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| // SPDX-License-Identifier: GPL-2.0
| // Copyright (C) 2005-2017 Andes Technology Corporation
|
| #include <linux/linkage.h>
| #include <asm/unistd.h>
| #include <asm/assembler.h>
| #include <asm/nds32.h>
| #include <asm/asm-offsets.h>
| #include <asm/thread_info.h>
| #include <asm/current.h>
|
| /*
| * $r0 = previous task_struct,
| * $r1 = next task_struct,
| * previous and next are guaranteed not to be the same.
| */
|
| ENTRY(__switch_to)
|
| la $p0, __entry_task
| sw $r1, [$p0]
| addi $p1, $r0, #THREAD_CPU_CONTEXT
| smw.bi $r6, [$p1], $r14, #0xb ! push r6~r14, fp, lp, sp
| move $r25, $r1
| #if defined(CONFIG_FPU)
| call _switch_fpu
| #endif
| addi $r1, $r25, #THREAD_CPU_CONTEXT
| lmw.bi $r6, [$r1], $r14, #0xb ! pop r6~r14, fp, lp, sp
| ret
|
|
| #define tbl $r8
|
| /*
| * $r7 will be writen as syscall nr
| */
| .macro get_scno
| lwi $r7, [$sp + R15_OFFSET]
| swi $r7, [$sp + SYSCALLNO_OFFSET]
| .endm
|
| .macro updateipc
| addi $r17, $r13, #4 ! $r13 is $IPC
| swi $r17, [$sp + IPC_OFFSET]
| .endm
|
| ENTRY(eh_syscall)
| updateipc
|
| get_scno
| gie_enable
|
| lwi $p0, [tsk+#TSK_TI_FLAGS] ! check for syscall tracing
|
| andi $p1, $p0, #_TIF_WORK_SYSCALL_ENTRY ! are we tracing syscalls?
| bnez $p1, __sys_trace
|
| la $lp, ret_fast_syscall ! return address
| jmp_systbl:
| addi $p1, $r7, #-__NR_syscalls ! syscall number of syscall instruction is guarded by addembler
| bgez $p1, _SCNO_EXCEED ! call sys_* routine
| la tbl, sys_call_table ! load syscall table pointer
| slli $p1, $r7, #2
| add $p1, tbl, $p1
| lwi $p1, [$p1]
| jr $p1 ! no return
|
| _SCNO_EXCEED:
| ori $r0, $r7, #0
| ori $r1, $sp, #0
| b bad_syscall
|
| /*
| * This is the really slow path. We're going to be doing
| * context switches, and waiting for our parent to respond.
| */
| __sys_trace:
| move $r0, $sp
| bal syscall_trace_enter
| move $r7, $r0
| la $lp, __sys_trace_return ! return address
|
| addi $p1, $r7, #1
| beqz $p1, ret_slow_syscall ! fatal signal is pending
|
| addi $p1, $sp, #R0_OFFSET ! pointer to regs
| lmw.bi $r0, [$p1], $r5 ! have to reload $r0 - $r5
| b jmp_systbl
|
| __sys_trace_return:
| swi $r0, [$sp+#R0_OFFSET] ! T: save returned $r0
| move $r0, $sp ! set pt_regs for syscall_trace_leave
| bal syscall_trace_leave
| b ret_slow_syscall
|
| ENTRY(sys_rt_sigreturn_wrapper)
| addi $r0, $sp, #0
| b sys_rt_sigreturn
| ENDPROC(sys_rt_sigreturn_wrapper)
|
|
