From: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org
[ Upstream commit 0328947c50324cf4b2d8b181bf948edb8101f59f ]
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.
Link: https://lore.kernel.org/linux-pci/20240828-pci-qcom-hotplug-v4-5-263a385fbbc... Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org Reviewed-by: Frank Li Frank.Li@nxp.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 47d27ec7439d9..141840fceb798 100644 --- a/drivers/pci/endpoint/pci-epc-core.c +++ b/drivers/pci/endpoint/pci-epc-core.c @@ -810,6 +810,10 @@ 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);
@@ -872,6 +876,16 @@ __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 acc5f96161fe1..cac04ce7f2ed7 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; };