checks: Add an interrupt-map check

Add a check for parsing 'interrupt-map' properties. The check primarily
tests parsing 'interrupt-map' properties which depends on and the parent
interrupt controller (or another map) node.

Note that this does not require '#address-cells' in the interrupt-map
parent, but treats missing '#address-cells' as 0 which is how the Linux
kernel parses it. There's numerous cases that expect this behavior.

Cc: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Message-Id: <20211015213527.2237774-1-robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

checks.c

@@ -1590,6 +1590,90 @@ static void check_interrupt_provider(struct check *c,
 }
 WARNING(interrupt_provider, check_interrupt_provider, NULL, &interrupts_extended_is_cell);
 
+static void check_interrupt_map(struct check *c,
+				struct dt_info *dti,
+				struct node *node)
+{
+	struct node *root = dti->dt;
+	struct property *prop, *irq_map_prop;
+	size_t cellsize, cell, map_cells;
+
+	irq_map_prop = get_property(node, "interrupt-map");
+	if (!irq_map_prop)
+		return;
+
+	if (node->addr_cells < 0) {
+		FAIL(c, dti, node,
+		     "Missing '#address-cells' in interrupt-map provider");
+		return;
+	}
+	cellsize = node_addr_cells(node);
+	cellsize += propval_cell(get_property(node, "#interrupt-cells"));
+
+	prop = get_property(node, "interrupt-map-mask");
+	if (prop && (prop->val.len != (cellsize * sizeof(cell_t))))
+		FAIL_PROP(c, dti, node, prop,
+			  "property size (%d) is invalid, expected %zu",
+			  prop->val.len, cellsize * sizeof(cell_t));
+
+	if (!is_multiple_of(irq_map_prop->val.len, sizeof(cell_t))) {
+		FAIL_PROP(c, dti, node, irq_map_prop,
+			  "property size (%d) is invalid, expected multiple of %zu",
+			  irq_map_prop->val.len, sizeof(cell_t));
+		return;
+	}
+
+	map_cells = irq_map_prop->val.len / sizeof(cell_t);
+	for (cell = 0; cell < map_cells; ) {
+		struct node *provider_node;
+		struct property *cellprop;
+		int phandle;
+		size_t parent_cellsize;
+
+		if ((cell + cellsize) >= map_cells) {
+			FAIL_PROP(c, dti, node, irq_map_prop,
+				  "property size (%d) too small, expected > %zu",
+				  irq_map_prop->val.len, (cell + cellsize) * sizeof(cell_t));
+			break;
+		}
+		cell += cellsize;
+
+		phandle = propval_cell_n(irq_map_prop, cell);
+		if (!phandle_is_valid(phandle)) {
+			/* Give up if this is an overlay with external references */
+			if (!(dti->dtsflags & DTSF_PLUGIN))
+				FAIL_PROP(c, dti, node, irq_map_prop,
+					  "Cell %zu is not a phandle(%d)",
+					  cell, phandle);
+			break;
+		}
+
+		provider_node = get_node_by_phandle(root, phandle);
+		if (!provider_node) {
+			FAIL_PROP(c, dti, node, irq_map_prop,
+				  "Could not get phandle(%d) node for (cell %zu)",
+				  phandle, cell);
+			break;
+		}
+
+		cellprop = get_property(provider_node, "#interrupt-cells");
+		if (cellprop) {
+			parent_cellsize = propval_cell(cellprop);
+		} else {
+			FAIL(c, dti, node, "Missing property '#interrupt-cells' in node %s or bad phandle (referred from interrupt-map[%zu])",
+			     provider_node->fullpath, cell);
+			break;
+		}
+
+		cellprop = get_property(provider_node, "#address-cells");
+		if (cellprop)
+			parent_cellsize += propval_cell(cellprop);
+
+		cell += 1 + parent_cellsize;
+	}
+}
+WARNING(interrupt_map, check_interrupt_map, NULL, &phandle_references, &addr_size_cells, &interrupt_provider);
+
 static void check_interrupts_property(struct check *c,
 				      struct dt_info *dti,
 				      struct node *node)
@@ -1888,6 +1972,7 @@ static struct check *check_table[] = {
 	&gpios_property,
 	&interrupts_property,
 	&interrupt_provider,
+	&interrupt_map,
 
 	&alias_paths,
 

tests/bad-interrupt-map-mask.dts

@@ -0,0 +1,20 @@
+/dts-v1/;
+
+/ {
+	interrupt-parent = <&intc>;
+	intc: interrupt-controller {
+		#interrupt-cells = <3>;
+		interrupt-controller;
+	};
+
+	node {
+		#address-cells = <0>;
+		#interrupt-cells = <1>;
+		interrupt-map = <1 &intc 1 2 3>;
+		interrupt-map-mask = <0 0>;
+
+		child {
+			interrupts = <1>;
+		};
+	};
+};

tests/bad-interrupt-map-parent.dts

@@ -0,0 +1,17 @@
+/dts-v1/;
+
+/ {
+	interrupt-parent = <&intc>;
+	intc: interrupt-controller {
+	};
+
+	node {
+		#address-cells = <0>;
+		#interrupt-cells = <1>;
+		interrupt-map = <1 &intc 1 2 3>;
+
+		child {
+			interrupts = <1>;
+		};
+	};
+};

tests/bad-interrupt-map.dts

@@ -0,0 +1,19 @@
+/dts-v1/;
+
+/ {
+	interrupt-parent = <&intc>;
+	intc: interrupt-controller {
+		#interrupt-cells = <3>;
+		interrupt-controller;
+	};
+
+	node {
+		/* Missing #address-cells = <0>; */
+		#interrupt-cells = <1>;
+		interrupt-map = <1 &intc 1 2 3>;
+
+		child {
+			interrupts = <1>;
+		};
+	};
+};

tests/run_tests.sh

@@ -717,6 +717,9 @@ dtc_tests () {
     run_sh_test "$SRCDIR/dtc-checkfails.sh" -n deprecated_gpio_property -- -Wdeprecated_gpio_property -I dts -O dtb "$SRCDIR/good-gpio.dts"
     check_tests "$SRCDIR/bad-interrupt-cells.dts" interrupts_property
     check_tests "$SRCDIR/bad-interrupt-controller.dts" interrupt_provider
+    check_tests "$SRCDIR/bad-interrupt-map.dts" interrupt_map
+    check_tests "$SRCDIR/bad-interrupt-map-parent.dts" interrupt_map
+    check_tests "$SRCDIR/bad-interrupt-map-mask.dts" interrupt_map
     run_sh_test "$SRCDIR/dtc-checkfails.sh" node_name_chars -- -I dtb -O dtb bad_node_char.dtb
     run_sh_test "$SRCDIR/dtc-checkfails.sh" node_name_format -- -I dtb -O dtb bad_node_format.dtb
     run_sh_test "$SRCDIR/dtc-checkfails.sh" property_name_chars -- -I dtb -O dtb bad_prop_char.dtb