of/unittest: Add empty dma-ranges address translation tests

Intermediate DT PCI nodes dynamically generated by enabling
CONFIG_PCI_DYNAMIC_OF_NODES have empty dma-ranges property. PCI address
specifiers have 3 cells and when dma-ranges is missing or empty,
of_translate_one() is currently dropping the flag portion of PCI addresses
which are subnodes of the aforementioned ones, failing the translation.
Add new tests covering this case.

With this test, we get 1 new failure which is fixed in subsequent
commit:

FAIL of_unittest_pci_empty_dma_ranges():1245 for_each_of_pci_range wrong CPU addr (ffffffffffffffff) on node /testcase-data/address-tests2/pcie@d1070000/pci@0,0/dev@0,0/local-bus@0

Signed-off-by: Andrea della Porta <[e-mail]>
Link: https://lore.kernel.org/r/08f8[e-mail]
Signed-off-by: Rob Herring (Arm) <[e-mail]>

drivers/of/unittest-data/tests-address.dtsi

···
 				device_type = "pci";
 				ranges = <0x82000000 0 0xe8000000 0 0xe8000000 0 0x7f00000>,
 					 <0x81000000 0 0x00000000 0 0xefff0000 0 0x0010000>;
+				dma-ranges = <0x43000000 0x10 0x00 0x00 0x00 0x00 0x10000000>;
 				reg = <0x00000000 0xd1070000 0x20000>;
 
 				pci@0,0 {
···
 							#size-cells = <0x01>;
 							ranges = <0xa0000000 0 0 0 0x2000000>,
 								 <0xb0000000 1 0 0 0x1000000>;
+							dma-ranges = <0xc0000000 0x43000000 0x10 0x00 0x10000000>;
 
 							dev@e0000000 {
 								reg = <0xa0001000 0x1000>,

drivers/of/unittest.c

···
 	of_node_put(np);
 }
 
+static void __init of_unittest_pci_empty_dma_ranges(void)
+{
+	struct device_node *np;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return;
+
+	np = of_find_node_by_path("/testcase-data/address-tests2/pcie@d1070000/pci@0,0/dev@0,0/local-bus@0");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	if (of_pci_dma_range_parser_init(&parser, np)) {
+		pr_err("missing dma-ranges property\n");
+		return;
+	}
+
+	/*
+	 * Get the dma-ranges from the device tree
+	 */
+	for_each_of_pci_range(&parser, &range) {
+		unittest(range.size == 0x10000000,
+			 "for_each_of_pci_range wrong size on node %pOF size=%llx\n",
+			 np, range.size);
+		unittest(range.cpu_addr == 0x00000000,
+			 "for_each_of_pci_range wrong CPU addr (%llx) on node %pOF",
+			 range.cpu_addr, np);
+		unittest(range.pci_addr == 0xc0000000,
+			 "for_each_of_pci_range wrong DMA addr (%llx) on node %pOF",
+			 range.pci_addr, np);
+	}
+
+	of_node_put(np);
+}
+
 static void __init of_unittest_bus_ranges(void)
 {
 	struct device_node *np;
···
 	of_unittest_dma_get_max_cpu_address();
 	of_unittest_parse_dma_ranges();
 	of_unittest_pci_dma_ranges();
+	of_unittest_pci_empty_dma_ranges();
 	of_unittest_bus_ranges();
 	of_unittest_bus_3cell_ranges();
 	of_unittest_reg();