1/* SPDX-License-Identifier: GPL-2.0-or-later 2 * 3 * entry.S -- non-mmu 68000 interrupt and exception entry points 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * Linux/m68k support by Hamish Macdonald 8 */ 9 10#include <linux/linkage.h> 11#include <asm/thread_info.h> 12#include <asm/unistd.h> 13#include <asm/errno.h> 14#include <asm/setup.h> 15#include <asm/traps.h> 16#include <asm/asm-offsets.h> 17#include <asm/entry.h> 18 19.text 20 21/* get thread_info pointer into a2 */ 22 .macro getthreadinfo 23 movel %sp,%d1 24 andl #-THREAD_SIZE,%d1 25 movel %d1,%a2 26 .endm 27 28.globl system_call 29.globl resume 30.globl ret_from_exception 31.globl sys_call_table 32.globl bad_interrupt 33.globl inthandler1 34.globl inthandler2 35.globl inthandler3 36.globl inthandler4 37.globl inthandler5 38.globl inthandler6 39.globl inthandler7 40 41badsys: 42 movel #-ENOSYS,%sp@(PT_OFF_D0) 43 jra ret_from_exception 44 45do_trace: 46 movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/ 47 subql #4,%sp 48 SAVE_SWITCH_STACK 49 jbsr syscall_trace_enter 50 RESTORE_SWITCH_STACK 51 addql #4,%sp 52 addql #1,%d0 53 jeq ret_from_exception 54 movel %sp@(PT_OFF_ORIG_D0),%d1 55 movel #-ENOSYS,%d0 56 cmpl #NR_syscalls,%d1 57 jcc 1f 58 lsl #2,%d1 59 lea sys_call_table, %a0 60 jbsr %a0@(%d1) 61 621: movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 63 subql #4,%sp /* dummy return address */ 64 SAVE_SWITCH_STACK 65 jbsr syscall_trace_leave 66 RESTORE_SWITCH_STACK 67 addql #4,%sp 68 jra ret_from_exception 69 70ENTRY(system_call) 71 SAVE_ALL_SYS 72 73 /* save top of frame*/ 74 pea %sp@ 75 jbsr set_esp0 76 addql #4,%sp 77 78 movel %sp@(PT_OFF_ORIG_D0),%d0 79 80 /* Doing a trace ? */ 81 getthreadinfo 82 btst #(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) 83 jne do_trace 84 cmpl #NR_syscalls,%d0 85 jcc badsys 86 lsl #2,%d0 87 lea sys_call_table,%a0 88 movel %a0@(%d0), %a0 89 jbsr %a0@ 90 movel %d0,%sp@(PT_OFF_D0) /* save the return value*/ 91 92ret_from_exception: 93 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/ 94 jeq Luser_return /* if so, skip resched, signals*/ 95 96Lkernel_return: 97 RESTORE_ALL 98 99Luser_return: 100 /* only allow interrupts when we are really the last one on the*/ 101 /* kernel stack, otherwise stack overflow can occur during*/ 102 /* heavy interrupt load*/ 103 andw #ALLOWINT,%sr 104 105 getthreadinfo 1061: 107 /* check if any of the flags are set */ 108 moveb %a2@(TINFO_FLAGS + 3),%d1 /* thread_info->flags (low 8 bits) */ 109 jne Lwork_to_do 110 RESTORE_ALL 111 112Lwork_to_do: 113 /* check if reschedule needs to be called */ 114 btst #TIF_NEED_RESCHED,%d1 115 jne reschedule 116 117Lsignal_return: 118 subql #4,%sp /* dummy return address*/ 119 SAVE_SWITCH_STACK 120 pea %sp@(SWITCH_STACK_SIZE) 121 bsrw do_notify_resume 122 addql #4,%sp 123 RESTORE_SWITCH_STACK 124 addql #4,%sp 125 jra 1b 126 127/* 128 * This is the main interrupt handler, responsible for calling process_int() 129 */ 130inthandler1: 131 SAVE_ALL_INT 132 movew %sp@(PT_OFF_FORMATVEC), %d0 133 and #0x3ff, %d0 134 135 