[PATCH v2] pci: fix handling of PCI bridges with subordinate bus number 0xff

[Igor Druzhinin]

Bus number 0xff is valid according to the PCI spec. Using u8 typed sub_bus
and assigning 0xff to it will result in the following loop getting stuck.

    for ( ; sec_bus <= sub_bus; sec_bus++ ) {...}

Just change its type to unsigned int similarly to what is already done in
dmar_scope_add_buses().

Signed-off-by: Igor Druzhinin <igor.druzhi...@citrix.com>
---
v2:
- fix free_pdev() as well
- style fixes
---
 xen/drivers/passthrough/pci.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index fc4fa2e..d65cda8 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -363,8 +363,7 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, u8 
bus, u8 devfn)
     /* update bus2bridge */
     switch ( pdev->type = pdev_type(pseg->nr, bus, devfn) )
     {
-        u16 cap;
-        u8 sec_bus, sub_bus;
+        unsigned int cap, sec_bus, sub_bus;
 
         case DEV_TYPE_PCIe2PCI_BRIDGE:
         case DEV_TYPE_LEGACY_PCI_BRIDGE:
@@ -431,7 +430,7 @@ static void free_pdev(struct pci_seg *pseg, struct pci_dev 
*pdev)
     /* update bus2bridge */
     switch ( pdev->type )
     {
-        uint8_t sec_bus, sub_bus;
+        unsigned int sec_bus, sub_bus;
 
         case DEV_TYPE_PCIe2PCI_BRIDGE:
         case DEV_TYPE_LEGACY_PCI_BRIDGE:
-- 
2.7.4