mbed-os/features/FEATURE_UVISOR/source/page_allocator_config.h

87 lines
3.3 KiB
C

/*
* Copyright (c) 2016, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __PAGE_ALLOCATOR_CONFIG_H__
#define __PAGE_ALLOCATOR_CONFIG_H__
/* This file can be compiled externally to provide the page allocator algorithm
* for devices NOT supported by uVisor. For this purpose this file is copied as
* is into the target build folder and compiled by the target build system. */
/* We can only protect a small number of pages efficiently, so there should be
* a relatively low limit to the number of pages.
* By default a maximum of 16 pages are allowed. This can only be overwritten
* by the porting engineer for the current platform. */
#ifndef UVISOR_PAGE_MAX_COUNT
#define UVISOR_PAGE_MAX_COUNT (16UL)
#endif
/* The number of pages is decided by the page size. A small page size leads to
* a lot of pages, however, number of pages is capped for efficiency.
* Furthermore, when allocating large continous memory, a too small page size
* will lead to allocation failures. This can only be overwritten
* by the porting engineer for the current platform. */
#ifndef UVISOR_PAGE_SIZE_MINIMUM
#define UVISOR_PAGE_SIZE_MINIMUM (1024UL)
#endif
/* Defines the number of uint32_t page owner masks in the owner map.
* +8 is used for ARMv7-M MPUs, where a shift of up to 7-bits may be required
* to align MPU regions. */
#define UVISOR_PAGE_MAP_COUNT ((UVISOR_PAGE_MAX_COUNT + 31 + 8) / 32)
/* The page box_id is the box id which is 8-bit large. */
typedef uint8_t page_owner_t;
/* Contains the total number of available pages. */
extern uint8_t g_page_count_total;
/* Contains the shift of the page owner mask. */
extern uint8_t g_page_map_shift;
/* Contains the ARMv7-MPU rounded page end. */
extern uint32_t g_page_head_end_rounded;
/** Sets the page bit in the page map array.
* @param map an array of `uint32_t` containing the page map
* @param page the index of the page to be set
*/
static inline void page_allocator_map_set(uint32_t * const map, uint8_t page)
{
page += g_page_map_shift;
map[page / 32] |= (1UL << (page % 32));
}
/** Clears the page bit in the page map array.
* @param map an array of `uint32_t` containing the page map
* @param page the index of the page to be set
*/
static inline void page_allocator_map_clear(uint32_t * const map, uint8_t page)
{
page += g_page_map_shift;
map[page / 32] &= ~(1UL << (page % 32));
}
/** Check if the page bit is set int the page map array.
* @param map an array of `uint32_t` containing the page map
* @param page the index of the page to be set
* @retval 0 if page bit is not set
* @retval 1 if page bit is set
*/
static inline int page_allocator_map_get(const uint32_t * const map, uint8_t page)
{
page += g_page_map_shift;
return (map[page / 32] >> (page % 32)) & 0x1;
}
#endif /* __PAGE_ALLOCATOR_CONFIG_H__ */