powerpc: Merge enough to start building in arch/powerpc.

This creates the directory structure under arch/powerpc and a bunch
of Kconfig files.  It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac.  This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.

For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel.  This makes some minor changes
to files in those directories and files outside arch/powerpc.

The boot directory is still not merged.  That's going to be interesting.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 1047 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
new file mode 100644
index 000000000000..c7afbbba0f36
--- /dev/null
+++ b/arch/powerpc/kernel/traps.c
@@ -0,0 +1,1047 @@
+/*
+ *  arch/powerpc/kernel/traps.c
+ *
+ *  Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ *  Modified by Cort Dougan (cort@cs.nmt.edu)
+ *  and Paul Mackerras (paulus@samba.org)
+ */
+
+/*
+ * This file handles the architecture-dependent parts of hardware exceptions
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/interrupt.h>
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/prctl.h>
+#include <linux/delay.h>
+#include <linux/kprobes.h>
+#include <asm/kdebug.h>
+
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/reg.h>
+#include <asm/xmon.h>
+#ifdef CONFIG_PMAC_BACKLIGHT
+#include <asm/backlight.h>
+#endif
+#include <asm/perfmon.h>
+
+#ifdef CONFIG_DEBUGGER
+int (*__debugger)(struct pt_regs *regs);
+int (*__debugger_ipi)(struct pt_regs *regs);
+int (*__debugger_bpt)(struct pt_regs *regs);
+int (*__debugger_sstep)(struct pt_regs *regs);
+int (*__debugger_iabr_match)(struct pt_regs *regs);
+int (*__debugger_dabr_match)(struct pt_regs *regs);
+int (*__debugger_fault_handler)(struct pt_regs *regs);
+
+EXPORT_SYMBOL(__debugger);
+EXPORT_SYMBOL(__debugger_ipi);
+EXPORT_SYMBOL(__debugger_bpt);
+EXPORT_SYMBOL(__debugger_sstep);
+EXPORT_SYMBOL(__debugger_iabr_match);
+EXPORT_SYMBOL(__debugger_dabr_match);
+EXPORT_SYMBOL(__debugger_fault_handler);
+#endif
+
+struct notifier_block *powerpc_die_chain;
+static DEFINE_SPINLOCK(die_notifier_lock);
+
+int register_die_notifier(struct notifier_block *nb)
+{
+	int err = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&die_notifier_lock, flags);
+	err = notifier_chain_register(&powerpc_die_chain, nb);
+	spin_unlock_irqrestore(&die_notifier_lock, flags);
+	return err;
+}
+
+/*
+ * Trap & Exception support
+ */
+
+static DEFINE_SPINLOCK(die_lock);
+
+int die(const char *str, struct pt_regs *regs, long err)
+{
+	static int die_counter;
+	int nl = 0;
+
+	if (debugger(regs))
+		return 1;
+
+	console_verbose();
+	spin_lock_irq(&die_lock);
+	bust_spinlocks(1);
+#ifdef CONFIG_PMAC_BACKLIGHT
+	if (_machine == _MACH_Pmac) {
+		set_backlight_enable(1);
+		set_backlight_level(BACKLIGHT_MAX);
+	}
+#endif
+	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
+#ifdef CONFIG_PREEMPT
+	printk("PREEMPT ");
+	nl = 1;
+#endif
+#ifdef CONFIG_SMP
+	printk("SMP NR_CPUS=%d ", NR_CPUS);
+	nl = 1;
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	printk("DEBUG_PAGEALLOC ");
+	nl = 1;
+#endif
+#ifdef CONFIG_NUMA
+	printk("NUMA ");
+	nl = 1;
+#endif
+#ifdef CONFIG_PPC64
+	switch (systemcfg->platform) {
+	case PLATFORM_PSERIES:
+		printk("PSERIES ");
+		nl = 1;
+		break;
+	case PLATFORM_PSERIES_LPAR:
+		printk("PSERIES LPAR ");
+		nl = 1;
+		break;
+	case PLATFORM_ISERIES_LPAR:
+		printk("ISERIES LPAR ");
+		nl = 1;
+		break;
+	case PLATFORM_POWERMAC:
+		printk("POWERMAC ");
+		nl = 1;
+		break;
+	case PLATFORM_BPA:
+		printk("BPA ");
+		nl = 1;
+		break;
+	}
+#endif
+	if (nl)
+		printk("\n");
+	print_modules();
+	show_regs(regs);
+	bust_spinlocks(0);
+	spin_unlock_irq(&die_lock);
+
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+
+	if (panic_on_oops) {
+		panic("Fatal exception");
+	}
+	do_exit(err);
+
+	return 0;
+}
+
+void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
+{
+	siginfo_t info;
+
+	if (!user_mode(regs)) {
+		if (die("Exception in kernel mode", regs, signr))
+			return;
+	}
+
+	memset(&info, 0, sizeof(info));
+	info.si_signo = signr;
+	info.si_code = code;
+	info.si_addr = (void __user *) addr;
+	force_sig_info(signr, &info, current);
+
+	/*
+	 * Init gets no signals that it doesn't have a handler for.
