release/src-rt-6.x.4708/linux/linux-2.6.36/arch/microblaze/kernel/exceptions.c

   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
  29 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
  30 #define MICROBLAZE_IBUS_EXCEPTION       0x03
  31 #define MICROBLAZE_DBUS_EXCEPTION       0x04
  32 #define MICROBLAZE_DIV_ZERO_EXCEPTION   0x05
  33 #define MICROBLAZE_FPU_EXCEPTION        0x06
  34 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
  35
  36 static DEFINE_SPINLOCK(die_lock);
  37
  38 void die(const char *str, struct pt_regs *fp, long err)
  39 {
  40         console_verbose();
  41         spin_lock_irq(&die_lock);
  42         printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err);
  43         show_regs(fp);
  44         spin_unlock_irq(&die_lock);
  45         /* do_exit() should take care of panic'ing from an interrupt
  46          * context so we don't handle it here
  47          */
  48         do_exit(err);
  49 }
  50
  51 /* for user application debugging */
  52 void sw_exception(struct pt_regs *regs)
  53 {
  54         _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
  55 }
  56
  57 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
  58 {
  59         siginfo_t info;
  60
  61         if (kernel_mode(regs)) {
  62                 die("Exception in kernel mode", regs, signr);
  63         }
  64         info.si_signo = signr;
  65         info.si_errno = 0;
  66         info.si_code = code;
  67         info.si_addr = (void __user *) addr;
  68         force_sig_info(signr, &info, current);
  69 }
  70
  71 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
  72                                                         int fsr, int addr)
  73 {
  74 #ifdef CONFIG_MMU
  75         int code;
  76         addr = regs->pc;
  77 #endif
  78
  79
  80         switch (type & 0x1F) {
  81         case MICROBLAZE_ILL_OPCODE_EXCEPTION:
  82                 if (user_mode(regs)) {
  83                         pr_debug(KERN_WARNING "Illegal opcode exception " \
  84                                                         "in user mode.\n");
  85                         _exception(SIGILL, regs, ILL_ILLOPC, addr);
  86                         return;
  87                 }
  88                 printk(KERN_WARNING "Illegal opcode exception " \
  89                                                         "in kernel mode.\n");
  90                 die("opcode exception", regs, SIGBUS);
  91                 break;
  92         case MICROBLAZE_IBUS_EXCEPTION:
  93                 if (user_mode(regs)) {
  94                         pr_debug(KERN_WARNING "Instruction bus error " \
  95                                                 "exception in user mode.\n");
  96                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
  97                         return;
  98                 }
  99                 printk(KERN_WARNING "Instruction bus error exception " \
 100                                                         "in kernel mode.\n");
 101                 die("bus exception", regs, SIGBUS);
 102                 break;
 103         case MICROBLAZE_DBUS_EXCEPTION:
 104                 if (user_mode(regs)) {
 105                         pr_debug(KERN_WARNING "Data bus error exception " \
 106                                                         "in user mode.\n");
 107                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 108                         return;
 109                 }
 110                 printk(KERN_WARNING "Data bus error exception " \
 111                                                         "in kernel mode.\n");
 112                 die("bus exception", regs, SIGBUS);
 113                 break;
 114         case MICROBLAZE_DIV_ZERO_EXCEPTION:
 115                 if (user_mode(regs)) {
 116                         pr_debug(KERN_WARNING "Divide by zero exception " \
 117                                                         "in user mode\n");
 118                         _exception(SIGILL, regs, FPE_INTDIV, addr);
 119                         return;
 120                 }
 121                 printk(KERN_WARNING "Divide by zero exception " \
 122                                                         "in kernel mode.\n");
 123                 die("Divide by zero exception", regs, SIGBUS);
 124                 break;
 125         case MICROBLAZE_FPU_EXCEPTION:
 126                 pr_debug(KERN_WARNING "FPU exception\n");
 127                 /* IEEE FP exception */
 128                 /* I removed fsr variable and use code var for storing fsr */
 129                 if (fsr & FSR_IO)
 130                         fsr = FPE_FLTINV;
 131                 else if (fsr & FSR_OF)
 132                         fsr = FPE_FLTOVF;
 133                 else if (fsr & FSR_UF)
 134                         fsr = FPE_FLTUND;
 135                 else if (fsr & FSR_DZ)
 136                         fsr = FPE_FLTDIV;
 137                 else if (fsr & FSR_DO)
 138                         fsr = FPE_FLTRES;
 139                 _exception(SIGFPE, regs, fsr, addr);
 140                 break;
 141
 142 #ifdef CONFIG_MMU
 143         case MICROBLAZE_PRIVILEGED_EXCEPTION:
 144                 pr_debug(KERN_WARNING "Privileged exception\n");
 145                 /* "brk r0,r0" - used as debug breakpoint - old toolchain */
 146                 if (get_user(code, (unsigned long *)regs->pc) == 0
 147                         && code == 0x980c0000) {
 148                         _exception(SIGTRAP, regs, TRAP_BRKPT, addr);
 149                 } else {
 150                         _exception(SIGILL, regs, ILL_PRVOPC, addr);
 151                 }
 152                 break;
 153 #endif
 154         default:
 155                 printk(KERN_WARNING "Unexpected exception %02x "
 156                         "PC=%08x in %s mode\n", type, (unsigned int) addr,
 157                         kernel_mode(regs) ? "kernel" : "user");
 158         }
 159         return;
 160 }