1;/*************************************************************************** 2; * Copyright (c) 2024 Microsoft Corporation 3; * 4; * This program and the accompanying materials are made available under the 5; * terms of the MIT License which is available at 6; * https://opensource.org/licenses/MIT. 7; * 8; * SPDX-License-Identifier: MIT 9; **************************************************************************/ 10; 11; 12;/**************************************************************************/ 13;/**************************************************************************/ 14;/** */ 15;/** ThreadX Component */ 16;/** */ 17;/** Timer */ 18;/** */ 19;/**************************************************************************/ 20;/**************************************************************************/ 21; 22;#define TX_SOURCE_CODE 23; 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;Define Assembly language external references... 33; 34 35 SWI0 .EQU 872E0H 36 37 .GLB __tx_timer_time_slice 38 .GLB __tx_timer_system_clock 39 .GLB __tx_timer_current_ptr 40 .GLB __tx_timer_list_start 41 .GLB __tx_timer_list_end 42 .GLB __tx_timer_expired_time_slice 43 .GLB __tx_timer_expired 44 .GLB __tx_timer_expiration_process 45 .GLB __tx_thread_context_save 46 .GLB __tx_thread_time_slice 47 .GLB __tx_thread_context_restore 48 .GLB __tx_thread_preempt_disable 49 .GLB __tx_thread_execute_ptr 50 .GLB __tx_thread_current_ptr 51; 52 .SECTION P,CODE 53;/**************************************************************************/ 54;/* */ 55;/* FUNCTION RELEASE */ 56;/* */ 57;/* _tx_timer_interrupt RXv1/CCRX */ 58;/* 6.1.11 */ 59;/* AUTHOR */ 60;/* */ 61;/* William E. Lamie, Microsoft Corporation */ 62;/* */ 63;/* DESCRIPTION */ 64;/* */ 65;/* This function processes the hardware timer interrupt. This */ 66;/* processing includes incrementing the system clock and checking for */ 67;/* time slice and/or timer expiration. If either is found, the */ 68;/* interrupt context save/restore functions are called along with the */ 69;/* expiration functions. */ 70;/* */ 71;/* INPUT */ 72;/* */ 73;/* None */ 74;/* */ 75;/* OUTPUT */ 76;/* */ 77;/* None */ 78;/* */ 79;/* CALLS */ 80;/* */ 81;/* _tx_thread_context_save Save interrupted context */ 82;/* _tx_timer_expiration_process Timer expiration processing */ 83;/* _tx_thread_time_slice Time slice interrupted thread */ 84;/* _tx_thread_context_restore Restore interrupted context */ 85;/* */ 86;/* CALLED BY */ 87;/* */ 88;/* interrupt vector */ 89;/* */ 90;/* RELEASE HISTORY */ 91;/* */ 92;/* DATE NAME DESCRIPTION */ 93;/* */ 94;/* 08-02-2021 William E. Lamie Initial Version 6.1.8 */ 95;/* 10-15-2021 William E. Lamie Modified comment(s), */ 96;/* resulting in version 6.1.9 */ 97;/* 01-31-2022 William E. Lamie Modified comment(s), and */ 98;/* added missing thread */ 99;/* preemption logic, */ 100;/* resulting in version 6.1.10 */ 101;/* 04-25-2022 William E. Lamie Modified comment(s), */ 102;/* resulting in version 6.1.11 */ 103;/* */ 104;/**************************************************************************/ 105;VOID _tx_timer_interrupt(VOID) 106;{ 107 .GLB __tx_timer_interrupt 108__tx_timer_interrupt: 109; 110; /* Upon entry to this routine, it is assumed that all interrupts are locked 111; out and the stack looks like the following: 112; SP+4 -> Interrupted PC 113; SP+8-> Interrupted SR 114; */ 115; 116; /* Increment the system clock. */ 117; _tx_timer_system_clock++; 118; 119 PUSHM R14-R15 120 PUSHM R1-R5 121 122 MOV.L #__tx_timer_system_clock, R1 ; Pickup address of system clock 123 MOV.L [R1], R2 ; Pickup system clock 124 ADD #1, R2 ; Increment system clock 125 MOV.L R2,[R1] ; Store new system clock 126; 127; /* Test for time-slice expiration. */ 128; if (_tx_timer_time_slice) 129; { 130; 131 MOV.L #__tx_timer_time_slice, R1 ; Pickup address of time slice 132 MOV.L [R1], R2 ; Pickup the current time slice 133 CMP #0, R2 ; Is a time slice active? 134 BEQ __tx_timer_no_time_slice ; No, skip timer slice processing 135; 136; /* Decrement the time_slice. */ 137; _tx_timer_time_slice--; 138; 139 SUB #1, R2 ; Decrement the time-slice 140 MOV.L R2, [R1] ; Store time-slice 141; 142; /* Check for expiration. */ 143; if (__tx_timer_time_slice == 0) 144; 145 CMP #0, R2 ; Has it expired? 