On Tue, Dec 09, 2025 at 01:11:24PM +0800, Yu Zhang wrote: > From: Easwar Hariharan <[email protected]> > > Hyper-V uses a logical device ID to identify a PCI endpoint device for > child partitions. This ID will also be required for future hypercalls > used by the Hyper-V IOMMU driver. > > Refactor the logic for building this logical device ID into a standalone > helper function and export the interface for wider use. > > Signed-off-by: Easwar Hariharan <[email protected]> > Signed-off-by: Yu Zhang <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]> > --- > drivers/pci/controller/pci-hyperv.c | 28 ++++++++++++++++++++-------- > include/asm-generic/mshyperv.h | 2 ++ > 2 files changed, 22 insertions(+), 8 deletions(-) > > diff --git a/drivers/pci/controller/pci-hyperv.c > b/drivers/pci/controller/pci-hyperv.c > index 146b43981b27..4b82e06b5d93 100644 > --- a/drivers/pci/controller/pci-hyperv.c > +++ b/drivers/pci/controller/pci-hyperv.c > @@ -598,15 +598,31 @@ static unsigned int hv_msi_get_int_vector(struct > irq_data *data) > > #define hv_msi_prepare pci_msi_prepare > > +/** > + * Build a "Device Logical ID" out of this PCI bus's instance GUID and the > + * function number of the device. > + */ > +u64 hv_build_logical_dev_id(struct pci_dev *pdev) > +{ > + struct pci_bus *pbus = pdev->bus; > + struct hv_pcibus_device *hbus = container_of(pbus->sysdata, > + struct hv_pcibus_device, > sysdata); > + > + return (u64)((hbus->hdev->dev_instance.b[5] << 24) | > + (hbus->hdev->dev_instance.b[4] << 16) | > + (hbus->hdev->dev_instance.b[7] << 8) | > + (hbus->hdev->dev_instance.b[6] & 0xf8) | > + PCI_FUNC(pdev->devfn)); > +} > +EXPORT_SYMBOL_GPL(hv_build_logical_dev_id); > + > /** > * hv_irq_retarget_interrupt() - "Unmask" the IRQ by setting its current > * affinity. > * @data: Describes the IRQ > * > * Build new a destination for the MSI and make a hypercall to > - * update the Interrupt Redirection Table. "Device Logical ID" > - * is built out of this PCI bus's instance GUID and the function > - * number of the device. > + * update the Interrupt Redirection Table. > */ > static void hv_irq_retarget_interrupt(struct irq_data *data) > { > @@ -642,11 +658,7 @@ static void hv_irq_retarget_interrupt(struct irq_data > *data) > params->int_entry.source = HV_INTERRUPT_SOURCE_MSI; > params->int_entry.msi_entry.address.as_uint32 = int_desc->address & > 0xffffffff; > params->int_entry.msi_entry.data.as_uint32 = int_desc->data; > - params->device_id = (hbus->hdev->dev_instance.b[5] << 24) | > - (hbus->hdev->dev_instance.b[4] << 16) | > - (hbus->hdev->dev_instance.b[7] << 8) | > - (hbus->hdev->dev_instance.b[6] & 0xf8) | > - PCI_FUNC(pdev->devfn); > + params->device_id = hv_build_logical_dev_id(pdev); > params->int_target.vector = hv_msi_get_int_vector(data); > > if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) { > diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h > index 64ba6bc807d9..1a205ed69435 100644 > --- a/include/asm-generic/mshyperv.h > +++ b/include/asm-generic/mshyperv.h > @@ -71,6 +71,8 @@ extern enum hv_partition_type hv_curr_partition_type; > extern void * __percpu *hyperv_pcpu_input_arg; > extern void * __percpu *hyperv_pcpu_output_arg; > > +extern u64 hv_build_logical_dev_id(struct pci_dev *pdev); Curious why you would include the "extern" in this declaration? It's not *wrong*, but it's not necessary, and other declarations in this file omit it, e.g., the ones below: > u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr); > u64 hv_do_fast_hypercall8(u16 control, u64 input8); > u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2); > -- > 2.49.0 >
