Re: [PATCH v2 5/6] drivers/hv/vmbus: Get the irq number from DeviceTree

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Roman Kisel <romank@linux.microsoft.com>,
	arnd@arndb.de, bhelgaas@google.com, bp@alien8.de,
	catalin.marinas@arm.com, dave.hansen@linux.intel.com,
	decui@microsoft.com, haiyangz@microsoft.com, hpa@zytor.com,
	kw@linux.com, kys@microsoft.com, lenb@kernel.org,
	lpieralisi@kernel.org, mingo@redhat.com, mhklinux@outlook.com,
	rafael@kernel.org, robh@kernel.org, tglx@linutronix.de,
	wei.liu@kernel.org, will@kernel.org, linux-acpi@vger.kernel.org,
	linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, x86@kernel.org
Cc: ssengar@microsoft.com, sunilmut@microsoft.com, vdso@hexbites.dev
Subject: Re: [PATCH v2 5/6] drivers/hv/vmbus: Get the irq number from DeviceTree
Date: Wed, 15 May 2024 09:47:28 +0200	[thread overview]
Message-ID: <ea9ce984-8a07-47a8-9533-a6cea5b318b5@linaro.org> (raw)
In-Reply-To: <20240514224508.212318-6-romank@linux.microsoft.com>

On 15/05/2024 00:43, Roman Kisel 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
> via DeviceTree.
> 
> Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
> ---
>  drivers/hv/vmbus_drv.c | 37 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index e25223cee3ab..52f01bd1c947 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -36,6 +36,7 @@
>  #include <linux/syscore_ops.h>
>  #include <linux/dma-map-ops.h>
>  #include <linux/pci.h>
> +#include <linux/of_irq.h>
>  #include <clocksource/hyperv_timer.h>
>  #include <asm/mshyperv.h>
>  #include "hyperv_vmbus.h"
> @@ -2316,6 +2317,34 @@ static int vmbus_acpi_add(struct platform_device *pdev)
>  }
>  #endif
>  
> +static int __maybe_unused vmbus_of_set_irq(struct device_node *np)
> +{
> +	struct irq_desc *desc;
> +	int irq;
> +
> +	irq = of_irq_get(np, 0);

Where is the binding for this?

> +	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;
> +	}
> +
> +	desc = irq_to_desc(irq);
> +	if (!desc) {
> +		pr_err("VMBus interrupt description can't be found for virq %d\n", irq);
> +		return -ENODEV;
> +	}
> +
> +	vmbus_irq = irq;
> +	vmbus_interrupt = desc->irq_data.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;
> @@ -2324,12 +2353,20 @@ static int vmbus_device_add(struct platform_device *pdev)
>  	struct device_node *np = pdev->dev.of_node;
>  	int ret;
>  
> +	pr_debug("VMBus is present in DeviceTree\n");

Not related and not really helpful. Simple entry/exit tracking is
provided already by tracing.

Best regards,
Krzysztof