| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | // Copyright (C) 2005-2017 Andes Technology Corporation |
| 3 | |
| 4 | #include <linux/linkage.h> |
| 5 | #include <asm/unistd.h> |
| 6 | #include <asm/assembler.h> |
| 7 | #include <asm/nds32.h> |
| 8 | #include <asm/asm-offsets.h> |
| 9 | #include <asm/thread_info.h> |
| 10 | #include <asm/current.h> |
| 11 | #include <asm/fpu.h> |
| 12 | |
| 13 | |
| 14 | |
| 15 | #ifdef CONFIG_HWZOL |
| 16 | .macro pop_zol |
| 17 | mtusr $r14, $LB |
| 18 | mtusr $r15, $LE |
| 19 | mtusr $r16, $LC |
| 20 | .endm |
| 21 | #endif |
| 22 | |
| 23 | .macro restore_user_regs_first |
| 24 | setgie.d |
| 25 | isb |
| 26 | #if defined(CONFIG_FPU) |
| 27 | addi $sp, $sp, OSP_OFFSET |
| 28 | lmw.adm $r12, [$sp], $r25, #0x0 |
| 29 | sethi $p0, hi20(has_fpu) |
| 30 | lbsi $p0, [$p0+lo12(has_fpu)] |
| 31 | beqz $p0, 2f |
| 32 | mtsr $r25, $FUCOP_CTL |
| 33 | 2: |
| 34 | #else |
| 35 | addi $sp, $sp, FUCOP_CTL_OFFSET |
| 36 | lmw.adm $r12, [$sp], $r24, #0x0 |
| 37 | #endif |
| 38 | mtsr $r12, $SP_USR |
| 39 | mtsr $r13, $IPC |
| 40 | #ifdef CONFIG_HWZOL |
| 41 | pop_zol |
| 42 | #endif |
| 43 | mtsr $r19, $PSW |
| 44 | mtsr $r20, $IPSW |
| 45 | mtsr $r21, $P_IPSW |
| 46 | mtsr $r22, $P_IPC |
| 47 | mtsr $r23, $P_P0 |
| 48 | mtsr $r24, $P_P1 |
| 49 | lmw.adm $sp, [$sp], $sp, #0xe |
| 50 | .endm |
| 51 | |
| 52 | .macro restore_user_regs_last |
| 53 | pop $p0 |
| 54 | cmovn $sp, $p0, $p0 |
| 55 | |
| 56 | iret |
| 57 | nop |
| 58 | |
| 59 | .endm |
| 60 | |
| 61 | .macro restore_user_regs |
| 62 | restore_user_regs_first |
| 63 | lmw.adm $r0, [$sp], $r25, #0x0 |
| 64 | addi $sp, $sp, OSP_OFFSET |
| 65 | restore_user_regs_last |
| 66 | .endm |
| 67 | |
| 68 | .macro fast_restore_user_regs |
| 69 | restore_user_regs_first |
| 70 | lmw.adm $r1, [$sp], $r25, #0x0 |
| 71 | addi $sp, $sp, OSP_OFFSET-4 |
| 72 | restore_user_regs_last |
| 73 | .endm |
| 74 | |
| 75 | #ifdef CONFIG_PREEMPT |
| 76 | .macro preempt_stop |
| 77 | .endm |
| 78 | #else |
| 79 | .macro preempt_stop |
| 80 | setgie.d |
| 81 | isb |
| 82 | .endm |
| 83 | #define resume_kernel no_work_pending |
| 84 | #endif |
| 85 | |
| 86 | ENTRY(ret_from_exception) |
| 87 | preempt_stop |
| 88 | ENTRY(ret_from_intr) |
| 89 | |
| 90 | /* |
| 91 | * judge Kernel or user mode |
| 92 | * |
| 93 | */ |
| 94 | lwi $p0, [$sp+(#IPSW_OFFSET)] ! Check if in nested interrupt |
| 95 | andi $p0, $p0, #PSW_mskINTL |
| 96 | bnez $p0, resume_kernel ! done with iret |
| 97 | j resume_userspace |
| 98 | |
| 99 | |
| 100 | /* |
| 101 | * This is the fast syscall return path. We do as little as |
| 102 | * possible here, and this includes saving $r0 back into the SVC |
| 103 | * stack. |
| 104 | * fixed: tsk - $r25, syscall # - $r7, syscall table pointer - $r8 |
| 105 | */ |
| 106 | ENTRY(ret_fast_syscall) |
