arch: arc: add support of mpu v3

Add support of ARC mpu version 3 which can have region size down to 32
bytes

Signed-off-by: Yuguo Zou <[email protected]>

Author: YuguoWH

arch/arc/core/mpu/arc_mpu_v2_internal.h

@@ -17,7 +17,12 @@
 #define AUX_MPU_RDP_SIZE_MASK (0xE03)
 
 /* For MPU version 2, the minimum protection region size is 2048 bytes */
+#if CONFIG_ARC_MPU_VER == 2
 #define ARC_FEATURE_MPU_ALIGNMENT_BITS 11
+/* For MPU version 3, the minimum protection region size is 32 bytes */
+#else
+#define ARC_FEATURE_MPU_ALIGNMENT_BITS 5
+#endif
 
 /**
  * This internal function initializes a MPU region

include/arch/arc/arch.h

@@ -66,7 +66,7 @@ extern "C" {
 #ifdef CONFIG_ARC_CORE_MPU
 #if CONFIG_ARC_MPU_VER == 2
 #define Z_ARC_MPU_ALIGN	2048
-#elif CONFIG_ARC_MPU_VER == 4
+#elif (CONFIG_ARC_MPU_VER == 3) || (CONFIG_ARC_MPU_VER == 4)
 #define Z_ARC_MPU_ALIGN	32
 #else
 #error "Unsupported MPU version"

include/arch/arc/v2/linker.ld

@@ -30,7 +30,7 @@
 #ifdef CONFIG_ARC_MPU_ENABLE
 	#if CONFIG_ARC_MPU_VER == 2
 		#define MPU_MIN_SIZE 2048
-	#elif CONFIG_ARC_MPU_VER == 4
+	#elif (CONFIG_ARC_MPU_VER == 3) || (CONFIG_ARC_MPU_VER == 4)
 		#define MPU_MIN_SIZE 32
 	#endif
 	#define MPU_MIN_SIZE_ALIGN . = ALIGN(MPU_MIN_SIZE);