mach-stm32: Factorize MPU's region config for STM32 SoCs

MPU's region setup can be factorized between STM32F4/F7/H7 SoCs family
and used a common MPU's region config.

Only one exception for STM32H7 which doesn't have device area
located at 0xA000 0000.

For STM32F4, configure_clocks() need to be moved from arch_cpu_init()
to board_early_init_f().

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Vikas Manocha <vikas.manocha@st.com>
diff --git a/arch/arm/mach-stm32/soc.c b/arch/arm/mach-stm32/soc.c
new file mode 100644
index 0000000..df20d54
--- /dev/null
+++ b/arch/arm/mach-stm32/soc.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/armv7m_mpu.h>
+
+int arch_cpu_init(void)
+{
+	int i;
+
+	struct mpu_region_config stm32_region_config[] = {
+		/*
+		 * Make all 4GB cacheable & executable. We are overriding it
+		 * with next region for any requirement. e.g. below region1,
+		 * 2 etc.
+		 * In other words, the area not coming in following
+		 * regions configuration is the one configured here in region_0
+		 * (cacheable & executable).
+		 */
+		{ 0x00000000, REGION_0, XN_DIS, PRIV_RW_USR_RW,
+		O_I_WB_RD_WR_ALLOC, REGION_4GB },
+
+		/* armv7m code area */
+		{ 0x00000000, REGION_1, XN_DIS, PRIV_RW_USR_RW,
+		STRONG_ORDER, REGION_512MB },
+
+		/* Device area : Not executable */
+		{ 0x40000000, REGION_2, XN_EN, PRIV_RW_USR_RW,
+		DEVICE_NON_SHARED, REGION_512MB },
+
+		/*
+		 * Armv7m fixed configuration: strongly ordered & not
+		 * executable, not cacheable
+		 */
+		{ 0xE0000000, REGION_3, XN_EN, PRIV_RW_USR_RW,
+		STRONG_ORDER, REGION_512MB },
+
+#if !defined(CONFIG_STM32H7)
+		/* Device area : Not executable */
+		{ 0xA0000000, REGION_4, XN_EN, PRIV_RW_USR_RW,
+		DEVICE_NON_SHARED, REGION_512MB },
+#endif
+	};
+
+	disable_mpu();
+	for (i = 0; i < ARRAY_SIZE(stm32_region_config); i++)
+		mpu_config(&stm32_region_config[i]);
+	enable_mpu();
+
+	return 0;
+}