1/* 2 * entry.S -- interrupt and exception processing for ColdFire 3 * 4 * Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com) 5 * Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>, 6 * Kenneth Albanowski <kjahds@kjahds.com>, 7 * Copyright (C) 2000 Lineo Inc. (www.lineo.com) 8 * Copyright (C) 2004-2006 Macq Electronique SA. (www.macqel.com) 9 * 10 * Based on: 11 * 12 * linux/arch/m68k/kernel/entry.S 13 * 14 * Copyright (C) 1991, 1992 Linus Torvalds 15 * 16 * This file is subject to the terms and conditions of the GNU General Public 17 * License. See the file README.legal in the main directory of this archive 18 * for more details. 19 * 20 * Linux/m68k support by Hamish Macdonald 21 * 22 * 68060 fixes by Jesper Skov 23 * ColdFire support by Greg Ungerer (gerg@snapgear.com) 24 * 5307 fixes by David W. Miller 25 * linux 2.4 support David McCullough <davidm@snapgear.com> 26 * Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be> 27 */ 28 29#include <linux/linkage.h> 30#include <asm/unistd.h> 31#include <asm/thread_info.h> 32#include <asm/errno.h> 33#include <asm/setup.h> 34#include <asm/segment.h> 35#include <asm/asm-offsets.h> 36#include <asm/entry.h> 37 38#ifdef CONFIG_COLDFIRE_SW_A7 39/* 40 * Define software copies of the supervisor and user stack pointers. 41 */ 42.bss 43sw_ksp: 44.long 0 45sw_usp: 46.long 0 47#endif /* CONFIG_COLDFIRE_SW_A7 */ 48 49.text 50 51.globl system_call 52.globl resume 53.globl ret_from_exception 54.globl ret_from_signal 55.globl sys_call_table 56.globl inthandler 57 58enosys: 59 mov.l #sys_ni_syscall,%d3 60 bra 1f 61 62ENTRY(system_call) 63 SAVE_ALL_SYS 64 move #0x2000,%sr /* enable intrs again */ 65 GET_CURRENT(%d2) 66 67 cmpl #NR_syscalls,%d0 68 jcc enosys 69 lea sys_call_table,%a0 70 lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */ 71 movel %a0@(%d0),%d3 72 jeq enosys 73 741: 75 movel %sp,%d2 /* get thread_info pointer */ 76 andl #-THREAD_SIZE,%d2 /* at start of kernel stack */ 77 movel %d2,%a0 78 movel %a0@,%a1 /* save top of frame */ 79 movel %sp,%a1@(TASK_THREAD+THREAD_ESP0) 80 btst #(TIF_SYSCALL_TRACE%8),%a0@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) 81 bnes 1f 82 83 movel %d3,%a0 84 jbsr %a0@ 85 movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 86 jra ret_from_exception 871: 88 movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_OFF_D0 */ 89 movel %d2,PT_OFF_D0(%sp) /* on syscall entry */ 90 subql #4,%sp 91 SAVE_SWITCH_STACK 92 jbsr syscall_trace_enter 93 RESTORE_SWITCH_STACK 94 addql #4,%sp 95 movel %d3,%a0 96 jbsr %a0@ 97 movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 98 subql #4,%sp /* dummy return address */ 99 SAVE_SWITCH_STACK 100 jbsr syscall_trace_leave 101 102ret_from_signal: 103 RESTORE_SWITCH_STACK 104 addql #4,%sp 105 106ret_from_exception: 107 move #0x2700,%sr /* disable intrs */ 108 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */ 109 jeq Luser_return /* if so, skip resched, signals */ 110 111#ifdef CONFIG_PREEMPT 112 movel %sp,%d1 /* get thread_info pointer */ 113 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 114 movel %d1,%a0 115 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 116 andl #(1<<TIF_NEED_RESCHED),%d1 117 jeq Lkernel_return 118 119 movel %a0@(TINFO_PREEMPT),%d1 120 cmpl #0,%d1 121 jne Lkernel_return 122 123 pea Lkernel_return 124 jmp preempt_schedule_irq /* preempt the kernel */ 125#endif 126 127Lkernel_return: 128 moveml %sp@,%d1-%d5/%a0-%a2 129 lea %sp@(32),%sp /* space for 8 regs */ 130 movel %sp@+,%d0 131 addql #4,%sp /* orig d0 */ 132 addl %sp@+,%sp /* stk adj */ 133 rte 134 135Luser_return: 136 movel %sp,%d1 /* get thread_info pointer */ 137 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 138 movel %d1,%a0 139 moveb %a0@(TINFO_FLAGS+3),%d1 /* thread_info->flags (low 8 bits) */ 140 jne Lwork_to_do /* still work to do */ 141 142Lreturn: 143 RESTORE_USER 144 145Lwork_to_do: 146 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 147 move #0x2000,%sr /* enable intrs again */ 148 btst #TIF_NEED_RESCHED,%d1 149 jne reschedule 150 151Lsignal_return: 152 subql #4,%sp /* dummy return address */ 153 SAVE_SWITCH_STACK 154 pea %sp@(SWITCH_STACK_SIZE) 155 jsr do_notify_resume 156 addql #4,%sp 157 RESTORE_SWITCH_STACK 158 addql #4,%sp 159 jmp Luser_return 160 161/* 162 * This is the generic interrupt handler (for all hardware interrupt 163 * sources). Calls up to high level code to do all the work. 164 */ 165ENTRY(inthandler) 166 SAVE_ALL_INT 167 GET_CURRENT(%d2) 168 169 movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */ 170 andl #0x03fc,%d0 /* mask out vector only */ 171 172 movel %sp,%sp@- /* push regs arg */ 173 lsrl #2,%d0 /* calculate real vector # */ 174 movel %d0,%sp@- /* push vector number */ 175 jbsr do_IRQ /* call high level irq handler */ 176 lea %sp@(8),%sp /* pop args off stack */ 177 178 bra ret_from_exception 179 180/* 181 * Beware - when entering resume, prev (the current task) is 182 * in a0, next (the new task) is in a1, so don't change these 183 * registers until their contents are no longer needed. 184 */ 185ENTRY(resume) 186 movew %sr,%d1 /* save current status */ 187 movew %d1,%a0@(TASK_THREAD+THREAD_SR) 188 movel %a0,%d1 /* get prev thread in d1 */ 189 SAVE_SWITCH_STACK 190 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */ 191 RDUSP /* movel %usp,%a3 */ 192 movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */ 193#ifdef CONFIG_MMU 194 movel %a1,%a2 /* set new current */ 195#endif 196 movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */ 197 WRUSP /* movel %a3,%usp */ 198 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */ 199 movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */ 200 movew %d7,%sr 201 RESTORE_SWITCH_STACK 202 rts 203 204