Drivers: hv: vmbus: Move virt_to_hvpfn() to hyperv header

There will be more places other than vmbus where we need to calculate
the Hyper-V page PFN from a virtual address, so move virt_to_hvpfn() to
hyperv generic header.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-6-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

drivers/hv/channel.c

@@ -22,19 +22,6 @@
 
 #include "hyperv_vmbus.h"
 
-static unsigned long virt_to_hvpfn(void *addr)
-{
-	phys_addr_t paddr;
-
-	if (is_vmalloc_addr(addr))
-		paddr = page_to_phys(vmalloc_to_page(addr)) +
-					 offset_in_page(addr);
-	else
-		paddr = __pa(addr);
-
-	return  paddr >> HV_HYP_PAGE_SHIFT;
-}
-
 /*
  * hv_gpadl_size - Return the real size of a gpadl, the size that Hyper-V uses
  *

include/linux/hyperv.h

@@ -14,6 +14,7 @@
 
 #include <uapi/linux/hyperv.h>
 
+#include <linux/mm.h>
 #include <linux/types.h>
 #include <linux/scatterlist.h>
 #include <linux/list.h>
@@ -23,6 +24,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/interrupt.h>
 #include <linux/reciprocal_div.h>
+#include <asm/hyperv-tlfs.h>
 
 #define MAX_PAGE_BUFFER_COUNT				32
 #define MAX_MULTIPAGE_BUFFER_COUNT			32 /* 128K */
@@ -1676,4 +1678,17 @@ struct hyperv_pci_block_ops {
 
 extern struct hyperv_pci_block_ops hvpci_block_ops;
 
+static inline unsigned long virt_to_hvpfn(void *addr)
+{
+	phys_addr_t paddr;
+
+	if (is_vmalloc_addr(addr))
+		paddr = page_to_phys(vmalloc_to_page(addr)) +
+				     offset_in_page(addr);
+	else
+		paddr = __pa(addr);
+
+	return  paddr >> HV_HYP_PAGE_SHIFT;
+}
+
 #endif /* _HYPERV_H */