xen/grant-table: Refactor gnttab_init

We have this odd scenario of where for PV paths we take a shortcut
but for the HVM paths we first ioremap xen_hvm_resume_frames, then
assign it to gnttab_shared.addr. This is needed because gnttab_map
uses gnttab_shared.addr.

Instead of having:
	if (pv)
		return gnttab_map
	if (hvm)
		...

	gnttab_map

Lets move the HVM part before the gnttab_map and remove the
first call to gnttab_map.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 99399cb..e69c778 100644 (file)
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -1173,10 +1173,7 @@ static int gnttab_setup(void)
        if (max_nr_gframes < nr_grant_frames)
                return -ENOSYS;
 
-       if (xen_pv_domain())
-               return gnttab_map(0, nr_grant_frames - 1);
-
-       if (gnttab_shared.addr == NULL) {
+       if (xen_feature(XENFEAT_auto_translated_physmap) && gnttab_shared.addr == NULL) {
                gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
                                                PAGE_SIZE * max_nr_gframes);
                if (gnttab_shared.addr == NULL) {
@@ -1185,10 +1182,7 @@ static int gnttab_setup(void)
                        return -ENOMEM;
                }
        }
-
-       gnttab_map(0, nr_grant_frames - 1);
-
-       return 0;
+       return gnttab_map(0, nr_grant_frames - 1);
 }
 
 int gnttab_resume(void)