From 046c5fd251fc2e616743830a937875b8f5e608cd Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Tue, 1 Nov 2016 09:58:55 +0100 Subject: PCI: split PCI hierarchy enumeration and config from device registration This gets rid of some of the special cases in the bus scanning function by splitting hierarchy enumeration and configuration and the actual device registration into 2 passes. This ensures that the PCI hierarchy below a root port is completely set up before any device driver is probed. This simplifies the code and makes it less error prone, while moving the PCI address space layout closer to the one used by Linux. Signed-off-by: Lucas Stach Signed-off-by: Sascha Hauer --- drivers/pci/pci.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 12aafccde5..b2570eb151 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -28,6 +28,20 @@ static struct pci_bus *pci_alloc_bus(void) return b; } +static void pci_bus_register_devices(struct pci_bus *bus) +{ + struct pci_dev *dev; + struct pci_bus *child_bus; + + /* activate all devices on this bus */ + list_for_each_entry(dev, &bus->devices, bus_list) + pci_register_device(dev); + + /* walk down the hierarchy */ + list_for_each_entry(child_bus, &bus->children, node) + pci_bus_register_devices(child_bus); +} + void register_pci_controller(struct pci_controller *hose) { struct pci_bus *bus; @@ -64,6 +78,7 @@ void register_pci_controller(struct pci_controller *hose) last_io = 0; pci_scan_bus(bus); + pci_bus_register_devices(bus); list_add_tail(&bus->node, &pci_root_buses); @@ -384,16 +399,8 @@ unsigned int pci_scan_bus(struct pci_bus *bus) dev->rom_address = (l == 0xffffffff) ? 0 : l; setup_device(dev, 6); - /* - * If this device is on the root bus, there is no bridge - * to configure, so we can activate it right away. - */ - if (!bus->parent_bus) - pci_register_device(dev); break; case PCI_HEADER_TYPE_BRIDGE: - setup_device(dev, 2); - child_bus = pci_alloc_bus(); /* inherit parent properties */ child_bus->host = bus->host; @@ -412,18 +419,12 @@ unsigned int pci_scan_bus(struct pci_bus *bus) list_add_tail(&child_bus->node, &bus->children); dev->subordinate = child_bus; - /* activate bridge device */ - pci_register_device(dev); - /* scan pci hierarchy behind bridge */ prescan_setup_bridge(dev); pci_scan_bus(child_bus); postscan_setup_bridge(dev); - /* finally active all devices behind the bridge */ - list_for_each_entry(dev, &child_bus->devices, bus_list) - if (!dev->subordinate) - pci_register_device(dev); + setup_device(dev, 2); break; default: bad: -- cgit v1.2.3