diff options
Diffstat (limited to 'src/drivers/bus')
| -rw-r--r-- | src/drivers/bus/pci.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/src/drivers/bus/pci.c b/src/drivers/bus/pci.c index 06b36a770..1b7350c8b 100644 --- a/src/drivers/bus/pci.c +++ b/src/drivers/bus/pci.c @@ -228,6 +228,9 @@ int pci_read_config ( struct pci_device *pci ) { */ int pci_find_next ( struct pci_device *pci, unsigned int busdevfn ) { static unsigned int end; + unsigned int sub_end; + uint8_t hdrtype; + uint8_t sub; int rc; /* Determine number of PCI buses */ @@ -236,10 +239,30 @@ int pci_find_next ( struct pci_device *pci, unsigned int busdevfn ) { /* Find next PCI device, if any */ for ( ; busdevfn < end ; busdevfn++ ) { + + /* Check for PCI device existence */ memset ( pci, 0, sizeof ( *pci ) ); pci_init ( pci, busdevfn ); - if ( ( rc = pci_read_config ( pci ) ) == 0 ) - return busdevfn; + if ( ( rc = pci_read_config ( pci ) ) != 0 ) + continue; + + /* If device is a bridge, expand the number of PCI + * buses as needed. + */ + pci_read_config_byte ( pci, PCI_HEADER_TYPE, &hdrtype ); + hdrtype &= PCI_HEADER_TYPE_MASK; + if ( hdrtype == PCI_HEADER_TYPE_BRIDGE ) { + pci_read_config_byte ( pci, PCI_SUBORDINATE, &sub ); + sub_end = PCI_BUSDEVFN ( 0, ( sub + 1 ), 0, 0 ); + if ( end < sub_end ) { + DBGC ( pci, PCI_FMT " found subordinate bus " + "%#02x\n", PCI_ARGS ( pci ), sub ); + end = sub_end; + } + } + + /* Return this device */ + return busdevfn; } return -ENODEV; |