146 BNE __tx_timer_no_time_slice ; No, time-slice has not expired 147; 148; /* Set the time-slice expired flag. */ 149; _tx_timer_expired_time_slice = TX_TRUE; 150; 151 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup address of expired time-slice 152 MOV.L #1, R2 ; Build expired value 153 MOV.L R2, [R1] ; Set expired time slice variable 154; } 155; 156__tx_timer_no_time_slice: 157; 158; /* Test for timer expiration. */ 159; if (*_tx_timer_current_ptr) 160; { 161; 162 MOV.L #__tx_timer_current_ptr, R1 ; Pickup address of current timer ptr 163 MOV.L [R1], R2 ; Pickup current pointer 164 MOV.L [R2+], R1 ; Pickup timer list entry, _tx_timer_current_ptr++ 165 CMP #0, R1 ; Is timer pointer NULL? 166 BEQ __tx_timer_no_timer ; Yes, no timer has expired 167 168; 169; /* Set expiration flag. */ 170; _tx_timer_expired = TX_TRUE; 171; 172 MOV.L #__tx_timer_expired,R2 ; Build address of expired flag 173 MOV.L #1, R1 ; Build expired value 174 MOV.L R1, [R2] 175 BRA __tx_timer_done ; Finished with timer processing 176; 177; } 178; else 179; { 180__tx_timer_no_timer: 181; 182; /* No timer expired, increment the timer pointer. */ 183; _tx_timer_current_ptr++; 184; 185; /* R2 already contains __tx_timer_current_ptr++ */ 186; 187; /* Check for wrap-around. */ 188; if (_tx_timer_current_ptr == _tx_timer_list_end) 189; 190 MOV.L #__tx_timer_list_end, R1 ; Pickup the timer list end ptr 191 MOV.L [R1], R1 ; Pickup actual timer list end 192 CMP R1, R2 ; Are we at list end? 193 BNE __tx_timer_skip_wrap ; No, don't move pointer to the 194 ; top of the list 195; 196; /* Wrap to beginning of list. */ 197; _tx_timer_current_ptr = _tx_timer_list_start; 198; 199 MOV.L #__tx_timer_list_start, R2 ; Pickup the timer list start ptr 200 MOV.L [R2], R2 ; Pickup the start of the list 201; } 202; 203__tx_timer_skip_wrap: 204 MOV.L #__tx_timer_current_ptr,R1 205 MOV.L R2, [R1] ; Store in updated pointer in _tx_timer_current_ptr 206 207__tx_timer_done: 208; 209; /* See if anything has expired. */ 210; if ((_tx_timer_expired_time_slice) || (_tx_timer_expired)) 211; { 212; 213 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup expired time slice addr 214 MOV.L [R1], R1 ; Pickup expired time slice 215 MOV.L #__tx_timer_expired, R2 ; Pickup expired timer flag address 216 MOV.L [R2], R2 ; Pickup actual flag 217 OR R1, R2 ; Or flags together 218 BEQ __tx_timer_nothing_expired ; If Z set, nothing has expired 219 220__tx_something_expired: 221; /* Did a timer expire? */ 222; if (_tx_timer_expired) 223; { 224 MOV.L #__tx_timer_expired,R1 ; Pickup expired flag address 225 MOV.L [R1], R1 ; Pickup expired flag 226 CMP #0,R1 ; Is the expired timer flag set? 227 BEQ __tx_timer_dont_activate ; No, skip timer activation 228; 229; /* Process timer expiration. */ 230; _tx_timer_expiration_process(); 231; 232 BSR __tx_timer_expiration_process ; Call the timer expiration handling routine 233; 234; } 235__tx_timer_dont_activate: 236; 237; /* Did time slice expire? */ 238; if (_tx_timer_expired_time_slice) 239; { 240; 241 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup time-slice expired flag addr 242 MOV.L [R1], R1 ; Pickup actual flag 243 CMP #0,R1 ; Has time-slice expired? 244 BEQ __tx_timer_not_ts_expiration ; No, skip time-slice expiration 245; 246; /* Time slice interrupted thread. */ 247; _tx_thread_time_slice(); 248 249 BSR __tx_thread_time_slice ; Call time-slice processing 250 251; /* Check if we must trigger a context switch. */ 252 MOV.L #__tx_thread_preempt_disable, R1 ; Load prempt disable flag. 253 MOV.L [R1], R1 254 CMP #0, R1 255 BNE __tx_timer_not_ts_expiration ; Skip if prempt disabled. 256 257 MOV.L #__tx_thread_execute_ptr, R1 258 MOV.L [R1], R1 259 MOV.L #__tx_thread_current_ptr, R2 260 MOV.L [R2], R2 261 CMP R1, R2 262 BEQ __tx_timer_not_ts_expiration 263 264 MOV.L #SWI0, R1 265 MOV.L #1, [R1] 266 267; } 268; 269__tx_timer_not_ts_expiration: 270 271__tx_timer_nothing_expired: 272 273 POPM R1-R5 274 POPM R14-R15 275; 276 RTS ; Return to point of interrupt 277; 278;} 279 280 .END 281 282
