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/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2018/10/02 Bernard The first version
* 2018/12/27 Jesven Add SMP schedule
* 2021/02/02 lizhirui Add userspace support
* 2021/12/24 JasonHu Add user setting save/restore
* 2022/10/22 Shell Support kernel mode RVV;
* Rewrite trap handling routine
*/
#include "cpuport.h"
#include "encoding.h"
#include "stackframe.h"
.align 2
.global trap_entry
.global debug_check_sp
trap_entry:
// distingush exception from kernel or user
csrrw sp, sscratch, sp
bnez sp, _save_context
// BE REALLY careful with sscratch,
// if it's wrong, we could looping here forever
// or accessing random memory and seeing things totally
// messy after a long time and don't even know why
_from_kernel:
csrr sp, sscratch
j _save_context
_save_context:
SAVE_ALL
// clear sscratch to say 'now in kernel mode'
csrw sscratch, zero
RESTORE_SYS_GP
// now we are ready to enter interrupt / excepiton handler
_distinguish_syscall:
csrr t0, scause
#ifdef RT_USING_SMART
// TODO swap 8 with config macro name
li t1, 8
bne t0, t1, _handle_interrupt_and_exception
call syscall_entry
// syscall never return here
#endif
_handle_interrupt_and_exception:
mv a0, t0
csrrc a1, stval, zero
csrr a2, sepc
// sp as exception frame pointer
mv a3, sp
call handle_trap
_interrupt_exit:
#ifndef RT_USING_SMP
la s0, rt_thread_switch_interrupt_flag
lw s2, 0(s0)
beqz s2, _resume_execution
sw zero, 0(s0)
#else
mv a0, sp
call rt_scheduler_do_irq_switch
// if failed, jump to __resume_execution
j _resume_execution
#endif /* RT_USING_SMP */
_context_switch:
la t0, rt_interrupt_from_thread
LOAD a0, 0(t0)
la t0, rt_interrupt_to_thread
LOAD a1, 0(t0)
csrr t0, sstatus
andi t0, t0, ~SSTATUS_SPIE
csrw sstatus, t0
jal rt_hw_context_switch
_resume_execution:
#ifdef RT_USING_SMART
LOAD t0, FRAME_OFF_SSTATUS(sp)
andi t0, t0, SSTATUS_SPP
bnez t0, _resume_kernel
call arch_ret_to_user
#endif
_resume_kernel:
RESTORE_ALL
csrw sscratch, zero
sret
#ifndef RT_USING_SMP
.global rt_hw_interrupt_enable
rt_hw_interrupt_enable:
csrs sstatus, a0 /* restore to old csr */
jr ra
.global rt_hw_interrupt_disable
rt_hw_interrupt_disable:
csrrci a0, sstatus, 2 /* clear SIE */
jr ra
#else
.global rt_hw_local_irq_disable
rt_hw_local_irq_disable:
csrrci a0, sstatus, 2
jr ra
.global rt_hw_local_irq_enable
rt_hw_local_irq_enable:
csrs sstatus, a0
jr ra
.global rt_hw_secondary_cpu_idle_exec
rt_hw_secondary_cpu_idle_exec:
jr ra
#endif /* RT_USING_SMP */
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