libfdt: fdt_address_cells() and fdt_size_cells()

Add internal fdt_cells() to avoid copy and paste.  Test error cases and
default values.  Fix typo in fdt_size_cells() documentation comment.

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

libfdt/fdt_addresses.c

@@ -1,6 +1,7 @@
 /*
  * libfdt - Flat Device Tree manipulation
  * Copyright (C) 2014 David Gibson <david@gibson.dropbear.id.au>
+ * Copyright (C) 2018 embedded brains GmbH
  *
  * libfdt is dual licensed: you can use it either under the terms of
  * the GPL, or the BSD license, at your option.
@@ -55,42 +56,32 @@
 
 #include "libfdt_internal.h"
 
-int fdt_address_cells(const void *fdt, int nodeoffset)
+static int fdt_cells(const void *fdt, int nodeoffset, const char *name)
 {
-	const fdt32_t *ac;
+	const fdt32_t *c;
 	int val;
 	int len;
 
-	ac = fdt_getprop(fdt, nodeoffset, "#address-cells", &len);
+	c = fdt_getprop(fdt, nodeoffset, name, &len);
-	if (!ac)
+	if (!c)
 		return 2;
 
-	if (len != sizeof(*ac))
+	if (len != sizeof(*c))
 		return -FDT_ERR_BADNCELLS;
 
-	val = fdt32_to_cpu(*ac);
+	val = fdt32_to_cpu(*c);
 	if ((val <= 0) || (val > FDT_MAX_NCELLS))
 		return -FDT_ERR_BADNCELLS;
 
 	return val;
 }
 
-int fdt_size_cells(const void *fdt, int nodeoffset)
+int fdt_address_cells(const void *fdt, int nodeoffset)
 {
-	const fdt32_t *sc;
+	return fdt_cells(fdt, nodeoffset, "#address-cells");
-	int val;
+}
-	int len;
-
-	sc = fdt_getprop(fdt, nodeoffset, "#size-cells", &len);
-	if (!sc)
-		return 2;
-
-	if (len != sizeof(*sc))
-		return -FDT_ERR_BADNCELLS;
-
-	val = fdt32_to_cpu(*sc);
-	if ((val < 0) || (val > FDT_MAX_NCELLS))
-		return -FDT_ERR_BADNCELLS;
 
-	return val;
+int fdt_size_cells(const void *fdt, int nodeoffset)
+{
+	return fdt_cells(fdt, nodeoffset, "#size-cells");
 }

libfdt/libfdt.h

@@ -1145,7 +1145,7 @@ int fdt_address_cells(const void *fdt, int nodeoffset);
  *
  * returns:
  *	0 <= n < FDT_MAX_NCELLS, on success
- *      2, if the node has no #address-cells property
+ *      2, if the node has no #size-cells property
  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
  *		#size-cells property
  *	-FDT_ERR_BADMAGIC,

tests/.gitignore

@@ -4,6 +4,7 @@
 tmp.*
 /add_subnode_with_nops
 /addr_size_cells
+/addr_size_cells2
 /appendprop[12]
 /asm_tree_dump
 /boot-cpuid

tests/Makefile.tests

@@ -9,6 +9,7 @@ LIB_TESTS_L = get_mem_rsv \
 	sized_cells \
 	notfound \
 	addr_size_cells \
+	addr_size_cells2 \
 	stringlist \
 	setprop_inplace nop_property nop_node \
 	sw_tree1 sw_states \

tests/addr_size_cells.c

@@ -60,5 +60,8 @@ int main(int argc, char *argv[])
 	check_node(fdt, "/", 2, 2);
 	check_node(fdt, "/identity-bus@0", 2, 2);
 	check_node(fdt, "/simple-bus@1000000", 2, 1);
+	check_node(fdt, "/c0", -FDT_ERR_BADNCELLS, -FDT_ERR_BADNCELLS);
+	check_node(fdt, "/c1", -FDT_ERR_BADNCELLS, -FDT_ERR_BADNCELLS);
+	check_node(fdt, "/c2", -FDT_ERR_BADNCELLS, -FDT_ERR_BADNCELLS);
 	PASS();
 }

tests/addr_size_cells2.c

@@ -0,0 +1,62 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ *	Testcase for #address-cells and #size-cells handling
+ * Copyright (C) 2014 David Gibson, <david@gibson.dropbear.id.au>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#include <libfdt.h>
+
+#include "tests.h"
+#include "testdata.h"
+
+static void check_node(const void *fdt, const char *path, int ac, int sc)
+{
+	int offset;
+	int xac, xsc;
+
+	offset = fdt_path_offset(fdt, path);
+	if (offset < 0)
+		FAIL("Couldn't find path %s", path);
+
+	xac = fdt_address_cells(fdt, offset);
+	xsc = fdt_size_cells(fdt, offset);
+
+	if (xac != ac)
+		FAIL("Address cells for %s is %d instead of %d\n",
+		     path, xac, ac);
+	if (xsc != sc)
+		FAIL("Size cells for %s is %d instead of %d\n",
+		     path, xsc, sc);
+}
+
+int main(int argc, char *argv[])
+{
+	void *fdt;
+
+	if (argc != 2)
+		CONFIG("Usage: %s <dtb file>\n", argv[0]);
+
+	test_init(argc, argv);
+	fdt = load_blob(argv[1]);
+
+	check_node(fdt, "/", 2, 2);
+	PASS();
+}

tests/addresses.dts

@@ -12,4 +12,19 @@
 		#address-cells = <2>;
 		#size-cells = <1>;
 	};
+
+	c0@0 {
+		#address-cells = <1 1>;
+		#size-cells = <1 1>;
+	};
+
+	c1@0 {
+		#address-cells = <0x80000000>;
+		#size-cells = <0x80000000>;
+	};
+
+	c2@0 {
+		#address-cells = <5>;
+		#size-cells = <5>;
+	};
 };

tests/run_tests.sh

@@ -336,6 +336,8 @@ libfdt_tests () {
 
     run_dtc_test -I dts -O dtb -o addresses.test.dtb addresses.dts
     run_test addr_size_cells addresses.test.dtb
+    run_dtc_test -I dts -O dtb -o addresses2.test.dtb empty.dts
+    run_test addr_size_cells2 addresses2.test.dtb
 
     run_dtc_test -I dts -O dtb -o stringlist.test.dtb stringlist.dts
     run_test stringlist stringlist.test.dtb