/* * entry.S -- non-mmu 68000 interrupt and exception entry points * * Copyright (C) 1991, 1992 Linus Torvalds * * This file is subject to the terms and conditions of the GNU General Public * License. See the file README.legal in the main directory of this archive * for more details. * * Linux/m68k support by Hamish Macdonald */ #include #include #include #include #include #include #include #include #include .text .globl system_call .globl resume .globl ret_from_exception .globl ret_from_signal .globl sys_call_table .globl bad_interrupt .globl inthandler1 .globl inthandler2 .globl inthandler3 .globl inthandler4 .globl inthandler5 .globl inthandler6 .globl inthandler7 badsys: movel #-ENOSYS,%sp@(PT_OFF_D0) jra ret_from_exception do_trace: movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/ subql #4,%sp SAVE_SWITCH_STACK jbsr syscall_trace_enter RESTORE_SWITCH_STACK addql #4,%sp movel %sp@(PT_OFF_ORIG_D0),%d1 movel #-ENOSYS,%d0 cmpl #NR_syscalls,%d1 jcc 1f lsl #2,%d1 lea sys_call_table, %a0 jbsr %a0@(%d1) 1: movel %d0,%sp@(PT_OFF_D0) /* save the return value */ subql #4,%sp /* dummy return address */ SAVE_SWITCH_STACK jbsr syscall_trace_leave ret_from_signal: RESTORE_SWITCH_STACK addql #4,%sp jra ret_from_exception ENTRY(system_call) SAVE_ALL_SYS /* save top of frame*/ pea %sp@ jbsr set_esp0 addql #4,%sp movel %sp@(PT_OFF_ORIG_D0),%d0 movel %sp,%d1 /* get thread_info pointer */ andl #-THREAD_SIZE,%d1 movel %d1,%a2 btst #(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) jne do_trace cmpl #NR_syscalls,%d0 jcc badsys lsl #2,%d0 lea sys_call_table,%a0 movel %a0@(%d0), %a0 jbsr %a0@ movel %d0,%sp@(PT_OFF_D0) /* save the return value*/ ret_from_exception: btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/ jeq Luser_return /* if so, skip resched, signals*/ Lkernel_return: RESTORE_ALL Luser_return: /* only allow interrupts when we are really the last one on the*/ /* kernel stack, otherwise stack overflow can occur during*/ /* heavy interrupt load*/ andw #ALLOWINT,%sr movel %sp,%d1 /* get thread_info pointer */ andl #-THREAD_SIZE,%d1 movel %d1,%a2 1: move %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */ jne Lwork_to_do RESTORE_ALL Lwork_to_do: movel %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */ btst #TIF_NEED_RESCHED,%d1 jne reschedule Lsignal_return: subql #4,%sp /* dummy return address*/ SAVE_SWITCH_STACK pea %sp@(SWITCH_STACK_SIZE) bsrw do_notify_resume addql #4,%sp RESTORE_SWITCH_STACK addql #4,%sp jra 1b /* * This is the main interrupt handler, responsible for calling process_int() */ inthandler1: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel #65,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception inthandler2: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel #66,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception inthandler3: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel #67,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception inthandler4: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel #68,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception inthandler5: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel #69,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception inthandler6: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel #70,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception inthandler7: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel #71,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception inthandler: SAVE_ALL_INT movew %sp@(PT_OFF_FORMATVEC), %d0 and #0x3ff, %d0 movel %sp,%sp@- movel %d0,%sp@- /* put vector # on stack*/ jbsr process_int /* process the IRQ*/ 3: addql #8,%sp /* pop parameters off stack*/ bra ret_from_exception /* * Handler for uninitialized and spurious interrupts. */ ENTRY(bad_interrupt) addql #1,irq_err_count rte /* * Beware - when entering resume, prev (the current task) is * in a0, next (the new task) is in a1, so don't change these * registers until their contents are no longer needed. */ ENTRY(resume) movel %a0,%d1 /* save prev thread in d1 */ movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */ SAVE_SWITCH_STACK movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */ movel %usp,%a3 /* save usp */ movel %a3,%a0@(TASK_THREAD+THREAD_USP) movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore user stack */ movel %a3,%usp movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */ RESTORE_SWITCH_STACK movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */ rts