Re: [PATCH v2 3/6] irqchip: gicv3-its: limit order of DT size to MAX_ORDER

From: Yun Wu (Abel)
Date: Tue Feb 17 2015 - 05:01:14 EST


On 2015/2/17 17:19, Marc Zyngier wrote:

> On Sun, 15 Feb 2015 09:32:00 +0000
> Yun Wu <wuyun.wu@xxxxxxxxxx> wrote:
>
>> When required DT size is out of the kmalloc()'s capability, the whole
>
> Nit: Using the DT acronym is very confusing here, as it means "Device
> Tree" to most people, including me. Please use "Device Table" instead.
>
> Also, the reference to kmalloc is wrong, as we're really using the page
> allocator.

OK, I will get the description fixed in the next version.

>
>> ITS will fail in probing. This actually is not the hardware's problem
>> and is mainly a limitation of the kernel memory allocator. This patch
>> will keep ITS going on to the next initializaion step with an explicit
>> warning.
>>
>> Signed-off-by: Yun Wu <wuyun.wu@xxxxxxxxxx>
>> ---
>> drivers/irqchip/irq-gic-v3-its.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c
>> b/drivers/irqchip/irq-gic-v3-its.c index f5bfa42..de36606 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -828,6 +828,12 @@ static int its_alloc_tables(struct its_node *its)
>> u32 ids = GITS_TYPER_DEVBITS(typer);
>>
>> order = get_order((1UL << ids) * entry_size);
>> + if (order >= MAX_ORDER) {
>> + pr_warn("%s: DT size too large,
>> reduce to %u pages\n",
>> +
>> its->msi_chip.of_node->full_name,
>> + 1 << order);
>> + order = MAX_ORDER;
>> + }
>> }
>
> Something is wrong here. Either (order == MAX_ORDER) is acceptable, or
> it is not. Also, your warning says that you're reducing the size to a
> new value, but you're displaying the size you can't handle. That
> message should be fixed.
>

Yes, my fault, I will fix them.

Thanks,
Abel


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/