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/*
* Copyright (c) 2006-2024, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2018/10/28 Bernard The unify RISC-V porting implementation
* 2018/12/27 Jesven Add SMP support
* 2021/02/02 lizhirui Add userspace support
* 2022/10/22 Shell Support User mode RVV;
* Trimming process switch context
*/
#include "cpuport.h"
#include "stackframe.h"
#define _REG_IDX(name) RT_HW_SWITCH_CONTEXT_##name
#define REG_IDX(name) _REG_IDX(name)
.macro SAVE_REG reg, index
STORE \reg, \index*REGBYTES(sp)
.endm
.macro LOAD_REG reg, index
LOAD \reg, \index*REGBYTES(sp)
.endm
.macro RESERVE_CONTEXT
addi sp, sp, -(RT_HW_SWITCH_CONTEXT_SIZE * REGBYTES)
SAVE_REG tp, REG_IDX(TP)
SAVE_REG ra, REG_IDX(RA)
SAVE_REG s0, REG_IDX(S0)
SAVE_REG s1, REG_IDX(S1)
SAVE_REG s2, REG_IDX(S2)
SAVE_REG s3, REG_IDX(S3)
SAVE_REG s4, REG_IDX(S4)
SAVE_REG s5, REG_IDX(S5)
SAVE_REG s6, REG_IDX(S6)
SAVE_REG s7, REG_IDX(S7)
SAVE_REG s8, REG_IDX(S8)
SAVE_REG s9, REG_IDX(S9)
SAVE_REG s10, REG_IDX(S10)
SAVE_REG s11, REG_IDX(S11)
csrr s11, sstatus
li s10, (SSTATUS_SPP)
or s11, s11, s10
SAVE_REG s11, REG_IDX(SSTATUS)
.endm
.macro RESTORE_CONTEXT
LOAD_REG s11, REG_IDX(SSTATUS)
csrw sstatus, s11
LOAD_REG s11, REG_IDX(S11)
LOAD_REG s10, REG_IDX(S10)
LOAD_REG s9, REG_IDX(S9)
LOAD_REG s8, REG_IDX(S8)
LOAD_REG s7, REG_IDX(S7)
LOAD_REG s6, REG_IDX(S6)
LOAD_REG s5, REG_IDX(S5)
LOAD_REG s4, REG_IDX(S4)
LOAD_REG s3, REG_IDX(S3)
LOAD_REG s2, REG_IDX(S2)
LOAD_REG s1, REG_IDX(S1)
LOAD_REG s0, REG_IDX(S0)
LOAD_REG ra, REG_IDX(RA)
LOAD_REG tp, REG_IDX(TP)
addi sp, sp, RT_HW_SWITCH_CONTEXT_SIZE * REGBYTES
csrw sepc, ra
.endm
/*
* #ifdef RT_USING_SMP
* void rt_hw_context_switch_to(rt_ubase_t to, stuct rt_thread *to_thread);
* #else
* void rt_hw_context_switch_to(rt_ubase_t to);
* #endif
* a0 --> to
* a1 --> to_thread
*/
.globl rt_hw_context_switch_to
rt_hw_context_switch_to:
LOAD sp, (a0)
#ifdef RT_USING_SMP
/* Pass the previous CPU lock status to rt_cpus_lock_status_restore for restoration */
mv a0, a1
call rt_cpus_lock_status_restore
#endif
call rt_thread_self
mv s1, a0
#ifndef RT_USING_SMP
//if enable RT_USING_SMP, it will finished by rt_cpus_lock_status_restore.
#ifdef RT_USING_SMART
call lwp_aspace_switch
#endif
#endif
RESTORE_CONTEXT
sret
/*
* #ifdef RT_USING_SMP
* void rt_hw_context_switch(rt_ubase_t from, rt_ubase_t to, struct rt_thread *to_thread);
* #else
* void rt_hw_context_switch(rt_ubase_t from, rt_ubase_t to);
* #endif
*
* a0 --> from SP pointer
* a1 --> to SP pointer
* a2 --> to_thread
*
* It should only be used on local interrupt disable
*/
.globl rt_hw_context_switch
rt_hw_context_switch:
RESERVE_CONTEXT
STORE sp, (a0)
// restore to thread SP
LOAD sp, (a1)
#ifdef RT_USING_SMP
/* Pass the previous CPU lock status to rt_cpus_lock_status_restore for restoration */
mv a0, a2
call rt_cpus_lock_status_restore
#endif /*RT_USING_SMP*/
// restore Address Space
call rt_thread_self
mv s1, a0
#ifndef RT_USING_SMP
// if enable RT_USING_SMP, it will finished by rt_cpus_lock_status_restore.
#ifdef RT_USING_SMART
call lwp_aspace_switch
#endif
#endif
RESTORE_CONTEXT
sret
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