4 files changed, 60 insertions, 2 deletions

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index aeccc911abb8..f6781e42d00d 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -735,3 +735,50 @@ int pci_num_vf(struct pci_dev *dev)
                 return dev->sriov->nr_virtfn;
 }
 EXPORT_SYMBOL_GPL(pci_num_vf);
+
+/**
+ * pci_sriov_set_totalvfs -- reduce the TotalVFs available
+ * @dev: the PCI PF device
+ * numvfs: number that should be used for TotalVFs supported
+ *
+ * Should be called from PF driver's probe routine with
+ * device's mutex held.
+ *
+ * Returns 0 if PF is an SRIOV-capable device and
+ * value of numvfs valid. If not a PF with VFS, return -EINVAL;
+ * if VFs already enabled, return -EBUSY.
+ */
+int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
+{
+        if (!dev || !dev->is_physfn || (numvfs > dev->sriov->total))
+                return -EINVAL;
+
+        /* Shouldn't change if VFs already enabled */
+        if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
+                return -EBUSY;
+        else
+                dev->sriov->drvttl = numvfs;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
+
+/**
+ * pci_sriov_get_totalvfs -- get total VFs supported on this devic3
+ * @dev: the PCI PF device
+ *
+ * For a PCIe device with SRIOV support, return the PCIe
+ * SRIOV capability value of TotalVFs or the value of drvttl
+ * if the driver reduced it.  Otherwise, -EINVAL.
+ */
+int pci_sriov_get_totalvfs(struct pci_dev *dev)
+{
+        if (!dev || !dev->is_physfn)
+                return -EINVAL;
+
+        if (dev->sriov->drvttl)
+                return dev->sriov->drvttl;
+        else
+                return dev->sriov->total;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 74508c63bd47..99b5f83d2468 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -411,7 +411,7 @@ static ssize_t sriov_totalvfs_show(struct device *dev,
 {
         struct pci_dev *pdev = to_pci_dev(dev);
 
-        return sprintf(buf, "%u\n", pdev->sriov->total);
+        return sprintf(buf, "%u\n", pci_sriov_get_totalvfs(pdev));
 }
 
 
@@ -452,7 +452,7 @@ static ssize_t sriov_numvfs_store(struct device *dev,
         }
 
         /* if enabling vf's ... */
-        total = pdev->sriov->total;
+        total = pci_sriov_get_totalvfs(pdev);
         /* Requested VFs to enable < totalvfs and none enabled already */
         if ((num_vfs > 0) && (num_vfs <= total)) {
                 if (pdev->sriov->nr_virtfn == 0) {
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6f6cd145bb7e..553bbba76eec 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -240,6 +240,7 @@ struct pci_sriov {
         u16 stride;             /* following VF stride */
         u32 pgsz;               /* page size for BAR alignment */
         u8 link;                /* Function Dependency Link */
+        u16 drvttl;             /* max num VFs driver supports */
         struct pci_dev *dev;    /* lowest numbered PF */
         struct pci_dev *self;   /* this PF */
         struct mutex lock;      /* lock for VF bus */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7ef8fba319da..1ad824966e64 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1611,6 +1611,8 @@ extern int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 extern void pci_disable_sriov(struct pci_dev *dev);
 extern irqreturn_t pci_sriov_migration(struct pci_dev *dev);
 extern int pci_num_vf(struct pci_dev *dev);
+extern int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
+extern int pci_sriov_get_totalvfs(struct pci_dev *dev);
 #else
 static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 {
@@ -1627,6 +1629,14 @@ static inline int pci_num_vf(struct pci_dev *dev)
 {
         return 0;
 }
+static inline int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
+{
+        return 0;
+}
+static inline int pci_sriov_get_totalvfs(struct pci_dev *dev)
+{
+        return 0;
+}
 #endif
 
 #if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)