[pci] Generalise pci_num_bus() to pci_discover()

Allow pci_find_next() to discover devices beyond the first PCI
segment, by generalising pci_num_bus() (which implicitly assumes that
there is only a single PCI segment) with pci_discover() (which has the
ability to return an arbitrary contiguous chunk of PCI bus:dev.fn
address space).

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 10 insertions, 6 deletions

diff --git a/src/include/ipxe/linux/linux_pci.h b/src/include/ipxe/linux/linux_pci.h
index de42f766b..ec6ff8b1c 100644
--- a/src/include/ipxe/linux/linux_pci.h
+++ b/src/include/ipxe/linux/linux_pci.h
@@ -23,14 +23,18 @@ extern int linux_pci_write ( struct pci_device *pci, unsigned long where,
 			     unsigned long value, size_t len );
 
 /**
- * Determine number of PCI buses within system
+ * Find next PCI bus:dev.fn address range in system
  *
- * @ret num_bus		Number of buses
+ * @v busdevfn		Starting PCI bus:dev.fn address
+ * @v range		PCI bus:dev.fn address range to fill in
  */
-static inline __always_inline int
-PCIAPI_INLINE ( linux, pci_num_bus ) ( void ) {
-	/* Assume all buses may exist */
-	return 0x100;
+static inline __always_inline void
+PCIAPI_INLINE ( linux, pci_discover ) ( uint32_t busdevfn __unused,
+					struct pci_range *range ) {
+
+	/* Assume all buses in segment 0 may exist */
+	range->start = PCI_BUSDEVFN ( 0, 0, 0, 0 );
+	range->count = PCI_BUSDEVFN ( 1, 0, 0, 0 );
 }
 
 /**