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|
;/***************************************************************************
; * Copyright (c) 2024 Microsoft Corporation
; *
; * This program and the accompanying materials are made available under the
; * terms of the MIT License which is available at
; * https://opensource.org/licenses/MIT.
; *
; * SPDX-License-Identifier: MIT
; **************************************************************************/
;/**************************************************************************/
;/**************************************************************************/
;/** */
;/** ThreadX Component */
;/** */
;/** Timer */
;/** */
;/**************************************************************************/
;/**************************************************************************/
#ifdef TX_INCLUDE_USER_DEFINE_FILE
#include "tx_user.h"
#endif
;/**************************************************************************/
;/* */
;/* FUNCTION RELEASE */
;/* */
;/* _tx_timer_interrupt ARCv2_EM/MetaWare */
;/* 6.2.1 */
;/* AUTHOR */
;/* */
;/* William E. Lamie, Microsoft Corporation */
;/* */
;/* DESCRIPTION */
;/* */
;/* This function processes the hardware timer interrupt. This */
;/* processing includes incrementing the system clock and checking for */
;/* time slice and/or timer expiration. If either is found, the */
;/* interrupt context save/restore functions are called along with the */
;/* expiration functions. */
;/* */
;/* INPUT */
;/* */
;/* None */
;/* */
;/* OUTPUT */
;/* */
;/* None */
;/* */
;/* CALLS */
;/* */
;/* _tx_timer_expiration_process Process timer expiration */
;/* _tx_thread_time_slice Time slice interrupted thread */
;/* _tx_thread_context_save Save interrupt context */
;/* _tx_thread_context_restore Restore interrupt context */
;/* */
;/* CALLED BY */
;/* */
;/* interrupt vector */
;/* */
;/**************************************************************************/
;VOID _tx_timer_interrupt(VOID)
;{
.global _tx_timer_interrupt
.type _tx_timer_interrupt, @function
_tx_timer_interrupt:
;
; /* Upon entry to this routine, it is assumed the interrupt stack frame has
; already been allocated and registers r0, r1, and r2 have already been saved
; at offsets 0, 4, and 8 respectively. */
;
; /* Increment the system clock. */
; _tx_timer_system_clock++;
;
clri ; Lockout interrupts
ld r0, [gp,_tx_timer_system_clock@sda] ; Pickup current system clock
ld r2, [gp, _tx_timer_time_slice@sda] ; Pickup current time-slice
add r0, r0, 1 ; Increment the system clock
st r0, [gp,_tx_timer_system_clock@sda] ; Store system clock back in memory
; /* Test for time-slice expiration. */
; if (_tx_timer_time_slice)
; {
;
mov r1, 0 ; Clear expiration flag
breq r2, 0, __tx_timer_no_time_slice ; If zero, no time-slice is active
;
; /* Decrement the time_slice. */
; _tx_timer_time_slice--;
;
sub r2, r2, 1 ; Decrement time-slice
st r2, [gp, _tx_timer_time_slice@sda] ; Store new time-slice value
;
; /* Check for expiration. */
; if (__tx_timer_time_slice == 0)
;
brne r2, 0, __tx_timer_no_time_slice ; If non-zero, skip over expiration
;
; /* Set the time-slice expired flag. */
; _tx_timer_expired_time_slice = TX_TRUE;
;
mov r1, 1 ; Set register flag
st r1, [gp, _tx_timer_expired_time_slice@sda] ; Set the time-slice expired flag
;
; }
;
__tx_timer_no_time_slice:
;
; /* Test for timer expiration. */
; if (*_tx_timer_current_ptr)
; {
;
ld r0, [gp, _tx_timer_current_ptr@sda] ; Pickup current timer pointer
ld r2, [r0, 0] ; Pickup examine actual list entry
breq r2, 0, __tx_timer_no_timer ;
; If NULL, no timer has expired, just move to the next entry
;
; /* Set expiration flag. */
; _tx_timer_expired = TX_TRUE;
;
mov r1, 1 ; Build expiration value
b.d __tx_timer_done ; Skip moving the timer pointer
st r1, [gp, _tx_timer_expired@sda] ; Set the expired value
;
; }
; else
; {
__tx_timer_no_timer:
;
; /* No timer expired, increment the timer pointer. */
; _tx_timer_current_ptr++;
;
ld r2, [gp, _tx_timer_list_end@sda] ; Pickup end of list
add r0, r0, 4 ; Move to next timer entry
;
; /* Check for wrap-around. */
; if (_tx_timer_current_ptr == _tx_timer_list_end)
;
st r0, [gp, _tx_timer_current_ptr@sda] ; Store the current timer
brne r0, r2, __tx_timer_skip_wrap ; If not equal, don't wrap the list
;
; /* Wrap to beginning of list. */
; _tx_timer_current_ptr = _tx_timer_list_start;
;
ld r2, [gp, _tx_timer_list_start@sda] ; Pickup start of timer list
st r2, [gp, _tx_timer_current_ptr@sda] ; Set current timer to the start
;
__tx_timer_skip_wrap:
;
; }
;
__tx_timer_done:
;
;
; /* See if anything has expired. */
; if ((_tx_timer_expired_time_slice) || (_tx_timer_expired))
; {
;
ld r0, [gp, _tx_thread_current_ptr@sda]
ld r2, [gp, _tx_thread_execute_ptr@sda]
brne r0, r2, __tx_something_expired
;
breq r1, 0, __tx_timer_nothing_expired ; If 0, nothing has expired
;
__tx_something_expired:
;
ld r0, [sp, 0] ; Recover r0
ld r1, [sp, 4] ; Recover r1
ld r2, [sp, 8] ; Recover r2
st blink, [sp, 16] ; Save blink
bl _tx_thread_context_save ; Save interrupted context
;
; /* Did a timer expire? */
; if (_tx_timer_expired)
; {
;
ld r2, [gp, _tx_timer_expired@sda] ; Pickup timer expired flag
breq r2, 0, __tx_timer_dont_activate ; If not set, skip expiration processing
;
; /* Process the timer expiration. */
; /* _tx_timer_expiration_process(); */
bl.d _tx_timer_expiration_process ; Call the timer expiration handling routine
sub sp, sp, 16 ; ..allocating some space on the stack
add sp, sp, 16 ; Recover the stack space
;
; }
__tx_timer_dont_activate:
;
; /* Did time slice expire? */
; if (_tx_timer_expired_time_slice)
; {
;
ld r2, [gp, _tx_timer_expired_time_slice@sda] ; Pickup expired time-slice flag
breq r2, 0, __tx_timer_not_ts_expiration ; If not set, skip time-slice
;
; /* Time slice interrupted thread. */
; /* _tx_thread_time_slice(); */
bl.d _tx_thread_time_slice ; Call time-slice processing
sub sp, sp, 16 ; ..allocating some stack space
add sp, sp, 16 ; Recover stack space
;
; }
;
__tx_timer_not_ts_expiration:
;
st 0, [gp, _tx_timer_expired_time_slice@sda]
b _tx_thread_context_restore ; Go restore interrupt context..
; ..clearing time-slice expired flag
; Note that we don't return from
; this function.
;
; }
;
__tx_timer_nothing_expired:
;
ld r0, [sp, 0] ; Recover r0
ld r1, [sp, 4] ; Recover r1
ld r2, [sp, 8] ; Recover r2
add sp, sp, 160 ; Recover interrupt stack frame
rtie ; Return to point of interrupt
;
;}
.end
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