1/* SPDX-License-Identifier: GPL-2.0-or-later 2 * 3 * entry.S -- interrupt and exception processing for ColdFire 4 * 5 * Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com) 6 * Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>, 7 * Kenneth Albanowski <kjahds@kjahds.com>, 8 * Copyright (C) 2000 Lineo Inc. (www.lineo.com) 9 * Copyright (C) 2004-2006 Macq Electronique SA. (www.macqel.com) 10 * 11 * Based on: 12 * 13 * linux/arch/m68k/kernel/entry.S 14 * 15 * Copyright (C) 1991, 1992 Linus Torvalds 16 * 17 * Linux/m68k support by Hamish Macdonald 18 * 19 * 68060 fixes by Jesper Skov 20 * ColdFire support by Greg Ungerer (gerg@snapgear.com) 21 * 5307 fixes by David W. Miller 22 * linux 2.4 support David McCullough <davidm@snapgear.com> 23 * Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be> 24 */ 25 26#include <linux/linkage.h> 27#include <asm/unistd.h> 28#include <asm/thread_info.h> 29#include <asm/errno.h> 30#include <asm/setup.h> 31#include <asm/asm-offsets.h> 32#include <asm/entry.h> 33 34#ifdef CONFIG_COLDFIRE_SW_A7 35/* 36 * Define software copies of the supervisor and user stack pointers. 37 */ 38.bss 39sw_ksp: 40.long 0 41sw_usp: 42.long 0 43#endif /* CONFIG_COLDFIRE_SW_A7 */ 44 45.text 46 47.globl system_call 48.globl resume 49.globl ret_from_exception 50.globl sys_call_table 51.globl inthandler 52 53enosys: 54 mov.l #sys_ni_syscall,%d3 55 bra 1f 56 57ENTRY(system_call) 58 SAVE_ALL_SYS 59 move #0x2000,%sr /* enable intrs again */ 60 GET_CURRENT(%d2) 61 62 cmpl #NR_syscalls,%d0 63 jcc enosys 64 lea sys_call_table,%a0 65 lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */ 66 movel %a0@(%d0),%d3 67 jeq enosys 68 691: 70 movel %sp,%d2 /* get thread_info pointer */ 71 andl #-THREAD_SIZE,%d2 /* at start of kernel stack */ 72 movel %d2,%a0 73 movel %a0@,%a1 /* save top of frame */ 74 movel %sp,%a1@(TASK_THREAD+THREAD_ESP0) 75 btst #(TIF_SYSCALL_TRACE%8),%a0@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) 76 bnes 1f 77 78 movel %d3,%a0 79 jbsr %a0@ 80 movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 81 jra ret_from_exception 821: 83 movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_OFF_D0 */ 84 movel %d2,PT_OFF_D0(%sp) /* on syscall entry */ 85 subql #4,%sp 86 SAVE_SWITCH_STACK 87 jbsr syscall_trace_enter 88 RESTORE_SWITCH_STACK 89 addql #4,%sp 90 addql #1,%d0 91 jeq ret_from_exception 92 movel %d3,%a0 93 jbsr %a0@ 94 movel %d0,%sp@(PT_OFF_D0) /* save the return value */ 95 subql #4,%sp /* dummy return address */ 96 SAVE_SWITCH_STACK 97 jbsr syscall_trace_leave 98 RESTORE_SWITCH_STACK 99 addql #4,%sp 100 101ret_from_exception: 102 move #0x2700,%sr /* disable intrs */ 103 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */ 104 jeq Luser_return /* if so, skip resched, signals */ 105 106#ifdef CONFIG_PREEMPTION 107 movel %sp,%d1 /* get thread_info pointer */ 108 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 109 movel %d1,%a0 110 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 111 andl #(1<<TIF_NEED_RESCHED),%d1 112 jeq Lkernel_return 113 114 movel %a0@(TINFO_PREEMPT),%d1 115 cmpl #0,%d1 116 jne Lkernel_return 117 118 pea Lkernel_return 119 jmp preempt_schedule_irq /* preempt the kernel */ 120#endif 121 122Lkernel_return: 123 moveml %sp@,%d1-%d5/%a0-%a2 124 lea %sp@(32),%sp /* space for 8 regs */ 125 movel %sp@+,%d0 126 addql #4,%sp /* orig d0 */ 127 addl %sp@+,%sp /* stk adj */ 128 rte 129 130Luser_return: 131 movel %sp,%d1 /* get thread_info pointer */ 132 andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ 133 movel %d1,%a0 134 moveb %a0@(TINFO_FLAGS+3),%d1 /* thread_info->flags (low 8 bits) */ 135 jne Lwork_to_do /* still work to do */ 136 137Lreturn: 138 RESTORE_USER 139 140Lwork_to_do: 141 movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ 142 move #0x2000,%sr /* enable intrs again */ 143 btst #TIF_NEED_RESCHED,%d1 144 jne reschedule 145 146Lsignal_return: 147 subql #4,%sp /* dummy return address */ 148 SAVE_SWITCH_STACK 149 pea %sp@(SWITCH_STACK_SIZE) 150 jsr do_notify_resume 151 addql #4,%sp 152 RESTORE_SWITCH_STACK 153 addql #4,%sp 154 jmp Luser_return 155 156/* 157 * This is the generic interrupt handler (for all hardware interrupt 158 * sources). Calls up to high level code to do all the work. 159 */ 160ENTRY(inthandler) 161 SAVE_ALL_INT 162 GET_CURRENT(%d2) 163 164 movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */ 165 andl #0x03fc,%d0 /* mask out vector only */ 166 167 movel %sp,%sp@- /* push regs arg */ 168 lsrl #2,%d0 /* calculate real vector # */ 169 movel %d0,%sp@- /* push vector number */ 170 jbsr do_IRQ /* call high level irq handler */ 171 lea %sp@(8),%sp /* pop args off stack */ 172 173 bra ret_from_exception 174 175/* 176 * Beware - when entering resume, prev (the current task) is 177 * in a0, next (the new task) is in a1, so don't change these 178 * registers until their contents are no longer needed. 179 */ 180ENTRY(resume) 181 movew %sr,%d1 /* save current status */ 182 movew %d1,%a0@(TASK_THREAD+THREAD_SR) 183 movel %a0,%d1 /* get prev thread in d1 */ 184 SAVE_SWITCH_STACK 185 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */ 186 RDUSP /* movel %usp,%a3 */ 187 movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */ 188#ifdef CONFIG_MMU 189 movel %a1,%a2 /* set new current */ 190#endif 191 movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */ 192 WRUSP /* movel %a3,%usp */ 193 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */ 194 movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */ 195 movew %d7,%sr 196 RESTORE_SWITCH_STACK 197 rts 198 199