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 42 sw_ksp: 43 .long 0 44 sw_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 56 enosys: 57 mov.l #sys_ni_syscall,%d3 58 bra 1f 59 60 ENTRY(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 72 1: 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 85 1: 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 addql #1,%d0 94 jeq ret_from_exception 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 RESTORE_SWITCH_STACK 102 addql #4,%sp 103 104 ret_from_exception: 105 move #0x2700,%sr /* disable intrs */ 106 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */ 107 jeq Luser_return /* if so, skip resched, signals */ 108 109 #ifdef CONFIG_PREEMPTION 110 movel %sp,%d1 /* get thread_info pointer */ 111 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 112 movel %d1,%a0 113 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 114 andl #(1<<TIF_NEED_RESCHED),%d1 115 jeq Lkernel_return 116 117 movel %a0@(TINFO_PREEMPT),%d1 118 cmpl #0,%d1 119 jne Lkernel_return 120 121 pea Lkernel_return 122 jmp preempt_schedule_irq /* preempt the kernel */ 123 #endif 124 125 Lkernel_return: 126 moveml %sp@,%d1-%d5/%a0-%a2 127 lea %sp@(32),%sp /* space for 8 regs */ 128 movel %sp@+,%d0 129 addql #4,%sp /* orig d0 */ 130 addl %sp@+,%sp /* stk adj */ 131 rte 132 133 Luser_return: 134 movel %sp,%d1 /* get thread_info pointer */ 135 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 136 movel %d1,%a0 137 moveb %a0@(TINFO_FLAGS+3),%d1 /* thread_info->flags (low 8 bits) */ 138 jne Lwork_to_do /* still work to do */ 139 140 Lreturn: 141 RESTORE_USER 142 143 Lwork_to_do: 144 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 145 move #0x2000,%sr /* enable intrs again */ 146 btst #TIF_NEED_RESCHED,%d1 147 jne reschedule 148 149 Lsignal_return: 150 subql #4,%sp /* dummy return address */ 151 SAVE_SWITCH_STACK 152 pea %sp@(SWITCH_STACK_SIZE) 153 jsr do_notify_resume 154 addql #4,%sp 155 RESTORE_SWITCH_STACK 156 addql #4,%sp 157 jmp Luser_return 158 159 /* 160 * This is the generic interrupt handler (for all hardware interrupt 161 * sources). Calls up to high level code to do all the work. 162 */ 163 ENTRY(inthandler) 164 SAVE_ALL_INT 165 GET_CURRENT(%d2) 166 167 movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */ 168 andl #0x03fc,%d0 /* mask out vector only */ 169 170 movel %sp,%sp@- /* push regs arg */ 171 lsrl #2,%d0 /* calculate real vector # */ 172 movel %d0,%sp@- /* push vector number */ 173 jbsr do_IRQ /* call high level irq handler */ 174 lea %sp@(8),%sp /* pop args off stack */ 175 176 bra ret_from_exception 177 178 /* 179 * Beware - when entering resume, prev (the current task) is 180 * in a0, next (the new task) is in a1, so don't change these 181 * registers until their contents are no longer needed. 182 */ 183 ENTRY(resume) 184 movew %sr,%d1 /* save current status */ 185 movew %d1,%a0@(TASK_THREAD+THREAD_SR) 186 movel %a0,%d1 /* get prev thread in d1 */ 187 SAVE_SWITCH_STACK 188 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */ 189 RDUSP /* movel %usp,%a3 */ 190 movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */ 191 #ifdef CONFIG_MMU 192 movel %a1,%a2 /* set new current */ 193 #endif 194 movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */ 195 WRUSP /* movel %a3,%usp */ 196 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */ 197 movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */ 198 movew %d7,%sr 199 RESTORE_SWITCH_STACK 200 rts 201 202