cacheinfo: Use RISC-V's init_cache_level() as generic OF implementation

RISC-V's implementation of init_of_cache_level() is following
the Devicetree Specification v0.3 regarding caches, cf.:
- s3.7.3 'Internal (L1) Cache Properties'
- s3.8 'Multi-level and Shared Cache Nodes'

Allow reusing the implementation by moving it.

Also make 'levels', 'leaves' and 'level' unsigned int.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230104183033.755668-2-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

arch/riscv/kernel/cacheinfo.c

@@ -115,44 +115,7 @@ static void fill_cacheinfo(struct cacheinfo **this_leaf,
 
 int init_cache_level(unsigned int cpu)
 {
-	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
-	struct device_node *np = of_cpu_device_node_get(cpu);
-	struct device_node *prev = NULL;
-	int levels = 0, leaves = 0, level;
-
-	if (of_property_read_bool(np, "cache-size"))
-		++leaves;
-	if (of_property_read_bool(np, "i-cache-size"))
-		++leaves;
-	if (of_property_read_bool(np, "d-cache-size"))
-		++leaves;
-	if (leaves > 0)
-		levels = 1;
-
-	prev = np;
-	while ((np = of_find_next_cache_node(np))) {
-		of_node_put(prev);
-		prev = np;
-		if (!of_device_is_compatible(np, "cache"))
-			break;
-		if (of_property_read_u32(np, "cache-level", &level))
-			break;
-		if (level <= levels)
-			break;
-		if (of_property_read_bool(np, "cache-size"))
-			++leaves;
-		if (of_property_read_bool(np, "i-cache-size"))
-			++leaves;
-		if (of_property_read_bool(np, "d-cache-size"))
-			++leaves;
-		levels = level;
-	}
-
-	of_node_put(np);
-	this_cpu_ci->num_levels = levels;
-	this_cpu_ci->num_leaves = leaves;
-
-	return 0;
+	return init_of_cache_level(cpu);
 }
 
 int populate_cache_leaves(unsigned int cpu)

drivers/base/cacheinfo.c

@@ -229,8 +229,52 @@ static int cache_setup_of_node(unsigned int cpu)
 
 	return 0;
 }
+
+int init_of_cache_level(unsigned int cpu)
+{
+	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+	struct device_node *np = of_cpu_device_node_get(cpu);
+	struct device_node *prev = NULL;
+	unsigned int levels = 0, leaves = 0, level;
+
+	if (of_property_read_bool(np, "cache-size"))
+		++leaves;
+	if (of_property_read_bool(np, "i-cache-size"))
+		++leaves;
+	if (of_property_read_bool(np, "d-cache-size"))
+		++leaves;
+	if (leaves > 0)
+		levels = 1;
+
+	prev = np;
+	while ((np = of_find_next_cache_node(np))) {
+		of_node_put(prev);
+		prev = np;
+		if (!of_device_is_compatible(np, "cache"))
+			break;
+		if (of_property_read_u32(np, "cache-level", &level))
+			break;
+		if (level <= levels)
+			break;
+		if (of_property_read_bool(np, "cache-size"))
+			++leaves;
+		if (of_property_read_bool(np, "i-cache-size"))
+			++leaves;
+		if (of_property_read_bool(np, "d-cache-size"))
+			++leaves;
+		levels = level;
+	}
+
+	of_node_put(np);
+	this_cpu_ci->num_levels = levels;
+	this_cpu_ci->num_leaves = leaves;
+
+	return 0;
+}
+
 #else
 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
+int init_of_cache_level(unsigned int cpu) { return 0; }
 #endif
 
 int __weak cache_setup_acpi(unsigned int cpu)

include/linux/cacheinfo.h

@@ -80,6 +80,7 @@ struct cpu_cacheinfo {
 
 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
 int init_cache_level(unsigned int cpu);
+int init_of_cache_level(unsigned int cpu);
 int populate_cache_leaves(unsigned int cpu);
 int cache_setup_acpi(unsigned int cpu);
 bool last_level_cache_is_valid(unsigned int cpu);