The VMBus driver uses ACPI for interrupt assignment on
arm64 hence it won't function in the VTL mode where only
DeviceTree can be used.

Update the VMBus driver to discover interrupt configuration
from DT.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
---
 drivers/hv/vmbus_drv.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 75eb1390b45c..c8474b48dcd2 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2345,6 +2345,36 @@ static int vmbus_acpi_add(struct platform_device *pdev)
 }
 #endif
 
+static int __maybe_unused vmbus_set_irq(struct platform_device *pdev)
+{
+	struct irq_data *data;
+	int irq;
+	irq_hw_number_t hwirq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq == 0) {
+		pr_err("VMBus interrupt mapping failure\n");
+		return -EINVAL;
+	}
+	if (irq < 0) {
+		pr_err("VMBus interrupt data can't be read from DeviceTree, error %d\n", irq);
+		return irq;
+	}
+
+	data = irq_get_irq_data(irq);
+	if (!data) {
+		pr_err("No interrupt data for VMBus virq %d\n", irq);
+		return -ENODEV;
+	}
+	hwirq = irqd_to_hwirq(data);
+
+	vmbus_irq = irq;
+	vmbus_interrupt = hwirq;
+	pr_debug("VMBus virq %d, hwirq %d\n", vmbus_irq, vmbus_interrupt);
+
+	return 0;
+}
+
 static int vmbus_device_add(struct platform_device *pdev)
 {
 	struct resource **cur_res = &hyperv_mmio;
@@ -2359,6 +2389,12 @@ static int vmbus_device_add(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+#ifndef HYPERVISOR_CALLBACK_VECTOR
+	ret = vmbus_set_irq(pdev);
+	if (ret)
+		return ret;
+#endif
+
 	for_each_of_range(&parser, &range) {
 		struct resource *res;
 
-- 
2.43.0

On Fri, Mar 7, 2025 at 4:03 PM Roman Kisel <romank@linux.microsoft.com> wrote:
>
> The VMBus driver uses ACPI for interrupt assignment on
> arm64 hence it won't function in the VTL mode where only
> DeviceTree can be used.
>
> Update the VMBus driver to discover interrupt configuration
> from DT.
>
> Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
> Reviewed-by: Michael Kelley <mhklinux@outlook.com>
> ---
>  drivers/hv/vmbus_drv.c | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index 75eb1390b45c..c8474b48dcd2 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -2345,6 +2345,36 @@ static int vmbus_acpi_add(struct platform_device *pdev)
>  }
>  #endif
>
> +static int __maybe_unused vmbus_set_irq(struct platform_device *pdev)
> +{
> +       struct irq_data *data;
> +       int irq;
> +       irq_hw_number_t hwirq;
> +
> +       irq = platform_get_irq(pdev, 0);
> +       if (irq == 0) {
> +               pr_err("VMBus interrupt mapping failure\n");
> +               return -EINVAL;
> +       }
> +       if (irq < 0) {
> +               pr_err("VMBus interrupt data can't be read from DeviceTree, error %d\n", irq);
> +               return irq;
> +       }

I don't think why you couldn't get the interrupt is important. Just
check for (irq <= 0) and be done with it. I'm not even sure if
returning 0 is possible now. There's a long history to that and
NO_IRQ.

Rob

On 3/13/2025 11:44 AM, Rob Herring wrote:
> On Fri, Mar 7, 2025 at 4:03 PM Roman Kisel <romank@linux.microsoft.com> wrote:

[...]

>> +       irq = platform_get_irq(pdev, 0);
>> +       if (irq == 0) {
>> +               pr_err("VMBus interrupt mapping failure\n");
>> +               return -EINVAL;
>> +       }
>> +       if (irq < 0) {
>> +               pr_err("VMBus interrupt data can't be read from DeviceTree, error %d\n", irq);
>> +               return irq;
>> +       }
> 
> I don't think why you couldn't get the interrupt is important. Just
> check for (irq <= 0) and be done with it. I'm not even sure if
> returning 0 is possible now. There's a long history to that and
> NO_IRQ.
> 

That will certainly make the code look much better!
Thank you very much for the idea!

> Rob

-- 
Thank you,
Roman

On Fri, Mar 7, 2025, at 23:03, Roman Kisel wrote:
> 
> +static int __maybe_unused vmbus_set_irq(struct platform_device *pdev)

Instead of the __maybe_unused annotation here

> 
> +#ifndef HYPERVISOR_CALLBACK_VECTOR
> +	ret = vmbus_set_irq(pdev);
> +	if (ret)
> +		return ret;
> +#endif
> +

you can use 

       if (!__is_defined(HYPERVISOR_CALLBACK_VECTOR))
                  ret = vmbus_set_irq(pdev);

and make it a little more readable.

    Arnd

On 3/8/2025 1:11 PM, Arnd Bergmann wrote:
> On Fri, Mar 7, 2025, at 23:03, Roman Kisel wrote:
>>
>> +static int __maybe_unused vmbus_set_irq(struct platform_device *pdev)
> 
> Instead of the __maybe_unused annotation here
> 
>>
>> +#ifndef HYPERVISOR_CALLBACK_VECTOR
>> +	ret = vmbus_set_irq(pdev);
>> +	if (ret)
>> +		return ret;
>> +#endif
>> +
> 
> you can use
> 
>         if (!__is_defined(HYPERVISOR_CALLBACK_VECTOR))
>                    ret = vmbus_set_irq(pdev);
> 
> and make it a little more readable.
> 

Thanks you very much, will update! Very neat :)

>      Arnd

-- 
Thank you,
Roman