xen/device-tree: Add ability to handle nodes with interrupts-extended…

… prop

The "interrupts-extended" property is a special form for use when
a node needs to reference multiple interrupt parents.

According to:
Linux/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt

But, there are cases when "interrupts-extended" property is used for
"outside /soc node" with a single interrupt parent as an equivalent of
pairs ("interrupt-parent" + "interrupts").

A good example here is ARCH timer node for R-Car Gen3/Gen2 family,
which is mandatory device for Xen usage on ARM. And without ability
to handle such nodes, Xen fails to operate.

So, this patch adds required support for Xen to be able to handle
nodes with that property.

Signed-off-by: Oleksandr Tyshchenko <[email protected]>
Reviewed-by: Julien Grall <[email protected]>

xen/common/device_tree.c

@@ -987,15 +987,27 @@ unsigned int dt_number_of_irq(const struct dt_device_node *device)
     const struct dt_device_node *p;
     const __be32 *intspec, *tmp;
     u32 intsize, intlen;
+    int intnum;
 
     dt_dprintk("dt_irq_number: dev=%s\n", device->full_name);
 
+    /* Try the new-style interrupts-extended first */
+    intnum = dt_count_phandle_with_args(device, "interrupts-extended",
+                                        "#interrupt-cells");
+    if ( intnum >= 0 )
+    {
+        dt_dprintk(" using 'interrupts-extended' property\n");
+        dt_dprintk(" intnum=%d\n", intnum);
+        return intnum;
+    }
+
     /* Get the interrupts property */
     intspec = dt_get_property(device, "interrupts", &intlen);
     if ( intspec == NULL )
         return 0;
     intlen /= sizeof(*intspec);
 
+    dt_dprintk(" using 'interrupts' property\n");
     dt_dprintk(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);
 
     /* Look for the interrupt parent. */
@@ -1420,21 +1432,39 @@ int dt_device_get_raw_irq(const struct dt_device_node *device,
     const __be32 *intspec, *tmp, *addr;
     u32 intsize, intlen;
     int res = -EINVAL;
+    struct dt_phandle_args args;
+    int i;
 
     dt_dprintk("dt_device_get_raw_irq: dev=%s, index=%u\n",
                device->full_name, index);
 
+    /* Get the reg property (if any) */
+    addr = dt_get_property(device, "reg", NULL);
+
+    /* Try the new-style interrupts-extended first */
+    res = dt_parse_phandle_with_args(device, "interrupts-extended",
+                                     "#interrupt-cells", index, &args);
+    if ( !res )
+    {
+        dt_dprintk(" using 'interrupts-extended' property\n");
+        dt_dprintk(" intspec=%d intsize=%d\n", args.args[0], args.args_count);
+
+        for ( i = 0; i < args.args_count; i++ )
+            args.args[i] = cpu_to_be32(args.args[i]);
+
+        return dt_irq_map_raw(args.np, args.args, args.args_count,
+                              addr, out_irq);
+    }
+
     /* Get the interrupts property */
     intspec = dt_get_property(device, "interrupts", &intlen);
     if ( intspec == NULL )
         return -EINVAL;
     intlen /= sizeof(*intspec);
 
+    dt_dprintk(" using 'interrupts' property\n");
     dt_dprintk(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);
 
-    /* Get the reg property (if any) */
-    addr = dt_get_property(device, "reg", NULL);
-
     /* Look for the interrupt parent. */
     p = dt_irq_find_parent(device);
     if ( p == NULL )