+	 * That's all very well, but if it has caused a synchronous
+	 * exception and we ignore the resulting signal, it will just
+	 * generate the same exception over and over again and we get
+	 * nowhere.  Better to kill it and let the kernel panic.
+	 */
+	if (current->pid == 1) {
+		__sighandler_t handler;
+
+		spin_lock_irq(&current->sighand->siglock);
+		handler = current->sighand->action[signr-1].sa.sa_handler;
+		spin_unlock_irq(&current->sighand->siglock);
+		if (handler == SIG_DFL) {
+			/* init has generated a synchronous exception
+			   and it doesn't have a handler for the signal */
+			printk(KERN_CRIT "init has generated signal %d "
+			       "but has no handler for it\n", signr);
+			do_exit(signr);
+		}
+	}
+}
+
+#ifdef CONFIG_PPC64
+void system_reset_exception(struct pt_regs *regs)
+{
+	/* See if any machine dependent calls */
+	if (ppc_md.system_reset_exception)
+		ppc_md.system_reset_exception(regs);
+
+	die("System Reset", regs, SIGABRT);
+
+	/* Must die if the interrupt is not recoverable */
+	if (!(regs->msr & MSR_RI))
+		panic("Unrecoverable System Reset");
+
+	/* What should we do here? We could issue a shutdown or hard reset. */
+}
+#endif
+
+/*
+ * I/O accesses can cause machine checks on powermacs.
+ * Check if the NIP corresponds to the address of a sync
+ * instruction for which there is an entry in the exception
+ * table.
+ * Note that the 601 only takes a machine check on TEA
+ * (transfer error ack) signal assertion, and does not
+ * set any of the top 16 bits of SRR1.
+ *  -- paulus.
+ */
+static inline int check_io_access(struct pt_regs *regs)
+{
+#ifdef CONFIG_PPC_PMAC
+	unsigned long msr = regs->msr;
+	const struct exception_table_entry *entry;
+	unsigned int *nip = (unsigned int *)regs->nip;
+
+	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
+	    && (entry = search_exception_tables(regs->nip)) != NULL) {
+		/*
+		 * Check that it's a sync instruction, or somewhere
+		 * in the twi; isync; nop sequence that inb/inw/inl uses.
+		 * As the address is in the exception table
+		 * we should be able to read the instr there.
+		 * For the debug message, we look at the preceding
+		 * load or store.
