// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2005-2017 Andes Technology Corporation
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#include <linux/linkage.h>
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#include <asm/unistd.h>
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#include <asm/assembler.h>
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#include <asm/nds32.h>
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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#include <asm/current.h>
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#include <asm/fpu.h>
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#ifdef CONFIG_HWZOL
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.macro pop_zol
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mtusr $r14, $LB
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mtusr $r15, $LE
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mtusr $r16, $LC
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.endm
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#endif
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.macro restore_user_regs_first
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setgie.d
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isb
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#if defined(CONFIG_FPU)
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addi $sp, $sp, OSP_OFFSET
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lmw.adm $r12, [$sp], $r25, #0x0
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sethi $p0, hi20(has_fpu)
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lbsi $p0, [$p0+lo12(has_fpu)]
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beqz $p0, 2f
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mtsr $r25, $FUCOP_CTL
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2:
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#else
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addi $sp, $sp, FUCOP_CTL_OFFSET
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lmw.adm $r12, [$sp], $r24, #0x0
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#endif
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mtsr $r12, $SP_USR
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mtsr $r13, $IPC
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#ifdef CONFIG_HWZOL
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pop_zol
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#endif
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mtsr $r19, $PSW
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mtsr $r20, $IPSW
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mtsr $r21, $P_IPSW
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mtsr $r22, $P_IPC
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mtsr $r23, $P_P0
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mtsr $r24, $P_P1
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lmw.adm $sp, [$sp], $sp, #0xe
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.endm
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.macro restore_user_regs_last
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pop $p0
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cmovn $sp, $p0, $p0
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iret
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nop
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.endm
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.macro restore_user_regs
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restore_user_regs_first
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lmw.adm $r0, [$sp], $r25, #0x0
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addi $sp, $sp, OSP_OFFSET
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restore_user_regs_last
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.endm
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.macro fast_restore_user_regs
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restore_user_regs_first
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lmw.adm $r1, [$sp], $r25, #0x0
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addi $sp, $sp, OSP_OFFSET-4
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restore_user_regs_last
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.endm
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#ifdef CONFIG_PREEMPTION
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.macro preempt_stop
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.endm
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#else
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.macro preempt_stop
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setgie.d
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isb
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.endm
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#define resume_kernel no_work_pending
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#endif
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ENTRY(ret_from_exception)
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preempt_stop
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ENTRY(ret_from_intr)
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/*
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* judge Kernel or user mode
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*
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*/
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lwi $p0, [$sp+(#IPSW_OFFSET)] ! Check if in nested interrupt
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andi $p0, $p0, #PSW_mskINTL
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bnez $p0, resume_kernel ! done with iret
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j resume_userspace
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/*
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* This is the fast syscall return path. We do as little as
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* possible here, and this includes saving $r0 back into the SVC
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* stack.
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* fixed: tsk - $r25, syscall # - $r7, syscall table pointer - $r8
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*/
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ENTRY(ret_fast_syscall)
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gie_disable
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lwi $r1, [tsk+#TSK_TI_FLAGS]
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andi $p1, $r1, #_TIF_WORK_MASK
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bnez $p1, fast_work_pending
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fast_restore_user_regs ! iret
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/*
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* Ok, we need to do extra processing,
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* enter the slow path returning from syscall, while pending work.
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*/
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fast_work_pending:
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swi $r0, [$sp+(#R0_OFFSET)] ! what is different from ret_from_exception
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work_pending:
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andi $p1, $r1, #_TIF_NEED_RESCHED
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bnez $p1, work_resched
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andi $p1, $r1, #_TIF_SIGPENDING|#_TIF_NOTIFY_RESUME|#_TIF_NOTIFY_SIGNAL
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beqz $p1, no_work_pending
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move $r0, $sp ! 'regs'
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gie_enable
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bal do_notify_resume
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b ret_slow_syscall
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work_resched:
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bal schedule ! path, return to user mode
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/*
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* "slow" syscall return path.
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*/
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ENTRY(resume_userspace)
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ENTRY(ret_slow_syscall)
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gie_disable
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lwi $p0, [$sp+(#IPSW_OFFSET)] ! Check if in nested interrupt
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andi $p0, $p0, #PSW_mskINTL
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bnez $p0, no_work_pending ! done with iret
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lwi $r1, [tsk+#TSK_TI_FLAGS]
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andi $p1, $r1, #_TIF_WORK_MASK
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bnez $p1, work_pending ! handle work_resched, sig_pend
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no_work_pending:
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#ifdef CONFIG_TRACE_IRQFLAGS
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lwi $p0, [$sp+(#IPSW_OFFSET)]
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andi $p0, $p0, #0x1
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la $r10, __trace_hardirqs_off
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la $r9, __trace_hardirqs_on
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cmovz $r9, $p0, $r10
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jral $r9
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#endif
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restore_user_regs ! return from iret
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/*
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* preemptive kernel
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*/
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#ifdef CONFIG_PREEMPTION
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resume_kernel:
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gie_disable
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lwi $t0, [tsk+#TSK_TI_PREEMPT]
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bnez $t0, no_work_pending
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lwi $t0, [tsk+#TSK_TI_FLAGS]
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andi $p1, $t0, #_TIF_NEED_RESCHED
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beqz $p1, no_work_pending
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lwi $t0, [$sp+(#IPSW_OFFSET)] ! Interrupts off?
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andi $t0, $t0, #1
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beqz $t0, no_work_pending
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jal preempt_schedule_irq
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b no_work_pending
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#endif
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/*
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* This is how we return from a fork.
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*/
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ENTRY(ret_from_fork)
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bal schedule_tail
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beqz $r6, 1f ! r6 stores fn for kernel thread
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move $r0, $r7 ! prepare kernel thread arg
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jral $r6
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1:
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lwi $r1, [tsk+#TSK_TI_FLAGS] ! check for syscall tracing
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andi $p1, $r1, #_TIF_WORK_SYSCALL_LEAVE ! are we tracing syscalls?
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beqz $p1, ret_slow_syscall
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move $r0, $sp
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bal syscall_trace_leave
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b ret_slow_syscall
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