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 .equ SWI0, 872E0H 24 .global __tx_timer_time_slice 25 .global __tx_timer_system_clock 26 .global __tx_timer_current_ptr 27 .global __tx_timer_list_start 28 .global __tx_timer_list_end 29 .global __tx_timer_expired_time_slice 30 .global __tx_timer_expired 31 .global __tx_timer_expiration_process 32 .global __tx_thread_context_save 33 .global __tx_thread_time_slice 34 .global __tx_thread_context_restore 35 .global __tx_thread_preempt_disable 36 .global __tx_thread_execute_ptr 37 .global __tx_thread_current_ptr 38 39 .SECTION P,CODE 40;/**************************************************************************/ 41;/* */ 42;/* FUNCTION RELEASE */ 43;/* */ 44;/* _tx_timer_interrupt RXv1/GNURX */ 45;/* 6.1.11 */ 46;/* AUTHOR */ 47;/* */ 48;/* William E. Lamie, Microsoft Corporation */ 49;/* */ 50;/* DESCRIPTION */ 51;/* */ 52;/* This function processes the hardware timer interrupt. This */ 53;/* processing includes incrementing the system clock and checking for */ 54;/* time slice and/or timer expiration. If either is found, the */ 55;/* interrupt context save/restore functions are called along with the */ 56;/* expiration functions. */ 57;/* */ 58;/* INPUT */ 59;/* */ 60;/* None */ 61;/* */ 62;/* OUTPUT */ 63;/* */ 64;/* None */ 65;/* */ 66;/* CALLS */ 67;/* */ 68;/* _tx_thread_context_save Save interrupted context */ 69;/* _tx_timer_expiration_process Timer expiration processing */ 70;/* _tx_thread_time_slice Time slice interrupted thread */ 71;/* _tx_thread_context_restore Restore interrupted context */ 72;/* */ 73;/* CALLED BY */ 74;/* */ 75;/* interrupt vector */ 76;/* */ 77;/* RELEASE HISTORY */ 78;/* */ 79;/* DATE NAME DESCRIPTION */ 80;/* */ 81;/* 08-02-2021 William E. Lamie Initial Version 6.1.8 */ 82;/* 10-15-2021 William E. Lamie Modified comment(s), */ 83;/* resulting in version 6.1.9 */ 84;/* 01-31-2022 William E. Lamie Modified comment(s), and */ 85;/* added missing thread */ 86;/* preemption logic, */ 87;/* resulting in version 6.1.10 */ 88;/* 04-25-2022 William E. Lamie Modified comment(s), */ 89;/* resulting in version 6.1.11 */ 90;/* */ 91;/**************************************************************************/ 92;VOID _tx_timer_interrupt(VOID) 93;{ 94 .global __tx_timer_interrupt 95__tx_timer_interrupt: 96; 97; /* Upon entry to this routine, it is assumed that all interrupts are locked 98; out and the stack looks like the following: 99; SP+4 -> Interrupted PC 100; SP+8-> Interrupted SR 101; */ 102; 103; /* Increment the system clock. */ 104; _tx_timer_system_clock++; 105; 106 PUSHM R14-R15 107 PUSHM R1-R5 108 109 MOV.L #__tx_timer_system_clock, R1 ; Pickup address of system clock 110 MOV.L [R1], R2 ; Pickup system clock 111 ADD #1, R2 ; Increment system clock 112 MOV.L R2,[R1] ; Store new system clock 113; 114; /* Test for time-slice expiration. */ 115; if (_tx_timer_time_slice) 116; { 117; 118 MOV.L #__tx_timer_time_slice, R1 ; Pickup address of time slice 119 MOV.L [R1], R2 ; Pickup the current time slice 120 CMP #0, R2 ; Is a time slice active? 121 BEQ __tx_timer_no_time_slice ; No, skip timer slice processing 122; 123; /* Decrement the time_slice. */ 124; _tx_timer_time_slice--; 125; 126 SUB #1, R2 ; Decrement the time-slice 127 MOV.L R2, [R1] ; Store time-slice 128; 129; /* Check for expiration. */ 130; if (__tx_timer_time_slice == 0) 131; 132 CMP #0, R2 ; Has it expired? 