1 /* SPDX-License-Identifier: Apache-2.0
2 *
3 * Copyright (c) 2019 Lexmark International, Inc.
4 */
5
6 #include <zephyr/sys/math_extras.h>
7
8 /**
9 * Get the number of supported MPU regions.
10 */
get_num_regions(void)11 static inline uint8_t get_num_regions(void)
12 {
13 uint32_t type;
14
15 __asm__ volatile("mrc p15, 0, %0, c0, c0, 4" : "=r" (type) ::);
16
17 type = (type & MPU_TYPE_DREGION_Msk) >> MPU_TYPE_DREGION_Pos;
18
19 return (uint8_t)type;
20 }
21
get_region_attributes(void)22 static inline uint32_t get_region_attributes(void)
23 {
24 uint32_t attr;
25
26 __asm__ volatile("mrc p15, 0, %0, c6, c1, 4" : "=r" (attr) ::);
27 return attr;
28 }
29
get_region_base_address(void)30 static inline uint32_t get_region_base_address(void)
31 {
32 uint32_t addr;
33
34 __asm__ volatile("mrc p15, 0, %0, c6, c1, 0" : "=r" (addr) ::);
35 return addr;
36 }
37
get_region_size(void)38 static inline uint32_t get_region_size(void)
39 {
40 uint32_t size;
41
42 __asm__ volatile("mrc p15, 0, %0, c6, c1, 2" : "=r" (size) ::);
43 return size;
44 }
45
set_region_attributes(uint32_t attr)46 static inline void set_region_attributes(uint32_t attr)
47 {
48 __asm__ volatile("mcr p15, 0, %0, c6, c1, 4" :: "r" (attr) :);
49 }
50
set_region_base_address(uint32_t addr)51 static inline void set_region_base_address(uint32_t addr)
52 {
53 __asm__ volatile("mcr p15, 0, %0, c6, c1, 0" :: "r" (addr) :);
54 }
55
set_region_number(uint32_t index)56 static inline void set_region_number(uint32_t index)
57 {
58 __asm__ volatile("mcr p15, 0, %0, c6, c2, 0" :: "r" (index) :);
59 }
60
mpu_region_get_base(uint32_t index)61 static inline uint32_t mpu_region_get_base(uint32_t index)
62 {
63 set_region_number(index);
64
65 return get_region_base_address() & MPU_RBAR_ADDR_Msk;
66 }
67
68 /**
69 * This internal function converts the SIZE field value of MPU_RASR
70 * to the region size (in bytes).
71 */
mpu_rasr_size_to_size(uint32_t rasr_size)72 static inline uint32_t mpu_rasr_size_to_size(uint32_t rasr_size)
73 {
74 return 1 << (rasr_size + 1U);
75 }
76
set_region_size(uint32_t size)77 static inline void set_region_size(uint32_t size)
78 {
79 __asm__ volatile("mcr p15, 0, %0, c6, c1, 2" :: "r" (size) :);
80 }
81
ARM_MPU_ClrRegion(uint32_t rnr)82 static inline void ARM_MPU_ClrRegion(uint32_t rnr)
83 {
84 set_region_number(rnr);
85 /* clear size field, which contains enable bit */
86 set_region_size(0);
87 }
88
89 /**
90 * This internal function checks if region is enabled or not.
91 *
92 * Note:
93 * The caller must provide a valid region number.
94 */
is_enabled_region(uint32_t index)95 static inline int is_enabled_region(uint32_t index)
96 {
97 set_region_number(index);
98
99 return (get_region_size() & MPU_RASR_ENABLE_Msk) ? 1 : 0;
100 }
101
102 /**
103 * This internal function returns the access permissions of an MPU region
104 * specified by its region index.
105 *
106 * Note:
107 * The caller must provide a valid region number.
108 */
get_region_ap(uint32_t r_index)109 static inline uint32_t get_region_ap(uint32_t r_index)
110 {
111 set_region_number(r_index);
112
113 return (get_region_attributes() & MPU_RASR_AP_Msk) >> MPU_RASR_AP_Pos;
114 }
115
116 /**
117 * This internal function checks if the given buffer is in the region.
118 *
119 * Note:
120 * The caller must provide a valid region number.
121 */
is_in_region(uint32_t r_index,uint32_t start,uint32_t size)122 static inline int is_in_region(uint32_t r_index, uint32_t start, uint32_t size)
123 {
124 uint32_t r_addr_start;
125 uint32_t r_size_lshift;
126 uint32_t r_addr_end;
127 uint32_t end;
128
129 set_region_number(r_index);
130
131 r_addr_start = get_region_base_address() & MPU_RBAR_ADDR_Msk;
132
133 r_size_lshift = ((get_region_size() & MPU_RASR_SIZE_Msk) >>
134 MPU_RASR_SIZE_Pos) + 1;
135
136 r_addr_end = r_addr_start + (1UL << r_size_lshift) - 1;
137
138 size = size == 0 ? 0 : size - 1;
139 if (u32_add_overflow(start, size, &end)) {
140 return 0;
141 }
142
143 if ((start >= r_addr_start) && (end <= r_addr_end)) {
144 return 1;
145 }
146
147 return 0;
148 }
149
mpu_region_get_size(uint32_t index)150 static inline uint32_t mpu_region_get_size(uint32_t index)
151 {
152 set_region_number(index);
153
154 uint32_t rasr_size =
155 (get_region_size() & MPU_RASR_SIZE_Msk) >> MPU_RASR_SIZE_Pos;
156
157 return mpu_rasr_size_to_size(rasr_size);
158 }
159
