XEN: Grant table address, xen_hvm_resume_frames, is a phys_addr not a pfn

From: Eric Trudeau <etrudeau@broadcom.com>

xen_hvm_resume_frames stores the physical address of the grant table.
englighten.c was incorrectly setting it as if it was a page frame number.
This caused the table to be mapped into the guest at an unexpected physical
address.

Additionally, a warning is improved to include the grant table address which
failed in xen_remap.
Signed-off-by: Eric Trudeau <etrudeau@broadcom.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

arch/arm/xen/enlighten.c

@@ -224,10 +224,10 @@ static int __init xen_guest_init(void)
 	}
 	if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res))
 		return 0;
-	xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
+	xen_hvm_resume_frames = res.start;
 	xen_events_irq = irq_of_parse_and_map(node, 0);
 	pr_info("Xen %s support found, events_irq=%d gnttab_frame_pfn=%lx\n",
-			version, xen_events_irq, xen_hvm_resume_frames);
+			version, xen_events_irq, (xen_hvm_resume_frames >> PAGE_SHIFT));
 	xen_domain_type = XEN_HVM_DOMAIN;
 
 	xen_setup_features();

drivers/xen/grant-table.c

@@ -1176,7 +1176,8 @@ static int gnttab_setup(void)
 		gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
 						PAGE_SIZE * max_nr_gframes);
 		if (gnttab_shared.addr == NULL) {
-			pr_warn("Failed to ioremap gnttab share frames!\n");
+			pr_warn("Failed to ioremap gnttab share frames (addr=0x%08lx)!\n",
+					xen_hvm_resume_frames);
 			return -ENOMEM;
 		}
 	}