* Re: [PATCH V1 1/2] irqchip/loongson-pch-pic: Support to set irq type for ACPI path
[not found] ` <86leq37duw.wl-maz@kernel.org>
@ 2022-09-29 2:35 ` Jianmin Lv
2022-09-29 9:44 ` Marc Zyngier
0 siblings, 1 reply; 3+ messages in thread
From: Jianmin Lv @ 2022-09-29 2:35 UTC (permalink / raw)
To: Marc Zyngier
Cc: Thomas Gleixner, linux-kernel, loongarch, Jiaxun Yang,
Huacai Chen, Bjorn Helgaas, Rafael J. Wysocki, Len Brown,
linux-pci, linux-acpi
On 2022/9/28 下午10:49, Marc Zyngier wrote:
> On Mon, 15 Aug 2022 22:01:30 -0400,
> Jianmin Lv <lvjianmin@loongson.cn> wrote:
>>
>> For ACPI path, the translate callback used IRQ_TYPE_NONE and ignored
>> the irq type in fwspec->param[1]. For supporting to set type for
>> irqs of the irqdomain, fwspec->param[1] should be used to get irq
>> type.
>>
>> On Loongson platform, the irq trigger type of PCI devices is
>> high level, so high level triggered type is inputed to acpi_register_gsi
>> when create irq mapping for PCI devices.
>>
>> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
>> ---
>> drivers/acpi/pci_irq.c | 3 ++-
>> drivers/irqchip/irq-loongson-pch-pic.c | 10 ++++++----
>> 2 files changed, 8 insertions(+), 5 deletions(-)
>
> $ ./scripts/get_maintainer.pl drivers/acpi/pci_irq.c
> Bjorn Helgaas <bhelgaas@google.com> (supporter:PCI SUBSYSTEM)
> "Rafael J. Wysocki" <rafael@kernel.org> (supporter:ACPI)
> Len Brown <lenb@kernel.org> (reviewer:ACPI)
> linux-pci@vger.kernel.org (open list:PCI SUBSYSTEM)
> linux-acpi@vger.kernel.org (open list:ACPI)
> linux-kernel@vger.kernel.org (open list)
>
> How about you start Cc-ing some of the relevant people?
>
Ok, thanks, I'll cc relevant people list here.
>>
>> diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
>> index 08e1577..34483b3 100644
>> --- a/drivers/acpi/pci_irq.c
>> +++ b/drivers/acpi/pci_irq.c
>> @@ -393,7 +393,8 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
>> * controller and must therefore be considered active high
>> * as default.
>> */
>> - int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ?
>> + int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ||
>> + acpi_irq_model == ACPI_IRQ_MODEL_LPIC ?
>> ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW;
>
> The comment just above this only talks about ARM. Should it be
> updated?
Ok, I'll update the comment.
Is this a limitation of the underlying interrupt controller?
>
It's the limitation that pci interrupt source of LoongArch only sends
high level trigger signal to interrupt controller(though, pci spec
requires asserted low).
>> char *link = NULL;
>> char link_desc[16];
>> diff --git a/drivers/irqchip/irq-loongson-pch-pic.c b/drivers/irqchip/irq-loongson-pch-pic.c
>> index b6f1392..5067010 100644
>> --- a/drivers/irqchip/irq-loongson-pch-pic.c
>> +++ b/drivers/irqchip/irq-loongson-pch-pic.c
>> @@ -177,13 +177,15 @@ static int pch_pic_domain_translate(struct irq_domain *d,
>> if (fwspec->param_count < 1)
>> return -EINVAL;
>>
>> - if (of_node) {
>> + if (of_node)
>> *hwirq = fwspec->param[0] + priv->ht_vec_base;
>> - *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
>> - } else {
>> + else
>> *hwirq = fwspec->param[0] - priv->gsi_base;
>> +
>> + if (fwspec->param_count > 1)
>> + *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
>> + else
>> *type = IRQ_TYPE_NONE;
>
> Isn't that a change in behaviour if of_node is non-NULL and
> param_count==1?
>
It seems that current code here has bug that if fwspec->param_count==1
and of_node is non-null, fwspec->param[1] will be accessed, which is
introduced from previous patch(irqchip/loongson-pch-pic: Add ACPI init
support). Before the patch, for non-null of_node, translate callback(use
irq_domain_translate_twocell) will return -EINVAL if fwspec->param_count
< 2.
For ACPI path, fwspec->param_count can be 1 or 2.
