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 36 SWI0 .EQU 872E0H 37 38 .GLB __tx_timer_time_slice 39 .GLB __tx_timer_system_clock 40 .GLB __tx_timer_current_ptr 41 .GLB __tx_timer_list_start 42 .GLB __tx_timer_list_end 43 .GLB __tx_timer_expired_time_slice 44 .GLB __tx_timer_expired 45 .GLB __tx_timer_expiration_process 46 .GLB __tx_thread_context_save 47 .GLB __tx_thread_time_slice 48 .GLB __tx_thread_context_restore 49 .GLB __tx_thread_preempt_disable 50 .GLB __tx_thread_execute_ptr 51 .GLB __tx_thread_current_ptr 52; 53 .SECTION P,CODE 54;/**************************************************************************/ 55;/* */ 56;/* FUNCTION RELEASE */ 57;/* */ 58;/* _tx_timer_interrupt RXv3/CCRX */ 59;/* 6.1.11 */ 60;/* AUTHOR */ 61;/* */ 62;/* William E. Lamie, Microsoft Corporation */ 63;/* */ 64;/* DESCRIPTION */ 65;/* */ 66;/* This function processes the hardware timer interrupt. This */ 67;/* processing includes incrementing the system clock and checking for */ 68;/* time slice and/or timer expiration. If either is found, the */ 69;/* interrupt context save/restore functions are called along with the */ 70;/* expiration functions. */ 71;/* */ 72;/* INPUT */ 73;/* */ 74;/* None */ 75;/* */ 76;/* OUTPUT */ 77;/* */ 78;/* None */ 79;/* */ 80;/* CALLS */ 81;/* */ 82;/* _tx_thread_context_save Save interrupted context */ 83;/* _tx_timer_expiration_process Timer expiration processing */ 84;/* _tx_thread_time_slice Time slice interrupted thread */ 85;/* _tx_thread_context_restore Restore interrupted context */ 86;/* */ 87;/* CALLED BY */ 88;/* */ 89;/* interrupt vector */ 90;/* */ 91;/* RELEASE HISTORY */ 92;/* */ 93;/* DATE NAME DESCRIPTION */ 94;/* */ 95;/* 06-02-2021 William E. Lamie Initial Version 6.1.7 */ 96;/* 10-15-2021 William E. Lamie Modified comment(s), */ 97;/* resulting in version 6.1.9 */ 98;/* 01-31-2022 William E. Lamie Modified comment(s), and */ 99;/* added missing thread */ 100;/* preemption logic, */ 101;/* resulting in version 6.1.10 */ 102;/* 04-25-2022 William E. Lamie Modified comment(s), */ 103;/* resulting in version 6.1.11 */ 104;/* */ 105;/**************************************************************************/ 106;VOID _tx_timer_interrupt(VOID) 107;{ 108 .GLB __tx_timer_interrupt 109__tx_timer_interrupt: 110; 111; /* Upon entry to this routine, it is assumed that all interrupts are locked 112; out and the stack looks like the following: 113; SP+4 -> Interrupted PC 114; SP+8-> Interrupted SR 115; */ 116; 117; /* Increment the system clock. */ 118; _tx_timer_system_clock++; 119; 120 PUSHM R14-R15 121 PUSHM R1-R5 122 123 MOV.L #__tx_timer_system_clock, R1 ; Pickup address of system clock 124 MOV.L [R1], R2 ; Pickup system clock 125 ADD #1, R2 ; Increment system clock 126 MOV.L R2,[R1] ; Store new system clock 127; 128; /* Test for time-slice expiration. */ 129; if (_tx_timer_time_slice) 130; { 131; 132 MOV.L #__tx_timer_time_slice, R1 ; Pickup address of time slice 133 MOV.L [R1], R2 ; Pickup the current time slice 134 CMP #0, R2 ; Is a time slice active? 135 BEQ __tx_timer_no_time_slice ; No, skip timer slice processing 136; 137; /* Decrement the time_slice. */ 138; _tx_timer_time_slice--; 139; 140 SUB #1, R2 ; Decrement the time-slice 141 MOV.L R2, [R1] ; Store time-slice 142; 143; /* Check for expiration. */ 144; if (__tx_timer_time_slice == 0) 145; 146 CMP #0, R2 ; Has it expired? 