Re: [PATCH v3 6/8] genirq: Add and use an irq_data_update_affinity helper

[Oleksandr Tyshchenko]

On 07.07.22 11:39, Marc Zyngier wrote:


Hello Marc

> On Sun, 03 Jul 2022 16:22:03 +0100,
> Oleksandr <olekstysh@xxxxxxxxx> wrote:
>>
>> On 01.07.22 23:00, Samuel Holland wrote:
>>
>>
>> Hello Samuel
>>
>>> Some architectures and irqchip drivers modify the cpumask returned by
>>> irq_data_get_affinity_mask, usually by copying in to it. This is
>>> problematic for uniprocessor configurations, where the affinity mask
>>> should be constant, as it is known at compile time.
>>>
>>> Add and use a setter for the affinity mask, following the pattern of
>>> irq_data_update_effective_affinity. This allows the getter function to
>>> return a const cpumask pointer.
>>>
>>> Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
>>> ---
>>>
>>> Changes in v3:
>>>    - New patch to introduce irq_data_update_affinity
>>>
>>>    arch/alpha/kernel/irq.c          | 2 +-
>>>    arch/ia64/kernel/iosapic.c       | 2 +-
>>>    arch/ia64/kernel/irq.c           | 4 ++--
>>>    arch/ia64/kernel/msi_ia64.c      | 4 ++--
>>>    arch/parisc/kernel/irq.c         | 2 +-
>>>    drivers/irqchip/irq-bcm6345-l1.c | 4 ++--
>>>    drivers/parisc/iosapic.c         | 2 +-
>>>    drivers/sh/intc/chip.c           | 2 +-
>>>    drivers/xen/events/events_base.c | 7 ++++---
>>>    include/linux/irq.h              | 6 ++++++
>>>    10 files changed, 21 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/arch/alpha/kernel/irq.c b/arch/alpha/kernel/irq.c
>>> index f6d2946edbd2..15f2effd6baf 100644
>>> --- a/arch/alpha/kernel/irq.c
>>> +++ b/arch/alpha/kernel/irq.c
>>> @@ -60,7 +60,7 @@ int irq_select_affinity(unsigned int irq)
>>>    		cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
>>>    	last_cpu = cpu;
>>>    -	cpumask_copy(irq_data_get_affinity_mask(data),
>>> cpumask_of(cpu));
>>> +	irq_data_update_affinity(data, cpumask_of(cpu));
>>>    	chip->irq_set_affinity(data, cpumask_of(cpu), false);
>>>    	return 0;
>>>    }
>>> diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c
>>> index 35adcf89035a..99300850abc1 100644
>>> --- a/arch/ia64/kernel/iosapic.c
>>> +++ b/arch/ia64/kernel/iosapic.c
>>> @@ -834,7 +834,7 @@ iosapic_unregister_intr (unsigned int gsi)
>>>    	if (iosapic_intr_info[irq].count == 0) {
>>>    #ifdef CONFIG_SMP
>>>    		/* Clear affinity */
>>> -		cpumask_setall(irq_get_affinity_mask(irq));
>>> +		irq_data_update_affinity(irq_get_irq_data(irq), cpu_all_mask);
>>>    #endif
>>>    		/* Clear the interrupt information */
>>>    		iosapic_intr_info[irq].dest = 0;
>>> diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c
>>> index ecef17c7c35b..275b9ea58c64 100644
>>> --- a/arch/ia64/kernel/irq.c
>>> +++ b/arch/ia64/kernel/irq.c
>>> @@ -57,8 +57,8 @@ static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
>>>    void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
>>>    {
>>>    	if (irq < NR_IRQS) {
>>> -		cpumask_copy(irq_get_affinity_mask(irq),
>>> -			     cpumask_of(cpu_logical_id(hwid)));
>>> +		irq_data_update_affinity(irq_get_irq_data(irq),
>>> +					 cpumask_of(cpu_logical_id(hwid)));
>>>    		irq_redir[irq] = (char) (redir & 0xff);
>>>    	}
>>>    }
>>> diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c
>>> index df5c28f252e3..025e5133c860 100644
>>> --- a/arch/ia64/kernel/msi_ia64.c
>>> +++ b/arch/ia64/kernel/msi_ia64.c
>>> @@ -37,7 +37,7 @@ static int ia64_set_msi_irq_affinity(struct irq_data *idata,
>>>    	msg.data = data;
>>>      	pci_write_msi_msg(irq, &msg);
>>> -	cpumask_copy(irq_data_get_affinity_mask(idata), cpumask_of(cpu));
>>> +	irq_data_update_affinity(idata, cpumask_of(cpu));
>>>      	return 0;
>>>    }
>>> @@ -132,7 +132,7 @@ static int dmar_msi_set_affinity(struct irq_data *data,
>>>    	msg.address_lo |= MSI_ADDR_DEST_ID_CPU(cpu_physical_id(cpu));
>>>      	dmar_msi_write(irq, &msg);
