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

source code of linux/arch/m68k/coldfire/entry.S