zephyr/include/sys/mem_manage.h

112 lines
3.3 KiB
C

/*
* Copyright (c) 2020 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_SYS_MEM_MANAGE_H
#define ZEPHYR_INCLUDE_SYS_MEM_MANAGE_H
#include <sys/util.h>
/*
* Caching mode definitions. These are mutually exclusive.
*/
/** No caching. Most drivers want this. */
#define K_MEM_CACHE_NONE 0
/** Write-through caching. Used by certain drivers. */
#define K_MEM_CACHE_WT 1
/** Full write-back caching. Any RAM mapped wants this. */
#define K_MEM_CACHE_WB 2
/** Reserved bits for cache modes in k_map() flags argument */
#define K_MEM_CACHE_MASK (BIT(3) - 1)
/*
* Region permission attributes. Default is read-only, no user, no exec
*/
/** Region will have read/write access (and not read-only) */
#define K_MEM_PERM_RW BIT(3)
/** Region will be executable (normally forbidden) */
#define K_MEM_PERM_EXEC BIT(4)
/** Region will be accessible to user mode (normally supervisor-only) */
#define K_MEM_PERM_USER BIT(5)
#ifndef _ASMLANGUAGE
#include <stdint.h>
#include <stddef.h>
#include <inttypes.h>
#include <sys/__assert.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* Map a physical memory region into the kernel's virtual address space
*
* Given a physical address and a size, return a linear address
* representing the base of where the physical region is mapped in
* the virtual address space for the Zephyr kernel.
*
* This function alters the active page tables in the area reserved
* for the kernel. This function will choose the virtual address
* and return it to the caller.
*
* Portable code should never assume that phys_addr and linear_addr will
* be equal.
*
* Once created, mappings are permanent.
*
* Caching and access properties are controlled by the 'flags' parameter.
* Unused bits in 'flags' are reserved for future expansion.
* A caching mode must be selected. By default, the region is read-only
* with user access and code execution forbidden. This policy is changed
* by passing K_MEM_CACHE_* and K_MEM_PERM_* macros into the 'flags' parameter.
*
* If there is insufficient virtual address space for the mapping, or
* bad flags are passed in, or if additional memory is needed to update
* page tables that is not available, this will generate a kernel panic.
*
* This API is only available if CONFIG_MMU is enabled.
*
* This API is part of infrastructure still under development and may
* change.
*
* @param linear_addr [out] Output linear address storage location
* @param phys_addr Physical address base of the memory region
* @param size Size of the memory region
* @param flags Caching mode and access flags, see K_MAP_* macros
*/
void z_mem_map(uint8_t **linear_addr, uintptr_t phys_addr, size_t size,
uint32_t flags);
/**
* Given an arbitrary region, provide a aligned region that covers it
*
* The returned region will have both its base address and size aligned
* to the provided alignment value.
*
* @param aligned_addr [out] Aligned address
* @param aligned_size [out] Aligned region size
* @param addr Region base address
* @param size Region size
* @param align What to align the address and size to
* @retval offset between aligned_addr and addr
*/
size_t k_mem_region_align(uintptr_t *aligned_addr, size_t *aligned_size,
uintptr_t addr, size_t size, size_t align);
#ifdef __cplusplus
}
#endif
#endif /* !_ASMLANGUAGE */
#endif /* ZEPHYR_INCLUDE_SYS_MEM_MANAGE_H */