian Campbell
2010-03-10 17:42 ` Eric W. Biederman
2010-03-10 17:50 ` Ian Campbell
2010-03-10 18:15 ` Eric W. Biederman
2010-03-10 18:28 ` Ian Campbell
2010-03-10 18:27 ` Jeremy Fitzhardinge
2010-03-10 18:59 ` Yinghai Lu
2010-03-10 19:15 ` Eric W. Biederman [this message]
2010-03-10 22:07 ` Michael Ellerman
2010-03-12 9:44 [GITPULL+PATCH 0/2] " Ian Campbell
2010-03-12 9:45 ` [PATCH] " Ian Campbell
2010-03-12 19:26 ` Yinghai Lu
2010-03-13 0:29 ` Eric W. Biederman
2010-03-16 8:50 ` Ian Campbell
2010-03-16 9:18 ` Eric W. Biederman
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