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; 26;/* Include necessary system files. */ 27; 28;#include "tx_api.h" 29;#include "tx_timer.h" 30;#include "tx_thread.h" 31; 32; 33;Define Assembly language external references... 34; 35 .equ SWI0, 872E0H 36 .global __tx_timer_time_slice 37 .global __tx_timer_system_clock 38 .global __tx_timer_current_ptr 39 .global __tx_timer_list_start 40 .global __tx_timer_list_end 41 .global __tx_timer_expired_time_slice 42 .global __tx_timer_expired 43 .global __tx_timer_expiration_process 44 .global __tx_thread_context_save 45 .global __tx_thread_time_slice 46 .global __tx_thread_context_restore 47 .global __tx_thread_preempt_disable 48 .global __tx_thread_execute_ptr 49 .global __tx_thread_current_ptr 50; 51 .SECTION P,CODE 52;/**************************************************************************/ 53;/* */ 54;/* FUNCTION RELEASE */ 55;/* */ 56;/* _tx_timer_interrupt RXv3/GNURX */ 57;/* 6.1.11 */ 58;/* AUTHOR */ 59;/* */ 60;/* William E. Lamie, Microsoft Corporation */ 61;/* */ 62;/* DESCRIPTION */ 63;/* */ 64;/* This function processes the hardware timer interrupt. This */ 65;/* processing includes incrementing the system clock and checking for */ 66;/* time slice and/or timer expiration. If either is found, the */ 67;/* interrupt context save/restore functions are called along with the */ 68;/* expiration functions. */ 69;/* */ 70;/* INPUT */ 71;/* */ 72;/* None */ 73;/* */ 74;/* OUTPUT */ 75;/* */ 76;/* None */ 77;/* */ 78;/* CALLS */ 79;/* */ 80;/* _tx_thread_context_save Save interrupted context */ 81;/* _tx_timer_expiration_process Timer expiration processing */ 82;/* _tx_thread_time_slice Time slice interrupted thread */ 83;/* _tx_thread_context_restore Restore interrupted context */ 84;/* */ 85;/* CALLED BY */ 86;/* */ 87;/* interrupt vector */ 88;/* */ 89;/* RELEASE HISTORY */ 90;/* */ 91;/* DATE NAME DESCRIPTION */ 92;/* */ 93;/* 06-02-2021 William E. Lamie Initial Version 6.1.7 */ 94;/* 10-15-2021 William E. Lamie Modified comment(s), */ 95;/* resulting in version 6.1.9 */ 96;/* 01-31-2022 William E. Lamie Modified comment(s), and */ 97;/* added missing thread */ 98;/* preemption logic, */ 99;/* resulting in version 6.1.10 */ 100;/* 04-25-2022 William E. Lamie Modified comment(s), */ 101;/* resulting in version 6.1.11 */ 102;/* */ 103;/**************************************************************************/ 104;VOID _tx_timer_interrupt(VOID) 105;{ 106 .global __tx_timer_interrupt 107__tx_timer_interrupt: 108; 109; /* Upon entry to this routine, it is assumed that all interrupts are locked 110; out and the stack looks like the following: 111; SP+4 -> Interrupted PC 112; SP+8-> Interrupted SR 113; */ 114; 115; /* Increment the system clock. */ 116; _tx_timer_system_clock++; 117; 118 PUSHM R14-R15 119 PUSHM R1-R5 120 121 MOV.L #__tx_timer_system_clock, R1 ; Pickup address of system clock 122 MOV.L [R1], R2 ; Pickup system clock 123 ADD #1, R2 ; Increment system clock 124 MOV.L R2,[R1] ; Store new system clock 125; 126; /* Test for time-slice expiration. */ 127; if (_tx_timer_time_slice) 128; { 129; 130 MOV.L #__tx_timer_time_slice, R1 ; Pickup address of time slice 131 MOV.L [R1], R2 ; Pickup the current time slice 132 CMP #0, R2 ; Is a time slice active? 133 BEQ __tx_timer_no_time_slice ; No, skip timer slice processing 134; 135; /* Decrement the time_slice. */ 136; _tx_timer_time_slice--; 137; 138 SUB #1, R2 ; Decrement the time-slice 139 MOV.L R2, [R1] ; Store time-slice 140; 141; /* Check for expiration. */ 142; if (__tx_timer_time_slice == 0) 143; 144 CMP #0, R2 ; Has it expired? 