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