So in this patch, I'll fix the bug and change the code as following:
if (fwspec->param_count < 1)
return -EINVAL;
if (of_node) {
if (fwspec->param_count < 2)
return -EINVAL;
*hwirq = fwspec->param[0] + priv->ht_vec_base;
*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
} else {
*hwirq = fwspec->param[0] - priv->gsi_base;
if (fwspec->param_count > 1)
*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
else
*type = IRQ_TYPE_NONE;
}
>> - }
>>
>> return 0;
>> }
>
> This irqchip change should probably be a separate patch.
>
As a separate patch, the input trigger type of pci devices will be low
level because of lacking of workaround to acpi_pci_irq_enable, which
will cause kernel hang, unless the patch of workaround to
acpi_pci_irq_enable is in front of this separated patch.
> M.
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH V1 1/2] irqchip/loongson-pch-pic: Support to set irq type for ACPI path
2022-09-29 2:35 ` [PATCH V1 1/2] irqchip/loongson-pch-pic: Support to set irq type for ACPI path Jianmin Lv
@ 2022-09-29 9:44 ` Marc Zyngier
2022-09-29 13:34 ` Jianmin Lv
0 siblings, 1 reply; 3+ messages in thread
From: Marc Zyngier @ 2022-09-29 9:44 UTC (permalink / raw)
To: Jianmin Lv
Cc: Thomas Gleixner, linux-kernel, loongarch, Jiaxun Yang,
Huacai Chen, Bjorn Helgaas, Rafael J. Wysocki, Len Brown,
linux-pci, linux-acpi
On Wed, 28 Sep 2022 22:35:17 -0400,
Jianmin Lv <lvjianmin@loongson.cn> wrote:
>
> On 2022/9/28 下午10:49, Marc Zyngier wrote:
> > On Mon, 15 Aug 2022 22:01:30 -0400,
> > Jianmin Lv <lvjianmin@loongson.cn> wrote:
> >>
> >> For ACPI path, the translate callback used IRQ_TYPE_NONE and ignored
> >> the irq type in fwspec->param[1]. For supporting to set type for
> >> irqs of the irqdomain, fwspec->param[1] should be used to get irq
> >> type.
> >>
> >> On Loongson platform, the irq trigger type of PCI devices is
> >> high level, so high level triggered type is inputed to acpi_register_gsi
> >> when create irq mapping for PCI devices.
> >>
> >> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
> >> ---
> >> drivers/acpi/pci_irq.c | 3 ++-
> >> drivers/irqchip/irq-loongson-pch-pic.c | 10 ++++++----
> >> 2 files changed, 8 insertions(+), 5 deletions(-)
> >
> > $ ./scripts/get_maintainer.pl drivers/acpi/pci_irq.c
> > Bjorn Helgaas <bhelgaas@google.com> (supporter:PCI SUBSYSTEM)
> > "Rafael J. Wysocki" <rafael@kernel.org> (supporter:ACPI)
> > Len Brown <lenb@kernel.org> (reviewer:ACPI)
> > linux-pci@vger.kernel.org (open list:PCI SUBSYSTEM)
> > linux-acpi@vger.kernel.org (open list:ACPI)
> > linux-kernel@vger.kernel.org (open list)
> >
> > How about you start Cc-ing some of the relevant people?
> >
> Ok, thanks, I'll cc relevant people list here.
>
> >>
> >> diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
> >> index 08e1577..34483b3 100644
> >> --- a/drivers/acpi/pci_irq.c
> >> +++ b/drivers/acpi/pci_irq.c
> >> @@ -393,7 +393,8 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
> >> * controller and must therefore be considered active high
> >> * as default.
> >> */
> >> - int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ?
> >> + int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ||
> >> + acpi_irq_model == ACPI_IRQ_MODEL_LPIC ?
> >> ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW;
> >
> > The comment just above this only talks about ARM. Should it be
> > updated?
>
> Ok, I'll update the comment.
>
>
> > Is this a limitation of the underlying interrupt controller?
> >
> It's the limitation that pci interrupt source of LoongArch only sends
> high level trigger signal to interrupt controller(though, pci spec
> requires asserted low).
Right, so this is the opposite problem ARM has.
But is it *always* intended to be built like this? Or is it a one-off
for this generation of Loongarch systems, to be fixed at a later time?
>
>
> >> char *link = NULL;
> >> char link_desc[16];
> >> diff --git a/drivers/irqchip/irq-loongson-pch-pic.c b/drivers/irqchip/irq-loongson-pch-pic.c
> >> index b6f1392..5067010 100644
> >> --- a/drivers/irqchip/irq-loongson-pch-pic.c
> >> +++ b/drivers/irqchip/irq-loongson-pch-pic.c
> >> @@ -177,13 +177,15 @@ static int pch_pic_domain_translate(struct irq_domain *d,
> >> if (fwspec->param_count < 1)
> >> return -EINVAL;
> >> - if (of_node) {
> >> + if (of_node)
> >> *hwirq = fwspec->param[0] + priv->ht_vec_base;
> >> - *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> >> - } else {
> >> + else
> >> *hwirq = fwspec->param[0] - priv->gsi_base;
> >> +
> >> + if (fwspec->param_count > 1)
> >> + *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> >> + else
> >> *type = IRQ_TYPE_NONE;
> >
> > Isn't that a change in behaviour if of_node is non-NULL and
> > param_count==1?
