linux-kernel - Re: [PATCH] irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES

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Message-ID: <CAKTKpr7tmavUKyqxYabdfYOpV0V9TLySmwCwTyng5zZoxy9nqg@mail.gmail.com>
Date:   Fri, 21 Jul 2017 17:12:50 +0530
From:   Ganapatrao Kulkarni <gklkml16@...il.com>
To:     Marc Zyngier <marc.zyngier@....com>
Cc:     Hanjun Guo <guohanjun@...wei.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        linux-kernel@...r.kernel.org, linuxarm@...wei.com,
        linux-acpi@...r.kernel.org, Hanjun Guo <hanjun.guo@...aro.org>,
        Ganapatrao Kulkarni <ganapatrao.kulkarni@...ium.com>,
        linux-arm-kernel@...ts.infradead.org, Jayachandran.Nair@...ium.com
Subject: Re: [PATCH] irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES

Hi Hanjun,

On Fri, Jul 21, 2017 at 4:50 PM, Marc Zyngier <marc.zyngier@....com> wrote:
> On 21/07/17 11:06, Hanjun Guo wrote:
>> On 2017/7/21 17:51, Hanjun Guo wrote:
>>> From: Hanjun Guo <hanjun.guo@...aro.org>
>>>
>>> When running 4.13-rc1 on top of D05, I got the boot log:
>>>
>>> [    0.000000] SRAT: PXM 0 -> ITS 0 -> Node 0
>>> [    0.000000] SRAT: PXM 0 -> ITS 1 -> Node 0
>>> [    0.000000] SRAT: PXM 0 -> ITS 2 -> Node 0
>>> [    0.000000] SRAT: PXM 1 -> ITS 3 -> Node 1
>>> [    0.000000] SRAT: ITS affinity exceeding max count[4]
>>>
>>> This is wrong on D05 as we have 8 ITSes with 4 NUMA nodes.

Used static array to keep it simple.  we can have either dynamic array
or increase static array size (which is in init data) to a larger
number.
We may have to go for dynamic array to be more sane. You can refer my
v2 patch [1], which was doing dynamic allocation and avoids
2 calls to acpi parser as done in this patch.

[1] https://patchwork.kernel.org/patch/9798659/

>
> I'm not seeing this on the D05 I have access to. Actually, I'm not
> seeing any data related to SRAT and the ITS. Is that a different firmware?
>
>>>
>>> So dynamically alloc the memory needed instead of using
>>> its_srat_maps[MAX_NUMNODES], which count the number of
>>> ITS entry(ies) in SRAT and alloc its_srat_maps as needed,
>>> then build the mapping of numa node to ITS ID.
>>>
>>> After doing this, I got what I wanted:
>>>
>>> [    0.000000] SRAT: PXM 0 -> ITS 0 -> Node 0
>>> [    0.000000] SRAT: PXM 0 -> ITS 1 -> Node 0
>>> [    0.000000] SRAT: PXM 0 -> ITS 2 -> Node 0
>>> [    0.000000] SRAT: PXM 1 -> ITS 3 -> Node 1
>>> [    0.000000] SRAT: PXM 2 -> ITS 4 -> Node 2
>>> [    0.000000] SRAT: PXM 2 -> ITS 5 -> Node 2
>>> [    0.000000] SRAT: PXM 2 -> ITS 6 -> Node 2
>>> [    0.000000] SRAT: PXM 3 -> ITS 7 -> Node 3
>>>
>>> Fixes: dbd2b8267233 ("irqchip/gic-v3-its: Add ACPI NUMA node mapping")
>>> Signed-off-by: Hanjun Guo <hanjun.guo@...aro.org>
>>> Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@...ium.com>
>>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
>>> Cc: Marc Zyngier <marc.zyngier@....com>
>>> ---
>>>  drivers/irqchip/irq-gic-v3-its.c | 28 +++++++++++++++++++++-------
>>>  1 file changed, 21 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>>> index 3ccdf76..fb1c090 100644
>>> --- a/drivers/irqchip/irq-gic-v3-its.c
>>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>>> @@ -1847,7 +1847,7 @@ struct its_srat_map {
>>>      u32     its_id;
>>>  };
>>>
>>> -static struct its_srat_map its_srat_maps[MAX_NUMNODES] __initdata;
>>> +static struct its_srat_map *its_srat_maps __initdata;
>>>  static int its_in_srat __initdata;
>>>
>>>  static int __init acpi_get_its_numa_node(u32 its_id)
>>> @@ -1861,6 +1861,12 @@ static int __init acpi_get_its_numa_node(u32 its_id)
>>>      return NUMA_NO_NODE;
>>>  }
>>
>> Oops, need to check if the its_srat_maps valid or not here, please
>> comment on what else I'm missing or wrong, then I will prepare another
>> version.
>
> Please post a patch that has all of the fixes, and I'll review that.
>
> Thanks,
>
>         M.
> --
> Jazz is not dead. It just smells funny...
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

thanks
Ganapat

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