| /* |
| * Copyright (c) 2017 Linaro Limited. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <device.h> |
| #include <init.h> |
| #include <kernel.h> |
| #include <soc.h> |
| #include <arch/arm/cortex_m/cmsis.h> |
| #include <arch/arm/cortex_m/mpu/arm_mpu.h> |
| #include <arch/arm/cortex_m/mpu/arm_core_mpu.h> |
| #include <logging/sys_log.h> |
| #include <linker/linker-defs.h> |
| |
| #define ARM_MPU_DEV ((volatile struct arm_mpu *) ARM_MPU_BASE) |
| |
| /* ARM MPU Enabled state */ |
| static u8_t arm_mpu_enabled; |
| |
| /** |
| * The attributes referenced in this function are described at: |
| * https://goo.gl/hMry3r |
| * This function is private to the driver. |
| */ |
| static inline u32_t _get_region_attr(u32_t xn, u32_t ap, u32_t tex, |
| u32_t c, u32_t b, u32_t s, |
| u32_t srd, u32_t size) |
| { |
| return ((xn << 28) | (ap) | (tex << 19) | (s << 18) |
| | (c << 17) | (b << 16) | (srd << 8) | (size)); |
| } |
| |
| /** |
| * This internal function converts the region size to |
| * the SIZE field value of MPU_RASR. |
| */ |
| static inline u32_t _size_to_mpu_rasr_size(u32_t size) |
| { |
| /* The minimal supported region size is 32 bytes */ |
| if (size <= 32) { |
| return REGION_32B; |
| } |
| |
| /* |
| * A size value greater than 2^31 could not be handled by |
| * round_up_to_next_power_of_two() properly. We handle |
| * it separately here. |
| */ |
| if (size > (1 << 31)) { |
| return REGION_4G; |
| } |
| |
| size = 1 << (32 - __builtin_clz(size - 1)); |
| return (32 - __builtin_clz(size) - 2) << 1; |
| } |
| |
| |
| /** |
| * This internal function is utilized by the MPU driver to parse the intent |
| * type (i.e. THREAD_STACK_REGION) and return the correct parameter set. |
| */ |
| static inline u32_t _get_region_attr_by_type(u32_t type, u32_t size) |
| { |
| int region_size = _size_to_mpu_rasr_size(size); |
| |
| switch (type) { |
| case THREAD_STACK_USER_REGION: |
| return _get_region_attr(1, P_RW_U_RW, 0, 1, 0, |
| 1, 0, region_size); |
| case THREAD_STACK_REGION: |
| return _get_region_attr(1, P_RW_U_RW, 0, 1, 0, |
| 1, 0, region_size); |
| case THREAD_STACK_GUARD_REGION: |
| return _get_region_attr(1, P_RO_U_NA, 0, 1, 0, |
| 1, 0, region_size); |
| case THREAD_APP_DATA_REGION: |
| return _get_region_attr(1, P_RW_U_RW, 0, 1, 0, |
| 1, 0, region_size); |
| default: |
| /* Size 0 region */ |
| return 0; |
| } |
| } |
| |
| static inline u8_t _get_num_regions(void) |
| { |
| u32_t type = ARM_MPU_DEV->type; |
| |
| type = (type & 0xFF00) >> 8; |
| |
| return (u8_t)type; |
| } |
| |
| static void _region_init(u32_t index, u32_t region_addr, |
| u32_t region_attr) |
| { |
| /* Select the region you want to access */ |
| ARM_MPU_DEV->rnr = index; |
| /* Configure the region */ |
| ARM_MPU_DEV->rbar = (region_addr & REGION_BASE_ADDR_MASK) |
| | REGION_VALID | index; |
| ARM_MPU_DEV->rasr = region_attr | REGION_ENABLE; |
| SYS_LOG_DBG("[%d] 0x%08x 0x%08x", index, region_addr, region_attr); |
| } |
| |
| /** |
| * This internal function is utilized by the MPU driver to parse the intent |
| * type (i.e. THREAD_STACK_REGION) and return the correct region index. |
| */ |
| static inline u32_t _get_region_index_by_type(u32_t type) |