> >
>
> It seems that current code here has bug that if fwspec->param_count==1
> and of_node is non-null, fwspec->param[1] will be accessed, which is
> introduced from previous patch(irqchip/loongson-pch-pic: Add ACPI init
> support). Before the patch, for non-null of_node, translate
> callback(use irq_domain_translate_twocell) will return -EINVAL if
> fwspec->param_count < 2.
>
> For ACPI path, fwspec->param_count can be 1 or 2.
>
> So in this patch, I'll fix the bug and change the code as following:
>
> if (fwspec->param_count < 1)
> return -EINVAL;
>
> if (of_node) {
> if (fwspec->param_count < 2)
> return -EINVAL;
>
> *hwirq = fwspec->param[0] + priv->ht_vec_base;
> *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> } else {
> *hwirq = fwspec->param[0] - priv->gsi_base;
>
> if (fwspec->param_count > 1)
> *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> else
> *type = IRQ_TYPE_NONE;
> }
>
>
> >> - }
> >> return 0;
> >> }
> >
> > This irqchip change should probably be a separate patch.
> >
>
> As a separate patch, the input trigger type of pci devices will be low
> level because of lacking of workaround to acpi_pci_irq_enable, which
> will cause kernel hang, unless the patch of workaround to
> acpi_pci_irq_enable is in front of this separated patch.
That seems like a sensible requirement, but I really want to
understand whether PCI Loongarch will *always* generate INTx as
ACTIVE_HIGH or not. Because if that is ever going to change, we will
need a different way to inform the irqchip about the polarity
inversion.
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH V1 1/2] irqchip/loongson-pch-pic: Support to set irq type for ACPI path
2022-09-29 9:44 ` Marc Zyngier
@ 2022-09-29 13:34 ` Jianmin Lv
0 siblings, 0 replies; 3+ messages in thread
From: Jianmin Lv @ 2022-09-29 13:34 UTC (permalink / raw)
To: Marc Zyngier
Cc: Thomas Gleixner, linux-kernel, loongarch, Jiaxun Yang,
Huacai Chen, Bjorn Helgaas, Rafael J. Wysocki, Len Brown,
linux-pci, linux-acpi
On 2022/9/29 下午5:44, Marc Zyngier wrote:
> On Wed, 28 Sep 2022 22:35:17 -0400,
> Jianmin Lv <lvjianmin@loongson.cn> wrote:
>>
>> On 2022/9/28 下午10:49, Marc Zyngier wrote:
>>> On Mon, 15 Aug 2022 22:01:30 -0400,
>>> Jianmin Lv <lvjianmin@loongson.cn> wrote:
>>>>
>>>> For ACPI path, the translate callback used IRQ_TYPE_NONE and ignored
>>>> the irq type in fwspec->param[1]. For supporting to set type for
>>>> irqs of the irqdomain, fwspec->param[1] should be used to get irq
>>>> type.
>>>>
>>>> On Loongson platform, the irq trigger type of PCI devices is
>>>> high level, so high level triggered type is inputed to acpi_register_gsi
>>>> when create irq mapping for PCI devices.
>>>>
>>>> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
>>>> ---
>>>> drivers/acpi/pci_irq.c | 3 ++-
>>>> drivers/irqchip/irq-loongson-pch-pic.c | 10 ++++++----
>>>> 2 files changed, 8 insertions(+), 5 deletions(-)
>>>
>>> $ ./scripts/get_maintainer.pl drivers/acpi/pci_irq.c
>>> Bjorn Helgaas <bhelgaas@google.com> (supporter:PCI SUBSYSTEM)
>>> "Rafael J. Wysocki" <rafael@kernel.org> (supporter:ACPI)
>>> Len Brown <lenb@kernel.org> (reviewer:ACPI)
>>> linux-pci@vger.kernel.org (open list:PCI SUBSYSTEM)
>>> linux-acpi@vger.kernel.org (open list:ACPI)
>>> linux-kernel@vger.kernel.org (open list)
>>>
>>> How about you start Cc-ing some of the relevant people?
>>>
>> Ok, thanks, I'll cc relevant people list here.
