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/export.h>
  17 #include <linux/kernel.h>
  18 #include <linux/signal.h>
  19 #include <linux/sched.h>
  20 #include <linux/sched/debug.h>
  21 #include <linux/kallsyms.h>
  22
  23 #include <asm/exceptions.h>
  24 #include <asm/entry.h>          /* For KM CPU var */
  25 #include <linux/uaccess.h>
  26 #include <linux/errno.h>
  27 #include <linux/ptrace.h>
  28 #include <asm/current.h>
  29 #include <asm/cacheflush.h>
  30
  31 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
  32 #define MICROBLAZE_IBUS_EXCEPTION       0x03
  33 #define MICROBLAZE_DBUS_EXCEPTION       0x04
  34 #define MICROBLAZE_DIV_ZERO_EXCEPTION   0x05
  35 #define MICROBLAZE_FPU_EXCEPTION        0x06
  36 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
  37
  38 static DEFINE_SPINLOCK(die_lock);
  39
  40 void die(const char *str, struct pt_regs *fp, long err)
  41 {
  42         console_verbose();
  43         spin_lock_irq(&die_lock);
  44         pr_warn("Oops: %s, sig: %ld\n", str, err);
  45         show_regs(fp);
  46         spin_unlock_irq(&die_lock);
  47         /* do_exit() should take care of panic'ing from an interrupt
  48          * context so we don't handle it here
  49          */
  50         do_exit(err);
  51 }
  52
  53 /* for user application debugging */
  54 asmlinkage void sw_exception(struct pt_regs *regs)
  55 {
  56         _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
  57         flush_dcache_range(regs->r16, regs->r16 + 0x4);
  58         flush_icache_range(regs->r16, regs->r16 + 0x4);
  59 }
  60
  61 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
  62 {
  63         siginfo_t info;
  64
  65         if (kernel_mode(regs))
  66                 die("Exception in kernel mode", regs, signr);
  67
  68         info.si_signo = signr;
  69         info.si_errno = 0;
  70         info.si_code = code;
  71         info.si_addr = (void __user *) addr;
  72         force_sig_info(signr, &info, current);
  73 }
  74
  75 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
  76                                                         int fsr, int addr)
  77 {
  78 #ifdef CONFIG_MMU
  79         addr = regs->pc;
  80 #endif
  81
  82 #if 0
  83         pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x 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                 pr_warn("Illegal opcode exception in kernel mode.\n");
  96                 die("opcode exception", regs, SIGBUS);
  97                 break;
  98         case MICROBLAZE_IBUS_EXCEPTION:
  99                 if (user_mode(regs)) {
 100                         pr_debug("Instruction bus error exception in user mode\n");
 101                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 102                         return;
 103                 }
 104                 pr_warn("Instruction bus error exception in kernel mode.\n");
 105                 die("bus exception", regs, SIGBUS);
 106                 break;
 107         case MICROBLAZE_DBUS_EXCEPTION:
 108                 if (user_mode(regs)) {
 109                         pr_debug("Data bus error exception in user mode\n");
 110                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 111                         return;
 112                 }
 113                 pr_warn("Data bus error exception in kernel mode.\n");
 114                 die("bus exception", regs, SIGBUS);
 115                 break;
 116         case MICROBLAZE_DIV_ZERO_EXCEPTION:
 117                 if (user_mode(regs)) {
 118                         pr_debug("Divide by zero exception in user mode\n");
 119                         _exception(SIGFPE, regs, FPE_INTDIV, addr);
 120                         return;
 121                 }
 122                 pr_warn("Divide by zero exception in kernel mode.\n");
 123                 die("Divide by zero exception", regs, SIGBUS);
 124                 break;
 125         case MICROBLAZE_FPU_EXCEPTION:
 126                 pr_debug("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("Privileged exception\n");
 145                 _exception(SIGILL, regs, ILL_PRVOPC, addr);
 146                 break;
 147 #endif
 148         default:
 149         /* FIXME what to do in unexpected exception */
 150                 pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
 151                         type, (unsigned int) addr,
 152                         kernel_mode(regs) ? "kernel" : "user");
 153         }
 154         return;
 155 }