+		 */
+		if (*nip == 0x60000000)		/* nop */
+			nip -= 2;
+		else if (*nip == 0x4c00012c)	/* isync */
+			--nip;
+		if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
+			/* sync or twi */
+			unsigned int rb;
+
+			--nip;
+			rb = (*nip >> 11) & 0x1f;
+			printk(KERN_DEBUG "%s bad port %lx at %p\n",
+			       (*nip & 0x100)? "OUT to": "IN from",
+			       regs->gpr[rb] - _IO_BASE, nip);
+			regs->msr |= MSR_RI;
+			regs->nip = entry->fixup;
+			return 1;
+		}
+	}
+#endif /* CONFIG_PPC_PMAC */
+	return 0;
+}
+
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+/* On 4xx, the reason for the machine check or program exception
+   is in the ESR. */
+#define get_reason(regs)	((regs)->dsisr)
+#ifndef CONFIG_FSL_BOOKE
+#define get_mc_reason(regs)	((regs)->dsisr)
+#else
+#define get_mc_reason(regs)	(mfspr(SPRN_MCSR))
+#endif
+#define REASON_FP		ESR_FP
+#define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
+#define REASON_PRIVILEGED	ESR_PPR
+#define REASON_TRAP		ESR_PTR
+
+/* single-step stuff */
+#define single_stepping(regs)	(current->thread.dbcr0 & DBCR0_IC)
+#define clear_single_step(regs)	(current->thread.dbcr0 &= ~DBCR0_IC)
+
+#else
+/* On non-4xx, the reason for the machine check or program
+   exception is in the MSR. */
+#define get_reason(regs)	((regs)->msr)
+#define get_mc_reason(regs)	((regs)->msr)
+#define REASON_FP		0x100000
+#define REASON_ILLEGAL		0x80000
+#define REASON_PRIVILEGED	0x40000
+#define REASON_TRAP		0x20000
+
+#define single_stepping(regs)	((regs)->msr & MSR_SE)
+#define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
+#endif
+
+/*
+ * This is "fall-back" implementation for configurations
+ * which don't provide platform-specific machine check info
+ */
+void __attribute__ ((weak))
+platform_machine_check(struct pt_regs *regs)
+{
+}
+
+void MachineCheckException(struct pt_regs *regs)
+{
+#ifdef CONFIG_PPC64
+	int recover = 0;
+
+	/* See if any machine dependent calls */
+	if (ppc_md.machine_check_exception)
+		recover = ppc_md.machine_check_exception(regs);
+
+	if (recover)
+		return;
+#else
+	unsigned long reason = get_mc_reason(regs);
+
+	if (user_mode(regs)) {
+		regs->msr |= MSR_RI;
+		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
+		return;
+	}
+
+#if defined(CONFIG_8xx) && defined(CONFIG_PCI)
+	/* the qspan pci read routines can cause machine checks -- Cort */
+	bad_page_fault(regs, regs->dar, SIGBUS);
+	return;
+#endif
+
+	if (debugger_fault_handler(regs)) {
+		regs->msr |= MSR_RI;
+		return;
+	}
+
+	if (check_io_access(regs))
+		return;
+
+#if defined(CONFIG_4xx) && !defined(CONFIG_440A)
+	if (reason & ESR_IMCP) {
+		printk("Instruction");
+		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
+	} else
+		printk("Data");
+	printk(" machine check in kernel mode.\n");
+#elif defined(CONFIG_440A)
+	printk("Machine check in kernel mode.\n");
+	if (reason & ESR_IMCP){
+		printk("Instruction Synchronous Machine Check exception\n");
+		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
+	}
+	else {
+		u32 mcsr = mfspr(SPRN_MCSR);
+		if (mcsr & MCSR_IB)
+			printk("Instruction Read PLB Error\n");
+		if (mcsr & MCSR_DRB)
+			printk("Data Read PLB Error\n");
+		if (mcsr & MCSR_DWB)
+			printk("Data Write PLB Error\n");
+		if (mcsr & MCSR_TLBP)
+			printk("TLB Parity Error\n");
+		if (mcsr & MCSR_ICP){
+			flush_instruction_cache();
+			printk("I-Cache Parity Error\n");
+		}
+		if (mcsr & MCSR_DCSP)
+			printk("D-Cache Search Parity Error\n");
+		if (mcsr & MCSR_DCFP)
+			printk("D-Cache Flush Parity Error\n");
+		if (mcsr & MCSR_IMPE)
+			printk("Machine Check exception is imprecise\n");
+
+		/* Clear MCSR */
+		mtspr(SPRN_MCSR, mcsr);
+	}
+#elif defined (CONFIG_E500)
+	printk("Machine check in kernel mode.\n");
+	printk("Caused by (from MCSR=%lx): ", reason);
+
+	if (reason & MCSR_MCP)
+		printk("Machine Check Signal\n");
+	if (reason & MCSR_ICPERR)
+		printk("Instruction Cache Parity Error\n");
+	if (reason & MCSR_DCP_PERR)
+		printk("Data Cache Push Parity Error\n");
+	if (reason & MCSR_DCPERR)
+		printk("Data Cache Parity Error\n");
