1 /*
2 * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include "hardware/exception.h"
8 #include "hardware/sync.h"
9 #include "pico/platform/cpu_regs.h"
10
11 #ifndef exception_is_compile_time_default
exception_is_compile_time_default(exception_handler_t handler)12 static bool exception_is_compile_time_default(exception_handler_t handler) {
13 #ifdef __riscv
14 extern char __unhandled_exception;
15 return (uintptr_t)handler == (uintptr_t)__unhandled_exception;
16 #else
17 extern char __default_isrs_start;
18 extern char __default_isrs_end;
19 return ((uintptr_t)handler) >= (uintptr_t)&__default_isrs_start &&
20 ((uintptr_t)handler) < (uintptr_t)&__default_isrs_end;
21 #endif
22 }
23 #endif
24
get_exception_table(void)25 static inline exception_handler_t *get_exception_table(void) {
26 #ifdef __riscv
27 extern uintptr_t __riscv_exception_table;
28 return (exception_handler_t *) &__riscv_exception_table;
29 #else
30 return (exception_handler_t *) scb_hw->vtor;
31 #endif
32 }
33
set_raw_exception_handler_and_restore_interrupts(enum exception_number num,exception_handler_t handler,uint32_t save)34 static void set_raw_exception_handler_and_restore_interrupts(enum exception_number num, exception_handler_t handler, uint32_t save) {
35 // update vtable (vtable_handler may be same or updated depending on cases, but we do it anyway for compactness)
36 get_exception_table()[num] = handler;
37 __dmb();
38 restore_interrupts_from_disabled(save);
39 }
40
check_exception_param(__unused enum exception_number num)41 static inline void check_exception_param(__unused enum exception_number num) {
42 invalid_params_if(HARDWARE_EXCEPTION, num < MIN_EXCEPTION_NUM || num > MAX_EXCEPTION_NUM);
43 }
44
exception_get_vtable_handler(enum exception_number num)45 exception_handler_t exception_get_vtable_handler(enum exception_number num) {
46 check_exception_param(num);
47 return get_exception_table()[num];
48 }
49
exception_set_exclusive_handler(enum exception_number num,exception_handler_t handler)50 exception_handler_t exception_set_exclusive_handler(enum exception_number num, exception_handler_t handler) {
51 check_exception_param(num);
52 #if !PICO_NO_RAM_VECTOR_TABLE
53 uint32_t save = save_and_disable_interrupts();
54 exception_handler_t current = exception_get_vtable_handler(num);
55 hard_assert(handler == current || exception_is_compile_time_default(current));
56 set_raw_exception_handler_and_restore_interrupts(num, handler, save);
57 #else
58 panic_unsupported();
59 #endif
60 return current;
61 }
62
exception_restore_handler(enum exception_number num,exception_handler_t original_handler)63 void exception_restore_handler(enum exception_number num, exception_handler_t original_handler) {
64 hard_assert(exception_is_compile_time_default(original_handler));
65 #if !PICO_NO_RAM_VECTOR_TABLE
66 uint32_t save = save_and_disable_interrupts();
67 set_raw_exception_handler_and_restore_interrupts(num, original_handler, save);
68 #else
69 panic_unsupported();
70 #endif
71 }
72
73 #ifndef __riscv
74
get_shpr0(uint num)75 static io_rw_32 *get_shpr0(uint num) {
76 io_rw_32 *shpr0 = NULL;
77 #if __ARM_ARCH_6M__
78 // only has shpr2-3
79 if (num >= 8 && num < 16) shpr0 = (io_rw_32 *) (PPB_BASE + ARM_CPU_PREFIXED(SHPR2_OFFSET) - 8);
80 #elif __ARM_ARCH_8M_MAIN__
81 // only has shpr1-3
82 if (num >= 4 && num < 16) shpr0 = (io_rw_32 *)(PPB_BASE + ARM_CPU_PREFIXED(SHPR1_OFFSET) - 4);
83 #endif
84 return shpr0;
85 }
86
exception_set_priority(uint num,uint8_t hardware_priority)87 bool exception_set_priority(uint num, uint8_t hardware_priority) {
88 io_rw_32 *shpr0 = get_shpr0(num);
89 if (shpr0) {
90 // note that only 32 bit writes are supported
91 shpr0[num / 4] = (shpr0[num/4] & ~(0xffu << (8 * (num & 3u)))) | (((uint32_t) hardware_priority) << (8 * (num & 3u)));
92 return true;
93 }
94 return false;
95 }
96
exception_get_priority(uint num)97 uint exception_get_priority(uint num) {
98 io_rw_32 *shpr0 = get_shpr0(num);
99 if (shpr0) {
100 // note that only 32 bit writes are supported
101 return (uint8_t) (shpr0[num/4] >> (8 * (num & 3)));
102 }
103 return PICO_LOWEST_EXCEPTION_PRIORITY;
104 }
105 #endif
