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