From 1228c4b6c19a76a2691cfb1403ad1eebf5852b76 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Wed, 28 Jun 2017 15:13:55 -0500 Subject: [PATCH] PCI: Add pci_scan_root_bus_bridge() interface The current pci_scan_root_bus() interface is made up of two main code paths: - pci_create_root_bus() - pci_scan_child_bus() pci_create_root_bus() is a wrapper function that allows to create a struct pci_host_bridge structure, initialize it with the passed parameters and register it with the kernel. As the struct pci_host_bridge require additional struct members, pci_create_root_bus() parameters list has grown in time, making it unwieldy to add further parameters to it in case the struct pci_host_bridge gains more members fields to augment its functionality. Since PCI core code provides functions to allocate struct pci_host_bridge, instead of forcing the pci_create_root_bus() interface to add new parameters to cater for new struct pci_host_bridge functionality, it is more suitable to add an interface in PCI core code to scan a PCI bus straight from a struct pci_host_bridge created and customized by each specific PCI host controller driver. Add a pci_scan_root_bus_bridge() function to allow PCI host controller drivers to create and initialize struct pci_host_bridge and scan the resulting bus. Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Cc: Arnd Bergmann --- drivers/pci/probe.c | 39 +++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 40 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index e3f6965..690f0b3 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2426,6 +2426,45 @@ void pci_bus_release_busn_res(struct pci_bus *b) res, ret ? "can not be" : "is"); } +int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge) +{ + struct resource_entry *window; + bool found = false; + struct pci_bus *b; + int max, bus, ret; + + if (!bridge) + return -EINVAL; + + resource_list_for_each_entry(window, &bridge->windows) + if (window->res->flags & IORESOURCE_BUS) { + found = true; + break; + } + + ret = pci_register_host_bridge(bridge); + if (ret < 0) + return ret; + + b = bridge->bus; + bus = bridge->busnr; + + if (!found) { + dev_info(&b->dev, + "No busn resource found for root bus, will use [bus %02x-ff]\n", + bus); + pci_bus_insert_busn_res(b, bus, 255); + } + + max = pci_scan_child_bus(b); + + if (!found) + pci_bus_update_busn_res_end(b, max); + + return 0; +} +EXPORT_SYMBOL(pci_scan_root_bus_bridge); + struct pci_bus *pci_scan_root_bus_msi(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources, struct msi_controller *msi) diff --git a/include/linux/pci.h b/include/linux/pci.h index d39a66d..fe1eafd 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -857,6 +857,7 @@ struct pci_bus *pci_scan_root_bus_msi(struct device *parent, int bus, struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources); +int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge); struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, int busnr); void pcie_update_link_speed(struct pci_bus *bus, u16 link_status); -- 2.7.4