xen/arm: gic: Allow the base address to be 0

0 is a valid physical address and dt_device_get_address would return
an error if a problem during the retrieving happen.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Zoltan Kiss <zoltan.kiss@huawei.com>

xen/arch/arm/gic-hip04.c

@@ -680,19 +680,19 @@ static int __init hip04gic_init(void)
     const struct dt_device_node *node = gicv2_info.node;
 
     res = dt_device_get_address(node, 0, &gicv2.dbase, NULL);
-    if ( res || !gicv2.dbase )
+    if ( res )
         panic("GIC-HIP04: Cannot find a valid address for the distributor");
 
     res = dt_device_get_address(node, 1, &gicv2.cbase, NULL);
-    if ( res || !gicv2.cbase )
+    if ( res )
         panic("GIC-HIP04: Cannot find a valid address for the CPU");
 
     res = dt_device_get_address(node, 2, &gicv2.hbase, NULL);
-    if ( res || !gicv2.hbase )
+    if ( res )
         panic("GIC-HIP04: Cannot find a valid address for the hypervisor");
 
     res = dt_device_get_address(node, 3, &gicv2.vbase, NULL);
-    if ( res || !gicv2.vbase )
+    if ( res )
         panic("GIC-HIP04: Cannot find a valid address for the virtual CPU");
 
     res = platform_get_irq(node, 0);

xen/arch/arm/gic-v2.c

@@ -666,19 +666,19 @@ static int __init gicv2_init(void)
     const struct dt_device_node *node = gicv2_info.node;
 
     res = dt_device_get_address(node, 0, &gicv2.dbase, NULL);
-    if ( res || !gicv2.dbase )
+    if ( res )
         panic("GICv2: Cannot find a valid address for the distributor");
 
     res = dt_device_get_address(node, 1, &gicv2.cbase, NULL);
-    if ( res || !gicv2.cbase )
+    if ( res )
         panic("GICv2: Cannot find a valid address for the CPU");
 
     res = dt_device_get_address(node, 2, &gicv2.hbase, NULL);
-    if ( res || !gicv2.hbase )
+    if ( res )
         panic("GICv2: Cannot find a valid address for the hypervisor");
 
     res = dt_device_get_address(node, 3, &gicv2.vbase, NULL);
-    if ( res || !gicv2.vbase )
+    if ( res )
         panic("GICv2: Cannot find a valid address for the virtual CPU");
 
     res = platform_get_irq(node, 0);

xen/arch/arm/gic-v3.c

@@ -1198,7 +1198,7 @@ static int __init gicv3_init(void)
     }
 
     res = dt_device_get_address(node, 0, &gicv3.dbase, NULL);
-    if ( res || !gicv3.dbase )
+    if ( res )
         panic("GICv3: Cannot find a valid distributor address");
 
     if ( (gicv3.dbase & ~PAGE_MASK) )
@@ -1230,7 +1230,7 @@ static int __init gicv3_init(void)
         uint64_t rdist_base, rdist_size;
 
         res = dt_device_get_address(node, 1 + i, &rdist_base, &rdist_size);
-        if ( res || !rdist_base )
+        if ( res )
             panic("GICv3: No rdist base found for region %d\n", i);
 
         rdist_regs[i].base = rdist_base;