1 /**************************************************************************/
2 /*                                                                        */
3 /*       Copyright (c) Microsoft Corporation. All rights reserved.        */
4 /*                                                                        */
5 /*       This software is licensed under the Microsoft Software License   */
6 /*       Terms for Microsoft Azure RTOS. Full text of the license can be  */
7 /*       found in the LICENSE file at https://aka.ms/AzureRTOS_EULA       */
8 /*       and in the root directory of this software.                      */
9 /*                                                                        */
10 /**************************************************************************/
11 
12 
13 /**************************************************************************/
14 /**************************************************************************/
15 /**                                                                       */
16 /** ThreadX Component                                                     */
17 /**                                                                       */
18 /**   Timer                                                               */
19 /**                                                                       */
20 /**************************************************************************/
21 /**************************************************************************/
22 
23 #define TX_SOURCE_CODE
24 
25 /* Include necessary system files.  */
26 
27 #include "tx_api.h"
28 #include "tx_timer.h"
29 #include "tx_thread.h"
30 
31 /**************************************************************************/
32 /*                                                                        */
33 /*  FUNCTION                                               RELEASE        */
34 /*                                                                        */
35 /*    _tx_timer_interrupt                                RISC-V64/GNU     */
36 /*                                                           6.2.1        */
37 /*  AUTHOR                                                                */
38 /*                                                                        */
39 /*    Scott Larson, Microsoft Corporation                                 */
40 /*                                                                        */
41 /*  DESCRIPTION                                                           */
42 /*                                                                        */
43 /*    This function processes the hardware timer interrupt.  This         */
44 /*    processing includes incrementing the system clock and checking for  */
45 /*    time slice and/or timer expiration.  If either is found, the        */
46 /*    interrupt context save/restore functions are called along with the  */
47 /*    expiration functions.                                               */
48 /*                                                                        */
49 /*  INPUT                                                                 */
50 /*                                                                        */
51 /*    None                                                                */
52 /*                                                                        */
53 /*  OUTPUT                                                                */
54 /*                                                                        */
55 /*    None                                                                */
56 /*                                                                        */
57 /*  CALLS                                                                 */
58 /*                                                                        */
59 /*    _tx_timer_expiration_process          Timer expiration processing   */
60 /*    _tx_thread_time_slice                 Time slice interrupted thread */
61 /*                                                                        */
62 /*  CALLED BY                                                             */
63 /*                                                                        */
64 /*    interrupt vector                                                    */
65 /*                                                                        */
66 /*  RELEASE HISTORY                                                       */
67 /*                                                                        */
68 /*    DATE              NAME                      DESCRIPTION             */
69 /*                                                                        */
70 /*  03-08-2023      Scott Larson            Initial Version 6.2.1         */
71 /*                                                                        */
72 /**************************************************************************/
_tx_timer_interrupt(VOID)73 VOID   _tx_timer_interrupt(VOID)
74 {
75     /* Increment system clock. */
76     _tx_timer_system_clock++;
77 
78     /* Test for time-slice expiration. */
79     if (_tx_timer_time_slice)
80     {
81         /* Decrement the time_slice.  */
82         _tx_timer_time_slice--;
83 
84         /* Check for expiration.  */
85         if (_tx_timer_time_slice == 0)
86         {
87 
88            /* Set the time-slice expired flag.  */
89            _tx_timer_expired_time_slice =  TX_TRUE;
90         }
91     }
92 
93     /* Test for timer expiration.  */
94     if (*_tx_timer_current_ptr)
95     {
96 
97         /* Set expiration flag.  */
98         _tx_timer_expired =  TX_TRUE;
99     }
100     else
101     {
102 
103         /* No timer expired, increment the timer pointer.  */
104         _tx_timer_current_ptr++;
105 
106         /* Check for wrap-around.  */
107         if (_tx_timer_current_ptr == _tx_timer_list_end)
108         {
109 
110             /* Wrap to beginning of list.  */
111             _tx_timer_current_ptr =  _tx_timer_list_start;
112         }
113     }
114 
115     /* See if anything has expired.  */
116     if ((_tx_timer_expired_time_slice) || (_tx_timer_expired))
117     {
118 
119         /* Did a timer expire?  */
120         if (_tx_timer_expired)
121         {
122 
123             /* Process timer expiration.  */
124             _tx_timer_expiration_process();
125         }
126 
127         /* Did time slice expire?  */
128         if (_tx_timer_expired_time_slice)
129         {
130 
131             /* Time slice interrupted thread.  */
132             _tx_thread_time_slice();
133         }
134     }
135 }
136