[PATCH v2 2/7] rust: pci: Add sriov_get_totalvfs() helper

[Zhi Wang]

Expose pci_sriov_get_totalvfs() to Rust PCI drivers so they can query
how many SR-IOV VFs a device supports.

The C helper now returns u16 and reports 0 when SR-IOV is unavailable
or the device is not a PF, so mirror that API directly instead of
modeling 0 VFs as an error.

Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Signed-off-by: Zhi Wang <zhiw@xxxxxxxxxx>
---
 rust/kernel/pci.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 5071cae6543f..adcb99fd0a2e 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -450,6 +450,12 @@ 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 the total number of VFs, or 0 if SR-IOV is not available.
+    pub fn sriov_get_totalvfs(&self) -> u16 {
+        // SAFETY: `self.as_raw()` is a valid pointer to a `struct pci_dev`.
+        unsafe { bindings::pci_sriov_get_totalvfs(self.as_raw()) }
+    }
 }
 
 impl<'a> Device<device::Core<'a>> {
-- 
2.51.0