aboutsummaryrefslogtreecommitdiff
path: root/arch/microblaze/kernel/exceptions.c
blob: 02cbdfe5aa8dd1619ef25e14e65e4f34cf825129 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
/*
 * HW exception handling
 *
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008 PetaLogix
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of this
 * archive for more details.
 */

/*
 * This file handles the architecture-dependent parts of hardware exceptions
 */

#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kallsyms.h>
#include <linux/module.h>

#include <asm/exceptions.h>
#include <asm/entry.h>		/* For KM CPU var */
#include <linux/uaccess.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <asm/current.h>

#define MICROBLAZE_ILL_OPCODE_EXCEPTION	0x02
#define MICROBLAZE_IBUS_EXCEPTION	0x03
#define MICROBLAZE_DBUS_EXCEPTION	0x04
#define MICROBLAZE_DIV_ZERO_EXCEPTION	0x05
#define MICROBLAZE_FPU_EXCEPTION	0x06
#define MICROBLAZE_PRIVILEGED_EXCEPTION	0x07

static DEFINE_SPINLOCK(die_lock);

void die(const char *str, struct pt_regs *fp, long err)
{
	console_verbose();
	spin_lock_irq(&die_lock);
	printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err);
	show_regs(fp);
	spin_unlock_irq(&die_lock);
	/* do_exit() should take care of panic'ing from an interrupt
	 * context so we don't handle it here
	 */
	do_exit(err);
}

void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
	siginfo_t info;

	if (kernel_mode(regs)) {
		debugger(regs);
		die("Exception in kernel mode", regs, signr);
	}
	info.si_signo = signr;
	info.si_errno = 0;
	info.si_code = code;
	info.si_addr = (void __user *) addr;
	force_sig_info(signr, &info, current);
}

asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
							int fsr, int addr)
{
#ifdef CONFIG_MMU
	int code;
	addr = regs->pc;
#endif

#if 0
	printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \
							"ESR=%08x\n",
			type, user_mode(regs) ? "user" : "kernel", fsr,
			(unsigned int) regs->pc, (unsigned int) regs->esr);
#endif

	switch (type & 0x1F) {
	case MICROBLAZE_ILL_OPCODE_EXCEPTION:
		if (user_mode(regs)) {
			pr_debug(KERN_WARNING "Illegal opcode exception " \
							"in user mode.\n");
			_exception(SIGILL, regs, ILL_ILLOPC, addr);
			return;
		}
		printk(KERN_WARNING "Illegal opcode exception " \
							"in kernel mode.\n");
		die("opcode exception", regs, SIGBUS);
		break;
	case MICROBLAZE_IBUS_EXCEPTION:
		if (user_mode(regs)) {
			pr_debug(KERN_WARNING "Instruction bus error " \
						"exception in user mode.\n");
			_exception(SIGBUS, regs, BUS_ADRERR, addr);
			return;
		}
		printk(KERN_WARNING "Instruction bus error exception " \
							"in kernel mode.\n");
		die("bus exception", regs, SIGBUS);
		break;
	case MICROBLAZE_DBUS_EXCEPTION:
		if (user_mode(regs)) {
			pr_debug(KERN_WARNING "Data bus error exception " \
							"in user mode.\n");
			_exception(SIGBUS, regs, BUS_ADRERR, addr);
			return;
		}
		printk(KERN_WARNING "Data bus error exception " \
							"in kernel mode.\n");
		die("bus exception", regs, SIGBUS);
		break;
	case MICROBLAZE_DIV_ZERO_EXCEPTION:
		if (user_mode(regs)) {
			pr_debug(KERN_WARNING "Divide by zero exception " \
							"in user mode\n");
			_exception(SIGILL, regs, FPE_INTDIV, addr);
			return;
		}
		printk(KERN_WARNING "Divide by zero exception " \
							"in kernel mode.\n");
		die("Divide by zero exception", regs, SIGBUS);
		break;
	case MICROBLAZE_FPU_EXCEPTION:
		pr_debug(KERN_WARNING "FPU exception\n");
		/* IEEE FP exception */
		/* I removed fsr variable and use code var for storing fsr */
		if (fsr & FSR_IO)
			fsr = FPE_FLTINV;
		else if (fsr & FSR_OF)
			fsr = FPE_FLTOVF;
		else if (fsr & FSR_UF)
			fsr = FPE_FLTUND;
		else if (fsr & FSR_DZ)
			fsr = FPE_FLTDIV;
		else if (fsr & FSR_DO)
			fsr = FPE_FLTRES;
		_exception(SIGFPE, regs, fsr, addr);
		break;

#ifdef CONFIG_MMU
	case MICROBLAZE_PRIVILEGED_EXCEPTION:
		pr_debug(KERN_WARNING "Privileged exception\n");
		/* "brk r0,r0" - used as debug breakpoint */
		if (get_user(code, (unsigned long *)regs->pc) == 0
			&& code == 0x980c0000) {
			_exception(SIGTRAP, regs, TRAP_BRKPT, addr);
		} else {
			_exception(SIGILL, regs, ILL_PRVOPC, addr);
		}
		break;
#endif
	default:
	/* FIXME what to do in unexpected exception */
		printk(KERN_WARNING "Unexpected exception %02x "
			"PC=%08x in %s mode\n", type, (unsigned int) addr,
			kernel_mode(regs) ? "kernel" : "user");
	}
	return;
}