[RFC 02/23] xen/xenbus: client: Fix call of virt_to_mfn in xenbus_grant_ring

[Julien Grall]

virt_to_mfn should take a void* rather an unsigned long. While it
doesn't really matter now, it would throw a compiler warning later when
virt_to_mfn will enforce the type.

At the same time, avoid to compute new virtual address every time in the
loop and directly increment the parameter as we don't use it later.

Signed-off-by: Julien Grall <julien.grall at citrix.com>
Cc: Wei Liu <wei.liu2 at citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky at oracle.com>
Cc: David Vrabel <david.vrabel at citrix.com>
---
 drivers/xen/xenbus/xenbus_client.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index a014016..d204562 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -379,16 +379,16 @@ int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
 	int i, j;
 
 	for (i = 0; i < nr_pages; i++) {
-		unsigned long addr = (unsigned long)vaddr +
-			(PAGE_SIZE * i);
 		err = gnttab_grant_foreign_access(dev->otherend_id,
-						  virt_to_mfn(addr), 0);
+						  virt_to_mfn(vaddr), 0);
 		if (err < 0) {
 			xenbus_dev_fatal(dev, err,
 					 "granting access to ring page");
 			goto fail;
 		}
 		grefs[i] = err;
+
+		vaddr = (char *)vaddr + PAGE_SIZE;
 	}
 
 	return 0;
-- 
2.1.4