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