Files
ThreadX4TGFS/port/threadx/src/tx_thread_context_save.S
2026-01-27 20:58:23 +01:00

284 lines
16 KiB
ArmAsm

/***************************************************************************
* 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 */
/** */
/** Thread */
/** */
/**************************************************************************/
/**************************************************************************/
#include "tx_port.h"
.section .text
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_thread_context_save RISC-V64/GNU */
/* 6.2.1 */
/* AUTHOR */
/* */
/* Scott Larson, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function saves the context of an executing thread in the */
/* beginning of interrupt processing. The function also ensures that */
/* the system stack is used upon return to the calling ISR. */
/* */
/* INPUT */
/* */
/* None */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* None */
/* */
/* CALLED BY */
/* */
/* ISRs */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 03-08-2023 Scott Larson Initial Version 6.2.1 */
/* */
/**************************************************************************/
/* VOID _tx_thread_context_save(VOID)
{ */
.global _tx_thread_context_save
_tx_thread_context_save:
/* Upon entry to this routine, it is assumed that interrupts are locked
out and the interrupt stack fame has been allocated and x1 (ra) has
been saved on the stack. */
STORE t0, 19*REGBYTES(sp) // First store t0 and t1
STORE t1, 18*REGBYTES(sp)
la t0, _tx_thread_system_state // Pickup address of system state
lw t1, 0(t0) // Pickup system state
/* Check for a nested interrupt condition. */
/* if (_tx_thread_system_state++)
{ */
beqz t1, _tx_thread_not_nested_save // If 0, first interrupt condition
addi t1, t1, 1 // Increment the interrupt counter
sw t1, 0(t0) // Store the interrupt counter
/* Nested interrupt condition.
Save the reset of the scratch registers on the stack and return to the
calling ISR. */
STORE x7, 17*REGBYTES(sp) // Store t2
STORE x8, 12*REGBYTES(sp) // Store s0
STORE x10, 27*REGBYTES(sp) // Store a0
STORE x11, 26*REGBYTES(sp) // Store a1
STORE x12, 25*REGBYTES(sp) // Store a2
STORE x13, 24*REGBYTES(sp) // Store a3
STORE x14, 23*REGBYTES(sp) // Store a4
STORE x15, 22*REGBYTES(sp) // Store a5
STORE x16, 21*REGBYTES(sp) // Store a6
STORE x17, 20*REGBYTES(sp) // Store a7
STORE x28, 16*REGBYTES(sp) // Store t3
STORE x29, 15*REGBYTES(sp) // Store t4
STORE x30, 14*REGBYTES(sp) // Store t5
STORE x31, 13*REGBYTES(sp) // Store t6
csrr t0, mepc // Load exception program counter
STORE t0, 30*REGBYTES(sp) // Save it on the stack
/* Save floating point scratch registers. */
#if defined(__riscv_float_abi_single)
fsw f0, 31*REGBYTES(sp) // Store ft0
fsw f1, 32*REGBYTES(sp) // Store ft1
fsw f2, 33*REGBYTES(sp) // Store ft2
fsw f3, 34*REGBYTES(sp) // Store ft3
fsw f4, 35*REGBYTES(sp) // Store ft4
fsw f5, 36*REGBYTES(sp) // Store ft5
fsw f6, 37*REGBYTES(sp) // Store ft6
fsw f7, 38*REGBYTES(sp) // Store ft7
fsw f10,41*REGBYTES(sp) // Store fa0
fsw f11,42*REGBYTES(sp) // Store fa1
fsw f12,43*REGBYTES(sp) // Store fa2
fsw f13,44*REGBYTES(sp) // Store fa3
fsw f14,45*REGBYTES(sp) // Store fa4
fsw f15,46*REGBYTES(sp) // Store fa5
fsw f16,47*REGBYTES(sp) // Store fa6
fsw f17,48*REGBYTES(sp) // Store fa7
fsw f28,59*REGBYTES(sp) // Store ft8
fsw f29,60*REGBYTES(sp) // Store ft9
fsw f30,61*REGBYTES(sp) // Store ft10
fsw f31,62*REGBYTES(sp) // Store ft11
csrr t0, fcsr
STORE t0, 63*REGBYTES(sp) // Store fcsr
#elif defined(__riscv_float_abi_double)
fsd f0, 31*REGBYTES(sp) // Store ft0
fsd f1, 32*REGBYTES(sp) // Store ft1
fsd f2, 33*REGBYTES(sp) // Store ft2
fsd f3, 34*REGBYTES(sp) // Store ft3
fsd f4, 35*REGBYTES(sp) // Store ft4
fsd f5, 36*REGBYTES(sp) // Store ft5
fsd f6, 37*REGBYTES(sp) // Store ft6
fsd f7, 38*REGBYTES(sp) // Store ft7
fsd f10,41*REGBYTES(sp) // Store fa0
fsd f11,42*REGBYTES(sp) // Store fa1
fsd f12,43*REGBYTES(sp) // Store fa2
fsd f13,44*REGBYTES(sp) // Store fa3
fsd f14,45*REGBYTES(sp) // Store fa4
fsd f15,46*REGBYTES(sp) // Store fa5
fsd f16,47*REGBYTES(sp) // Store fa6
fsd f17,48*REGBYTES(sp) // Store fa7
fsd f28,59*REGBYTES(sp) // Store ft8
fsd f29,60*REGBYTES(sp) // Store ft9
