| // 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) |
