pci: Honour pci_skip_dev()

When enumerating devices, honour the pci_skip_dev() function. This can
be used by PCI controller drivers to restrict which devices will be
probed.

This is required by the NVIDIA Tegra PCIe controller driver, which will
fail with a data abort exception if an access is attempted to a device
number larger than 0 outside of bus 0. pci_skip_dev() is therefore
implemented to prevent any such accesses.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Simon Glass <sjg@chromium.org>

common/cmd_pci.c

@@ -71,6 +71,9 @@ void pciinfo(int BusNum, int ShortPCIListing)
 
 			dev = PCI_BDF(BusNum, Device, Function);
 
+			if (pci_skip_dev(hose, dev))
+				continue;
+
 			pci_read_config_word(dev, PCI_VENDOR_ID, &VendorID);
 			if ((VendorID == 0xFFFF) || (VendorID == 0x0000))
 				continue;

drivers/pci/pci.c

@@ -195,6 +195,9 @@ pci_dev_t pci_find_devices(struct pci_device_id *ids, int index)
 			     bdf < PCI_BDF(bus + 1, 0, 0);
 #endif
 			     bdf += PCI_BDF(0, 0, 1)) {
+				if (pci_skip_dev(hose, bdf))
+					continue;
+
 				if (!PCI_FUNC(bdf)) {
 					pci_read_config_byte(bdf,
 							     PCI_HEADER_TYPE,

include/pci.h

@@ -623,6 +623,7 @@ extern void pci_register_hose(struct pci_controller* hose);
 extern struct pci_controller* pci_bus_to_hose(int bus);
 extern struct pci_controller *find_hose_by_cfg_addr(void *cfg_addr);
 
+extern int pci_skip_dev(struct pci_controller *hose, pci_dev_t dev);
 extern int pci_hose_scan(struct pci_controller *hose);
 extern int pci_hose_scan_bus(struct pci_controller *hose, int bus);