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/asm-offsets.h> 35#include <asm/entry.h> 36 37#ifdef CONFIG_COLDFIRE_SW_A7 38/* 39 * Define software copies of the supervisor and user stack pointers. 40 */ 41.bss 42sw_ksp: 43.long 0 44sw_usp: 45.long 0 46#endif /* CONFIG_COLDFIRE_SW_A7 */ 47 48.text 49 50.globl system_call 51.globl resume 52.globl ret_from_exception 53.globl sys_call_table 54.globl inthandler 55 56enosys: 57 mov.l #sys_ni_syscall,%d3 58 bra 1f 59 60ENTRY(system_call) 61 SAVE_ALL_SYS 62 move #0x2000,%sr /* enable intrs again */ 63 GET_CURRENT(%d2) 64 65 cmpl #NR_syscalls,%d0 66 jcc enosys 67 lea sys_call_table,%a0 68 lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */ 69 movel %a0@(%d0),%d3 70 jeq enosys 71 721: 73 movel %sp,%d2 /* get thread_info pointer */ 74 andl #-THREAD_SIZE,%d2 /* at start of kernel stack */ 75 movel %d2,%a0 76 movel %a0@,%a1 /* save top of frame */ 77 movel %sp,%a1@(TASK_THREAD+THREAD_ESP0) 78 btst #(TIF_SYSCALL_TRACE%8),%a0@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) 79 bnes 1f 80 81 movel %d3,%a0 82 jbsr %a0@ 83 movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 84 jra ret_from_exception 851: 86 movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_OFF_D0 */ 87 movel %d2,PT_OFF_D0(%sp) /* on syscall entry */ 88 subql #4,%sp 89 SAVE_SWITCH_STACK 90 jbsr syscall_trace_enter 91 RESTORE_SWITCH_STACK 92 addql #4,%sp 93 movel %d3,%a0 94 jbsr %a0@ 95 movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 96 subql #4,%sp /* dummy return address */ 97 SAVE_SWITCH_STACK 98 jbsr syscall_trace_leave 99 RESTORE_SWITCH_STACK 100 addql #4,%sp 101 102ret_from_exception: 103 move #0x2700,%sr /* disable intrs */ 104 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */ 105 jeq Luser_return /* if so, skip resched, signals */ 106 107#ifdef CONFIG_PREEMPTION 108 movel %sp,%d1 /* get thread_info pointer */ 109 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 110 movel %d1,%a0 111 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 112 andl #(1<<TIF_NEED_RESCHED),%d1 113 jeq Lkernel_return 114 115 movel %a0@(TINFO_PREEMPT),%d1 116 cmpl #0,%d1 117 jne Lkernel_return 118 119 pea Lkernel_return 120 jmp preempt_schedule_irq /* preempt the kernel */ 121#endif 122 123Lkernel_return: 124 moveml %sp@,%d1-%d5/%a0-%a2 125 lea %sp@(32),%sp /* space for 8 regs */ 126 movel %sp@+,%d0 127 addql #4,%sp /* orig d0 */ 128 addl %sp@+,%sp /* stk adj */ 129 rte 130 131Luser_return: 132 movel %sp,%d1 /* get thread_info pointer */ 133 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 134 movel %d1,%a0 135 moveb %a0@(TINFO_FLAGS+3),%d1 /* thread_info->flags (low 8 bits) */ 136 jne Lwork_to_do /* still work to do */ 137 138Lreturn: 139 RESTORE_USER 140 141Lwork_to_do: 142 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 143 move #0x2000,%sr /* enable intrs again */ 144 btst #TIF_NEED_RESCHED,%d1 145 jne reschedule 146 147Lsignal_return: 148 subql #4,%sp /* dummy return address */ 149 SAVE_SWITCH_STACK 150 pea %sp@(SWITCH_STACK_SIZE) 151 jsr do_notify_resume 152 addql #4,%sp 153 RESTORE_SWITCH_STACK 154 addql #4,%sp 155 jmp Luser_return 156 157/* 158 * This is the generic interrupt handler (for all hardware interrupt 159 * sources). Calls up to high level code to do all the work. 160 */ 161ENTRY(inthandler) 162 SAVE_ALL_INT 163 GET_CURRENT(%d2) 164 165 movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */ 166 andl #0x03fc,%d0 /* mask out vector only */ 167 168 movel %sp,%sp@- /* push regs arg */ 169 lsrl #2,%d0 /* calculate real vector # */ 170 movel %d0,%sp@- /* push vector number */ 171 jbsr do_IRQ /* call high level irq handler */ 172 lea %sp@(8),%sp /* pop args off stack */ 173 174 bra ret_from_exception 175 176/* 177 * Beware - when entering resume, prev (the current task) is 178 * in a0, next (the new task) is in a1, so don't change these 179 * registers until their contents are no longer needed. 180 */ 181ENTRY(resume) 182 movew %sr,%d1 /* save current status */ 183 movew %d1,%a0@(TASK_THREAD+THREAD_SR) 184 movel %a0,%d1 /* get prev thread in d1 */ 185 SAVE_SWITCH_STACK 186 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */ 187 RDUSP /* movel %usp,%a3 */ 188 movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */ 189#ifdef CONFIG_MMU 190 movel %a1,%a2 /* set new current */ 191#endif 192 movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */ 193 WRUSP /* movel %a3,%usp */ 194 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */ 195 movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */ 196 movew %d7,%sr 197 RESTORE_SWITCH_STACK 198 rts 199 200