Re: [PATCH v3 7/7] PCI: hv: Get vPCI MSI IRQ domain from DT

[Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>]

On 8/2/2024 6:20 PM, Wei Liu wrote:
> On Fri, Jul 26, 2024 at 03:59:10PM -0700, Roman Kisel wrote:
> > The hyperv-pci driver uses ACPI for MSI IRQ domain configuration on
> > arm64. It won't be able to do that in the VTL mode where only DeviceTree
> > can be used.
> >
> > Update the hyperv-pci driver to get vPCI MSI IRQ domain in the DeviceTree
> > case, too.
> >
> > Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/hv/vmbus_drv.c              | 23 +++++++-----
> >   drivers/pci/controller/pci-hyperv.c | 55 +++++++++++++++++++++++++++--
> >   include/linux/hyperv.h              |  2 ++
> >   3 files changed, 69 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> > index 7eee7caff5f6..038bd9be64b7 100644
> > --- a/drivers/hv/vmbus_drv.c
> > +++ b/drivers/hv/vmbus_drv.c
> > @@ -45,7 +45,8 @@ struct vmbus_dynid {
> >   	struct hv_vmbus_device_id id;
> >   };
> >   
> > -static struct device  *hv_dev;
> > +/* VMBus Root Device */
> > +static struct device  *vmbus_root_device;
>
> You're changing the name of the variable. That should preferably be done
> in a separate patch. That's going to make this patch shorter and easier
> to review.
Will fix in v4, thanks!

> >   
> >   static int hyperv_cpuhp_online;
> >   
> > @@ -80,9 +81,15 @@ static struct resource *fb_mmio;
> >   static struct resource *hyperv_mmio;
> >   static DEFINE_MUTEX(hyperv_mmio_lock);
> >   
> > +struct device *get_vmbus_root_device(void)
> > +{
> > +	return vmbus_root_device;
> > +}
> > +EXPORT_SYMBOL_GPL(get_vmbus_root_device);
>
> I would like you to add "hv_" prefix to this exported symbol, or rename
> it to "vmbus_get_root_device()".
>
> > +
> >   static int vmbus_exists(void)
> >   {
> > -	if (hv_dev == NULL)
> > +	if (vmbus_root_device == NULL)
> >   		return -ENODEV;
> >   
> >   	return 0;
> > @@ -861,7 +868,7 @@ static int vmbus_dma_configure(struct device *child_device)
> >   	 * On x86/x64 coherence is assumed and these calls have no effect.
> >   	 */
> >   	hv_setup_dma_ops(child_device,
> > -		device_get_dma_attr(hv_dev) == DEV_DMA_COHERENT);
> > +		device_get_dma_attr(vmbus_root_device) == DEV_DMA_COHERENT);
> >   	return 0;
> >   }
> >   
> > @@ -1892,7 +1899,7 @@ int vmbus_device_register(struct hv_device *child_device_obj)
> >   		     &child_device_obj->channel->offermsg.offer.if_instance);
> >   
> >   	child_device_obj->device.bus = &hv_bus;
> > -	child_device_obj->device.parent = hv_dev;
> > +	child_device_obj->device.parent = vmbus_root_device;
> >   	child_device_obj->device.release = vmbus_device_release;
> >   
> >   	child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
> > @@ -2253,7 +2260,7 @@ static int vmbus_acpi_add(struct platform_device *pdev)
> >   	struct acpi_device *ancestor;
> >   	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
> >   
> > -	hv_dev = &device->dev;
> > +	vmbus_root_device = &device->dev;
> >   
> >   	/*
> >   	 * Older versions of Hyper-V for ARM64 fail to include the _CCA
> > @@ -2342,7 +2349,7 @@ static int vmbus_device_add(struct platform_device *pdev)
> >   	struct device_node *np = pdev->dev.of_node;
> >   	int ret;
> >   
> > -	hv_dev = &pdev->dev;
> > +	vmbus_root_device = &pdev->dev;
> >   
> >   	ret = of_range_parser_init(&parser, np);
> >   	if (ret)
> > @@ -2675,7 +2682,7 @@ static int __init hv_acpi_init(void)
> >   	if (ret)
> >   		return ret;
> >   
> > -	if (!hv_dev) {
> > +	if (!vmbus_root_device) {
> >   		ret = -ENODEV;
> >   		goto cleanup;
> >   	}
> > @@ -2706,7 +2713,7 @@ static int __init hv_acpi_init(void)
> >   
> >   cleanup:
> >   	platform_driver_unregister(&vmbus_platform_driver);
> > -	hv_dev = NULL;
> > +	vmbus_root_device = NULL;
> >   	return ret;
> >   }
> >   
> > diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> > index 5992280e8110..cdecefd1f9bd 100644
> > --- a/drivers/pci/controller/pci-hyperv.c
> > +++ b/drivers/pci/controller/pci-hyperv.c
> > @@ -50,6 +50,7 @@
> >   #include <linux/irqdomain.h>
> >   #include <linux/acpi.h>
> >   #include <linux/sizes.h>
> > +#include <linux/of_irq.h>
> >   #include <asm/mshyperv.h>
> >   
> >   /*
> > @@ -887,6 +888,35 @@ static const struct irq_domain_ops hv_pci_domain_ops = {
> >   	.activate = hv_pci_vec_irq_domain_activate,
> >   };
> >   
> > +#ifdef CONFIG_OF
> > +
> > +static struct irq_domain *hv_pci_of_irq_domain_parent(void)
> > +{
> > +	struct device_node *parent;
> > +	struct irq_domain *domain;
> > +
> > +	parent = of_irq_find_parent(to_platform_device(get_vmbus_root_device())->dev.of_node);
> > +	domain = NULL;
> > +	if (parent) {
> > +		domain = irq_find_host(parent);
> > +		of_node_put(parent);
> > +	}
> > +
>
> I cannot really comment on the ARM side of things around how this system
> is set up. I will leave that to someone who's more familiar with the
> matter to review.
>
> Thanks,
> Wei.

--
Thank you,
Roman