arm_mmu.h

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/*
 * Copyright 2019 Broadcom
 * The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef ZEPHYR_INCLUDE_ARCH_ARM64_ARM_MMU_H_
#define ZEPHYR_INCLUDE_ARCH_ARM64_ARM_MMU_H_
 
#ifndef _ASMLANGUAGE
#include <stdint.h>
#include <stdlib.h>
#endif
 
/* Following Memory types supported through MAIR encodings can be passed
 * by user through "attrs"(attributes) field of specified memory region.
 * As MAIR supports such 8 encodings, we will reserve attrs[2:0];
 * so that we can provide encodings upto 7 if needed in future.
 */
#define MT_TYPE_MASK            0x7U
#define MT_TYPE(attr)           (attr & MT_TYPE_MASK)
#define MT_DEVICE_nGnRnE        0U
#define MT_DEVICE_nGnRE         1U
#define MT_DEVICE_GRE           2U
#define MT_NORMAL_NC            3U
#define MT_NORMAL               4U
#define MT_NORMAL_WT            5U
 
#define MEMORY_ATTRIBUTES       ((0x00 << (MT_DEVICE_nGnRnE * 8)) |     \
                                (0x04 << (MT_DEVICE_nGnRE * 8))   |     \
                                (0x0c << (MT_DEVICE_GRE * 8))     |     \
                                (0x44 << (MT_NORMAL_NC * 8))      |     \
                                (0xffUL << (MT_NORMAL * 8))       |     \
                                (0xbbUL << (MT_NORMAL_WT * 8)))
 
/* More flags from user's perspective are supported using remaining bits
 * of "attrs" field, i.e. attrs[31:3], underlying code will take care
 * of setting PTE fields correctly.
 *
 * current usage of attrs[31:3] is:
 * attrs[3] : Access Permissions
 * attrs[4] : Memory access from secure/ns state
 * attrs[5] : Execute Permissions privileged mode (PXN)
 * attrs[6] : Execute Permissions unprivileged mode (UXN)
 * attrs[7] : Mirror RO/RW permissions to EL0
 * attrs[8] : Overwrite existing mapping if any
 * attrs[9] : non-Global mapping (nG)
 *
 */
#define MT_PERM_SHIFT           3U
#define MT_SEC_SHIFT            4U
#define MT_P_EXECUTE_SHIFT      5U
#define MT_U_EXECUTE_SHIFT      6U
#define MT_RW_AP_SHIFT          7U
#define MT_NO_OVERWRITE_SHIFT   8U
#define MT_NON_GLOBAL_SHIFT     9U
 
#define MT_RO                   (0U << MT_PERM_SHIFT)
#define MT_RW                   (1U << MT_PERM_SHIFT)
 
#define MT_RW_AP_ELx            (1U << MT_RW_AP_SHIFT)
#define MT_RW_AP_EL_HIGHER      (0U << MT_RW_AP_SHIFT)
 
#define MT_SECURE               (0U << MT_SEC_SHIFT)
#define MT_NS                   (1U << MT_SEC_SHIFT)
 
#define MT_P_EXECUTE            (0U << MT_P_EXECUTE_SHIFT)
#define MT_P_EXECUTE_NEVER      (1U << MT_P_EXECUTE_SHIFT)
 
#define MT_U_EXECUTE            (0U << MT_U_EXECUTE_SHIFT)
#define MT_U_EXECUTE_NEVER      (1U << MT_U_EXECUTE_SHIFT)
 
#define MT_NO_OVERWRITE         (1U << MT_NO_OVERWRITE_SHIFT)
 
#define MT_G                    (0U << MT_NON_GLOBAL_SHIFT)
#define MT_NG                   (1U << MT_NON_GLOBAL_SHIFT)
 
#define MT_P_RW_U_RW            (MT_RW | MT_RW_AP_ELx | MT_P_EXECUTE_NEVER | MT_U_EXECUTE_NEVER)
#define MT_P_RW_U_NA            (MT_RW | MT_RW_AP_EL_HIGHER  | MT_P_EXECUTE_NEVER | MT_U_EXECUTE_NEVER)
#define MT_P_RO_U_RO            (MT_RO | MT_RW_AP_ELx | MT_P_EXECUTE_NEVER | MT_U_EXECUTE_NEVER)
#define MT_P_RO_U_NA            (MT_RO | MT_RW_AP_EL_HIGHER  | MT_P_EXECUTE_NEVER | MT_U_EXECUTE_NEVER)
#define MT_P_RO_U_RX            (MT_RO | MT_RW_AP_ELx | MT_P_EXECUTE_NEVER | MT_U_EXECUTE)
#define MT_P_RX_U_RX            (MT_RO | MT_RW_AP_ELx | MT_P_EXECUTE | MT_U_EXECUTE)
#define MT_P_RX_U_NA            (MT_RO | MT_RW_AP_EL_HIGHER  | MT_P_EXECUTE | MT_U_EXECUTE_NEVER)
 