145 BNE __tx_timer_no_time_slice ; No, time-slice has not expired 146; 147; /* Set the time-slice expired flag. */ 148; _tx_timer_expired_time_slice = TX_TRUE; 149; 150 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup address of expired time-slice 151 MOV.L #1, R2 ; Build expired value 152 MOV.L R2, [R1] ; Set expired time slice variable 153; } 154; 155__tx_timer_no_time_slice: 156; 157; /* Test for timer expiration. */ 158; if (*_tx_timer_current_ptr) 159; { 160; 161 MOV.L #__tx_timer_current_ptr, R1 ; Pickup address of current timer ptr 162 MOV.L [R1], R2 ; Pickup current pointer 163 MOV.L [R2+], R1 ; Pickup timer list entry, _tx_timer_current_ptr++ 164 CMP #0, R1 ; Is timer pointer NULL? 165 BEQ __tx_timer_no_timer ; Yes, no timer has expired 166 167; 168; /* Set expiration flag. */ 169; _tx_timer_expired = TX_TRUE; 170; 171 MOV.L #__tx_timer_expired,R2 ; Build address of expired flag 172 MOV.L #1, R1 ; Build expired value 173 MOV.L R1, [R2] 174 BRA __tx_timer_done ; Finished with timer processing 175; 176; } 177; else 178; { 179__tx_timer_no_timer: 180; 181; /* No timer expired, increment the timer pointer. */ 182; _tx_timer_current_ptr++; 183; 184; /* R2 already contains __tx_timer_current_ptr++ */ 185; 186; /* Check for wrap-around. */ 187; if (_tx_timer_current_ptr == _tx_timer_list_end) 188; 189 MOV.L #__tx_timer_list_end, R1 ; Pickup the timer list end ptr 190 MOV.L [R1], R1 ; Pickup actual timer list end 191 CMP R1, R2 ; Are we at list end? 192 BNE __tx_timer_skip_wrap ; No, don't move pointer to the 193 ; top of the list 194; 195; /* Wrap to beginning of list. */ 196; _tx_timer_current_ptr = _tx_timer_list_start; 197; 198 MOV.L #__tx_timer_list_start, R2 ; Pickup the timer list start ptr 199 MOV.L [R2], R2 ; Pickup the start of the list 200; } 201; 202__tx_timer_skip_wrap: 203 MOV.L #__tx_timer_current_ptr,R1 204 MOV.L R2, [R1] ; Store in updated pointer in _tx_timer_current_ptr 205 206__tx_timer_done: 207; 208; /* See if anything has expired. */ 209; if ((_tx_timer_expired_time_slice) || (_tx_timer_expired)) 210; { 211; 212 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup expired time slice addr 213 MOV.L [R1], R1 ; Pickup expired time slice 214 MOV.L #__tx_timer_expired, R2 ; Pickup expired timer flag address 215 MOV.L [R2], R2 ; Pickup actual flag 216 OR R1, R2 ; Or flags together 217 BEQ __tx_timer_nothing_expired ; If Z set, nothing has expired 218 219__tx_something_expired: 220; /* Did a timer expire? */ 221; if (_tx_timer_expired) 222; { 223 MOV.L #__tx_timer_expired,R1 ; Pickup expired flag address 224 MOV.L [R1], R1 ; Pickup expired flag 225 CMP #0,R1 ; Is the expired timer flag set? 226 BEQ __tx_timer_dont_activate ; No, skip timer activation 227; 228; /* Process timer expiration. */ 229; _tx_timer_expiration_process(); 230; 231 BSR __tx_timer_expiration_process ; Call the timer expiration handling routine 232; 233; } 234__tx_timer_dont_activate: 235; 236; /* Did time slice expire? */ 237; if (_tx_timer_expired_time_slice) 238; { 239; 240 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup time-slice expired flag addr 241 MOV.L [R1], R1 ; Pickup actual flag 242 CMP #0,R1 ; Has time-slice expired? 243 BEQ __tx_timer_not_ts_expiration ; No, skip time-slice expiration 244; 245; /* Time slice interrupted thread. */ 246; _tx_thread_time_slice(); 247 248 BSR __tx_thread_time_slice ; Call time-slice processing 249 250; /* Check if we must trigger a context switch. */ 251 MOV.L #__tx_thread_preempt_disable, R1 ; Load prempt disable flag. 252 MOV.L [R1], R1 253 CMP #0, R1 254 BNE __tx_timer_not_ts_expiration ; Skip if prempt disabled. 255 256 MOV.L #__tx_thread_execute_ptr, R1 257 MOV.L [R1], R1 258 MOV.L #__tx_thread_current_ptr, R2 259 MOV.L [R2], R2 260 CMP R1, R2 261 BEQ __tx_timer_not_ts_expiration 262 263 MOV.L #SWI0, R1 264 MOV.L #1, [R1] 265 266; } 267; 268__tx_timer_not_ts_expiration: 269 270__tx_timer_nothing_expired: 271 272 POPM R1-R5 273 POPM R14-R15 274; 275 RTS ; Return to point of interrupt 276; 277;} 278 279 .end 280 281 282 283
