xref: /Kernel-v10.6.2/portable/ThirdParty/XCC/Xtensa/xtensa_intr.c (revision ef7b253b56c9788077f5ecd6c9deb4021923d646) 
1  /*
2  * FreeRTOS Kernel V10.6.2
3  * Copyright (C) 2015-2019 Cadence Design Systems, Inc.
4  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
5  *
6  * SPDX-License-Identifier: MIT
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy of
9  * this software and associated documentation files (the "Software"), to deal in
10  * the Software without restriction, including without limitation the rights to
11  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
12  * the Software, and to permit persons to whom the Software is furnished to do so,
13  * subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in all
16  * copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
20  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
21  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
22  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  *
25  * https://www.FreeRTOS.org
26  * https://github.com/FreeRTOS
27  *
28  */
29 
30 /*
31  * Xtensa-specific interrupt and exception functions for RTOS ports.
32  * Also see xtensa_intr_asm.S.
33  */
34 
35 #include <stdlib.h>
36 
37 #include <xtensa/config/core.h>
38 
39 #include "xtensa_api.h"
40 
41 
42 #if XCHAL_HAVE_EXCEPTIONS
43 
44 /* Handler table is in xtensa_intr_asm.S */
45 
46 extern xt_exc_handler _xt_exception_table[XCHAL_EXCCAUSE_NUM];
47 
48 
49 /*
50   Default handler for unhandled exceptions.
51 */
xt_unhandled_exception(XtExcFrame * frame)52 void xt_unhandled_exception(XtExcFrame *frame)
53 {
54     exit(-1);
55 }
56 
57 
58 /*
59   This function registers a handler for the specified exception.
60   The function returns the address of the previous handler.
61   On error, it returns 0.
62 */
xt_set_exception_handler(int n,xt_exc_handler f)63 xt_exc_handler xt_set_exception_handler(int n, xt_exc_handler f)
64 {
65     xt_exc_handler old;
66 
67     if( n < 0 || n >= XCHAL_EXCCAUSE_NUM )
68         return 0;       /* invalid exception number */
69 
70     old = _xt_exception_table[n];
71 
72     if (f) {
73         _xt_exception_table[n] = f;
74     }
75     else {
76         _xt_exception_table[n] = &xt_unhandled_exception;
77     }
78 
79     return ((old == &xt_unhandled_exception) ? 0 : old);
80 }
81 
82 #endif
83 
84 #if XCHAL_HAVE_INTERRUPTS
85 
86 /* Handler table is in xtensa_intr_asm.S */
87 
88 typedef struct xt_handler_table_entry {
89     void * handler;
90     void * arg;
91 } xt_handler_table_entry;
92 
93 extern xt_handler_table_entry _xt_interrupt_table[XCHAL_NUM_INTERRUPTS];
94 
95 
96 /*
97   Default handler for unhandled interrupts.
98 */
xt_unhandled_interrupt(void * arg)99 void xt_unhandled_interrupt(void * arg)
100 {
101     exit(-1);
102 }
103 
104 
105 /*
106   This function registers a handler for the specified interrupt. The "arg"
107   parameter specifies the argument to be passed to the handler when it is
108   invoked. The function returns the address of the previous handler.
109   On error, it returns 0.
110 */
xt_set_interrupt_handler(int n,xt_handler f,void * arg)111 xt_handler xt_set_interrupt_handler(int n, xt_handler f, void * arg)
112 {
113     xt_handler_table_entry * entry;
114     xt_handler               old;
115 
116     if( n < 0 || n >= XCHAL_NUM_INTERRUPTS )
117         return 0;       /* invalid interrupt number */
118     if( Xthal_intlevel[n] > XCHAL_EXCM_LEVEL )
119         return 0;       /* priority level too high to safely handle in C */
120 
121     entry = _xt_interrupt_table + n;
122     old   = entry->handler;
123 
124     if (f) {
125         entry->handler = f;
126         entry->arg     = arg;
127     }
128     else {
129         entry->handler = &xt_unhandled_interrupt;
130         entry->arg     = (void*)n;
131     }
132 
133     return ((old == &xt_unhandled_interrupt) ? 0 : old);
134 }
135 
136 
137 #endif /* XCHAL_HAVE_INTERRUPTS */
138