[deliverable/linux.git] / arch / sparc / kernel / traps_32.c

/*
 * arch/sparc/kernel/traps.c
 *
 * Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
 * Copyright 2000 Jakub Jelinek (jakub@redhat.com)
 */

/*
 * I hate traps on the sparc, grrr...
 */

#include <linux/sched.h>  /* for jiffies */
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/kdebug.h>

#include <asm/delay.h>
#include <asm/system.h>
#include <asm/ptrace.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/unistd.h>
#include <asm/traps.h>

#include "entry.h"
#include "kernel.h"

/* #define TRAP_DEBUG */

static void instruction_dump(unsigned long *pc)
{
	int i;
	
	if((((unsigned long) pc) & 3))
                return;

	for(i = -3; i < 6; i++)
		printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
	printk("\n");
}

#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")

void die_if_kernel(char *str, struct pt_regs *regs)
{
	static int die_counter;
	int count = 0;

	/* Amuse the user. */
	printk(
"              \\|/ ____ \\|/\n"
"              \"@'/ ,. \\`@\"\n"
"              /_| \\__/ |_\\\n"
"                 \\__U_/\n");

	printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
	show_regs(regs);
	add_taint(TAINT_DIE);

	__SAVE; __SAVE; __SAVE; __SAVE;
	__SAVE; __SAVE; __SAVE; __SAVE;
	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	__RESTORE; __RESTORE; __RESTORE; __RESTORE;

	{
		struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];

		/* Stop the back trace when we hit userland or we
		 * find some badly aligned kernel stack. Set an upper
		 * bound in case our stack is trashed and we loop.
		 */
		while(rw					&&
		      count++ < 30				&&
                      (((unsigned long) rw) >= PAGE_OFFSET)	&&
		      !(((unsigned long) rw) & 0x7)) {
			printk("Caller[%08lx]: %pS\n", rw->ins[7],
			       (void *) rw->ins[7]);
			rw = (struct reg_window32 *)rw->ins[6];
		}
	}
	printk("Instruction DUMP:");
	instruction_dump ((unsigned long *) regs->pc);
	if(regs->psr & PSR_PS)
		do_exit(SIGKILL);
	do_exit(SIGSEGV);
}

void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
{
	siginfo_t info;

	if(type < 0x80) {
		/* Sun OS's puke from bad traps, Linux survives! */
		printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
		die_if_kernel("Whee... Hello Mr. Penguin", regs);
	}	

	if(regs->psr & PSR_PS)
		die_if_kernel("Kernel bad trap", regs);

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_ILLTRP;
	info.si_addr = (void __user *)regs->pc;
	info.si_trapno = type - 0x80;
	force_sig_info(SIGILL, &info, current);
}

void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			    unsigned long psr)
{
	siginfo_t info;

	if(psr & PSR_PS)
		die_if_kernel("Kernel illegal instruction", regs);
#ifdef TRAP_DEBUG
	printk("Ill instr. at pc=%08lx instruction is %08lx\n",
	       regs->pc, *(unsigned long *)regs->pc);
#endif
	if (!do_user_muldiv (regs, pc))
		return;

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_ILLOPC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, current);
}

void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	siginfo_t info;

	if(psr & PSR_PS)
		die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_PRVOPC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, current);
}

/* XXX User may want to be allowed to do this. XXX */

void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			    unsigned long psr)
{
	siginfo_t info;

	if(regs->psr & PSR_PS) {
		printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
		       regs->u_regs[UREG_RETPC]);
		die_if_kernel("BOGUS", regs);
		/* die_if_kernel("Kernel MNA access", regs); */
	}
#if 0
	show_regs (regs);
	instruction_dump ((unsigned long *) regs->pc);
	printk ("do_MNA!\n");
#endif
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRALN;
	info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
	info.si_trapno = 0;
	send_sig_info(SIGBUS, &info, current);
}

static unsigned long init_fsr = 0x0UL;
static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
                { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
		  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
		  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
		  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };

void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		 unsigned long psr)
{
	/* Sanity check... */
	if(psr & PSR_PS)
		die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);

	put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
	regs->psr |= PSR_EF;
#ifndef CONFIG_SMP
	if(last_task_used_math == current)
		return;
	if(last_task_used_math) {
		/* Other processes fpu state, save away */
		struct task_struct *fptask = last_task_used_math;
		fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
		       &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
	}
	last_task_used_math = current;
	if(used_math()) {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
	} else {
		/* Set initial sane state. */
		fpload(&init_fregs[0], &init_fsr);
		set_used_math();
	}
#else
	if(!used_math()) {
		fpload(&init_fregs[0], &init_fsr);
		set_used_math();
	} else {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
	}
	set_thread_flag(TIF_USEDFPU);
#endif
}

static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
static unsigned long fake_fsr;
static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
static unsigned long fake_depth;

extern int do_mathemu(struct pt_regs *, struct task_struct *);

