[PATCH 13/16 v6] PCI: reserve bus range for SR-IOV device

[Yu Zhao]

Reserve bus range for SR-IOV at device scanning stage.

Cc: Alex Chiang <achiang@xxxxxx>
Cc: Grant Grundler <grundler@xxxxxxxxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <matthew@xxxxxx>
Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Cc: Roland Dreier <rdreier@xxxxxxxxx>
Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx>

---
 drivers/pci/iov.c   |   24 ++++++++++++++++++++++++
 drivers/pci/pci.h   |    5 +++++
 drivers/pci/probe.c |    3 +++
 3 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index dd299aa..c86bd54 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -498,6 +498,30 @@ int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 }
 
 /**
+ * pci_iov_bus_range - find bus range used by SR-IOV capability
+ * @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;
+		vf_rid(dev, dev->iov->totalvfs - 1, &busnr, &devfn);
+		if (busnr > max)
+			max = busnr;
+	}
+
+	return max ? max - bus->number : 0;
+}
+
+/**
  * pci_iov_register - register SR-IOV service
  * @dev: the PCI device
  * @callback: callback function for SR-IOV events
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 7735d92..5206ae7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -204,6 +204,7 @@ void pci_iov_remove_sysfs(struct pci_dev *dev);
 extern int pci_iov_resource_align(struct pci_dev *dev, int resno);
 extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 				enum pci_bar_type *type);
+extern int pci_iov_bus_range(struct pci_bus *bus);
 #else
 static inline int pci_iov_init(struct pci_dev *dev)
 {
@@ -227,6 +228,10 @@ static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 {
 	return 0;
 }
+extern 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 18ce9c0..50a1380 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1068,6 +1068,9 @@ 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

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