1 files changed, 65 insertions, 36 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 0edd639898a6..d378d4b4109f 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -625,6 +625,47 @@ const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 	return fdt_getprop(initial_boot_params, node, name, size);
 }
 
+const __be32 *__init of_flat_dt_get_addr_size_prop(unsigned long node,
+						   const char *name,
+						   int *entries)
+{
+	const __be32 *prop;
+	int len, elen = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+
+	prop = of_get_flat_dt_prop(node, name, &len);
+	if (!prop || len % elen) {
+		*entries = 0;
+		return NULL;
+	}
+
+	*entries = len / elen;
+	return prop;
+}
+
+bool __init of_flat_dt_get_addr_size(unsigned long node, const char *name,
+				     u64 *addr, u64 *size)
+{
+	const __be32 *prop;
+	int entries;
+
+	prop = of_flat_dt_get_addr_size_prop(node, name, &entries);
+	if (!prop || entries != 1)
+		return false;
+
+	of_flat_dt_read_addr_size(prop, 0, addr, size);
+	return true;
+}
+
+void __init of_flat_dt_read_addr_size(const __be32 *prop, int entry_index,
+				      u64 *addr, u64 *size)
+{
+	int entry_cells = dt_root_addr_cells + dt_root_size_cells;
+	prop += entry_cells * entry_index;
+
+	*addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	*size = dt_mem_next_cell(dt_root_size_cells, &prop);
+}
+
 /**
  * of_fdt_is_compatible - Return true if given node from the given blob has
  * compat in its compatible list
@@ -812,21 +853,15 @@ static void __init early_init_dt_check_for_initrd(unsigned long node)
  */
 static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
 {
-	const __be32 *prop;
-	int len;
-
 	if (!IS_ENABLED(CONFIG_CRASH_DUMP))
 		return;
 
 	pr_debug("Looking for elfcorehdr property... ");
 
-	prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
-	if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
+	if (!of_flat_dt_get_addr_size(node, "linux,elfcorehdr",
+				      &elfcorehdr_addr, &elfcorehdr_size))
 		return;
 
-	elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
-	elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
-
 	pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
 		 elfcorehdr_addr, elfcorehdr_size);
 }
@@ -849,8 +884,9 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
 void __init early_init_dt_check_for_usable_mem_range(void)
 {
 	struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
-	const __be32 *prop, *endp;
+	const __be32 *prop;
 	int len, i;
+	u64 base, size;
 	unsigned long node = chosen_node_offset;
 
 	if ((long)node < 0)
@@ -858,14 +894,17 @@ void __init early_init_dt_check_for_usable_mem_range(void)
 
 	pr_debug("Looking for usable-memory-range property... ");
 
-	prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
-	if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
+	prop = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory-range",
+					     &len);
+	if (!prop)
 		return;
 
-	endp = prop + (len / sizeof(__be32));
-	for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
-		rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
-		rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
+	len = min(len, MAX_USABLE_RANGES);
+
+	for (i = 0; i < len; i++) {
+		of_flat_dt_read_addr_size(prop, i, &base, &size);
+		rgn[i].base = base;
+		rgn[i].size = size;
 
 		pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
 			 i, &rgn[i].base, &rgn[i].size);
@@ -883,26 +922,18 @@ static void __init early_init_dt_check_kho(void)
 {
 	unsigned long node = chosen_node_offset;
 	u64 fdt_start, fdt_size, scratch_start, scratch_size;
-	const __be32 *p;
-	int l;
 
 	if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER) || (long)node < 0)
 		return;
 
-	p = of_get_flat_dt_prop(node, "linux,kho-fdt", &l);
-	if (l != (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32))
+	if (!of_flat_dt_get_addr_size(node, "linux,kho-fdt",
+				      &fdt_start, &fdt_size))
 		return;
 
-	fdt_start = dt_mem_next_cell(dt_root_addr_cells, &p);
-	fdt_size = dt_mem_next_cell(dt_root_addr_cells, &p);
-
-	p = of_get_flat_dt_prop(node, "linux,kho-scratch", &l);
-	if (l != (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32))
+	if (!of_flat_dt_get_addr_size(node, "linux,kho-scratch",
+				      &scratch_start, &scratch_size))
 		return;
 
-	scratch_start = dt_mem_next_cell(dt_root_addr_cells, &p);
-	scratch_size = dt_mem_next_cell(dt_root_addr_cells, &p);
-
 	kho_populate(fdt_start, fdt_size, scratch_start, scratch_size);
 }
 
@@ -1002,8 +1033,8 @@ int __init early_init_dt_scan_memory(void)
 
 	fdt_for_each_subnode(node, fdt, 0) {
 		const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
-		const __be32 *reg, *endp;
-		int l;
+		const __be32 *reg;
+		int i, l;
 		bool hotpluggable;
 
 		/* We are scanning "memory" nodes only */
@@ -1013,23 +1044,21 @@ int __init early_init_dt_scan_memory(void)
 		if (!of_fdt_device_is_available(fdt, node))
 			continue;
 
-		reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
+		reg = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory", &l);
 		if (reg == NULL)
-			reg = of_get_flat_dt_prop(node, "reg", &l);
+			reg = of_flat_dt_get_addr_size_prop(node, "reg", &l);
 		if (reg == NULL)
 			continue;
 
-		endp = reg + (l / sizeof(__be32));
 		hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
 
-		pr_debug("memory scan node %s, reg size %d,\n",
+		pr_debug("memory scan node %s, reg {addr,size} entries %d,\n",
 			 fdt_get_name(fdt, node, NULL), l);
 
-		while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
+		for (i = 0; i < l; i++) {
 			u64 base, size;
 
-			base = dt_mem_next_cell(dt_root_addr_cells, &reg);
-			size = dt_mem_next_cell(dt_root_size_cells, &reg);
+			of_flat_dt_read_addr_size(reg, i, &base, &size);
 
 			if (size == 0)
 				continue;