>>> -	cpumask_copy(irq_data_get_affinity_mask(data), mask);
>>> +	irq_data_update_affinity(data, mask);
>>>      	return 0;
>>>    }
>>> diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
>>> index 0fe2d79fb123..5ebb1771b4ab 100644
>>> --- a/arch/parisc/kernel/irq.c
>>> +++ b/arch/parisc/kernel/irq.c
>>> @@ -315,7 +315,7 @@ unsigned long txn_affinity_addr(unsigned int irq, int cpu)
>>>    {
>>>    #ifdef CONFIG_SMP
>>>    	struct irq_data *d = irq_get_irq_data(irq);
>>> -	cpumask_copy(irq_data_get_affinity_mask(d), cpumask_of(cpu));
>>> +	irq_data_update_affinity(d, cpumask_of(cpu));
>>>    #endif
>>>      	return per_cpu(cpu_data, cpu).txn_addr;
>>> diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
>>> index 142a7431745f..6899e37810a8 100644
>>> --- a/drivers/irqchip/irq-bcm6345-l1.c
>>> +++ b/drivers/irqchip/irq-bcm6345-l1.c
>>> @@ -216,11 +216,11 @@ static int bcm6345_l1_set_affinity(struct irq_data *d,
>>>    		enabled = intc->cpus[old_cpu]->enable_cache[word] & mask;
>>>    		if (enabled)
>>>    			__bcm6345_l1_mask(d);
>>> -		cpumask_copy(irq_data_get_affinity_mask(d), dest);
>>> +		irq_data_update_affinity(d, dest);
>>>    		if (enabled)
>>>    			__bcm6345_l1_unmask(d);
>>>    	} else {
>>> -		cpumask_copy(irq_data_get_affinity_mask(d), dest);
>>> +		irq_data_update_affinity(d, dest);
>>>    	}
>>>    	raw_spin_unlock_irqrestore(&intc->lock, flags);
>>>    diff --git a/drivers/parisc/iosapic.c b/drivers/parisc/iosapic.c
>>> index 8a3b0c3a1e92..3a8c98615634 100644
>>> --- a/drivers/parisc/iosapic.c
>>> +++ b/drivers/parisc/iosapic.c
>>> @@ -677,7 +677,7 @@ static int iosapic_set_affinity_irq(struct irq_data *d,
>>>    	if (dest_cpu < 0)
>>>    		return -1;
>>>    -	cpumask_copy(irq_data_get_affinity_mask(d),
>>> cpumask_of(dest_cpu));
>>> +	irq_data_update_affinity(d, cpumask_of(dest_cpu));
>>>    	vi->txn_addr = txn_affinity_addr(d->irq, dest_cpu);
>>>      	spin_lock_irqsave(&iosapic_lock, flags);
>>> diff --git a/drivers/sh/intc/chip.c b/drivers/sh/intc/chip.c
>>> index 358df7510186..828d81e02b37 100644
>>> --- a/drivers/sh/intc/chip.c
>>> +++ b/drivers/sh/intc/chip.c
>>> @@ -72,7 +72,7 @@ static int intc_set_affinity(struct irq_data *data,
>>>    	if (!cpumask_intersects(cpumask, cpu_online_mask))
>>>    		return -1;
>>>    -	cpumask_copy(irq_data_get_affinity_mask(data), cpumask);
>>> +	irq_data_update_affinity(data, cpumask);
>>>      	return IRQ_SET_MASK_OK_NOCOPY;
>>>    }
>>> diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
>>> index 46d9295d9a6e..5e8321f43cbd 100644
>>> --- a/drivers/xen/events/events_base.c
>>> +++ b/drivers/xen/events/events_base.c
>>> @@ -528,9 +528,10 @@ static void bind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
>>>    	BUG_ON(irq == -1);
>>>      	if (IS_ENABLED(CONFIG_SMP) && force_affinity) {
>>> -		cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(cpu));
>>> -		cpumask_copy(irq_get_effective_affinity_mask(irq),
>>> -			     cpumask_of(cpu));
>>> +		struct irq_data *data = irq_get_irq_data(irq);
>>> +
>>> +		irq_data_update_affinity(data, cpumask_of(cpu));
>>> +		irq_data_update_effective_affinity(data, cpumask_of(cpu));
>>>    	}
>>
>>
>> Nit: commit description says about reusing irq_data_update_affinity()
>> only, but here we also reuse irq_data_update_effective_affinity(), so
>> I would mention that in the description.
>>
>> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx> # Xen bits
> b4 shouts because of your email address:
>
> NOTE: some trailers ignored due to from/email mismatches:
>      ! Trailer: Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx> # Xen bits
>       Msg From: Oleksandr <olekstysh@xxxxxxxxx>

sorry for the inconvenience


>
> I've used the tag anyway,


thank you


>   but you may want to fix your setup in the
> future.

yes, will do


>
> Thanks,
>
> 	M.
>
-- 
Regards,

Oleksandr Tyshchenko