[PATCH 11/13 v7] PCI: reserve bus range for SR-IOV device

Yu Zhao
2008-11-21T19:40:59Z

Reserve bus range for SR-IOV at device scanning stage when the kernel
boot parameter 'pci=assign-busses' is used .

Signed-off-by: Yu Zhao <yu.zhao@intel.com>

---
drivers/pci/iov.c | 24 ++++++++++++++++++++++++
drivers/pci/pci.h | 6 ++++++
drivers/pci/probe.c | 3 +++
3 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 03f62ca..c1a3cea 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -489,3 +489,27 @@ void pci_iov_unregister(struct pci_dev *dev)
iov_disable(dev);
kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
}
+
+/**
+ * pci_iov_bus_range - find bus range used by the Virtual Function
+ * @bus: the PCI bus
+ *
+ * Returns max number of buses (exclude current one) used by Virtual
+ * Functions.
+ */
+int pci_iov_bus_range(struct pci_bus *bus)
+{
+ int max = 0;
+ u8 busnr, devfn;
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ if (!dev->iov)
+ continue;
+ virtfn_bdf(dev, dev->iov->total - 1, &busnr, &devfn);
+ if (busnr > max)
+ max = busnr;
+ }
+
+ return max ? max - bus->number : 0;
+}
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 3113d11..574bbc7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -205,6 +205,7 @@ extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
extern int pci_iov_register(struct pci_dev* dev);
extern void pci_iov_unregister(struct pci_dev* dev);
extern void pci_restore_iov_state(struct pci_dev *dev);
+extern int pci_iov_bus_range(struct pci_bus *bus);
#else
static inline int pci_iov_init(struct pci_dev *dev)
{
@@ -232,6 +233,11 @@ static inline void pci_iov_unregister(struct pci_dev* dev)
static inline void pci_restore_iov_state(struct pci_dev *dev)
{
}
+
+static inline int pci_iov_bus_range(struct pci_bus *bus)
+{
+ return 0;
+}
#endif /* CONFIG_PCI_IOV */

#endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index cb26e64..7b591e5 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1074,6 +1074,9 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
for (devfn = 0; devfn < 0x100; devfn += 8)
pci_scan_slot(bus, devfn);

+ /* Reserve buses for SR-IOV capability. */
+ max += pci_iov_bus_range(bus);
+
/*
* After performing arch-dependent fixup of the bus, look behind
* all PCI-to-PCI bridges on this bus.
--
1.5.6.4