+	if (reason & MCSR_GL_CI)
+		printk("Guarded Load or Cache-Inhibited stwcx.\n");
+	if (reason & MCSR_BUS_IAERR)
+		printk("Bus - Instruction Address Error\n");
+	if (reason & MCSR_BUS_RAERR)
+		printk("Bus - Read Address Error\n");
+	if (reason & MCSR_BUS_WAERR)
+		printk("Bus - Write Address Error\n");
+	if (reason & MCSR_BUS_IBERR)
+		printk("Bus - Instruction Data Error\n");
+	if (reason & MCSR_BUS_RBERR)
+		printk("Bus - Read Data Bus Error\n");
+	if (reason & MCSR_BUS_WBERR)
+		printk("Bus - Read Data Bus Error\n");
+	if (reason & MCSR_BUS_IPERR)
+		printk("Bus - Instruction Parity Error\n");
+	if (reason & MCSR_BUS_RPERR)
+		printk("Bus - Read Parity Error\n");
+#elif defined (CONFIG_E200)
+	printk("Machine check in kernel mode.\n");
+	printk("Caused by (from MCSR=%lx): ", reason);
+
+	if (reason & MCSR_MCP)
+		printk("Machine Check Signal\n");
+	if (reason & MCSR_CP_PERR)
+		printk("Cache Push Parity Error\n");
+	if (reason & MCSR_CPERR)
+		printk("Cache Parity Error\n");
+	if (reason & MCSR_EXCP_ERR)
+		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
+	if (reason & MCSR_BUS_IRERR)
+		printk("Bus - Read Bus Error on instruction fetch\n");
+	if (reason & MCSR_BUS_DRERR)
+		printk("Bus - Read Bus Error on data load\n");
+	if (reason & MCSR_BUS_WRERR)
+		printk("Bus - Write Bus Error on buffered store or cache line push\n");
+#else /* !CONFIG_4xx && !CONFIG_E500 && !CONFIG_E200 */
+	printk("Machine check in kernel mode.\n");
+	printk("Caused by (from SRR1=%lx): ", reason);
+	switch (reason & 0x601F0000) {
+	case 0x80000:
+		printk("Machine check signal\n");
+		break;
+	case 0:		/* for 601 */
+	case 0x40000:
+	case 0x140000:	/* 7450 MSS error and TEA */
+		printk("Transfer error ack signal\n");
+		break;
+	case 0x20000:
+		printk("Data parity error signal\n");
+		break;
+	case 0x10000:
+		printk("Address parity error signal\n");
+		break;
+	case 0x20000000:
+		printk("L1 Data Cache error\n");
+		break;
+	case 0x40000000:
+		printk("L1 Instruction Cache error\n");
+		break;
+	case 0x00100000:
+		printk("L2 data cache parity error\n");
+		break;
+	default:
+		printk("Unknown values in msr\n");
+	}
+#endif /* CONFIG_4xx */
+
+	/*
+	 * Optional platform-provided routine to print out
+	 * additional info, e.g. bus error registers.
+	 */
+	platform_machine_check(regs);
+#endif /* CONFIG_PPC64 */
+
+	if (debugger_fault_handler(regs))
+		return;
+	die("Machine check", regs, SIGBUS);
+
+	/* Must die if the interrupt is not recoverable */
+	if (!(regs->msr & MSR_RI))
+		panic("Unrecoverable Machine check");
+}
+
+void SMIException(struct pt_regs *regs)
+{
+	die("System Management Interrupt", regs, SIGABRT);
+}
+
+void UnknownException(struct pt_regs *regs)
+{
+	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
+	       regs->nip, regs->msr, regs->trap);
+
+	_exception(SIGTRAP, regs, 0, 0);
+}
+
+void InstructionBreakpoint(struct pt_regs *regs)
+{
+	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
+					5, SIGTRAP) == NOTIFY_STOP)
+		return;
+	if (debugger_iabr_match(regs))
+		return;
+	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
+}
+
+void RunModeException(struct pt_regs *regs)
+{
+	_exception(SIGTRAP, regs, 0, 0);
+}
+
+void SingleStepException(struct pt_regs *regs)
+{
+	regs->msr &= ~(MSR_SE | MSR_BE);  /* Turn off 'trace' bits */
+
+	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
+					5, SIGTRAP) == NOTIFY_STOP)
+		return;
+	if (debugger_sstep(regs))
+		return;
+
+	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
+}
+
+/*
+ * After we have successfully emulated an instruction, we have to
+ * check if the instruction was being single-stepped, and if so,
+ * pretend we got a single-step exception.  This was pointed out
+ * by Kumar Gala.  -- paulus
+ */
+static void emulate_single_step(struct pt_regs *regs)
+{
+	if (single_stepping(regs)) {
+		clear_single_step(regs);
+		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
+	}
+}
+
+/* Illegal instruction emulation support.  Originally written to
+ * provide the PVR to user applications using the mfspr rd, PVR.
