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path: root/drivers/pci/iov.c
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Diffstat (limited to 'drivers/pci/iov.c')
-rw-r--r--drivers/pci/iov.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index a8752c2c2b53..2ae921f84bd3 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -46,6 +46,30 @@ static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
}
+/*
+ * The PF consumes one bus number. NumVFs, First VF Offset, and VF Stride
+ * determine how many additional bus numbers will be consumed by VFs.
+ *
+ * Iterate over all valid NumVFs and calculate the maximum number of bus
+ * numbers that could ever be required.
+ */
+static inline u8 virtfn_max_buses(struct pci_dev *dev)
+{
+ struct pci_sriov *iov = dev->sriov;
+ int nr_virtfn;
+ u8 max = 0;
+ u8 busnr;
+
+ for (nr_virtfn = 1; nr_virtfn <= iov->total_VFs; nr_virtfn++) {
+ pci_iov_set_numvfs(dev, nr_virtfn);
+ busnr = virtfn_bus(dev, nr_virtfn - 1);
+ if (busnr > max)
+ max = busnr;
+ }
+
+ return max;
+}
+
static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
{
struct pci_bus *child;
@@ -427,6 +451,7 @@ found:
dev->sriov = iov;
dev->is_physfn = 1;
+ iov->max_VF_buses = virtfn_max_buses(dev);
return 0;
@@ -556,15 +581,13 @@ void pci_restore_iov_state(struct pci_dev *dev)
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_VFs - 1);
- if (busnr > max)
- max = busnr;
+ if (dev->sriov->max_VF_buses > max)
+ max = dev->sriov->max_VF_buses;
}
return max ? max - bus->number : 0;