[PATCH] libpayload: Fix the PCI search function

Remove a possiblity for evil recusion and fix the function and slot
definition in the PCI search loop

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Acked-by: Patrick Georgi <patrick.georgi@coresystems.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3674 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

diff --git a/payloads/libpayload/drivers/pci.c b/payloads/libpayload/drivers/pci.c
index be92613e886b6b9d1a2d2d192d09b6089b7c731a..31b29f86de8e9b0cff36fd08bd50ee3499192a15 100644 (file)
--- a/payloads/libpayload/drivers/pci.c
+++ b/payloads/libpayload/drivers/pci.c
@@ -75,27 +75,36 @@ static int find_on_bus(int bus, unsigned short vid, unsigned short did,
        unsigned char hdr;
 
        for (devfn = 0; devfn < 0x100; devfn++) {
-               val = pci_read_config32(PCI_DEV(bus, PCI_SLOT(devfn),
-                                       PCI_FUNC(devfn)), REG_VENDOR_ID);
+               int func = devfn & 0x7;
+               int slot = (devfn >> 3) & 0x1f;
+
+               val = pci_read_config32(PCI_DEV(bus, slot, func),
+                                       REG_VENDOR_ID);
 
                if (val == 0xffffffff || val == 0x00000000 ||
                    val == 0x0000ffff || val == 0xffff0000)
                        continue;
 
                if (val == ((did << 16) | vid)) {
-                       *dev = PCI_DEV(bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+                       *dev = PCI_DEV(bus, slot, func);
                        return 1;
                }
 
-               hdr = pci_read_config8(PCI_DEV(bus, PCI_SLOT(devfn),
-                                       PCI_FUNC(devfn)), REG_HEADER_TYPE);
+               hdr = pci_read_config8(PCI_DEV(bus, slot, func),
+                                      REG_HEADER_TYPE);
                hdr &= 0x7F;
 
                if (hdr == HEADER_TYPE_BRIDGE || hdr == HEADER_TYPE_CARDBUS) {
                        unsigned int busses;
-                       busses = pci_read_config32(PCI_DEV(bus, PCI_SLOT(devfn),
-                                               PCI_FUNC(devfn)), REG_PRIMARY_BUS);
-                       if (find_on_bus((busses >> 8) & 0xFF, vid, did, dev))
+                       busses = pci_read_config32(PCI_DEV(bus, slot, func),
+                                                  REG_PRIMARY_BUS);
+                       busses = (busses >> 8) & 0xFF;
+
+                       /* Avoid recursion if the new bus is the same as
+                        * the old bus (insert lame The Who joke here) */
+
+                       if ((busses != bus) &&
+                           find_on_bus(busses, vid, did, dev))
                                return 1;
                }
        }