FreeRTOS-Kernel/portable/MPLAB/PIC32MEC14xx/ISR_Support.h
Joseph Julicher 989bc332b2
Feature: SMP (#278)
* Add XMOS XCore ports

Some minor modifications are also made to the kernel to support the
XCore compiler's automatic stack size calculation.

* Update kernel to support SMP

The XMOS XCore ports are also updated to support SMP.

* Fix compiler warnings in xcore ports

The port set and clear interrupt mask from ISR macros were removed from
the ports so that the default macros found in FreeRTOS.h are used
instead. The default macros do not result in warnings when they are
used.

* Remove inline function from timers.h

Inline function converted to macro. This should now build when
optimizations are off and inlining is disabled.

* Fix compiler warnings in xcore ports and tasks.c

* fixed documentation for ulTaskNotifyTake() and ulTaskNotifyTakeIndexed()

* spelling fixes for tasks.c

Co-authored-by: Michael Bruno <mikeb@xmos.com>
2021-03-15 17:29:08 -07:00

215 lines
5.3 KiB
C

/*
* FreeRTOS Kernel V10.4.3
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
* 1 tab == 4 spaces!
*/
#include "FreeRTOSConfig.h"
#define portCONTEXT_SIZE 132
#define portEPC_STACK_LOCATION 124
#define portSTATUS_STACK_LOCATION 128
#ifdef __LANGUAGE_ASSEMBLY__
/******************************************************************/
.macro portSAVE_CONTEXT
/* Make room for the context. First save the current status so it can be
manipulated, and the cause and EPC registers so their original values are
captured. */
mfc0 k0, _CP0_CAUSE
addiu sp, sp, -portCONTEXT_SIZE
mfc0 k1, _CP0_STATUS
/* Also save s6 and s5 so they can be used. Any nesting interrupts should
maintain the values of these registers across the ISR. */
sw s6, 44(sp)
sw s5, 40(sp)
sw k1, portSTATUS_STACK_LOCATION(sp)
/* Prepare to enable interrupts above the current priority.
k0 = k0 >> 10. Moves RIPL[17:10] to [7:0] */
srl k0, k0, 0xa
/* Insert bit field. 7 bits k0[6:0] to k1[16:10] */
ins k1, k0, 10, 7
/* Sets CP0.Status.IPL = CP0.Cause.RIPL
Copy the MSB of the IPL, but it would be an error if it was set anyway. */
srl k0, k0, 0x7
/* MSB of IPL is bit[18] of CP0.Status */
ins k1, k0, 18, 1
/* CP0.Status[5:1] = 0 b[5]=Rsvd, b[4]=UM,
b[3]=Rsvd, b[2]=ERL, b[1]=EXL
Setting EXL=0 allows higher priority interrupts
to preempt this handler */
ins k1, zero, 1, 4
/* s5 is used as the frame pointer. */
add s5, zero, sp
/* Check the nesting count value. */
la k0, uxInterruptNesting
lw s6, (k0)
/* If the nesting count is 0 then swap to the the system stack, otherwise
the system stack is already being used. */
bne s6, zero, 1f
nop
/* Swap to the system stack. */
la sp, xISRStackTop
lw sp, (sp)
/* Increment and save the nesting count. */
1: addiu s6, s6, 1
sw s6, 0(k0)
/* s6 holds the EPC value, this is saved after interrupts are re-enabled. */
mfc0 s6, _CP0_EPC
/* Re-enable interrupts. */
mtc0 k1, _CP0_STATUS
/* Save the context into the space just created. s6 is saved again
here as it now contains the EPC value. No other s registers need be
saved. */
sw ra, 120(s5) /* Return address (RA=R31) */
sw s8, 116(s5) /* Frame Pointer (FP=R30) */
sw t9, 112(s5)
sw t8, 108(s5)
sw t7, 104(s5)
sw t6, 100(s5)
sw t5, 96(s5)
sw t4, 92(s5)
sw t3, 88(s5)
sw t2, 84(s5)
sw t1, 80(s5)
sw t0, 76(s5)
sw a3, 72(s5)
sw a2, 68(s5)
sw a1, 64(s5)
sw a0, 60(s5)
sw v1, 56(s5)
sw v0, 52(s5)
sw s6, portEPC_STACK_LOCATION(s5)
sw $1, 16(s5)
/* MEC14xx does not have DSP, removed 7 words */
mfhi s6
sw s6, 12(s5)
mflo s6
sw s6, 8(s5)
/* Update the task stack pointer value if nesting is zero. */
la s6, uxInterruptNesting
lw s6, (s6)
addiu s6, s6, -1
bne s6, zero, 1f
nop
/* Save the stack pointer. */
la s6, uxSavedTaskStackPointer
sw s5, (s6)
1:
.endm
/******************************************************************/
.macro portRESTORE_CONTEXT
/* Restore the stack pointer from the TCB. This is only done if the
nesting count is 1. */
la s6, uxInterruptNesting
lw s6, (s6)
addiu s6, s6, -1
bne s6, zero, 1f
nop
la s6, uxSavedTaskStackPointer
lw s5, (s6)
/* Restore the context.
MCHP MEC14xx does not include DSP */
1:
lw s6, 8(s5)
mtlo s6
lw s6, 12(s5)
mthi s6
lw $1, 16(s5)
/* s6 is loaded as it was used as a scratch register and therefore saved
as part of the interrupt context. */
lw s6, 44(s5)
lw v0, 52(s5)
lw v1, 56(s5)
lw a0, 60(s5)
lw a1, 64(s5)
lw a2, 68(s5)
lw a3, 72(s5)
lw t0, 76(s5)
lw t1, 80(s5)
lw t2, 84(s5)
lw t3, 88(s5)
lw t4, 92(s5)
lw t5, 96(s5)
lw t6, 100(s5)
lw t7, 104(s5)
lw t8, 108(s5)
lw t9, 112(s5)
lw s8, 116(s5)
lw ra, 120(s5)
/* Protect access to the k registers, and others. */
di
ehb
/* Decrement the nesting count. */
la k0, uxInterruptNesting
lw k1, (k0)
addiu k1, k1, -1
sw k1, 0(k0)
lw k0, portSTATUS_STACK_LOCATION(s5)
lw k1, portEPC_STACK_LOCATION(s5)
/* Leave the stack in its original state. First load sp from s5, then
restore s5 from the stack. */
add sp, zero, s5
lw s5, 40(sp)
addiu sp, sp, portCONTEXT_SIZE
mtc0 k0, _CP0_STATUS
mtc0 k1, _CP0_EPC
ehb
eret
nop
.endm
#endif /* #ifdef __LANGUAGE_ASSEMBLY__ */