| { |
| /* |
| * The new MPU regions are allocated per type after the statically |
| * configured regions. The type is one-indexed rather than |
| * zero-indexed, therefore we need to subtract by one to get the region |
| * index. |
| */ |
| switch (type) { |
| case THREAD_STACK_USER_REGION: |
| return mpu_config.num_regions + THREAD_STACK_REGION - 1; |
| case THREAD_STACK_REGION: |
| case THREAD_STACK_GUARD_REGION: |
| case THREAD_APP_DATA_REGION: |
| return mpu_config.num_regions + type - 1; |
| case THREAD_DOMAIN_PARTITION_REGION: |
| #if defined(CONFIG_USERSPACE) |
| return mpu_config.num_regions + type - 1; |
| #elif defined(CONFIG_MPU_STACK_GUARD) |
| return mpu_config.num_regions + type - 2; |
| #else |
| /* |
| * Start domain partition region from stack guard region |
| * since stack guard is not enabled. |
| */ |
| return mpu_config.num_regions + type - 3; |
| #endif |
| default: |
| __ASSERT(0, "Unsupported type"); |
| return 0; |
| } |
| } |
| |
| /** |
| * This internal function check if region is enabled or not |
| */ |
| static inline int _is_enabled_region(u32_t r_index) |
| { |
| ARM_MPU_DEV->rnr = r_index; |
| |
| return ARM_MPU_DEV->rasr & REGION_ENABLE_MASK; |
| } |
| |
| /** |
| * This internal function check if the given buffer in in the region |
| */ |
| static inline int _is_in_region(u32_t r_index, u32_t start, u32_t size) |
| { |
| u32_t r_addr_start; |
| u32_t r_size_lshift; |
| u32_t r_addr_end; |
| |
| ARM_MPU_DEV->rnr = r_index; |
| r_addr_start = ARM_MPU_DEV->rbar & REGION_BASE_ADDR_MASK; |
| r_size_lshift = ((ARM_MPU_DEV->rasr & REGION_SIZE_MASK) >> |
| REGION_SIZE_OFFSET) + 1; |
| r_addr_end = r_addr_start + (1 << r_size_lshift) - 1; |
| |
| if (start >= r_addr_start && (start + size - 1) <= r_addr_end) { |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * This internal function check if the region is user accessible or not |
| */ |
| static inline int _is_user_accessible_region(u32_t r_index, int write) |
| { |
| u32_t r_ap; |
| |
| ARM_MPU_DEV->rnr = r_index; |
| r_ap = ARM_MPU_DEV->rasr & ACCESS_PERMS_MASK; |
| |
| /* always return true if this is the thread stack region */ |
| if (_get_region_index_by_type(THREAD_STACK_REGION) == r_index) { |
| return 1; |
| } |
| |
| if (write) { |
| return r_ap == P_RW_U_RW; |
| } |
| |
| /* For all user accessible permissions, their AP[1] bit is l */ |
| return r_ap & (0x2 << ACCESS_PERMS_OFFSET); |
| } |
| |
| /* ARM Core MPU Driver API Implementation for ARM MPU */ |
| |
| /** |
| * @brief enable the MPU |
| */ |
| void arm_core_mpu_enable(void) |
| { |
| if (arm_mpu_enabled == 0) { |
| /* Enable MPU */ |
| ARM_MPU_DEV->ctrl = ARM_MPU_ENABLE | ARM_MPU_PRIVDEFENA; |
| |
| arm_mpu_enabled = 1; |
| } |
| } |
| |
| /** |
| * @brief disable the MPU |
| */ |
| void arm_core_mpu_disable(void) |
| { |
| if (arm_mpu_enabled == 1) { |
| /* Disable MPU */ |
| ARM_MPU_DEV->ctrl = 0; |
| |
| arm_mpu_enabled = 0; |
| } |
| } |
| |
| /** |
| * @brief configure the base address and size for an MPU region |
| * |
| * @param type MPU region type |
| * @param base base address in RAM |
| * @param size size of the region |
| */ |
| void arm_core_mpu_configure(u8_t type, u32_t base, u32_t size) |
