[PATCH v12 3/8] PCI: reserve bus range for SR-IOV device

From: Yu Zhao
Date: Thu Mar 19 2009 - 23:26:18 EST


Reserve the bus number range used by the Virtual Function when
pcibios_assign_all_busses() returns true.

Reviewed-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx>
---
drivers/pci/iov.c | 36 ++++++++++++++++++++++++++++++++++++
drivers/pci/pci.h | 5 +++++
drivers/pci/probe.c | 3 +++
3 files changed, 44 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index b121e47..5ddfc09 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -14,6 +14,18 @@
#include "pci.h"


+static inline u8 virtfn_bus(struct pci_dev *dev, int id)
+{
+ return dev->bus->number + ((dev->devfn + dev->sriov->offset +
+ dev->sriov->stride * id) >> 8);
+}
+
+static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
+{
+ return (dev->devfn + dev->sriov->offset +
+ dev->sriov->stride * id) & 0xff;
+}
+
static int sriov_init(struct pci_dev *dev, int pos)
{
int i;
@@ -209,3 +221,27 @@ void pci_restore_iov_state(struct pci_dev *dev)
if (dev->is_physfn)
sriov_restore_state(dev);
}
+
+/**
+ * pci_iov_bus_range - find bus range used by 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;
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ if (!dev->is_physfn)
+ continue;
+ busnr = virtfn_bus(dev, dev->sriov->total - 1);
+ if (busnr > max)
+ max = busnr;
+ }
+
+ return max ? max - bus->number : 0;
+}
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index efd79a2..7abdef6 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -217,6 +217,7 @@ extern void pci_iov_release(struct pci_dev *dev);
extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
enum pci_bar_type *type);
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)
{
@@ -234,6 +235,10 @@ static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno,
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 03b6f29..4c8abd0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1078,6 +1078,9 @@ 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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