soc: xlnx: zynqmp: overhaul MPU regions

Overhaul the MPU region definitions that are being
configured when the MPU is set up:
- drop local attribute definitions in favor of those
  already provided in arm_mpu_v7m.h
- actually tie the RAM region to the device tree
- set up a (potentially overlapping) R/O region for
  .text and .rodata, which hasn't existed so far
- Consider XIP

Signed-off-by: Immo Birnbaum <[email protected]>

soc/xlnx/zynqmp/arm_mpu_regions.c

@@ -1,62 +1,76 @@
 /* SPDX-License-Identifier: Apache-2.0
  *
  * Copyright (c) 2021 Lexmark International, Inc.
+ * Copyright (c) 2024 Immo Birnbaum
  */
 
 #include <zephyr/kernel.h>
-#include <zephyr/arch/arm/mpu/arm_mpu.h>
+#include <zephyr/arch/arm/cortex_m/arm_mpu_mem_cfg.h>
 
-#define MPUTYPE_READ_ONLY \
-	{ \
-		.rasr = (P_RO_U_RO_Msk \
-				| (7 << MPU_RASR_TEX_Pos) \
-				| MPU_RASR_C_Msk \
-				| MPU_RASR_B_Msk \
-				| MPU_RASR_XN_Msk) \
-	}
+extern const uint32_t __rom_region_start;
+extern const uint32_t __rom_region_mpu_size_bits;
 
-#define MPUTYPE_READ_ONLY_PRIV \
-	{ \
-		.rasr = (P_RO_U_RO_Msk \
-				| (5 << MPU_RASR_TEX_Pos) \
-				| MPU_RASR_B_Msk) \
-	}
-
-#define MPUTYPE_PRIV_WBWACACHE_XN \
-	{ \
-		.rasr = (P_RW_U_NA_Msk \
-				| (5 << MPU_RASR_TEX_Pos) \
-				| MPU_RASR_B_Msk \
-				| MPU_RASR_XN_Msk) \
-	}
-
-#define MPUTYPE_PRIV_DEVICE \
-	{ \
-		.rasr = (P_RW_U_NA_Msk \
-				| (2 << MPU_RASR_TEX_Pos)) \
-	}
-
-extern uint32_t _image_rom_end_order;
 static const struct arm_mpu_region mpu_regions[] = {
-	MPU_REGION_ENTRY("FLASH0",
-			0xc0000000,
-			REGION_32M,
-			MPUTYPE_READ_ONLY),
-
-	MPU_REGION_ENTRY("SRAM_PRIV",
-			0x00000000,
-			REGION_2G,
-			MPUTYPE_PRIV_WBWACACHE_XN),
-
-	MPU_REGION_ENTRY("SRAM",
-			0x00000000,
-			((uint32_t)&_image_rom_end_order),
-			MPUTYPE_READ_ONLY_PRIV),
-
-	MPU_REGION_ENTRY("REGISTERS",
-			0xf8000000,
-			REGION_128M,
-			MPUTYPE_PRIV_DEVICE),
+	/*
+	 * The address of the vectors is determined by arch/arm/core/cortex_a_r/prep_c.c
+	 * -> for v7-R, there's no other option than 0x0, HIVECS always gets cleared
+	 */
+	MPU_REGION_ENTRY(
+		"vectors",
+		0x00000000,
+		REGION_64B,
+		{.rasr = P_RO_U_NA_Msk |
+			 NORMAL_OUTER_INNER_NON_CACHEABLE_NON_SHAREABLE}),
+	/* Basic SRAM mapping is all data, R/W + XN */
+	MPU_REGION_ENTRY(
+		"sram",
+		CONFIG_SRAM_BASE_ADDRESS,
+		REGION_SRAM_SIZE,
+		{.rasr = P_RW_U_NA_Msk |
+			 NORMAL_OUTER_INNER_WRITE_BACK_WRITE_READ_ALLOCATE_NON_SHAREABLE |
+			 NOT_EXEC}),
+#if defined(CONFIG_XIP)
+	/* .text and .rodata (=rom_region) are in flash, must be RO + executable */
+	MPU_REGION_ENTRY(
+		"rom_region",
+		CONFIG_FLASH_BASE_ADDRESS,
+		REGION_FLASH_SIZE,
+		{.rasr = P_RO_U_RO_Msk |
+			 NORMAL_OUTER_INNER_WRITE_BACK_NON_SHAREABLE}),
+	/* RAM contains R/W data, non-executable */
+#else /* !CONFIG_XIP */
+	/* .text and .rodata are in RAM, flash is data only -> RO + XN */
+	MPU_REGION_ENTRY(
+		"flash",
+		CONFIG_FLASH_BASE_ADDRESS,
+		REGION_FLASH_SIZE,
+		{.rasr = P_RO_U_RO_Msk |
+			 NORMAL_OUTER_INNER_WRITE_BACK_NON_SHAREABLE |
+			 NOT_EXEC}),
+	/* add rom_region mapping for SRAM which is RO + executable */
+	MPU_REGION_ENTRY(
+		"rom_region",
+		(uint32_t)(&__rom_region_start),
+		(uint32_t)(&__rom_region_mpu_size_bits),
+		{.rasr = P_RO_U_RO_Msk |
+			 NORMAL_OUTER_INNER_WRITE_BACK_WRITE_READ_ALLOCATE_NON_SHAREABLE}),
+#endif /* CONFIG_XIP */
+	MPU_REGION_ENTRY(
+		"peripherals",
+		0xf8000000,
+		REGION_128M,
+		{.rasr = P_RW_U_NA_Msk |
+			 DEVICE_SHAREABLE |
+			 NOT_EXEC}),
+#if DT_NODE_HAS_STATUS(DT_CHOSEN(zephyr_ocm), okay)
+	MPU_REGION_ENTRY(
+		"ocm",
+		DT_REG_ADDR(DT_CHOSEN(zephyr_ocm)),
+		REGION_256K,
+		{.rasr = FULL_ACCESS_Msk |
+			 STRONGLY_ORDERED_SHAREABLE |
+			 NOT_EXEC}),
+#endif
 };
 
 const struct arm_mpu_config mpu_config = {