+/* When fist initialized, VFs need to know the Interrupt Throttle Rate (ITR)
+ * scale which is based on the PCIe speed but the speed information in the PCI
+ * configuration space may not be accurate. The PF already knows the ITR scale
+ * but there is no defined method to pass that information from the PF to the
+ * VF. This is accomplished during VF initialization by temporarily co-opting
+ * the yet-to-be-used TDLEN register to have the PF store the ITR shift for
+ * the VF to retrieve before the VF needs to use the TDLEN register for its
+ * intended purpose, i.e. before the Tx resources are allocated.
+ */
+#define FM10K_TDLEN_ITR_SCALE_SHIFT 9
+#define FM10K_TDLEN_ITR_SCALE_MASK 0x00000E00
+#define FM10K_TDLEN_ITR_SCALE_GEN1 2
+#define FM10K_TDLEN_ITR_SCALE_GEN2 1
+#define FM10K_TDLEN_ITR_SCALE_GEN3 0