| 107 | gie_disable |
| 108 | lwi $r1, [tsk+#TSK_TI_FLAGS] |
| 109 | andi $p1, $r1, #_TIF_WORK_MASK |
| 110 | bnez $p1, fast_work_pending |
| 111 | fast_restore_user_regs ! iret |
| 112 | |
| 113 | /* |
| 114 | * Ok, we need to do extra processing, |
| 115 | * enter the slow path returning from syscall, while pending work. |
| 116 | */ |
| 117 | fast_work_pending: |
| 118 | swi $r0, [$sp+(#R0_OFFSET)] ! what is different from ret_from_exception |
| 119 | work_pending: |
| 120 | andi $p1, $r1, #_TIF_NEED_RESCHED |
| 121 | bnez $p1, work_resched |
| 122 | |
| 123 | andi $p1, $r1, #_TIF_SIGPENDING|#_TIF_NOTIFY_RESUME |
| 124 | beqz $p1, no_work_pending |
| 125 | |
| 126 | move $r0, $sp ! 'regs' |
| 127 | gie_enable |
| 128 | bal do_notify_resume |
| 129 | b ret_slow_syscall |
| 130 | work_resched: |
| 131 | bal schedule ! path, return to user mode |
| 132 | |
| 133 | /* |
| 134 | * "slow" syscall return path. |
| 135 | */ |
| 136 | ENTRY(resume_userspace) |
| 137 | ENTRY(ret_slow_syscall) |
| 138 | gie_disable |
| 139 | lwi $p0, [$sp+(#IPSW_OFFSET)] ! Check if in nested interrupt |
| 140 | andi $p0, $p0, #PSW_mskINTL |
| 141 | bnez $p0, no_work_pending ! done with iret |
| 142 | lwi $r1, [tsk+#TSK_TI_FLAGS] |
| 143 | andi $p1, $r1, #_TIF_WORK_MASK |
| 144 | bnez $p1, work_pending ! handle work_resched, sig_pend |
| 145 | |
| 146 | no_work_pending: |
| 147 | #ifdef CONFIG_TRACE_IRQFLAGS |
| 148 | lwi $p0, [$sp+(#IPSW_OFFSET)] |
| 149 | andi $p0, $p0, #0x1 |
| 150 | la $r10, __trace_hardirqs_off |
| 151 | la $r9, __trace_hardirqs_on |
| 152 | cmovz $r9, $p0, $r10 |
| 153 | jral $r9 |
| 154 | #endif |
| 155 | restore_user_regs ! return from iret |
| 156 | |
| 157 | |
| 158 | /* |
| 159 | * preemptive kernel |
| 160 | */ |
| 161 | #ifdef CONFIG_PREEMPT |
| 162 | resume_kernel: |
| 163 | gie_disable |
| 164 | lwi $t0, [tsk+#TSK_TI_PREEMPT] |
| 165 | bnez $t0, no_work_pending |
| 166 | |
| 167 | lwi $t0, [tsk+#TSK_TI_FLAGS] |
| 168 | andi $p1, $t0, #_TIF_NEED_RESCHED |
| 169 | beqz $p1, no_work_pending |
| 170 | |
| 171 | lwi $t0, [$sp+(#IPSW_OFFSET)] ! Interrupts off? |
| 172 | andi $t0, $t0, #1 |
| 173 | beqz $t0, no_work_pending |
| 174 | |
| 175 | jal preempt_schedule_irq |
| 176 | b no_work_pending |
| 177 | #endif |
| 178 | |
| 179 | /* |
| 180 | * This is how we return from a fork. |
| 181 | */ |
| 182 | ENTRY(ret_from_fork) |
| 183 | bal schedule_tail |
| 184 | beqz $r6, 1f ! r6 stores fn for kernel thread |
| 185 | move $r0, $r7 ! prepare kernel thread arg |
| 186 | jral $r6 |
| 187 | 1: |
| 188 | lwi $r1, [tsk+#TSK_TI_FLAGS] ! check for syscall tracing |
| 189 | andi $p1, $r1, #_TIF_WORK_SYSCALL_LEAVE ! are we tracing syscalls? |
| 190 | beqz $p1, ret_slow_syscall |
| 191 | move $r0, $sp |
| 192 | bal syscall_trace_leave |
| 193 | b ret_slow_syscall |