+ * Return non-zero if we can't emulate, or -EFAULT if the associated
+ * memory access caused an access fault.  Return zero on success.
+ *
+ * There are a couple of ways to do this, either "decode" the instruction
+ * or directly match lots of bits.  In this case, matching lots of
+ * bits is faster and easier.
+ *
+ */
+#define INST_MFSPR_PVR		0x7c1f42a6
+#define INST_MFSPR_PVR_MASK	0xfc1fffff
+
+#define INST_DCBA		0x7c0005ec
+#define INST_DCBA_MASK		0x7c0007fe
+
+#define INST_MCRXR		0x7c000400
+#define INST_MCRXR_MASK		0x7c0007fe
+
+#define INST_STRING		0x7c00042a
+#define INST_STRING_MASK	0x7c0007fe
+#define INST_STRING_GEN_MASK	0x7c00067e
+#define INST_LSWI		0x7c0004aa
+#define INST_LSWX		0x7c00042a
+#define INST_STSWI		0x7c0005aa
+#define INST_STSWX		0x7c00052a
+
+static int emulate_string_inst(struct pt_regs *regs, u32 instword)
+{
+	u8 rT = (instword >> 21) & 0x1f;
+	u8 rA = (instword >> 16) & 0x1f;
+	u8 NB_RB = (instword >> 11) & 0x1f;
+	u32 num_bytes;
+	unsigned long EA;
+	int pos = 0;
+
+	/* Early out if we are an invalid form of lswx */
+	if ((instword & INST_STRING_MASK) == INST_LSWX)
+		if ((rT == rA) || (rT == NB_RB))
+			return -EINVAL;
+
+	EA = (rA == 0) ? 0 : regs->gpr[rA];
+
+	switch (instword & INST_STRING_MASK) {
+		case INST_LSWX:
+		case INST_STSWX:
+			EA += NB_RB;
+			num_bytes = regs->xer & 0x7f;
+			break;
+		case INST_LSWI:
+		case INST_STSWI:
+			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
+			break;
+		default:
+			return -EINVAL;
+	}
+
+	while (num_bytes != 0)
+	{
+		u8 val;
+		u32 shift = 8 * (3 - (pos & 0x3));
+
+		switch ((instword & INST_STRING_MASK)) {
+			case INST_LSWX:
+			case INST_LSWI:
+				if (get_user(val, (u8 __user *)EA))
+					return -EFAULT;
+				/* first time updating this reg,
+				 * zero it out */
+				if (pos == 0)
+					regs->gpr[rT] = 0;
+				regs->gpr[rT] |= val << shift;
+				break;
+			case INST_STSWI:
+			case INST_STSWX:
+				val = regs->gpr[rT] >> shift;
+				if (put_user(val, (u8 __user *)EA))
+					return -EFAULT;
+				break;
+		}
+		/* move EA to next address */
+		EA += 1;
+		num_bytes--;
+
+		/* manage our position within the register */
+		if (++pos == 4) {
+			pos = 0;
+			if (++rT == 32)
+				rT = 0;
+		}
+	}
+
+	return 0;
+}
+
+static int emulate_instruction(struct pt_regs *regs)
+{
+	u32 instword;
+	u32 rd;
+
+	if (!user_mode(regs))
+		return -EINVAL;
+	CHECK_FULL_REGS(regs);
+
+	if (get_user(instword, (u32 __user *)(regs->nip)))
+		return -EFAULT;
+
+	/* Emulate the mfspr rD, PVR. */
+	if ((instword & INST_MFSPR_PVR_MASK) == INST_MFSPR_PVR) {
+		rd = (instword >> 21) & 0x1f;
+		regs->gpr[rd] = mfspr(SPRN_PVR);
+		return 0;
+	}
+
+	/* Emulating the dcba insn is just a no-op.  */
+	if ((instword & INST_DCBA_MASK) == INST_DCBA)
+		return 0;
+
+	/* Emulate the mcrxr insn.  */
+	if ((instword & INST_MCRXR_MASK) == INST_MCRXR) {
+		int shift = (instword >> 21) & 0x1c;
+		unsigned long msk = 0xf0000000UL >> shift;
+
+		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
+		regs->xer &= ~0xf0000000UL;
+		return 0;
+	}
+
+	/* Emulate load/store string insn. */
+	if ((instword & INST_STRING_GEN_MASK) == INST_STRING)
+		return emulate_string_inst(regs, instword);
+
+	return -EINVAL;
+}
+
+/*
+ * Look through the list of trap instructions that are used for BUG(),
+ * BUG_ON() and WARN_ON() and see if we hit one.  At this point we know
+ * that the exception was caused by a trap instruction of some kind.
+ * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0
+ * otherwise.
+ */
+extern struct bug_entry __start___bug_table[], __stop___bug_table[];
+
+#ifndef CONFIG_MODULES
+#define module_find_bug(x)	NULL
+#endif
+
+struct bug_entry *find_bug(unsigned long bugaddr)
+{
+	struct bug_entry *bug;
+
+	for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
+		if (bugaddr == bug->bug_addr)
+			return bug;
+	return module_find_bug(bugaddr);
+}
+
+int check_bug_trap(struct pt_regs *regs)
+{
+	struct bug_entry *bug;
+	unsigned long addr;
+
+	if (regs->msr & MSR_PR)
+		return 0;	/* not in kernel */
+	addr = regs->nip;	/* address of trap instruction */
+	if (addr < PAGE_OFFSET)
+		return 0;
+	bug = find_bug(regs->nip);
+	if (bug == NULL)
+		return 0;
+	if (bug->line & BUG_WARNING_TRAP) {
+		/* this is a WARN_ON rather than BUG/BUG_ON */
+#ifdef CONFIG_XMON
+		xmon_printf(KERN_ERR "Badness in %s at %s:%d\n",
+		       bug->function, bug->file,
+		       bug->line & ~BUG_WARNING_TRAP);
+#endif /* CONFIG_XMON */		
+		printk(KERN_ERR "Badness in %s at %s:%d\n",
+		       bug->function, bug->file,
+		       bug->line & ~BUG_WARNING_TRAP);
+		dump_stack();
+		return 1;
+	}
+#ifdef CONFIG_XMON
+	xmon_printf(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
+	       bug->function, bug->file, bug->line);
+	xmon(regs);
+#endif /* CONFIG_XMON */
+	printk(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
+	       bug->function, bug->file, bug->line);
+
+	return 0;
+}
+
+void ProgramCheckException(struct pt_regs *regs)
+{
+	unsigned int reason = get_reason(regs);
+	extern int do_mathemu(struct pt_regs *regs);
+
+#ifdef CONFIG_MATH_EMULATION
+	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
+	 * but there seems to be a hardware bug on the 405GP (RevD)
+	 * that means ESR is sometimes set incorrectly - either to
+	 * ESR_DST (!?) or 0.  In the process of chasing this with the
+	 * hardware people - not sure if it can happen on any illegal
+	 * instruction or only on FP instructions, whether there is a
+	 * pattern to occurences etc. -dgibson 31/Mar/2003 */
+	if (!(reason & REASON_TRAP) && do_mathemu(regs) == 0) {
+		emulate_single_step(regs);
+		return;
+	}
+#endif /* CONFIG_MATH_EMULATION */
+
+	if (reason & REASON_FP) {
+		/* IEEE FP exception */
+		int code = 0;
+		u32 fpscr;
+
+		/* We must make sure the FP state is consistent with
+		 * our MSR_FP in regs
+		 */
+		preempt_disable();
+		if (regs->msr & MSR_FP)
+			giveup_fpu(current);
+		preempt_enable();
+
+		fpscr = current->thread.fpscr;
+		fpscr &= fpscr << 22;	/* mask summary bits with enables */
+		if (fpscr & FPSCR_VX)
+			code = FPE_FLTINV;
+		else if (fpscr & FPSCR_OX)
+			code = FPE_FLTOVF;
+		else if (fpscr & FPSCR_UX)
+			code = FPE_FLTUND;
+		else if (fpscr & FPSCR_ZX)
+			code = FPE_FLTDIV;
+		else if (fpscr & FPSCR_XX)
+			code = FPE_FLTRES;
+		_exception(SIGFPE, regs, code, regs->nip);
+		return;
+	}
+
+	if (reason & REASON_TRAP) {
+		/* trap exception */
+		if (debugger_bpt(regs))
+			return;
+		if (check_bug_trap(regs)) {
+			regs->nip += 4;
+			return;
+		}
+		_exception(SIGTRAP, regs, TRAP_BRKPT, 0);
+		return;
+	}
+
+	/* Try to emulate it if we should. */
+	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
+		switch (emulate_instruction(regs)) {
+		case 0:
