drivers:hv: Export a function that maps Linux CPU num onto Hyper-V proc num

This patch exposes the mapping between Linux CPU number and Hyper-V virtual
processor number.  This is necessary because the hypervisor needs to know which
virtual processors to target when making a mapping in the Interrupt Redirection
Table in the I/O MMU.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 8fdc17b..fddb3e0 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -983,6 +983,8 @@
 			resource_size_t size, resource_size_t align,
 			bool fb_overlap_ok);
 
+int vmbus_cpu_number_to_vp_number(int cpu_number);
+
 /**
  * VMBUS_DEVICE - macro used to describe a specific hyperv vmbus device
  *