1/* 2 * linux/arch/m68knommu/platform/68360/entry.S 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * Copyright (C) 2001 SED Systems, a Division of Calian Ltd. 6 * 7 * This file is subject to the terms and conditions of the GNU General Public 8 * License. See the file README.legal in the main directory of this archive 9 * for more details. 10 * 11 * Linux/m68k support by Hamish Macdonald 12 * M68360 Port by SED Systems, and Lineo. 13 */ 14 15#include <linux/sys.h> 16#include <linux/linkage.h> 17#include <asm/thread_info.h> 18#include <asm/unistd.h> 19#include <asm/errno.h> 20#include <asm/setup.h> 21#include <asm/segment.h> 22#include <asm/traps.h> 23#include <asm/asm-offsets.h> 24#include <asm/entry.h> 25 26.text 27 28.globl system_call 29.globl resume 30.globl ret_from_exception 31.globl ret_from_signal 32.globl sys_call_table 33.globl ret_from_interrupt 34.globl bad_interrupt 35.globl inthandler 36 37badsys: 38 movel #-ENOSYS,%sp@(PT_D0) 39 jra ret_from_exception 40 41do_trace: 42 movel #-ENOSYS,%sp@(PT_D0) /* needed for strace*/ 43 subql #4,%sp 44 SAVE_SWITCH_STACK 45 jbsr syscall_trace 46 RESTORE_SWITCH_STACK 47 addql #4,%sp 48 movel %sp@(PT_ORIG_D0),%d1 49 movel #-ENOSYS,%d0 50 cmpl #NR_syscalls,%d1 51 jcc 1f 52 lsl #2,%d1 53 lea sys_call_table, %a0 54 jbsr %a0@(%d1) 55 561: movel %d0,%sp@(PT_D0) /* save the return value */ 57 subql #4,%sp /* dummy return address */ 58 SAVE_SWITCH_STACK 59 jbsr syscall_trace 60 61ret_from_signal: 62 RESTORE_SWITCH_STACK 63 addql #4,%sp 64 jra ret_from_exception 65 66ENTRY(system_call) 67 SAVE_ALL 68 69 /* save top of frame*/ 70 pea %sp@ 71 jbsr set_esp0 72 addql #4,%sp 73 74 btst #PF_TRACESYS_BIT,%a2@(TASK_FLAGS+PF_TRACESYS_OFF) 75 jne do_trace 76 cmpl #NR_syscalls,%d0 77 jcc badsys 78 lsl #2,%d0 79 lea sys_call_table,%a0 80 movel %a0@(%d0), %a0 81 jbsr %a0@ 82 movel %d0,%sp@(PT_D0) /* save the return value*/ 83 84ret_from_exception: 85 btst #5,%sp@(PT_SR) /* check if returning to kernel*/ 86 jeq Luser_return /* if so, skip resched, signals*/ 87 88Lkernel_return: 89 RESTORE_ALL 90 91Luser_return: 92 /* only allow interrupts when we are really the last one on the*/ 93 /* kernel stack, otherwise stack overflow can occur during*/ 94 /* heavy interrupt load*/ 95 andw #ALLOWINT,%sr 96 97 movel %sp,%d1 /* get thread_info pointer */ 98 andl #-THREAD_SIZE,%d1 99 movel %d1,%a2 100 move %a2@(TI_FLAGS),%d1 /* thread_info->flags */ 101 andl #_TIF_WORK_MASK,%d1 102 jne Lwork_to_do 103 RESTORE_ALL 104 105Lwork_to_do: 106 movel %a2@(TI_FLAGS),%d1 /* thread_info->flags */ 107 btst #TIF_NEED_RESCHED,%d1 108 jne reschedule 109 110Lsignal_return: 111 subql #4,%sp /* dummy return address*/ 112 SAVE_SWITCH_STACK 113 pea %sp@(SWITCH_STACK_SIZE) 114 clrl %sp@- 115 bsrw do_signal 116 addql #8,%sp 117 RESTORE_SWITCH_STACK 118 addql #4,%sp 119Lreturn: 120 RESTORE_ALL 121 122/* 123 * This is the main interrupt handler, responsible for calling process_int() 124 */ 125inthandler: 126 SAVE_ALL 127 addql #1,local_irq_count /* put exception # in d0*/ 128 movew %sp@(PT_VECTOR), %d0 129 and.l #0x3ff, %d0 130 lsr.l #0x02, %d0 131 132 movel %sp,%sp@- 133 movel %d0,%sp@- /* put vector # on stack*/ 134 jbsr process_int /* process the IRQ*/ 1353: addql #8,%sp /* pop parameters off stack*/ 136 bra ret_from_interrupt 137 138ret_from_interrupt: 139 subql #1,local_irq_count 140 jeq 1f 1412: 142 RESTORE_ALL 1431: 144 moveb %sp@(PT_SR), %d0 145 and #7, %d0 146 jhi 2b 147 /* check if we need to do software interrupts */ 148 149 movel irq_stat+CPUSTAT_SOFTIRQ_PENDING,%d0 150 jeq ret_from_exception 151 152 pea ret_from_exception 153 jra do_softirq 154 155 156/* 157 * Handler for uninitialized and spurious interrupts. 158 */ 159bad_interrupt: 160 addql #1,num_spurious 161 rte 162 163/* 164 * Beware - when entering resume, prev (the current task) is 165 * in a0, next (the new task) is in a1,so don't change these 166 * registers until their contents are no longer needed. 167 */ 168ENTRY(resume) 169 movel %a0,%d1 /* save prev thread in d1 */ 170 movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */ 171 movel %usp,%a2 /* save usp */ 172 movel %a2,%a0@(TASK_THREAD+THREAD_USP) 173 174 SAVE_SWITCH_STACK 175 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */ 176 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */ 177 RESTORE_SWITCH_STACK 178 179 movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore user stack */ 180 movel %a0,%usp 181 movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */ 182 rts 183