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 #if defined(NUM_MPU_REGIONS)
14 /* Retrieve the number of regions from DTS configuration. */
15 return NUM_MPU_REGIONS;
16 #else
17 uint32_t type;
18
19 __asm__ volatile("mrc p15, 0, %0, c0, c0, 4" : "=r" (type) ::);
20
21 type = (type & MPU_TYPE_DREGION_Msk) >> MPU_TYPE_DREGION_Pos;
22
23 return (uint8_t)type;
24 #endif /* NUM_MPU_REGIONS */
25 }
26
get_region_attributes(void)27 static inline uint32_t get_region_attributes(void)
28 {
29 uint32_t attr;
30
31 __asm__ volatile("mrc p15, 0, %0, c6, c1, 4" : "=r" (attr) ::);
32 return attr;
33 }
34
get_region_base_address(void)35 static inline uint32_t get_region_base_address(void)
36 {
37 uint32_t addr;
38
39 __asm__ volatile("mrc p15, 0, %0, c6, c1, 0" : "=r" (addr) ::);
40 return addr;
41 }
42
get_region_size(void)43 static inline uint32_t get_region_size(void)
44 {
45 uint32_t size;
46
47 __asm__ volatile("mrc p15, 0, %0, c6, c1, 2" : "=r" (size) ::);
48 return size;
49 }
50
set_region_attributes(uint32_t attr)51 static inline void set_region_attributes(uint32_t attr)
52 {
53 __asm__ volatile("mcr p15, 0, %0, c6, c1, 4" :: "r" (attr) :);
54 }
55
set_region_base_address(uint32_t addr)56 static inline void set_region_base_address(uint32_t addr)
57 {
58 __asm__ volatile("mcr p15, 0, %0, c6, c1, 0" :: "r" (addr) :);
59 }
60
set_region_number(uint32_t index)61 static inline void set_region_number(uint32_t index)
62 {
63 __asm__ volatile("mcr p15, 0, %0, c6, c2, 0" :: "r" (index) :);
64 }
65
mpu_region_get_base(uint32_t index)66 static inline uint32_t mpu_region_get_base(uint32_t index)
67 {
68 set_region_number(index);
69
70 return get_region_base_address() & MPU_RBAR_ADDR_Msk;
71 }
72
73 /**
74 * This internal function converts the SIZE field value of MPU_RASR
75 * to the region size (in bytes).
76 */
mpu_rasr_size_to_size(uint32_t rasr_size)77 static inline uint32_t mpu_rasr_size_to_size(uint32_t rasr_size)
78 {
79 return 1 << (rasr_size + 1U);
80 }
81
set_region_size(uint32_t size)82 static inline void set_region_size(uint32_t size)
83 {
84 __asm__ volatile("mcr p15, 0, %0, c6, c1, 2" :: "r" (size) :);
85 }
86
ARM_MPU_ClrRegion(uint32_t rnr)87 static inline void ARM_MPU_ClrRegion(uint32_t rnr)
88 {
89 set_region_number(rnr);
90 /* clear size field, which contains enable bit */
91 set_region_size(0);
92 }
93
94 /**
95 * This internal function checks if region is enabled or not.
96 *
97 * Note:
98 * The caller must provide a valid region number.
99 */
is_enabled_region(uint32_t index)100 static inline int is_enabled_region(uint32_t index)
101 {
102 set_region_number(index);
103
104 return (get_region_size() & MPU_RASR_ENABLE_Msk) ? 1 : 0;
105 }
106
107 /**
108 * This internal function returns the access permissions of an MPU region
109 * specified by its region index.
110 *
111 * Note:
112 * The caller must provide a valid region number.
113 */
get_region_ap(uint32_t r_index)114 static inline uint32_t get_region_ap(uint32_t r_index)
115 {
116 set_region_number(r_index);
117
118 return (get_region_attributes() & MPU_RASR_AP_Msk) >> MPU_RASR_AP_Pos;
119 }
120
121 /**
122 * This internal function checks if the given buffer is in the region.
123 *
124 * Note:
125 * The caller must provide a valid region number.
126 */
is_in_region(uint32_t r_index,uint32_t start,uint32_t size)127 static inline int is_in_region(uint32_t r_index, uint32_t start, uint32_t size)
128 {
129 uint32_t r_addr_start;
130 uint32_t r_size_lshift;
131 uint32_t r_addr_end;
132 uint32_t end;
133
134 set_region_number(r_index);
135
136 r_addr_start = get_region_base_address() & MPU_RBAR_ADDR_Msk;
137
138 r_size_lshift = ((get_region_size() & MPU_RASR_SIZE_Msk) >>
139 MPU_RASR_SIZE_Pos) + 1;
140
141 r_addr_end = r_addr_start + (1UL << r_size_lshift) - 1;
142
143 size = size == 0 ? 0 : size - 1;
144 if (u32_add_overflow(start, size, &end)) {
145 return 0;
146 }
147
148 if ((start >= r_addr_start) && (end <= r_addr_end)) {
149 return 1;
150 }
151
152 return 0;
153 }
154
mpu_region_get_size(uint32_t index)155 static inline uint32_t mpu_region_get_size(uint32_t index)
156 {
157 set_region_number(index);
158
159 uint32_t rasr_size =
160 (get_region_size() & MPU_RASR_SIZE_Msk) >> MPU_RASR_SIZE_Pos;
161
162 return mpu_rasr_size_to_size(rasr_size);
163 }
164