fsd f30,61*REGBYTES(sp) // Store ft10
fsd f31,62*REGBYTES(sp) // Store ft11
csrr t0, fcsr
STORE t0, 63*REGBYTES(sp) // Store fcsr
#endif
#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY
call _tx_execution_isr_enter // Call the ISR execution enter function
#endif
ret // Return to calling ISR
_tx_thread_not_nested_save:
/* } */
/* Otherwise, not nested, check to see if a thread was running. */
/* else if (_tx_thread_current_ptr)
{ */
addi t1, t1, 1 // Increment the interrupt counter
sw t1, 0(t0) // Store the interrupt counter
/* Not nested: Find the user thread that was running and load our SP */
LOAD t0, _tx_thread_current_ptr // Pickup current thread pointer
beqz t0, _tx_thread_idle_system_save // If NULL, idle system was interrupted
/* Save the standard scratch registers. */
STORE x7, 17*REGBYTES(sp) // Store t2
STORE x8, 12*REGBYTES(sp) // Store s0
STORE x10, 27*REGBYTES(sp) // Store a0
STORE x11, 26*REGBYTES(sp) // Store a1
STORE x12, 25*REGBYTES(sp) // Store a2
STORE x13, 24*REGBYTES(sp) // Store a3
STORE x14, 23*REGBYTES(sp) // Store a4
STORE x15, 22*REGBYTES(sp) // Store a5
STORE x16, 21*REGBYTES(sp) // Store a6
STORE x17, 20*REGBYTES(sp) // Store a7
STORE x28, 16*REGBYTES(sp) // Store t3
STORE x29, 15*REGBYTES(sp) // Store t4
STORE x30, 14*REGBYTES(sp) // Store t5
STORE x31, 13*REGBYTES(sp) // Store t6
csrr t0, mepc // Load exception program counter
STORE t0, 30*REGBYTES(sp) // Save it on the stack
/* Save floating point scratch registers. */
#if defined(__riscv_float_abi_single)
fsw f0, 31*REGBYTES(sp) // Store ft0
fsw f1, 32*REGBYTES(sp) // Store ft1
fsw f2, 33*REGBYTES(sp) // Store ft2
fsw f3, 34*REGBYTES(sp) // Store ft3
fsw f4, 35*REGBYTES(sp) // Store ft4
fsw f5, 36*REGBYTES(sp) // Store ft5
fsw f6, 37*REGBYTES(sp) // Store ft6
fsw f7, 38*REGBYTES(sp) // Store ft7
fsw f10,41*REGBYTES(sp) // Store fa0
fsw f11,42*REGBYTES(sp) // Store fa1
fsw f12,43*REGBYTES(sp) // Store fa2
fsw f13,44*REGBYTES(sp) // Store fa3
fsw f14,45*REGBYTES(sp) // Store fa4
fsw f15,46*REGBYTES(sp) // Store fa5
fsw f16,47*REGBYTES(sp) // Store fa6
fsw f17,48*REGBYTES(sp) // Store fa7
fsw f28,59*REGBYTES(sp) // Store ft8
fsw f29,60*REGBYTES(sp) // Store ft9
fsw f30,61*REGBYTES(sp) // Store ft10
fsw f31,62*REGBYTES(sp) // Store ft11
csrr t0, fcsr
STORE t0, 63*REGBYTES(sp) // Store fcsr
#elif defined(__riscv_float_abi_double)
fsd f0, 31*REGBYTES(sp) // Store ft0
fsd f1, 32*REGBYTES(sp) // Store ft1
fsd f2, 33*REGBYTES(sp) // Store ft2
fsd f3, 34*REGBYTES(sp) // Store ft3
fsd f4, 35*REGBYTES(sp) // Store ft4
fsd f5, 36*REGBYTES(sp) // Store ft5
fsd f6, 37*REGBYTES(sp) // Store ft6
fsd f7, 38*REGBYTES(sp) // Store ft7
fsd f10,41*REGBYTES(sp) // Store fa0
fsd f11,42*REGBYTES(sp) // Store fa1
fsd f12,43*REGBYTES(sp) // Store fa2
fsd f13,44*REGBYTES(sp) // Store fa3
fsd f14,45*REGBYTES(sp) // Store fa4
fsd f15,46*REGBYTES(sp) // Store fa5
fsd f16,47*REGBYTES(sp) // Store fa6
fsd f17,48*REGBYTES(sp) // Store fa7
fsd f28,59*REGBYTES(sp) // Store ft8
fsd f29,60*REGBYTES(sp) // Store ft9
fsd f30,61*REGBYTES(sp) // Store ft10
fsd f31,62*REGBYTES(sp) // Store ft11
csrr t0, fcsr
STORE t0, 63*REGBYTES(sp) // Store fcsr
#endif
/* Save the current stack pointer in the thread's control block. */
/* _tx_thread_current_ptr -> tx_thread_stack_ptr = sp; */
/* Switch to the system stack. */
/* sp = _tx_thread_system_stack_ptr; */
LOAD t1, _tx_thread_current_ptr // Pickup current thread pointer
STORE sp, 2*REGBYTES(t1) // Save stack pointer
#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY
/* _tx_execution_isr_enter is called with thread stack pointer */
call _tx_execution_isr_enter // Call the ISR execution enter function
#endif
LOAD sp, _tx_thread_system_stack_ptr // Switch to system stack
ret // Return to calling ISR
/* }
else
{ */
_tx_thread_idle_system_save:
#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY
call _tx_execution_isr_enter // Call the ISR execution enter function
#endif
/* Interrupt occurred in the scheduling loop. */
/* }
} */
#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double)
addi sp, sp, 65*REGBYTES // Recover stack frame - with floating point enabled
#else
addi sp, sp, 32*REGBYTES // Recover the reserved stack space
#endif
ret // Return to calling ISR