movel %sp,%sp@- 136 movel #65,%sp@- /* put vector # on stack*/ 137 jbsr process_int /* process the IRQ*/ 1383: addql #8,%sp /* pop parameters off stack*/ 139 bra ret_from_exception 140 141inthandler2: 142 SAVE_ALL_INT 143 movew %sp@(PT_OFF_FORMATVEC), %d0 144 and #0x3ff, %d0 145 146 movel %sp,%sp@- 147 movel #66,%sp@- /* put vector # on stack*/ 148 jbsr process_int /* process the IRQ*/ 1493: addql #8,%sp /* pop parameters off stack*/ 150 bra ret_from_exception 151 152inthandler3: 153 SAVE_ALL_INT 154 movew %sp@(PT_OFF_FORMATVEC), %d0 155 and #0x3ff, %d0 156 157 movel %sp,%sp@- 158 movel #67,%sp@- /* put vector # on stack*/ 159 jbsr process_int /* process the IRQ*/ 1603: addql #8,%sp /* pop parameters off stack*/ 161 bra ret_from_exception 162 163inthandler4: 164 SAVE_ALL_INT 165 movew %sp@(PT_OFF_FORMATVEC), %d0 166 and #0x3ff, %d0 167 168 movel %sp,%sp@- 169 movel #68,%sp@- /* put vector # on stack*/ 170 jbsr process_int /* process the IRQ*/ 1713: addql #8,%sp /* pop parameters off stack*/ 172 bra ret_from_exception 173 174inthandler5: 175 SAVE_ALL_INT 176 movew %sp@(PT_OFF_FORMATVEC), %d0 177 and #0x3ff, %d0 178 179 movel %sp,%sp@- 180 movel #69,%sp@- /* put vector # on stack*/ 181 jbsr process_int /* process the IRQ*/ 1823: addql #8,%sp /* pop parameters off stack*/ 183 bra ret_from_exception 184 185inthandler6: 186 SAVE_ALL_INT 187 movew %sp@(PT_OFF_FORMATVEC), %d0 188 and #0x3ff, %d0 189 190 movel %sp,%sp@- 191 movel #70,%sp@- /* put vector # on stack*/ 192 jbsr process_int /* process the IRQ*/ 1933: addql #8,%sp /* pop parameters off stack*/ 194 bra ret_from_exception 195 196inthandler7: 197 SAVE_ALL_INT 198 movew %sp@(PT_OFF_FORMATVEC), %d0 199 and #0x3ff, %d0 200 201 movel %sp,%sp@- 202 movel #71,%sp@- /* put vector # on stack*/ 203 jbsr process_int /* process the IRQ*/ 2043: addql #8,%sp /* pop parameters off stack*/ 205 bra ret_from_exception 206 207inthandler: 208 SAVE_ALL_INT 209 movew %sp@(PT_OFF_FORMATVEC), %d0 210 and #0x3ff, %d0 211 212 movel %sp,%sp@- 213 movel %d0,%sp@- /* put vector # on stack*/ 214 jbsr process_int /* process the IRQ*/ 2153: addql #8,%sp /* pop parameters off stack*/ 216 bra ret_from_exception 217 218/* 219 * Handler for uninitialized and spurious interrupts. 220 */ 221ENTRY(bad_interrupt) 222 addql #1,irq_err_count 223 rte 224 225/* 226 * Beware - when entering resume, prev (the current task) is 227 * in a0, next (the new task) is in a1, so don't change these 228 * registers until their contents are no longer needed. 229 */ 230ENTRY(resume) 231 movel %a0,%d1 /* save prev thread in d1 */ 232 movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */ 233 SAVE_SWITCH_STACK 234 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */ 235 movel %usp,%a3 /* save usp */ 236 movel %a3,%a0@(TASK_THREAD+THREAD_USP) 237 238 movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore user stack */ 239 movel %a3,%usp 240 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */ 241 RESTORE_SWITCH_STACK 242 movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */ 243 rts 244 245