147 BNE __tx_timer_no_time_slice ; No, time-slice has not expired 148; 149; /* Set the time-slice expired flag. */ 150; _tx_timer_expired_time_slice = TX_TRUE; 151; 152 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup address of expired time-slice 153 MOV.L #1, R2 ; Build expired value 154 MOV.L R2, [R1] ; Set expired time slice variable 155; } 156; 157__tx_timer_no_time_slice: 158; 159; /* Test for timer expiration. */ 160; if (*_tx_timer_current_ptr) 161; { 162; 163 MOV.L #__tx_timer_current_ptr, R1 ; Pickup address of current timer ptr 164 MOV.L [R1], R2 ; Pickup current pointer 165 MOV.L [R2+], R1 ; Pickup timer list entry, _tx_timer_current_ptr++ 166 CMP #0, R1 ; Is timer pointer NULL? 167 BEQ __tx_timer_no_timer ; Yes, no timer has expired 168 169; 170; /* Set expiration flag. */ 171; _tx_timer_expired = TX_TRUE; 172; 173 MOV.L #__tx_timer_expired,R2 ; Build address of expired flag 174 MOV.L #1, R1 ; Build expired value 175 MOV.L R1, [R2] 176 BRA __tx_timer_done ; Finished with timer processing 177; 178; } 179; else 180; { 181__tx_timer_no_timer: 182; 183; /* No timer expired, increment the timer pointer. */ 184; _tx_timer_current_ptr++; 185; 186; /* R2 already contains __tx_timer_current_ptr++ */ 187; 188; /* Check for wrap-around. */ 189; if (_tx_timer_current_ptr == _tx_timer_list_end) 190; 191 MOV.L #__tx_timer_list_end, R1 ; Pickup the timer list end ptr 192 MOV.L [R1], R1 ; Pickup actual timer list end 193 CMP R1, R2 ; Are we at list end? 194 BNE __tx_timer_skip_wrap ; No, don't move pointer to the 195 ; top of the list 196; 197; /* Wrap to beginning of list. */ 198; _tx_timer_current_ptr = _tx_timer_list_start; 199; 200 MOV.L #__tx_timer_list_start, R2 ; Pickup the timer list start ptr 201 MOV.L [R2], R2 ; Pickup the start of the list 202; } 203; 204__tx_timer_skip_wrap: 205 MOV.L #__tx_timer_current_ptr,R1 206 MOV.L R2, [R1] ; Store in updated pointer in _tx_timer_current_ptr 207 208__tx_timer_done: 209; 210; /* See if anything has expired. */ 211; if ((_tx_timer_expired_time_slice) || (_tx_timer_expired)) 212; { 213; 214 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup expired time slice addr 215 MOV.L [R1], R1 ; Pickup expired time slice 216 MOV.L #__tx_timer_expired, R2 ; Pickup expired timer flag address 217 MOV.L [R2], R2 ; Pickup actual flag 218 OR R1, R2 ; Or flags together 219 BEQ __tx_timer_nothing_expired ; If Z set, nothing has expired 220 221__tx_something_expired: 222; /* Did a timer expire? */ 223; if (_tx_timer_expired) 224; { 225 MOV.L #__tx_timer_expired,R1 ; Pickup expired flag address 226 MOV.L [R1], R1 ; Pickup expired flag 227 CMP #0,R1 ; Is the expired timer flag set? 228 BEQ __tx_timer_dont_activate ; No, skip timer activation 229; 230; /* Process timer expiration. */ 231; _tx_timer_expiration_process(); 232; 233 BSR __tx_timer_expiration_process ; Call the timer expiration handling routine 234; 235; } 236__tx_timer_dont_activate: 237; 238; /* Did time slice expire? */ 239; if (_tx_timer_expired_time_slice) 240; { 241; 242 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup time-slice expired flag addr 243 MOV.L [R1], R1 ; Pickup actual flag 244 CMP #0,R1 ; Has time-slice expired? 245 BEQ __tx_timer_not_ts_expiration ; No, skip time-slice expiration 246; 247; /* Time slice interrupted thread. */ 248; _tx_thread_time_slice(); 249 250 BSR __tx_thread_time_slice ; Call time-slice processing 251 252; /* Check if we must trigger a context switch. */ 253 MOV.L #__tx_thread_preempt_disable, R1 ; Load prempt disable flag. 254 MOV.L [R1], R1 255 CMP #0, R1 256 BNE __tx_timer_not_ts_expiration ; Skip if prempt disabled. 257 258 MOV.L #__tx_thread_execute_ptr, R1 259 MOV.L [R1], R1 260 MOV.L #__tx_thread_current_ptr, R2 261 MOV.L [R2], R2 262 CMP R1, R2 263 BEQ __tx_timer_not_ts_expiration 264 265 MOV.L #SWI0, R1 266 MOV.L #1, [R1] 267 268; } 269; 270__tx_timer_not_ts_expiration: 271 272__tx_timer_nothing_expired: 273 274 POPM R1-R5 275 POPM R14-R15 276; 277 RTS ; Return to point of interrupt 278; 279;} 280 281 .END 282 283 284
