On Wed, Aug 28, 2024 at 09:16:15PM +0530, Manivannan Sadhasivam wrote:
> Right now, PCI endpoint subsystem doesn't assign PCI domain number for the
> PCI endpoint controllers. But this domain number could be useful to the EPC
> drivers to uniquely identify each controller based on the hardware instance
> when there are multiple ones present in an SoC (even multiple RC/EP).
>
> So let's make use of the existing pci_bus_find_domain_nr() API to allocate
> domain numbers based on either Devicetree (linux,pci-domain) property or
> dynamic domain number allocation scheme.
>
> It should be noted that the domain number allocated by this API will be
> based on both RC and EP controllers in a SoC. If the 'linux,pci-domain' DT
> property is present, then the domain number represents the actual hardware
> instance of the PCI endpoint controller. If not, then the domain number
> will be allocated based on the PCI EP/RC controller probe order.
>
> If the architecture doesn't support CONFIG_PCI_DOMAINS_GENERIC (rare), then
> currently a warning is thrown to indicate that the architecture specific
> implementation is needed.
>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> ---
> drivers/pci/endpoint/pci-epc-core.c | 14 ++++++++++++++
> include/linux/pci-epc.h | 2 ++
> 2 files changed, 16 insertions(+)
>
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index 84309dfe0c68..085a2de8b923 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -838,6 +838,10 @@ void pci_epc_destroy(struct pci_epc *epc)
> {
> pci_ep_cfs_remove_epc_group(epc->group);
> device_unregister(&epc->dev);
> +
> +#ifdef CONFIG_PCI_DOMAINS_GENERIC
> + pci_bus_release_domain_nr(NULL, &epc->dev);
> +#endif
> }
> EXPORT_SYMBOL_GPL(pci_epc_destroy);
>
> @@ -900,6 +904,16 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
> epc->dev.release = pci_epc_release;
> epc->ops = ops;
>
> +#ifdef CONFIG_PCI_DOMAINS_GENERIC
> + epc->domain_nr = pci_bus_find_domain_nr(NULL, dev);
> +#else
> + /*
> + * TODO: If the architecture doesn't support generic PCI
> + * domains, then a custom implementation has to be used.
> + */
> + WARN_ONCE(1, "This architecture doesn't support generic PCI domains\n");
> +#endif
> +
> ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
> if (ret)
> goto put_dev;
> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> index 85bdf2adb760..8e3dcac55dcd 100644
> --- a/include/linux/pci-epc.h
> +++ b/include/linux/pci-epc.h
> @@ -128,6 +128,7 @@ struct pci_epc_mem {
> * @group: configfs group representing the PCI EPC device
> * @lock: mutex to protect pci_epc ops
> * @function_num_map: bitmap to manage physical function number
> + * @domain_nr: PCI domain number of the endpoint controller
> * @init_complete: flag to indicate whether the EPC initialization is complete
> * or not
> */
> @@ -145,6 +146,7 @@ struct pci_epc {
> /* mutex to protect against concurrent access of EP controller */
> struct mutex lock;
> unsigned long function_num_map;
> + int domain_nr;
> bool init_complete;
> };
>
>
> --
> 2.25.1
>
