Drivers: hv: vmbus: Always use HV_HYP_PAGE_SIZE for gpadl

Since the hypervisor always uses 4K as its page size, the size of PFNs
used for gpadl should be HV_HYP_PAGE_SIZE rather than PAGE_SIZE, so
adjust this accordingly as the preparation for supporting 16K/64K page
size guests. No functional changes on x86, since PAGE_SIZE is always 4k
(equals to HV_HYP_PAGE_SIZE).

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-2-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

drivers/hv/channel.c

@@ -22,9 +22,6 @@
 
 #include "hyperv_vmbus.h"
 
-#define NUM_PAGES_SPANNED(addr, len) \
-((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
-
 static unsigned long virt_to_hvpfn(void *addr)
 {
 	phys_addr_t paddr;
@@ -35,7 +32,7 @@ static unsigned long virt_to_hvpfn(void *addr)
 	else
 		paddr = __pa(addr);
 
-	return  paddr >> PAGE_SHIFT;
+	return  paddr >> HV_HYP_PAGE_SHIFT;
 }
 
 /*
@@ -330,7 +327,7 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 
 	int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 
-	pagecount = size >> PAGE_SHIFT;
+	pagecount = size >> HV_HYP_PAGE_SHIFT;
 
 	/* do we need a gpadl body msg */
 	pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
@@ -360,7 +357,7 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 		gpadl_header->range[0].byte_count = size;
 		for (i = 0; i < pfncount; i++)
 			gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
-				kbuffer + PAGE_SIZE * i);
+				kbuffer + HV_HYP_PAGE_SIZE * i);
 		*msginfo = msgheader;
 
 		pfnsum = pfncount;
@@ -412,7 +409,7 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 			 */
 			for (i = 0; i < pfncurr; i++)
 				gpadl_body->pfn[i] = virt_to_hvpfn(
-					kbuffer + PAGE_SIZE * (pfnsum + i));
+					kbuffer + HV_HYP_PAGE_SIZE * (pfnsum + i));
 
 			/* add to msg header */
 			list_add_tail(&msgbody->msglistentry,
@@ -441,7 +438,7 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 		gpadl_header->range[0].byte_count = size;
 		for (i = 0; i < pagecount; i++)
 			gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
-				kbuffer + PAGE_SIZE * i);
+				kbuffer + HV_HYP_PAGE_SIZE * i);
 
 		*msginfo = msgheader;
 	}