On 06/03/2014 20:05, Jason Cooper wrote:
> Thomas,
>
> nit: s/armanda/armada/ in the patch subject.
>
> Gregory,
>
> Mind providing an Ack on this?
Well sorry but with this patch the kernel doesn't
work anymore.
I am investigating to find if some part could be kept.
>
> thx,
>
> Jason.
>
> On Tue, Mar 04, 2014 at 08:43:41PM -0000, Thomas Gleixner wrote:
>> The set_irq_affinity() function has two issues:
>>
>> 1) It has no protection against selecting an offline cpu from the
>> given mask.
>>
>> 2) It pointlessly restricts the affinity masks to have a single cpu
>> set. This collides with the irq migration code of arm.
>>
>> irq affinity is set to core 3
>> core 3 goes offline
>>
>> migration code sets mask to cpu_online_mask and calls the
>> irq_set_affinity() callback of the irq_chip which fails due to bit
>> 0,1,2 set.
>>
>> So instead of doing silly for_each_cpu() loops just pick any bit of
>> the mask which intersects with the online mask.
>>
>> The read back of the routing register is pointless as well. We can
>> simply write the new mask as the bits in this register reflect one
>> core.
>>
>> Get rid of fiddling with the default_irq_affinity as well.
>>
>> Signed-off-by: Thomas Gleixner <t...@linutronix.de>
>> Cc: Gregory CLEMENT <gregory.clem...@free-electrons.com>
>> Cc: Jason Cooper <ja...@lakedaemon.net>
>>
>> ---
>> drivers/irqchip/irq-armada-370-xp.c | 38
>> ++++--------------------------------
>> 1 file changed, 5 insertions(+), 33 deletions(-)
>>
>> Index: tip/drivers/irqchip/irq-armada-370-xp.c
>> ===================================================================
>> --- tip.orig/drivers/irqchip/irq-armada-370-xp.c
>> +++ tip/drivers/irqchip/irq-armada-370-xp.c
>> @@ -244,35 +244,16 @@ static DEFINE_RAW_SPINLOCK(irq_controlle
>> static int armada_xp_set_affinity(struct irq_data *d,
>> const struct cpumask *mask_val, bool force)
>> {
>> - unsigned long reg;
>> - unsigned long new_mask = 0;
>> - unsigned long online_mask = 0;
>> - unsigned long count = 0;
>> irq_hw_number_t hwirq = irqd_to_hwirq(d);
>> + unsigned long mask;
>> int cpu;
>>
>> - for_each_cpu(cpu, mask_val) {
>> - new_mask |= 1 << cpu_logical_map(cpu);
>> - count++;
>> - }
>> -
>> - /*
>> - * Forbid mutlicore interrupt affinity
>> - * This is required since the MPIC HW doesn't limit
>> - * several CPUs from acknowledging the same interrupt.
>> - */
>> - if (count > 1)
>> - return -EINVAL;
>> -
>> - for_each_cpu(cpu, cpu_online_mask)
>> - online_mask |= 1 << cpu_logical_map(cpu);
>> + /* Select a single core from the affinity mask which is online */
>> + cpu = cpumask_any_and(mask_val, cpu_online_mask);
>> + mask = 1UL << cpu_logical_map(cpu);
>>
>> raw_spin_lock(&irq_controller_lock);
>> -
>> - reg = readl(main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
>> - reg = (reg & (~online_mask)) | new_mask;
>> - writel(reg, main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
>> -
>> + writel(mask, main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
>> raw_spin_unlock(&irq_controller_lock);
>>
>> return 0;
>> @@ -494,15 +475,6 @@ static int __init armada_370_xp_mpic_of_
>>
>> #ifdef CONFIG_SMP
>> armada_xp_mpic_smp_cpu_init();
>> -
>> - /*
>> - * Set the default affinity from all CPUs to the boot cpu.
>> - * This is required since the MPIC doesn't limit several CPUs
>> - * from acknowledging the same interrupt.
>> - */
>> - cpumask_clear(irq_default_affinity);
>> - cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
>> -
>> #endif
>>
>> armada_370_xp_msi_init(node, main_int_res.start);
>>
>>
>> --
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--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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