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
 
/*
 * ARM guarantees at least 8 ASID bits.
 * We may have more available, but do not make use of them for the time being.
 */
#define VM_ASID_BITS 8
#define TTBR_ASID_SHIFT 48
 
/*
 * PTE descriptor can be Block descriptor or Table descriptor
 * or Page descriptor.
 */
#define PTE_DESC_TYPE_MASK      3U
#define PTE_BLOCK_DESC          1U
#define PTE_TABLE_DESC          3U
#define PTE_PAGE_DESC           3U
#define PTE_INVALID_DESC        0U
 
/*
 * Block and Page descriptor attributes fields
 */
#define PTE_BLOCK_DESC_MEMTYPE(x)       (x << 2)
#define PTE_BLOCK_DESC_NS               (1ULL << 5)
#define PTE_BLOCK_DESC_AP_ELx           (1ULL << 6)
#define PTE_BLOCK_DESC_AP_EL_HIGHER     (0ULL << 6)
#define PTE_BLOCK_DESC_AP_RO            (1ULL << 7)
#define PTE_BLOCK_DESC_AP_RW            (0ULL << 7)
#define PTE_BLOCK_DESC_NON_SHARE        (0ULL << 8)
#define PTE_BLOCK_DESC_OUTER_SHARE      (2ULL << 8)
#define PTE_BLOCK_DESC_INNER_SHARE      (3ULL << 8)
#define PTE_BLOCK_DESC_AF               (1ULL << 10)
#define PTE_BLOCK_DESC_NG               (1ULL << 11)
#define PTE_BLOCK_DESC_PXN              (1ULL << 53)
#define PTE_BLOCK_DESC_UXN              (1ULL << 54)
 
/*
 * TCR definitions.
 */
#define TCR_EL1_IPS_SHIFT       32U
#define TCR_EL2_PS_SHIFT        16U
#define TCR_EL3_PS_SHIFT        16U
 
#define TCR_T0SZ_SHIFT          0U
#define TCR_T0SZ(x)             ((64 - (x)) << TCR_T0SZ_SHIFT)
 
#define TCR_IRGN_NC             (0ULL << 8)
#define TCR_IRGN_WBWA           (1ULL << 8)
#define TCR_IRGN_WT             (2ULL << 8)
#define TCR_IRGN_WBNWA          (3ULL << 8)
#define TCR_IRGN_MASK           (3ULL << 8)
#define TCR_ORGN_NC             (0ULL << 10)
#define TCR_ORGN_WBWA           (1ULL << 10)
#define TCR_ORGN_WT             (2ULL << 10)
#define TCR_ORGN_WBNWA          (3ULL << 10)
#define TCR_ORGN_MASK           (3ULL << 10)
#define TCR_SHARED_NON          (0ULL << 12)
#define TCR_SHARED_OUTER        (2ULL << 12)
#define TCR_SHARED_INNER        (3ULL << 12)
#define TCR_TG0_4K              (0ULL << 14)
#define TCR_TG0_64K             (1ULL << 14)
#define TCR_TG0_16K             (2ULL << 14)
#define TCR_EPD1_DISABLE        (1ULL << 23)
#define TCR_TG1_16K             (1ULL << 30)
#define TCR_TG1_4K              (2ULL << 30)
#define TCR_TG1_64K             (3ULL << 30)
 
#define TCR_PS_BITS_4GB         0x0ULL
#define TCR_PS_BITS_64GB        0x1ULL
#define TCR_PS_BITS_1TB         0x2ULL
#define TCR_PS_BITS_4TB         0x3ULL
#define TCR_PS_BITS_16TB        0x4ULL
#define TCR_PS_BITS_256TB       0x5ULL
 
#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)
 
/* 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_ */