+			regs->nip += 4;
+			emulate_single_step(regs);
+			return;
+		case -EFAULT:
+			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
+			return;
+		}
+	}
+
+	if (reason & REASON_PRIVILEGED)
+		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
+	else
+		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+}
+
+void AlignmentException(struct pt_regs *regs)
+{
+	int fixed;
+
+	fixed = fix_alignment(regs);
+
+	if (fixed == 1) {
+		regs->nip += 4;	/* skip over emulated instruction */
+		emulate_single_step(regs);
+		return;
+	}
+
+	/* Operand address was bad */	
+	if (fixed == -EFAULT) {
+		if (user_mode(regs))
+			_exception(SIGSEGV, regs, SEGV_ACCERR, regs->dar);
+		else
+			/* Search exception table */
+			bad_page_fault(regs, regs->dar, SIGSEGV);
+		return;
+	}
+	_exception(SIGBUS, regs, BUS_ADRALN, regs->dar);
+}
+
+void StackOverflow(struct pt_regs *regs)
+{
+	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
+	       current, regs->gpr[1]);
+	debugger(regs);
+	show_regs(regs);
+	panic("kernel stack overflow");
+}
+
+void nonrecoverable_exception(struct pt_regs *regs)
+{
+	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
+	       regs->nip, regs->msr);
+	debugger(regs);
+	die("nonrecoverable exception", regs, SIGKILL);
+}
+
+void trace_syscall(struct pt_regs *regs)
+{
+	printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld    %s\n",
+	       current, current->pid, regs->nip, regs->link, regs->gpr[0],
+	       regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
+}
+
+#ifdef CONFIG_8xx
+void SoftwareEmulation(struct pt_regs *regs)
+{
+	extern int do_mathemu(struct pt_regs *);
+	extern int Soft_emulate_8xx(struct pt_regs *);
+	int errcode;
+
+	CHECK_FULL_REGS(regs);
+
+	if (!user_mode(regs)) {
+		debugger(regs);
+		die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
+	}
+
+#ifdef CONFIG_MATH_EMULATION
+	errcode = do_mathemu(regs);
+#else
+	errcode = Soft_emulate_8xx(regs);
+#endif
+	if (errcode) {
+		if (errcode > 0)
+			_exception(SIGFPE, regs, 0, 0);
+		else if (errcode == -EFAULT)
+			_exception(SIGSEGV, regs, 0, 0);
+		else
+			_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+	} else
+		emulate_single_step(regs);
+}
+#endif /* CONFIG_8xx */
+
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+
+void DebugException(struct pt_regs *regs, unsigned long debug_status)
+{
+	if (debug_status & DBSR_IC) {	/* instruction completion */
+		regs->msr &= ~MSR_DE;
+		if (user_mode(regs)) {
+			current->thread.dbcr0 &= ~DBCR0_IC;
+		} else {
+			/* Disable instruction completion */
+			mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
+			/* Clear the instruction completion event */
+			mtspr(SPRN_DBSR, DBSR_IC);
+			if (debugger_sstep(regs))
+				return;
+		}
+		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
+	}
+}
+#endif /* CONFIG_4xx || CONFIG_BOOKE */
+
+#if !defined(CONFIG_TAU_INT)
+void TAUException(struct pt_regs *regs)
+{
+	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
+	       regs->nip, regs->msr, regs->trap, print_tainted());
+}
+#endif /* CONFIG_INT_TAU */
+
+void AltivecUnavailException(struct pt_regs *regs)
+{
+	static int kernel_altivec_count;
+
+#ifndef CONFIG_ALTIVEC
+	if (user_mode(regs)) {
+		/* A user program has executed an altivec instruction,
