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 #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
  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 */
  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
  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
  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(SIGFPE, 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 }