| { |
| SYS_LOG_DBG("Region info: 0x%x 0x%x", base, size); |
| u32_t region_index = _get_region_index_by_type(type); |
| u32_t region_attr = _get_region_attr_by_type(type, size); |
| |
| /* ARM MPU supports up to 16 Regions */ |
| if (region_index > _get_num_regions()) { |
| return; |
| } |
| |
| _region_init(region_index, base, region_attr); |
| } |
| |
| #if defined(CONFIG_USERSPACE) |
| void arm_core_mpu_configure_user_context(struct k_thread *thread) |
| { |
| u32_t base = (u32_t)thread->stack_obj; |
| u32_t size = thread->stack_info.size; |
| u32_t index = _get_region_index_by_type(THREAD_STACK_USER_REGION); |
| u32_t region_attr = _get_region_attr_by_type(THREAD_STACK_USER_REGION, |
| size); |
| |
| if (!thread->arch.priv_stack_start) { |
| ARM_MPU_DEV->rnr = index; |
| ARM_MPU_DEV->rbar = 0; |
| ARM_MPU_DEV->rasr = 0; |
| return; |
| } |
| /* configure stack */ |
| _region_init(index, base, region_attr); |
| |
| #if defined(CONFIG_APPLICATION_MEMORY) |
| /* configure app data portion */ |
| index = _get_region_index_by_type(THREAD_APP_DATA_REGION); |
| size = (u32_t)&__app_ram_end - (u32_t)&__app_ram_start; |
| region_attr = _get_region_attr_by_type(THREAD_APP_DATA_REGION, size); |
| if (size > 0) |
| _region_init(index, (u32_t)&__app_ram_start, region_attr); |
| #endif |
| } |
| |
| /** |
| * @brief configure MPU regions for the memory partitions of the memory domain |
| * |
| * @param mem_domain memory domain that thread belongs to |
| */ |
| void arm_core_mpu_configure_mem_domain(struct k_mem_domain *mem_domain) |
| { |
| u32_t region_index = |
| _get_region_index_by_type(THREAD_DOMAIN_PARTITION_REGION); |
| u32_t region_attr; |
| u32_t num_partitions; |
| struct k_mem_partition *pparts; |
| |
| if (mem_domain) { |
| SYS_LOG_DBG("configure domain: %p", mem_domain); |
| num_partitions = mem_domain->num_partitions; |
| pparts = mem_domain->partitions; |
| } else { |
| SYS_LOG_DBG("disable domain partition regions"); |
| num_partitions = 0; |
| pparts = NULL; |
| } |
| |
| for (; region_index < _get_num_regions(); region_index++) { |
| if (num_partitions && pparts->size) { |
| SYS_LOG_DBG("set region 0x%x 0x%x 0x%x", |
| region_index, pparts->start, pparts->size); |
| region_attr = pparts->attr | |
| _size_to_mpu_rasr_size(pparts->size); |
| _region_init(region_index, pparts->start, region_attr); |
| num_partitions--; |
| } else { |
| SYS_LOG_DBG("disable region 0x%x", region_index); |
| /* Disable region */ |
| ARM_MPU_DEV->rnr = region_index; |
| ARM_MPU_DEV->rbar = 0; |
| ARM_MPU_DEV->rasr = 0; |
| } |
| pparts++; |
| } |
| } |
| |
| /** |
| * @brief configure MPU region for a single memory partition |
| * |
| * @param part_index memory partition index |
| * @param part memory partition info |
| */ |
| void arm_core_mpu_configure_mem_partition(u32_t part_index, |
| struct k_mem_partition *part) |
| { |
| u32_t region_index = |
| _get_region_index_by_type(THREAD_DOMAIN_PARTITION_REGION); |
| u32_t region_attr; |
| |
| SYS_LOG_DBG("configure partition index: %u", part_index); |
| |
| if (part) { |
| SYS_LOG_DBG("set region 0x%x 0x%x 0x%x", |
| region_index + part_index, part->start, part->size); |
| region_attr = part->attr | _size_to_mpu_rasr_size(part->size); |
