The hyperv-pci driver uses ACPI for MSI IRQ domain configuration
on arm64 thereby it won't be able to do that in the VTL mode where
only DeviceTree can be used.

Update the hyperv-pci driver to discover interrupt configuration
via DeviceTree.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
---
 drivers/pci/controller/pci-hyperv.c | 13 ++++++++++---
 include/linux/acpi.h                |  9 +++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 1eaffff40b8d..ccc2b54206f4 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -906,9 +906,16 @@ static int hv_pci_irqchip_init(void)
 	 * way to ensure that all the corresponding devices are also gone and
 	 * no interrupts will be generated.
 	 */
-	hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
-							  fn, &hv_pci_domain_ops,
-							  chip_data);
+	if (acpi_disabled)
+		hv_msi_gic_irq_domain = irq_domain_create_hierarchy(
+			irq_find_matching_fwnode(fn, DOMAIN_BUS_ANY),
+			0, HV_PCI_MSI_SPI_NR,
+			fn, &hv_pci_domain_ops,
+			chip_data);
+	else
+		hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
+			fn, &hv_pci_domain_ops,
+			chip_data);
 
 	if (!hv_msi_gic_irq_domain) {
 		pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n");
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index b7165e52b3c6..498cbb2c40a1 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1077,6 +1077,15 @@ static inline bool acpi_sleep_state_supported(u8 sleep_state)
 	return false;
 }
 
+static inline struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
+					     unsigned int size,
+					     struct fwnode_handle *fwnode,
+					     const struct irq_domain_ops *ops,
+					     void *host_data)
+{
+	return NULL;
+}
+
 #endif	/* !CONFIG_ACPI */
 
 extern void arch_post_acpi_subsys_init(void);
-- 
2.45.0

On Tue, May 14, 2024 at 03:43:53PM -0700, Roman Kisel wrote:
> The hyperv-pci driver uses ACPI for MSI IRQ domain configuration
> on arm64 thereby it won't be able to do that in the VTL mode where
> only DeviceTree can be used.
> 
> Update the hyperv-pci driver to discover interrupt configuration
> via DeviceTree.

Subject prefix should be "PCI: hv:"

> 
> Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
> ---
>  drivers/pci/controller/pci-hyperv.c | 13 ++++++++++---
>  include/linux/acpi.h                |  9 +++++++++
>  2 files changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 1eaffff40b8d..ccc2b54206f4 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -906,9 +906,16 @@ static int hv_pci_irqchip_init(void)
>  	 * way to ensure that all the corresponding devices are also gone and
>  	 * no interrupts will be generated.
>  	 */
> -	hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
> -							  fn, &hv_pci_domain_ops,
> -							  chip_data);
> +	if (acpi_disabled)
> +		hv_msi_gic_irq_domain = irq_domain_create_hierarchy(
> +			irq_find_matching_fwnode(fn, DOMAIN_BUS_ANY),
> +			0, HV_PCI_MSI_SPI_NR,
> +			fn, &hv_pci_domain_ops,
> +			chip_data);
> +	else
> +		hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
> +			fn, &hv_pci_domain_ops,
> +			chip_data);

Upto 100 characters per line are supported now, we can have less
line breaks.

>  
>  	if (!hv_msi_gic_irq_domain) {
>  		pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n");
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index b7165e52b3c6..498cbb2c40a1 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -1077,6 +1077,15 @@ static inline bool acpi_sleep_state_supported(u8 sleep_state)
>  	return false;
>  }
>  
> +static inline struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
> +					     unsigned int size,
> +					     struct fwnode_handle *fwnode,
> +					     const struct irq_domain_ops *ops,
> +					     void *host_data)
> +{
> +	return NULL;
> +}
> +
>  #endif	/* !CONFIG_ACPI */
>  
>  extern void arch_post_acpi_subsys_init(void);
> -- 
> 2.45.0
>

On 5/15/2024 2:48 AM, Saurabh Singh Sengar wrote:
> On Tue, May 14, 2024 at 03:43:53PM -0700, Roman Kisel wrote:
>> The hyperv-pci driver uses ACPI for MSI IRQ domain configuration
>> on arm64 thereby it won't be able to do that in the VTL mode where
>> only DeviceTree can be used.
>>
>> Update the hyperv-pci driver to discover interrupt configuration
>> via DeviceTree.
> 
> Subject prefix should be "PCI: hv:"
> 
Thanks!

