1 /*
2 * HW exception handling
3 *
4 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
5 * Copyright (C) 2008 PetaLogix
6 *
7 * This file is subject to the terms and conditions of the GNU General
8 * Public License. See the file COPYING in the main directory of this
9 * archive for more details.
10 */
11
12 /*
13 * This file handles the architecture-dependent parts of hardware exceptions
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/signal.h>
18 #include <linux/sched.h>
19 #include <linux/kallsyms.h>
20 #include <linux/module.h>
21
22 #include <asm/exceptions.h>
23 #include <asm/entry.h> /* For KM CPU var */
24 #include <linux/uaccess.h>
25 #include <linux/errno.h>
26 #include <linux/ptrace.h>
27 #include <asm/current.h>
28 #include <asm/cacheflush.h>
29
30 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
31 #define MICROBLAZE_IBUS_EXCEPTION 0x03
32 #define MICROBLAZE_DBUS_EXCEPTION 0x04
33 #define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05
34 #define MICROBLAZE_FPU_EXCEPTION 0x06
35 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
36
37 static DEFINE_SPINLOCK(die_lock);
38
die(const char * str,struct pt_regs * fp,long err)39 void die(const char *str, struct pt_regs *fp, long err)
40 {
41 console_verbose();
42 spin_lock_irq(&die_lock);
43 printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err);
44 show_regs(fp);
45 spin_unlock_irq(&die_lock);
46 /* do_exit() should take care of panic'ing from an interrupt
47 * context so we don't handle it here
48 */
49 do_exit(err);
50 }
51
52 /* for user application debugging */
sw_exception(struct pt_regs * regs)53 asmlinkage void sw_exception(struct pt_regs *regs)
54 {
55 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
56 flush_dcache_range(regs->r16, regs->r16 + 0x4);
57 flush_icache_range(regs->r16, regs->r16 + 0x4);
58 }
59
_exception(int signr,struct pt_regs * regs,int code,unsigned long addr)60 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
61 {
62 siginfo_t info;
63
64 if (kernel_mode(regs)) {
65 die("Exception in kernel mode", regs, signr);
66 }
67 info.si_signo = signr;
68 info.si_errno = 0;
69 info.si_code = code;
70 info.si_addr = (void __user *) addr;
71 force_sig_info(signr, &info, current);
72 }
73
full_exception(struct pt_regs * regs,unsigned int type,int fsr,int addr)74 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
75 int fsr, int addr)
76 {
77 #ifdef CONFIG_MMU
78 addr = regs->pc;
79 #endif
80
81 #if 0
82 printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \
83 "ESR=%08x\n",
84 type, user_mode(regs) ? "user" : "kernel", fsr,
85 (unsigned int) regs->pc, (unsigned int) regs->esr);
86 #endif
87
88 switch (type & 0x1F) {
89 case MICROBLAZE_ILL_OPCODE_EXCEPTION:
90 if (user_mode(regs)) {
91 pr_debug("Illegal opcode exception in user mode\n");
92 _exception(SIGILL, regs, ILL_ILLOPC, addr);
93 return;
94 }
95 printk(KERN_WARNING "Illegal opcode exception " \
96 "in kernel mode.\n");
97 die("opcode exception", regs, SIGBUS);
98 break;
99 case MICROBLAZE_IBUS_EXCEPTION:
100 if (user_mode(regs)) {
101 pr_debug("Instruction bus error exception in user mode\n");
102 _exception(SIGBUS, regs, BUS_ADRERR, addr);
103 return;
104 }
105 printk(KERN_WARNING "Instruction bus error exception " \
106 "in kernel mode.\n");
107 die("bus exception", regs, SIGBUS);
108 break;
109 case MICROBLAZE_DBUS_EXCEPTION:
110 if (user_mode(regs)) {
111 pr_debug("Data bus error exception in user mode\n");
112 _exception(SIGBUS, regs, BUS_ADRERR, addr);
113 return;
114 }
115 printk(KERN_WARNING "Data bus error exception " \
116 "in kernel mode.\n");
117 die("bus exception", regs, SIGBUS);
118 break;
119 case MICROBLAZE_DIV_ZERO_EXCEPTION:
120 if (user_mode(regs)) {
121 pr_debug("Divide by zero exception in user mode\n");
122 _exception(SIGILL, regs, FPE_INTDIV, addr);
123 return;
124 }
125 printk(KERN_WARNING "Divide by zero exception " \
126 "in kernel mode.\n");
127 die("Divide by zero exception", regs, SIGBUS);
128 break;
129 case MICROBLAZE_FPU_EXCEPTION:
130 pr_debug("FPU exception\n");
131 /* IEEE FP exception */
132 /* I removed fsr variable and use code var for storing fsr */
133 if (fsr & FSR_IO)
134 fsr = FPE_FLTINV;
135 else if (fsr & FSR_OF)
136 fsr = FPE_FLTOVF;
137 else if (fsr & FSR_UF)
138 fsr = FPE_FLTUND;
139 else if (fsr & FSR_DZ)
140 fsr = FPE_FLTDIV;
141 else if (fsr & FSR_DO)
142 fsr = FPE_FLTRES;
143 _exception(SIGFPE, regs, fsr, addr);
144 break;
145
146 #ifdef CONFIG_MMU
147 case MICROBLAZE_PRIVILEGED_EXCEPTION:
148 pr_debug("Privileged exception\n");
149 _exception(SIGILL, regs, ILL_PRVOPC, addr);
150 break;
151 #endif
152 default:
153 /* FIXME what to do in unexpected exception */
154 printk(KERN_WARNING "Unexpected exception %02x "
155 "PC=%08x in %s mode\n", type, (unsigned int) addr,
156 kernel_mode(regs) ? "kernel" : "user");
157 }
158 return;
159 }
160