133 BNE __tx_timer_no_time_slice ; No, time-slice has not expired 134; 135; /* Set the time-slice expired flag. */ 136; _tx_timer_expired_time_slice = TX_TRUE; 137; 138 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup address of expired time-slice 139 MOV.L #1, R2 ; Build expired value 140 MOV.L R2, [R1] ; Set expired time slice variable 141; } 142; 143__tx_timer_no_time_slice: 144; 145; /* Test for timer expiration. */ 146; if (*_tx_timer_current_ptr) 147; { 148; 149 MOV.L #__tx_timer_current_ptr, R1 ; Pickup address of current timer ptr 150 MOV.L [R1], R2 ; Pickup current pointer 151 MOV.L [R2+], R1 ; pickup timer list entry, _tx_timer_current_ptr++ 152 CMP #0, R1 ; Is timer pointer NULL? 153 BEQ __tx_timer_no_timer ; Yes, no timer has expired 154 155; 156; /* Set expiration flag. */ 157; _tx_timer_expired = TX_TRUE; 158; 159 MOV.L #__tx_timer_expired,R2 ; Build address of expired flag 160 MOV.L #1, R1 ; Build expired value 161 MOV.L R1, [R2] 162 BRA __tx_timer_done ; Finished with timer processing 163; 164; } 165; else 166; { 167__tx_timer_no_timer: 168; 169; /* No timer expired, increment the timer pointer. */ 170; _tx_timer_current_ptr++; 171; 172; /* R2 already contains __tx_timer_current_ptr++ */ 173; 174; /* Check for wrap-around. */ 175; if (_tx_timer_current_ptr == _tx_timer_list_end) 176; 177 MOV.L #__tx_timer_list_end, R1 ; Pickup the timer list end ptr 178 MOV.L [R1], R1 ; Pickup actual timer list end 179 CMP R1, R2 ; Are we at list end? 180 BNE __tx_timer_skip_wrap ; No, don't move pointer to the 181 ; top of the list 182; 183; /* Wrap to beginning of list. */ 184; _tx_timer_current_ptr = _tx_timer_list_start; 185; 186 MOV.L #__tx_timer_list_start, R2 ; Pickup the timer list start ptr 187 MOV.L [R2], R2 ; Pickup the start of the list 188; } 189; 190__tx_timer_skip_wrap: 191 MOV.L #__tx_timer_current_ptr,R1 192 MOV.L R2, [R1] ; Store in updated pointer in _tx_timer_current_ptr 193 194__tx_timer_done: 195; 196; /* See if anything has expired. */ 197; if ((_tx_timer_expired_time_slice) || (_tx_timer_expired)) 198; { 199; 200 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup expired time slice addr 201 MOV.L [R1], R1 ; Pickup expired time slice 202 MOV.L #__tx_timer_expired, R2 ; Pickup expired timer flag address 203 MOV.L [R2], R2 ; Pickup actual flag 204 OR R1, R2 ; Or flags together 205 BEQ __tx_timer_nothing_expired ; If Z set, nothing has expired 206 207__tx_something_expired: 208; /* Did a timer expire? */ 209; if (_tx_timer_expired) 210; { 211 MOV.L #__tx_timer_expired,R1 ; Pickup expired flag address 212 MOV.L [R1], R1 ; Pickup expired flag 213 CMP #0,R1 ; Is the expired timer flag set? 214 BEQ __tx_timer_dont_activate ; No, skip timer activation 215; 216; /* Process timer expiration. */ 217; _tx_timer_expiration_process(); 218; 219 BSR __tx_timer_expiration_process ; Call the timer expiration handling routine 220; 221; } 222__tx_timer_dont_activate: 223; 224; /* Did time slice expire? */ 225; if (_tx_timer_expired_time_slice) 226; { 227; 228 MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup time-slice expired flag addr 229 MOV.L [R1], R1 ; Pickup actual flag 230 CMP #0,R1 ; Has time-slice expired? 231 BEQ __tx_timer_not_ts_expiration ; No, skip time-slice expiration 232; 233; /* Time slice interrupted thread. */ 234; _tx_thread_time_slice(); 235 236 BSR __tx_thread_time_slice ; Call time-slice processing 237 238; /* Check if we must trigger a context switch. */ 239 MOV.L #__tx_thread_preempt_disable, R1 ; Load prempt disable flag. 240 MOV.L [R1], R1 241 CMP #0, R1 242 BNE __tx_timer_not_ts_expiration ; Skip if prempt disabled. 243 244 MOV.L #__tx_thread_execute_ptr, R1 245 MOV.L [R1], R1 246 MOV.L #__tx_thread_current_ptr, R2 247 MOV.L [R2], R2 248 CMP R1, R2 249 BEQ __tx_timer_not_ts_expiration 250 251 MOV.L #SWI0, R1 252 MOV.L #1, [R1] 253 254 255; } 256; 257__tx_timer_not_ts_expiration: 258 259__tx_timer_nothing_expired: 260 261 POPM R1-R5 262 POPM R14-R15 263; 264 RTS ; Return to point of interrupt 265; 266;} 267 268 .end 269