>>
>> Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
>> ---
>>   drivers/pci/controller/pci-hyperv.c | 13 ++++++++++---
>>   include/linux/acpi.h                |  9 +++++++++
>>   2 files changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
>> index 1eaffff40b8d..ccc2b54206f4 100644
>> --- a/drivers/pci/controller/pci-hyperv.c
>> +++ b/drivers/pci/controller/pci-hyperv.c
>> @@ -906,9 +906,16 @@ static int hv_pci_irqchip_init(void)
>>   	 * way to ensure that all the corresponding devices are also gone and
>>   	 * no interrupts will be generated.
>>   	 */
>> -	hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
>> -							  fn, &hv_pci_domain_ops,
>> -							  chip_data);
>> +	if (acpi_disabled)
>> +		hv_msi_gic_irq_domain = irq_domain_create_hierarchy(
>> +			irq_find_matching_fwnode(fn, DOMAIN_BUS_ANY),
>> +			0, HV_PCI_MSI_SPI_NR,
>> +			fn, &hv_pci_domain_ops,
>> +			chip_data);
>> +	else
>> +		hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
>> +			fn, &hv_pci_domain_ops,
>> +			chip_data);
> 
> Upto 100 characters per line are supported now, we can have less
> line breaks.
> 
Fewer line breaks would make this look nicer, let me know if you had any 
particular style in mind.

>>   
>>   	if (!hv_msi_gic_irq_domain) {
>>   		pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n");
>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
>> index b7165e52b3c6..498cbb2c40a1 100644
>> --- a/include/linux/acpi.h
>> +++ b/include/linux/acpi.h
>> @@ -1077,6 +1077,15 @@ static inline bool acpi_sleep_state_supported(u8 sleep_state)
>>   	return false;
>>   }
>>   
>> +static inline struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
>> +					     unsigned int size,
>> +					     struct fwnode_handle *fwnode,
>> +					     const struct irq_domain_ops *ops,
>> +					     void *host_data)
>> +{
>> +	return NULL;
>> +}
>> +
>>   #endif	/* !CONFIG_ACPI */
>>   
>>   extern void arch_post_acpi_subsys_init(void);
>> -- 
>> 2.45.0
>>

-- 
Thank you,
Roman

On Wed, May 15, 2024 at 09:34:09AM -0700, Roman Kisel wrote:
> 
> 
> On 5/15/2024 2:48 AM, Saurabh Singh Sengar wrote:
> > On Tue, May 14, 2024 at 03:43:53PM -0700, Roman Kisel wrote:
> > > The hyperv-pci driver uses ACPI for MSI IRQ domain configuration
> > > on arm64 thereby it won't be able to do that in the VTL mode where
> > > only DeviceTree can be used.
> > > 
> > > Update the hyperv-pci driver to discover interrupt configuration
> > > via DeviceTree.
> > 
> > Subject prefix should be "PCI: hv:"
> > 
> Thanks!

"git log --oneline <file>" is a good guide in general and could be
used for other patches in this series as well.

> > > +		hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
> > > +			fn, &hv_pci_domain_ops,
> > > +			chip_data);
> > 
> > Upto 100 characters per line are supported now, we can have less
> > line breaks.
> > 
> Fewer line breaks would make this look nicer, let me know if you had any
> particular style in mind.

Let's not use the checkpatch "$max_line_length = 100" as a guide.

The pci-hyperv.c file as a whole is obviously formatted to fit in 80
columns with few exceptions.

IMO it would not be an improvement to scatter random 100-column lines
throughout.  That would just mean the file would look bad in an
80-column terminal and there would be a lot of wasted space in a
100-column terminal.

