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 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
  52 {
  53         siginfo_t info;
  54
  55         if (kernel_mode(regs)) {
  56                 debugger(regs);
  57                 die("Exception in kernel mode", regs, signr);
  58         }
  59         info.si_signo = signr;
  60         info.si_errno = 0;
  61         info.si_code = code;
  62         info.si_addr = (void __user *) addr;
  63         force_sig_info(signr, &info, current);
  64 }
  65
  66 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
  67                                                         int fsr, int addr)
  68 {
  69 #ifdef CONFIG_MMU
  70         int code;
  71         addr = regs->pc;
  72 #endif
  73
  74 #if 0
  75         printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
  76                         type, user_mode(regs) ? "user" : "kernel", fsr,
  77                         (unsigned int) regs->pc, (unsigned int) regs->esr);
  78 #endif
  79
  80         switch (type & 0x1F) {
  81         case MICROBLAZE_ILL_OPCODE_EXCEPTION:
  82                 if (user_mode(regs)) {
  83                         printk(KERN_WARNING "Illegal opcode exception in user mode.\n");
  84                         _exception(SIGILL, regs, ILL_ILLOPC, addr);
  85                         return;
  86                 }
  87                 printk(KERN_WARNING "Illegal opcode exception in kernel mode.\n");
  88                 die("opcode exception", regs, SIGBUS);
  89                 break;
  90         case MICROBLAZE_IBUS_EXCEPTION:
  91                 if (user_mode(regs)) {
  92                         printk(KERN_WARNING "Instruction bus error exception in user mode.\n");
  93                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
  94                         return;
  95                 }
  96                 printk(KERN_WARNING "Instruction bus error exception in kernel mode.\n");
  97                 die("bus exception", regs, SIGBUS);
  98                 break;
  99         case MICROBLAZE_DBUS_EXCEPTION:
 100                 if (user_mode(regs)) {
 101                         printk(KERN_WARNING "Data bus error exception in user mode.\n");
 102                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 103                         return;
 104                 }
 105                 printk(KERN_WARNING "Data bus error exception in kernel mode.\n");
 106                 die("bus exception", regs, SIGBUS);
 107                 break;
 108         case MICROBLAZE_DIV_ZERO_EXCEPTION:
 109                 if (user_mode(regs)) {
 110                         printk(KERN_WARNING "Divide by zero exception in user mode\n");
 111                         _exception(SIGILL, regs, ILL_ILLOPC, addr);
 112                         return;
 113                 }
 114                 printk(KERN_WARNING "Divide by zero exception in kernel mode.\n");
 115                 die("Divide by exception", regs, SIGBUS);
 116                 break;
 117         case MICROBLAZE_FPU_EXCEPTION:
 118                 printk(KERN_WARNING "FPU exception\n");
 119                 /* IEEE FP exception */
 120                 /* I removed fsr variable and use code var for storing fsr */
 121                 if (fsr & FSR_IO)
 122                         fsr = FPE_FLTINV;
 123                 else if (fsr & FSR_OF)
 124                         fsr = FPE_FLTOVF;
 125                 else if (fsr & FSR_UF)
 126                         fsr = FPE_FLTUND;
 127                 else if (fsr & FSR_DZ)
 128                         fsr = FPE_FLTDIV;
 129                 else if (fsr & FSR_DO)
 130                         fsr = FPE_FLTRES;
 131                 _exception(SIGFPE, regs, fsr, addr);
 132                 break;
 133
 134 #ifdef CONFIG_MMU
 135         case MICROBLAZE_PRIVILEGED_EXCEPTION:
 136                 printk(KERN_WARNING "Privileged exception\n");
 137                 /* "brk r0,r0" - used as debug breakpoint */
 138                 if (get_user(code, (unsigned long *)regs->pc) == 0
 139                         && code == 0x980c0000) {
 140                         _exception(SIGTRAP, regs, TRAP_BRKPT, addr);
 141                 } else {
 142                         _exception(SIGILL, regs, ILL_PRVOPC, addr);
 143                 }
 144                 break;
 145 #endif
 146         default:
 147         /* FIXME what to do in unexpected exception */
 148                 printk(KERN_WARNING "Unexpected exception %02x "
 149                         "PC=%08x in %s mode\n", type, (unsigned int) addr,
 150                         kernel_mode(regs) ? "kernel" : "user");
 151         }
 152         return;
 153 }