#ifdef CONFIG_ARMV8_A_NS
#define MT_DEFAULT_SECURE_STATE MT_NS
#else
#define MT_DEFAULT_SECURE_STATE MT_SECURE
#endif
 
#ifndef _ASMLANGUAGE
 
/* Region definition data structure */
struct arm_mmu_region {
        /* Region Base Physical Address */
        uintptr_t base_pa;
        /* Region Base Virtual Address */
        uintptr_t base_va;
        /* Region size */
        size_t size;
        /* Region Name */
        const char *name;
        /* Region Attributes */
        uint32_t attrs;
};
 
/* MMU configuration data structure */
struct arm_mmu_config {
        /* Number of regions */
        unsigned int num_regions;
        /* Regions */
        const struct arm_mmu_region *mmu_regions;
};
 
struct arm_mmu_ptables {
        uint64_t *base_xlat_table;
        uint64_t ttbr0;
};
 
/* Convenience macros to represent the ARMv8-A-specific
 * configuration for memory access permission and
 * cache-ability attribution.
 */
 
#define MMU_REGION_ENTRY(_name, _base_pa, _base_va, _size, _attrs) \
        {\
                .name = _name, \
                .base_pa = _base_pa, \
                .base_va = _base_va, \
                .size = _size, \
                .attrs = _attrs, \
        }
 
#define MMU_REGION_FLAT_ENTRY(name, adr, sz, attrs) \
        MMU_REGION_ENTRY(name, adr, adr, sz, attrs)
 
/*
 * @brief Auto generate mmu region entry for node_id
 *
 * Example usage:
 *
 * @code{.c}
 *      DT_FOREACH_STATUS_OKAY_VARGS(nxp_imx_gpio,
 *                                MMU_REGION_DT_FLAT_ENTRY,
 *                               (MT_DEVICE_nGnRnE | MT_P_RW_U_NA | MT_NS))
 * @endcode
 *
 * @note  Since devicetree_generated.h does not include
 *        node_id##_P_reg_FOREACH_PROP_ELEM* definitions,
 *        we can't automate dts node with multiple reg
 *        entries.
 */
#define MMU_REGION_DT_FLAT_ENTRY(node_id, attrs)  \
        MMU_REGION_FLAT_ENTRY(DT_NODE_FULL_NAME(node_id), \
                                  DT_REG_ADDR(node_id), \
                                  DT_REG_SIZE(node_id), \
                                  attrs),
 
/*
 * @brief Auto generate mmu region entry for status = "okay"
 *        nodes compatible to a driver
 *
 * Example usage:
 *
 * @code{.c}
 *      MMU_REGION_DT_COMPAT_FOREACH_FLAT_ENTRY(nxp_imx_gpio,
 *                               (MT_DEVICE_nGnRnE | MT_P_RW_U_NA | MT_NS))
 * @endcode
 *
 * @note  This is a wrapper of @ref MMU_REGION_DT_FLAT_ENTRY
 */
#define MMU_REGION_DT_COMPAT_FOREACH_FLAT_ENTRY(compat, attr) \
        DT_FOREACH_STATUS_OKAY_VARGS(compat, \
        MMU_REGION_DT_FLAT_ENTRY, attr)
 
/* Kernel macros for memory attribution
 * (access permissions and cache-ability).
 *
 * The macros are to be stored in k_mem_partition_attr_t
 * objects. The format of a k_mem_partition_attr_t object
 * is an uint32_t composed by permission and attribute flags
 * located in include/arch/arm64/arm_mmu.h
 */
 
/* Read-Write access permission attributes */
#define K_MEM_PARTITION_P_RW_U_RW ((k_mem_partition_attr_t) \
                        {MT_P_RW_U_RW})
#define K_MEM_PARTITION_P_RW_U_NA ((k_mem_partition_attr_t) \
                        {MT_P_RW_U_NA})
#define K_MEM_PARTITION_P_RO_U_RO ((k_mem_partition_attr_t) \
                        {MT_P_RO_U_RO})
#define K_MEM_PARTITION_P_RO_U_NA ((k_mem_partition_attr_t) \
                        {MT_P_RO_U_NA})
/* Execution-allowed attributes */
#define K_MEM_PARTITION_P_RX_U_RX ((k_mem_partition_attr_t) \
                        {MT_P_RX_U_RX})
/* Typedef for the k_mem_partition attribute */
typedef struct { uint32_t attrs; } k_mem_partition_attr_t;
 
/* Reference to the MMU configuration.
 *
 * This struct is defined and populated for each SoC (in the SoC definition),
 * and holds the build-time configuration information for the fixed MMU
 * regions enabled during kernel initialization.
 */
extern const struct arm_mmu_config mmu_config;
 
#endif /* _ASMLANGUAGE */
 
#endif /* ZEPHYR_INCLUDE_ARCH_ARM64_ARM_MMU_H_ */