Merge pull request #1842 from DavidPu/reduce_cyclomatic_complexity_metric

Reduce cyclomatic complexity metric

lib/xlat_tables_v2/xlat_tables_core.c

@@ -231,52 +231,49 @@ typedef enum {
 
 } action_t;
 
-#if PLAT_XLAT_TABLES_DYNAMIC
-
 /*
- * Recursive function that writes to the translation tables and unmaps the
- * specified region.
+ * Function that returns the first VA of the table affected by the specified
+ * mmap region.
  */
-static void xlat_tables_unmap_region(xlat_ctx_t *ctx, mmap_region_t *mm,
+static uintptr_t xlat_tables_find_start_va(mmap_region_t *mm,
 				   const uintptr_t table_base_va,
-				     uint64_t *const table_base,
-				     const unsigned int table_entries,
 				   const unsigned int level)
 {
-	assert((level >= ctx->base_level) && (level <= XLAT_TABLE_LEVEL_MAX));
-
-	uint64_t *subtable;
-	uint64_t desc;
-
 	uintptr_t table_idx_va;
-	uintptr_t table_idx_end_va; /* End VA of this entry */
-
-	uintptr_t region_end_va = mm->base_va + mm->size - 1U;
-
-	unsigned int table_idx;
 
 	if (mm->base_va > table_base_va) {
 		/* Find the first index of the table affected by the region. */
 		table_idx_va = mm->base_va & ~XLAT_BLOCK_MASK(level);
-
-		table_idx = (unsigned int)((table_idx_va - table_base_va) >>
-			    XLAT_ADDR_SHIFT(level));
-
-		assert(table_idx < table_entries);
 	} else {
 		/* Start from the beginning of the table. */
 		table_idx_va = table_base_va;
-		table_idx = 0;
 	}
 
-	while (table_idx < table_entries) {
+	return table_idx_va;
+}
 
-		table_idx_end_va = table_idx_va + XLAT_BLOCK_SIZE(level) - 1U;
+/*
+ * Function that returns table index for the given VA and level arguments.
+ */
+static inline unsigned int  xlat_tables_va_to_index(const uintptr_t table_base_va,
+						const uintptr_t va,
+						const unsigned int level)
+{
+	return (unsigned int)((va - table_base_va) >> XLAT_ADDR_SHIFT(level));
+}
 
-		desc = table_base[table_idx];
-		uint64_t desc_type = desc & DESC_MASK;
+#if PLAT_XLAT_TABLES_DYNAMIC
 
+/*
+ * From the given arguments, it decides which action to take when unmapping the
+ * specified region.
+ */
+static action_t xlat_tables_unmap_region_action(const mmap_region_t *mm,
+		const uintptr_t table_idx_va, const uintptr_t table_idx_end_va,
+		const unsigned int level, const uint64_t desc_type)
+{
 	action_t action;
+	uintptr_t region_end_va = mm->base_va + mm->size - 1U;
 
 	if ((mm->base_va <= table_idx_va) &&
 	    (region_end_va >= table_idx_end_va)) {
@@ -326,6 +323,44 @@ static void xlat_tables_unmap_region(xlat_ctx_t *ctx, mmap_region_t *mm,
 		action = ACTION_NONE;
 	}
 
+	return action;
+}
+/*
+ * Recursive function that writes to the translation tables and unmaps the
+ * specified region.
+ */
+static void xlat_tables_unmap_region(xlat_ctx_t *ctx, mmap_region_t *mm,
+				     const uintptr_t table_base_va,
+				     uint64_t *const table_base,
+				     const unsigned int table_entries,
+				     const unsigned int level)
+{
+	assert((level >= ctx->base_level) && (level <= XLAT_TABLE_LEVEL_MAX));
+
+	uint64_t *subtable;
+	uint64_t desc;
+
+	uintptr_t table_idx_va;
+	uintptr_t table_idx_end_va; /* End VA of this entry */
+
+	uintptr_t region_end_va = mm->base_va + mm->size - 1U;
+
+	unsigned int table_idx;
+
+	table_idx_va = xlat_tables_find_start_va(mm, table_base_va, level);
+	table_idx = xlat_tables_va_to_index(table_base_va, table_idx_va, level);
+
+	while (table_idx < table_entries) {
+
+		table_idx_end_va = table_idx_va + XLAT_BLOCK_SIZE(level) - 1U;
+
+		desc = table_base[table_idx];
+		uint64_t desc_type = desc & DESC_MASK;
+
+		action_t action = xlat_tables_unmap_region_action(mm,
+				table_idx_va, table_idx_end_va, level,
+				desc_type);
+
 		if (action == ACTION_WRITE_BLOCK_ENTRY) {
 
 			table_base[table_idx] = INVALID_DESC;
@@ -525,19 +560,8 @@ static uintptr_t xlat_tables_map_region(xlat_ctx_t *ctx, mmap_region_t *mm,
 
 	unsigned int table_idx;
 
-	if (mm->base_va > table_base_va) {
-		/* Find the first index of the table affected by the region. */
-		table_idx_va = mm->base_va & ~XLAT_BLOCK_MASK(level);
-
-		table_idx = (unsigned int)((table_idx_va - table_base_va) >>
-			    XLAT_ADDR_SHIFT(level));
-
-		assert(table_idx < table_entries);
-	} else {
-		/* Start from the beginning of the table. */
-		table_idx_va = table_base_va;
-		table_idx = 0U;
-	}
+	table_idx_va = xlat_tables_find_start_va(mm, table_base_va, level);
+	table_idx = xlat_tables_va_to_index(table_base_va, table_idx_va, level);
 
 #if PLAT_XLAT_TABLES_DYNAMIC
 	if (level > ctx->base_level)