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_OFF_D0) 39 jra ret_from_exception 40 41do_trace: 42 movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/ 43 subql #4,%sp 44 SAVE_SWITCH_STACK 45 jbsr syscall_trace_enter 46 RESTORE_SWITCH_STACK 47 addql #4,%sp 48 movel %sp@(PT_OFF_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_OFF_D0) /* save the return value */ 57 subql #4,%sp /* dummy return address */ 58 SAVE_SWITCH_STACK 59 jbsr syscall_trace_leave 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 movel %sp@(PT_OFF_ORIG_D0),%d0 75 76 movel %sp,%d1 /* get thread_info pointer */ 77 andl #-THREAD_SIZE,%d1 78 movel %d1,%a2 79 btst #(TIF_SYSCALL_TRACE%8),%a2@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8) 80 jne do_trace 81 cmpl #NR_syscalls,%d0 82 jcc badsys 83 lsl #2,%d0 84 lea sys_call_table,%a0 85 movel %a0@(%d0), %a0 86 jbsr %a0@ 87 movel %d0,%sp@(PT_OFF_D0) /* save the return value*/ 88 89ret_from_exception: 90 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/ 91 jeq Luser_return /* if so, skip resched, signals*/ 92 93Lkernel_return: 94 RESTORE_ALL 95 96Luser_return: 97 /* only allow interrupts when we are really the last one on the*/ 98 /* kernel stack, otherwise stack overflow can occur during*/ 99 /* heavy interrupt load*/ 100 andw #ALLOWINT,%sr 101 102 movel %sp,%d1 /* get thread_info pointer */ 103 andl #-THREAD_SIZE,%d1 104 movel %d1,%a2 1051: 106 move %a2@(TI_FLAGS),%d1 /* thread_info->flags */ 107 jne Lwork_to_do 108 RESTORE_ALL 109 110Lwork_to_do: 111 movel %a2@(TI_FLAGS),%d1 /* thread_info->flags */ 112 btst #TIF_NEED_RESCHED,%d1 113 jne reschedule 114 115Lsignal_return: 116 subql #4,%sp /* dummy return address*/ 117 SAVE_SWITCH_STACK 118 pea %sp@(SWITCH_STACK_SIZE) 119 bsrw do_signal 120 addql #4,%sp 121 RESTORE_SWITCH_STACK 122 addql #4,%sp 123 jra 1b 124 125/* 126 * This is the main interrupt handler, responsible for calling do_IRQ() 127 */ 128inthandler: 129 SAVE_ALL 130 movew %sp@(PT_OFF_FORMATVEC), %d0 131 and.l #0x3ff, %d0 132 lsr.l #0x02, %d0 133 134 movel %sp,%sp@- 135 movel %d0,%sp@- /* put vector # on stack*/ 136 jbsr do_IRQ /* process the IRQ*/ 1373: addql #8,%sp /* pop parameters off stack*/ 138 bra ret_from_interrupt 139 140ret_from_interrupt: 141 jeq 1f 1422: 143 RESTORE_ALL 1441: 145 moveb %sp@(PT_OFF_SR), %d0 146 and #7, %d0 147 jhi 2b 148 /* check if we need to do software interrupts */ 149 150 movel irq_stat+CPUSTAT_SOFTIRQ_PENDING,%d0 151 jeq ret_from_exception 152 153 pea ret_from_exception 154 jra do_softirq 155 156 157/* 158 * Handler for uninitialized and spurious interrupts. 159 */ 160bad_interrupt: 161 addql #1,num_spurious 162 rte 163 164/* 165 * Beware - when entering resume, prev (the current task) is 166 * in a0, next (the new task) is in a1,so don't change these 167 * registers until their contents are no longer needed. 168 */ 169ENTRY(resume) 170 movel %a0,%d1 /* save prev thread in d1 */ 171 movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */ 172 movel %usp,%a2 /* save usp */ 173 movel %a2,%a0@(TASK_THREAD+THREAD_USP) 174 175 SAVE_SWITCH_STACK 176 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */ 177 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */ 178 RESTORE_SWITCH_STACK 179 180 movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore user stack */ 181 movel %a0,%usp 182 movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */ 183 rts 184 185