checks: Fix signedness comparisons warnings

With -Wsign-compare, compilers warn about a mismatching signedness in
comparisons in various parts in checks.c.

Fix those by making all affected variables unsigned. This covers return
values of the (unsigned) size_t type, phandles, variables holding sizes
in general and loop counters only ever counting positives values.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Message-Id: <20210618172030.9684-5-andre.przywara@arm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

checks.c

@@ -312,7 +312,7 @@ ERROR(duplicate_property_names, check_duplicate_property_names, NULL);
 static void check_node_name_chars(struct check *c, struct dt_info *dti,
 				  struct node *node)
 {
-	int n = strspn(node->name, c->data);
+	size_t n = strspn(node->name, c->data);
 
 	if (n < strlen(node->name))
 		FAIL(c, dti, node, "Bad character '%c' in node name",
@@ -386,7 +386,7 @@ static void check_property_name_chars(struct check *c, struct dt_info *dti,
 	struct property *prop;
 
 	for_each_property(node, prop) {
-		int n = strspn(prop->name, c->data);
+		size_t n = strspn(prop->name, c->data);
 
 		if (n < strlen(prop->name))
 			FAIL_PROP(c, dti, node, prop, "Bad character '%c' in property name",
@@ -403,7 +403,7 @@ static void check_property_name_chars_strict(struct check *c,
 
 	for_each_property(node, prop) {
 		const char *name = prop->name;
-		int n = strspn(name, c->data);
+		size_t n = strspn(name, c->data);
 
 		if (n == strlen(prop->name))
 			continue;
@@ -579,7 +579,7 @@ static void check_name_properties(struct check *c, struct dt_info *dti,
 	if (!prop)
 		return; /* No name property, that's fine */
 
-	if ((prop->val.len != node->basenamelen+1)
+	if ((prop->val.len != node->basenamelen + 1U)
 	    || (memcmp(prop->val.val, node->name, node->basenamelen) != 0)) {
 		FAIL(c, dti, node, "\"name\" property is incorrect (\"%s\" instead"
 		     " of base node name)", prop->val.val);
@@ -1388,7 +1388,7 @@ static void check_property_phandle_args(struct check *c,
 				          const struct provider *provider)
 {
 	struct node *root = dti->dt;
-	int cell, cellsize = 0;
+	unsigned int cell, cellsize = 0;
 
 	if (!is_multiple_of(prop->val.len, sizeof(cell_t))) {
 		FAIL_PROP(c, dti, node, prop,
@@ -1596,7 +1596,7 @@ static void check_interrupts_property(struct check *c,
 	struct node *root = dti->dt;
 	struct node *irq_node = NULL, *parent = node;
 	struct property *irq_prop, *prop = NULL;
-	int irq_cells, phandle;
+	cell_t irq_cells, phandle;
 
 	irq_prop = get_property(node, "interrupts");
 	if (!irq_prop)
@@ -1762,7 +1762,7 @@ WARNING(graph_port, check_graph_port, NULL, &graph_nodes);
 static struct node *get_remote_endpoint(struct check *c, struct dt_info *dti,
 					struct node *endpoint)
 {
-	int phandle;
+	cell_t phandle;
 	struct node *node;
 	struct property *prop;
 
@@ -1910,7 +1910,7 @@ static void enable_warning_error(struct check *c, bool warn, bool error)
 
 static void disable_warning_error(struct check *c, bool warn, bool error)
 {
-	int i;
+	unsigned int i;
 
 	/* Lowering level, also lower it for things this is the prereq
 	 * for */
@@ -1931,7 +1931,7 @@ static void disable_warning_error(struct check *c, bool warn, bool error)
 
 void parse_checks_option(bool warn, bool error, const char *arg)
 {
-	int i;
+	unsigned int i;
 	const char *name = arg;
 	bool enable = true;
 
@@ -1958,7 +1958,7 @@ void parse_checks_option(bool warn, bool error, const char *arg)
 
 void process_checks(bool force, struct dt_info *dti)
 {
-	int i;
+	unsigned int i;
 	int error = 0;
 
 	for (i = 0; i < ARRAY_SIZE(check_table); i++) {