| _region_init(region_index + part_index, part->start, |
| region_attr); |
| } else { |
| SYS_LOG_DBG("disable region 0x%x", region_index + part_index); |
| /* Disable region */ |
| ARM_MPU_DEV->rnr = region_index + part_index; |
| ARM_MPU_DEV->rbar = 0; |
| ARM_MPU_DEV->rasr = 0; |
| } |
| } |
| |
| /** |
| * @brief Reset MPU region for a single memory partition |
| * |
| * @param part_index memory partition index |
| */ |
| void arm_core_mpu_mem_partition_remove(u32_t part_index) |
| { |
| u32_t region_index = |
| _get_region_index_by_type(THREAD_DOMAIN_PARTITION_REGION); |
| |
| SYS_LOG_DBG("disable region 0x%x", region_index + part_index); |
| /* Disable region */ |
| ARM_MPU_DEV->rnr = region_index + part_index; |
| ARM_MPU_DEV->rbar = 0; |
| ARM_MPU_DEV->rasr = 0; |
| } |
| |
| /** |
| * @brief get the maximum number of free regions for memory domain partitions |
| */ |
| int arm_core_mpu_get_max_domain_partition_regions(void) |
| { |
| /* |
| * Subtract the start of domain partition regions from total regions |
| * will get the maximum number of free regions for memory domain |
| * partitions. |
| */ |
| return _get_num_regions() - |
| _get_region_index_by_type(THREAD_DOMAIN_PARTITION_REGION); |
| } |
| |
| /** |
| * @brief validate the given buffer is user accessible or not |
| */ |
| int arm_core_mpu_buffer_validate(void *addr, size_t size, int write) |
| { |
| u32_t r_index; |
| |
| /* Iterate all mpu regions in reversed order */ |
| for (r_index = _get_num_regions() + 1; r_index-- > 0;) { |
| if (!_is_enabled_region(r_index) || |
| !_is_in_region(r_index, (u32_t)addr, size)) { |
| continue; |
| } |
| |
| /* For ARM MPU, higher region number takes priority. |
| * Since we iterate all mpu regions in reversed order, so |
| * we can stop the iteration immediately once we find the |
| * matched region that grants permission or denies access. |
| */ |
| if (_is_user_accessible_region(r_index, write)) { |
| return 0; |
| } else { |
| return -EPERM; |
| } |
| } |
| |
| return -EPERM; |
| } |
| #endif /* CONFIG_USERSPACE */ |
| |
| /* ARM MPU Driver Initial Setup */ |
| |
| /* |
| * @brief MPU default configuration |
| * |
| * This function provides the default configuration mechanism for the Memory |
| * Protection Unit (MPU). |
| */ |
| static void _arm_mpu_config(void) |
| { |
| u32_t r_index; |
| |
| /* ARM MPU supports up to 16 Regions */ |
| if (mpu_config.num_regions > _get_num_regions()) { |
| return; |
| } |
| |
| /* Disable MPU */ |
| ARM_MPU_DEV->ctrl = 0; |
| |
| /* Configure regions */ |
| for (r_index = 0; r_index < mpu_config.num_regions; r_index++) { |
| _region_init(r_index, |
| mpu_config.mpu_regions[r_index].base, |
| mpu_config.mpu_regions[r_index].attr); |
| } |
| |
| /* Enable MPU */ |
| ARM_MPU_DEV->ctrl = ARM_MPU_ENABLE | ARM_MPU_PRIVDEFENA; |
| |
| arm_mpu_enabled = 1; |
| |
| /* Make sure that all the registers are set before proceeding */ |
| __DSB(); |
| __ISB(); |
| } |
| |
| static int arm_mpu_init(struct device *arg) |
| { |
| ARG_UNUSED(arg); |
| |
| _arm_mpu_config(); |
| |
| return 0; |
| } |
| |
| SYS_INIT(arm_mpu_init, PRE_KERNEL_1, |
| CONFIG_KERNEL_INIT_PRIORITY_DEFAULT); |