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 <asm/uaccess.h>
  25 #include <asm/errno.h>
  26 #include <asm/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_PRIVILEG_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 #if 0
  70         printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
  71                         type, user_mode(regs) ? "user" : "kernel", fsr,
  72                         (unsigned int) regs->pc, (unsigned int) regs->esr);
  73 #endif
  74
  75         switch (type & 0x1F) {
  76         case MICROBLAZE_ILL_OPCODE_EXCEPTION:
  77                 _exception(SIGILL, regs, ILL_ILLOPC, addr);
  78                 break;
  79         case MICROBLAZE_IBUS_EXCEPTION:
  80                 if (user_mode(regs)) {
  81                         printk(KERN_WARNING "Instruction bus error exception in user mode.\n");
  82                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
  83                         return;
  84                 }
  85                 printk(KERN_WARNING "Instruction bus error exception in kernel mode.\n");
  86                 die("bus exception", regs, SIGBUS);
  87                 break;
  88         case MICROBLAZE_DBUS_EXCEPTION:
  89                 if (user_mode(regs)) {
  90                         printk(KERN_WARNING "Data bus error exception in user mode.\n");
  91                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
  92                         return;
  93                 }
  94                 printk(KERN_WARNING "Data bus error exception in kernel mode.\n");
  95                 die("bus exception", regs, SIGBUS);
  96                 break;
  97         case MICROBLAZE_DIV_ZERO_EXCEPTION:
  98                 printk(KERN_WARNING "Divide by zero exception\n");
  99                 _exception(SIGILL, regs, ILL_ILLOPC, addr);
 100                 break;
 101
 102         case MICROBLAZE_FPU_EXCEPTION:
 103                 /* IEEE FP exception */
 104                 /* I removed fsr variable and use code var for storing fsr */
 105                 if (fsr & FSR_IO)
 106                         fsr = FPE_FLTINV;
 107                 else if (fsr & FSR_OF)
 108                         fsr = FPE_FLTOVF;
 109                 else if (fsr & FSR_UF)
 110                         fsr = FPE_FLTUND;
 111                 else if (fsr & FSR_DZ)
 112                         fsr = FPE_FLTDIV;
 113                 else if (fsr & FSR_DO)
 114                         fsr = FPE_FLTRES;
 115                 _exception(SIGFPE, regs, fsr, addr);
 116                 break;
 117
 118         default:
 119                 printk(KERN_WARNING "Unexpected exception %02x "
 120                         "PC=%08x in %s mode\n", type, (unsigned int) addr,
 121                         kernel_mode(regs) ? "kernel" : "user");
 122         }
 123         return;
 124 }