sfc: support VI strides other than 8k

Medford2 can also have 16k or 64k VI stride.  This is reported by MCDI in
 GET_CAPABILITIES, which fortunately is called before the driver does
 anything sensitive to the VI stride (such as accessing or even allocating
 VIs past the zeroth).

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/net_driver.h

@@ -708,6 +708,7 @@ struct vfdi_status;
  * @reset_work: Scheduled reset workitem
  * @membase_phys: Memory BAR value as physical address
  * @membase: Memory BAR value
+ * @vi_stride: step between per-VI registers / memory regions
  * @interrupt_mode: Interrupt mode
  * @timer_quantum_ns: Interrupt timer quantum, in nanoseconds
  * @timer_max_ns: Interrupt timer maximum value, in nanoseconds
@@ -842,6 +843,8 @@ struct efx_nic {
 	resource_size_t membase_phys;
 	void __iomem *membase;
 
+	unsigned int vi_stride;
+
 	enum efx_int_mode interrupt_mode;
 	unsigned int timer_quantum_ns;
 	unsigned int timer_max_ns;