Bjorn

On Wed, May 15, 2024 at 01:12:38PM -0500, Bjorn Helgaas wrote:
> On Wed, May 15, 2024 at 09:34:09AM -0700, Roman Kisel wrote:
> > 
> > 
> > On 5/15/2024 2:48 AM, Saurabh Singh Sengar wrote:
> > > On Tue, May 14, 2024 at 03:43:53PM -0700, Roman Kisel wrote:
> > > > The hyperv-pci driver uses ACPI for MSI IRQ domain configuration
> > > > on arm64 thereby it won't be able to do that in the VTL mode where
> > > > only DeviceTree can be used.
> > > > 
> > > > Update the hyperv-pci driver to discover interrupt configuration
> > > > via DeviceTree.
> > > 
> > > Subject prefix should be "PCI: hv:"

I forgot to also suggest that the subject line begin with a verb,
e.g., "Get vPCI MSI IRQ domain from DT" or similar, again so it reads
consistently with previous commits.

Oh, I see patch 5/6, "Get the irq number from DeviceTree" is also very
similar.  It would be nice if they matched, e.g., both used "IRQ" and
"DT".

Bjorn

On 6/7/2024 12:55 PM, Bjorn Helgaas wrote:
> On Wed, May 15, 2024 at 01:12:38PM -0500, Bjorn Helgaas wrote:
>> On Wed, May 15, 2024 at 09:34:09AM -0700, Roman Kisel wrote:
>>>
>>>
>>> On 5/15/2024 2:48 AM, Saurabh Singh Sengar wrote:
>>>> On Tue, May 14, 2024 at 03:43:53PM -0700, Roman Kisel wrote:
>>>>> The hyperv-pci driver uses ACPI for MSI IRQ domain configuration
>>>>> on arm64 thereby it won't be able to do that in the VTL mode where
>>>>> only DeviceTree can be used.
>>>>>
>>>>> Update the hyperv-pci driver to discover interrupt configuration
>>>>> via DeviceTree.
>>>>
>>>> Subject prefix should be "PCI: hv:"
> 
> I forgot to also suggest that the subject line begin with a verb,
> e.g., "Get vPCI MSI IRQ domain from DT" or similar, again so it reads
> consistently with previous commits.
> 
> Oh, I see patch 5/6, "Get the irq number from DeviceTree" is also very
> similar.  It would be nice if they matched, e.g., both used "IRQ" and
> "DT".
> 
> Bjorn

Will update, thanks! Going to send another version during the next week 
most likely.

-- 
Thank you,
Roman

On 5/15/2024 11:12 AM, Bjorn Helgaas wrote:
> On Wed, May 15, 2024 at 09:34:09AM -0700, Roman Kisel wrote:
>>
>>
>> On 5/15/2024 2:48 AM, Saurabh Singh Sengar wrote:
>>> On Tue, May 14, 2024 at 03:43:53PM -0700, Roman Kisel wrote:
>>>> The hyperv-pci driver uses ACPI for MSI IRQ domain configuration
>>>> on arm64 thereby it won't be able to do that in the VTL mode where
>>>> only DeviceTree can be used.
>>>>
>>>> Update the hyperv-pci driver to discover interrupt configuration
>>>> via DeviceTree.
>>>
>>> Subject prefix should be "PCI: hv:"
>>>
>> Thanks!
> 
> "git log --oneline <file>" is a good guide in general and could be
> used for other patches in this series as well.
> 
Many thanks for suggesting that :)

>>>> +		hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
>>>> +			fn, &hv_pci_domain_ops,
>>>> +			chip_data);
>>>
>>> Upto 100 characters per line are supported now, we can have less
>>> line breaks.
>>>
>> Fewer line breaks would make this look nicer, let me know if you had any
>> particular style in mind.
> 
> Let's not use the checkpatch "$max_line_length = 100" as a guide.
> 
> The pci-hyperv.c file as a whole is obviously formatted to fit in 80
> columns with few exceptions.
> 
> IMO it would not be an improvement to scatter random 100-column lines
> throughout.  That would just mean the file would look bad in an
> 80-column terminal and there would be a lot of wasted space in a
> 100-column terminal.
> 
Appreciate showing me the data-driven way of reasoning about that very much!

> Bjorn

-- 
Thank you,
Roman