+		   but this kernel doesn't support altivec. */
+		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+		return;
+	}
+#endif
+	/* The kernel has executed an altivec instruction without
+	   first enabling altivec.  Whinge but let it do it. */
+	if (++kernel_altivec_count < 10)
+		printk(KERN_ERR "AltiVec used in kernel (task=%p, pc=%lx)\n",
+		       current, regs->nip);
+	regs->msr |= MSR_VEC;
+}
+
+#ifdef CONFIG_ALTIVEC
+void AltivecAssistException(struct pt_regs *regs)
+{
+	int err;
+
+	preempt_disable();
+	if (regs->msr & MSR_VEC)
+		giveup_altivec(current);
+	preempt_enable();
+	if (!user_mode(regs)) {
+		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
+		       " at %lx\n", regs->nip);
+		die("Kernel Altivec assist exception", regs, SIGILL);
+	}
+
+	err = emulate_altivec(regs);
+	if (err == 0) {
+		regs->nip += 4;		/* skip emulated instruction */
+		emulate_single_step(regs);
+		return;
+	}
+
+	if (err == -EFAULT) {
+		/* got an error reading the instruction */
+		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
+	} else {
+		/* didn't recognize the instruction */
+		/* XXX quick hack for now: set the non-Java bit in the VSCR */
+		if (printk_ratelimit())
+			printk(KERN_ERR "Unrecognized altivec instruction "
+			       "in %s at %lx\n", current->comm, regs->nip);
+		current->thread.vscr.u[3] |= 0x10000;
+	}
+}
+#endif /* CONFIG_ALTIVEC */
+
+#ifdef CONFIG_E500
+void PerformanceMonitorException(struct pt_regs *regs)
+{
+	perf_irq(regs);
+}
+#endif
+
+#ifdef CONFIG_FSL_BOOKE
+void CacheLockingException(struct pt_regs *regs, unsigned long address,
+			   unsigned long error_code)
+{
+	/* We treat cache locking instructions from the user
+	 * as priv ops, in the future we could try to do
+	 * something smarter
+	 */
+	if (error_code & (ESR_DLK|ESR_ILK))
+		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
+	return;
+}
+#endif /* CONFIG_FSL_BOOKE */
+
+#ifdef CONFIG_SPE
+void SPEFloatingPointException(struct pt_regs *regs)
+{
+	unsigned long spefscr;
+	int fpexc_mode;
+	int code = 0;
+
+	spefscr = current->thread.spefscr;
+	fpexc_mode = current->thread.fpexc_mode;
+
+	/* Hardware does not neccessarily set sticky
+	 * underflow/overflow/invalid flags */
+	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
+		code = FPE_FLTOVF;
+		spefscr |= SPEFSCR_FOVFS;
+	}
+	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
+		code = FPE_FLTUND;
+		spefscr |= SPEFSCR_FUNFS;
+	}
+	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
+		code = FPE_FLTDIV;
+	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
+		code = FPE_FLTINV;
+		spefscr |= SPEFSCR_FINVS;
+	}
+	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
+		code = FPE_FLTRES;
+
+	current->thread.spefscr = spefscr;
+
+	_exception(SIGFPE, regs, code, regs->nip);
+	return;
+}
+#endif
+
+#ifdef CONFIG_BOOKE_WDT
+/*
+ * Default handler for a Watchdog exception,
+ * spins until a reboot occurs
+ */
+void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
+{
+	/* Generic WatchdogHandler, implement your own */
+	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
+	return;
+}
+
+void WatchdogException(struct pt_regs *regs)
+{
+	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
+	WatchdogHandler(regs);
+}
+#endif
+
+void __init trap_init(void)
+{
+}