>>
>>>>
>>>> diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
>>>> index 08e1577..34483b3 100644
>>>> --- a/drivers/acpi/pci_irq.c
>>>> +++ b/drivers/acpi/pci_irq.c
>>>> @@ -393,7 +393,8 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
>>>> * controller and must therefore be considered active high
>>>> * as default.
>>>> */
>>>> - int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ?
>>>> + int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ||
>>>> + acpi_irq_model == ACPI_IRQ_MODEL_LPIC ?
>>>> ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW;
>>>
>>> The comment just above this only talks about ARM. Should it be
>>> updated?
>>
>> Ok, I'll update the comment.
>>
>>
>>> Is this a limitation of the underlying interrupt controller?
>>>
>> It's the limitation that pci interrupt source of LoongArch only sends
>> high level trigger signal to interrupt controller(though, pci spec
>> requires asserted low).
>
> Right, so this is the opposite problem ARM has.
>
> But is it *always* intended to be built like this? Or is it a one-off
> for this generation of Loongarch systems, to be fixed at a later time?
>
Yes, new generations will always keep this unchanged.
>>
>>
>>>> char *link = NULL;
>>>> char link_desc[16];
>>>> diff --git a/drivers/irqchip/irq-loongson-pch-pic.c b/drivers/irqchip/irq-loongson-pch-pic.c
>>>> index b6f1392..5067010 100644
>>>> --- a/drivers/irqchip/irq-loongson-pch-pic.c
>>>> +++ b/drivers/irqchip/irq-loongson-pch-pic.c
>>>> @@ -177,13 +177,15 @@ static int pch_pic_domain_translate(struct irq_domain *d,
>>>> if (fwspec->param_count < 1)
>>>> return -EINVAL;
>>>> - if (of_node) {
>>>> + if (of_node)
>>>> *hwirq = fwspec->param[0] + priv->ht_vec_base;
>>>> - *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
>>>> - } else {
>>>> + else
>>>> *hwirq = fwspec->param[0] - priv->gsi_base;
>>>> +
>>>> + if (fwspec->param_count > 1)
>>>> + *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
>>>> + else
>>>> *type = IRQ_TYPE_NONE;
>>>
>>> Isn't that a change in behaviour if of_node is non-NULL and
>>> param_count==1?
>>>
>>
>> It seems that current code here has bug that if fwspec->param_count==1
>> and of_node is non-null, fwspec->param[1] will be accessed, which is
>> introduced from previous patch(irqchip/loongson-pch-pic: Add ACPI init
>> support). Before the patch, for non-null of_node, translate
>> callback(use irq_domain_translate_twocell) will return -EINVAL if
>> fwspec->param_count < 2.
>>
>> For ACPI path, fwspec->param_count can be 1 or 2.
>>
>> So in this patch, I'll fix the bug and change the code as following:
>>
>> if (fwspec->param_count < 1)
>> return -EINVAL;
>>
>> if (of_node) {
>> if (fwspec->param_count < 2)
>> return -EINVAL;
>>
>> *hwirq = fwspec->param[0] + priv->ht_vec_base;
>> *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
>> } else {
>> *hwirq = fwspec->param[0] - priv->gsi_base;
>>
>> if (fwspec->param_count > 1)
>> *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
>> else
>> *type = IRQ_TYPE_NONE;
>> }
>>
>>
>>>> - }
>>>> return 0;
>>>> }
>>>
>>> This irqchip change should probably be a separate patch.
>>>
>>
>> As a separate patch, the input trigger type of pci devices will be low
>> level because of lacking of workaround to acpi_pci_irq_enable, which
>> will cause kernel hang, unless the patch of workaround to
>> acpi_pci_irq_enable is in front of this separated patch.
>
> That seems like a sensible requirement, but I really want to
> understand whether PCI Loongarch will *always* generate INTx as
> ACTIVE_HIGH or not. Because if that is ever going to change, we will
> need a different way to inform the irqchip about the polarity
> inversion.
>
Above same. And in future, in case some generation use ACTIVE_LOW, I
think we can use use *Source*(means link) with triggering and polarity
property in pci route table of DSDT as following code to override
ACTIVE_HIGH, rather than *Source index*(gsi).
if (entry->link)
gsi = acpi_pci_link_allocate_irq(entry->link,
entry->index,
&triggering, &polarity,
&link);
Because of a lot of machines outside have been shipped with firmware
using *Source index*, for compatibility with such firmware, the
workaround to acpi_pci_irq_enable is required.
> M.
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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[not found] ` <86leq37duw.wl-maz@kernel.org>
2022-09-29 2:35 ` [PATCH V1 1/2] irqchip/loongson-pch-pic: Support to set irq type for ACPI path Jianmin Lv
2022-09-29 9:44 ` Marc Zyngier
2022-09-29 13:34 ` Jianmin Lv
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