[PATCH 1/9] rust: pci: expose sriov_get_totalvfs() helper

[Zhi Wang <zhiw@nvidia.com>]

Add a wrapper for the `pci_sriov_get_totalvfs()` helper, allowing drivers
to query the number of total SR-IOV virtual functions a PCI device
supports.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Signed-off-by: Zhi Wang <zhiw@nvidia.com>
---
 rust/kernel/pci.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 5071cae6543f..d04e5f6841f2 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -450,6 +450,18 @@ pub fn pci_class(&self) -> Class {
         // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
         Class::from_raw(unsafe { (*self.as_raw()).class })
     }
+
+    /// Returns total number of VFs, or `Err(ENODEV)` if none available.
+    pub fn sriov_get_totalvfs(&self) -> Result<i32> {
+        // SAFETY: `self.as_raw()` is a valid pointer to a `struct pci_dev`.
+        let vfs = unsafe { bindings::pci_sriov_get_totalvfs(self.as_raw()) };
+
+        if vfs == 0 {
+            return Err(ENODEV);
+        }
+
+        Ok(vfs)
+    }
 }
 
 impl<'a> Device<device::Core<'a>> {
-- 
2.51.0