1/* 2 * entry.S -- non-mmu 68000 interrupt and exception entry points 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file README.legal in the main directory of this archive 8 * for more details. 9 * 10 * Linux/m68k support by Hamish Macdonald 11 */ 12 13#include <linux/linkage.h> 14#include <asm/thread_info.h> 15#include <asm/unistd.h> 16#include <asm/errno.h> 17#include <asm/setup.h> 18#include <asm/segment.h> 19#include <asm/traps.h> 20#include <asm/asm-offsets.h> 21#include <asm/entry.h> 22 23.text 24 25.globl system_call 26.globl resume 27.globl ret_from_exception 28.globl ret_from_signal 29.globl sys_call_table 30.globl bad_interrupt 31.globl inthandler1 32.globl inthandler2 33.globl inthandler3 34.globl inthandler4 35.globl inthandler5 36.globl inthandler6 37.globl inthandler7 38 39badsys: 40 movel #-ENOSYS,%sp@(PT_OFF_D0) 41 jra ret_from_exception 42 43do_trace: 44 movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/ 45 subql #4,%sp 46 SAVE_SWITCH_STACK 47 jbsr syscall_trace_enter 48 RESTORE_SWITCH_STACK 49 addql #4,%sp 50 movel %sp@(PT_OFF_ORIG_D0),%d1 51 movel #-ENOSYS,%d0 52 cmpl #NR_syscalls,%d1 53 jcc 1f 54 lsl #2,%d1 55 lea sys_call_table, %a0 56 jbsr %a0@(%d1) 57 581: movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 59 subql #4,%sp /* dummy return address */ 60 SAVE_SWITCH_STACK 61 jbsr syscall_trace_leave 62 63ret_from_signal: 64 RESTORE_SWITCH_STACK 65 addql #4,%sp 66 jra ret_from_exception 67 68ENTRY(system_call) 69 SAVE_ALL_SYS 70 71 /* save top of frame*/ 72 pea %sp@ 73 jbsr set_esp0 74 addql #4,%sp 75 76 movel %sp@(PT_OFF_ORIG_D0),%d0 77 78 movel %sp,%d1 /* get thread_info pointer */ 79 andl #-THREAD_SIZE,%d1 80 movel %d1,%a2 81 btst #(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) 82 jne do_trace 83 cmpl #NR_syscalls,%d0 84 jcc badsys 85 lsl #2,%d0 86 lea sys_call_table,%a0 87 movel %a0@(%d0), %a0 88 jbsr %a0@ 89 movel %d0,%sp@(PT_OFF_D0) /* save the return value*/ 90 91ret_from_exception: 92 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/ 93 jeq Luser_return /* if so, skip resched, signals*/ 94 95Lkernel_return: 96 RESTORE_ALL 97 98Luser_return: 99 /* only allow interrupts when we are really the last one on the*/ 100 /* kernel stack, otherwise stack overflow can occur during*/ 101 /* heavy interrupt load*/ 102 andw #ALLOWINT,%sr 103 104 movel %sp,%d1 /* get thread_info pointer */ 105 andl #-THREAD_SIZE,%d1 106 movel %d1,%a2 1071: 108 move %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */ 109 jne Lwork_to_do 110 RESTORE_ALL 111 112Lwork_to_do: 113 movel %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */ 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