101 lines
2.2 KiB
ArmAsm
101 lines
2.2 KiB
ArmAsm
// 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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/*
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* $r0 = previous task_struct,
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* $r1 = next task_struct,
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* previous and next are guaranteed not to be the same.
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*/
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ENTRY(__switch_to)
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la $p0, __entry_task
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sw $r1, [$p0]
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addi $p1, $r0, #THREAD_CPU_CONTEXT
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smw.bi $r6, [$p1], $r14, #0xb ! push r6~r14, fp, lp, sp
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move $r25, $r1
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#if defined(CONFIG_FPU)
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call _switch_fpu
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#endif
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addi $r1, $r25, #THREAD_CPU_CONTEXT
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lmw.bi $r6, [$r1], $r14, #0xb ! pop r6~r14, fp, lp, sp
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ret
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#define tbl $r8
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/*
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* $r7 will be writen as syscall nr
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*/
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.macro get_scno
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lwi $r7, [$sp + R15_OFFSET]
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swi $r7, [$sp + SYSCALLNO_OFFSET]
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.endm
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.macro updateipc
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addi $r17, $r13, #4 ! $r13 is $IPC
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swi $r17, [$sp + IPC_OFFSET]
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.endm
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ENTRY(eh_syscall)
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updateipc
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get_scno
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gie_enable
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lwi $p0, [tsk+#TSK_TI_FLAGS] ! check for syscall tracing
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andi $p1, $p0, #_TIF_WORK_SYSCALL_ENTRY ! are we tracing syscalls?
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bnez $p1, __sys_trace
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la $lp, ret_fast_syscall ! return address
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jmp_systbl:
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addi $p1, $r7, #-__NR_syscalls ! syscall number of syscall instruction is guarded by addembler
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bgez $p1, _SCNO_EXCEED ! call sys_* routine
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la tbl, sys_call_table ! load syscall table pointer
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slli $p1, $r7, #2
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add $p1, tbl, $p1
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lwi $p1, [$p1]
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jr $p1 ! no return
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_SCNO_EXCEED:
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ori $r0, $r7, #0
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ori $r1, $sp, #0
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b bad_syscall
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/*
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* This is the really slow path. We're going to be doing
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* context switches, and waiting for our parent to respond.
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*/
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__sys_trace:
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move $r0, $sp
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bal syscall_trace_enter
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move $r7, $r0
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la $lp, __sys_trace_return ! return address
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addi $p1, $r7, #1
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beqz $p1, ret_slow_syscall ! fatal signal is pending
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addi $p1, $sp, #R0_OFFSET ! pointer to regs
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lmw.bi $r0, [$p1], $r5 ! have to reload $r0 - $r5
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b jmp_systbl
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__sys_trace_return:
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swi $r0, [$sp+#R0_OFFSET] ! T: save returned $r0
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move $r0, $sp ! set pt_regs for syscall_trace_leave
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bal syscall_trace_leave
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b ret_slow_syscall
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ENTRY(sys_rt_sigreturn_wrapper)
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addi $r0, $sp, #0
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b sys_rt_sigreturn
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ENDPROC(sys_rt_sigreturn_wrapper)
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