void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		 unsigned long psr)
{
	static int calls;
	siginfo_t info;
	unsigned long fsr;
	int ret = 0;
#ifndef CONFIG_SMP
	struct task_struct *fpt = last_task_used_math;
#else
	struct task_struct *fpt = current;
#endif
	put_psr(get_psr() | PSR_EF);
	/* If nobody owns the fpu right now, just clear the
	 * error into our fake static buffer and hope it don't
	 * happen again.  Thank you crashme...
	 */
#ifndef CONFIG_SMP
	if(!fpt) {
#else
	if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
#endif
		fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
		regs->psr &= ~PSR_EF;
		return;
	}
	fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
	       &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
#ifdef DEBUG_FPU
	printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
#endif

	switch ((fpt->thread.fsr & 0x1c000)) {
	/* switch on the contents of the ftt [floating point trap type] field */
#ifdef DEBUG_FPU
	case (1 << 14):
		printk("IEEE_754_exception\n");
		break;
#endif
	case (2 << 14):  /* unfinished_FPop (underflow & co) */
	case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
		ret = do_mathemu(regs, fpt);
		break;
#ifdef DEBUG_FPU
	case (4 << 14):
		printk("sequence_error (OS bug...)\n");
		break;
	case (5 << 14):
		printk("hardware_error (uhoh!)\n");
		break;
	case (6 << 14):
		printk("invalid_fp_register (user error)\n");
		break;
#endif /* DEBUG_FPU */
	}
	/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
	if (ret) {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
		return;
	}
	/* nope, better SIGFPE the offending process... */
	       
#ifdef CONFIG_SMP
	clear_tsk_thread_flag(fpt, TIF_USEDFPU);
#endif
	if(psr & PSR_PS) {
		/* The first fsr store/load we tried trapped,
		 * the second one will not (we hope).
		 */
		printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
		       regs->pc);
		regs->pc = regs->npc;
		regs->npc += 4;
		calls++;
		if(calls > 2)
			die_if_kernel("Too many Penguin-FPU traps from kernel mode",
				      regs);
		return;
	}

	fsr = fpt->thread.fsr;
	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	info.si_code = __SI_FAULT;
	if ((fsr & 0x1c000) == (1 << 14)) {
		if (fsr & 0x10)
			info.si_code = FPE_FLTINV;
		else if (fsr & 0x08)
			info.si_code = FPE_FLTOVF;
		else if (fsr & 0x04)
			info.si_code = FPE_FLTUND;
		else if (fsr & 0x02)
			info.si_code = FPE_FLTDIV;
		else if (fsr & 0x01)
			info.si_code = FPE_FLTRES;
	}
	send_sig_info(SIGFPE, &info, fpt);
#ifndef CONFIG_SMP
	last_task_used_math = NULL;
#endif
	regs->psr &= ~PSR_EF;
	if(calls > 0)
		calls=0;
}

void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	siginfo_t info;

	if(psr & PSR_PS)
		die_if_kernel("Penguin overflow trap from kernel mode", regs);
	info.si_signo = SIGEMT;
	info.si_errno = 0;
	info.si_code = EMT_TAGOVF;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGEMT, &info, current);
}

void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
#ifdef TRAP_DEBUG
	printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	if(psr & PSR_PS)
		panic("Tell me what a watchpoint trap is, and I'll then deal "
		      "with such a beast...");
}

void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
	siginfo_t info;

#ifdef TRAP_DEBUG
	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_OBJERR;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	force_sig_info(SIGBUS, &info, current);
}

void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			unsigned long psr)
{
	siginfo_t info;

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_COPROC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, current);
}

void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	siginfo_t info;

#ifdef TRAP_DEBUG
	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_COPROC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, current);
}

void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
	siginfo_t info;

	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_code = FPE_INTDIV;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGFPE, &info, current);
}

#ifdef CONFIG_DEBUG_BUGVERBOSE
void do_BUG(const char *file, int line)
{
        // bust_spinlocks(1);   XXX Not in our original BUG()
        printk("kernel BUG at %s:%d!\n", file, line);
}
#endif

/* Since we have our mappings set up, on multiprocessors we can spin them
 * up here so that timer interrupts work during initialization.
 */

void trap_init(void)
{
	extern void thread_info_offsets_are_bolixed_pete(void);

	/* Force linker to barf if mismatched */
	if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
	    TI_TASK        != offsetof(struct thread_info, task) ||
	    TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
	    TI_FLAGS       != offsetof(struct thread_info, flags) ||
	    TI_CPU         != offsetof(struct thread_info, cpu) ||
	    TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
	    TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
	    TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
	    TI_KSP         != offsetof(struct thread_info, ksp) ||
	    TI_KPC         != offsetof(struct thread_info, kpc) ||
	    TI_KPSR        != offsetof(struct thread_info, kpsr) ||
	    TI_KWIM        != offsetof(struct thread_info, kwim) ||
	    TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
	    TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
	    TI_W_SAVED     != offsetof(struct thread_info, w_saved))
		thread_info_offsets_are_bolixed_pete();

	/* Attach to the address space of init_task. */
	atomic_inc(&init_mm.mm_count);
	current->active_mm = &init_mm;

	/* NOTE: Other cpus have this done as they are started
	 *       up on SMP.
	 */
}
Commit	Line	Data
88278ca2	1	/*
1da177e4 LT	2	* arch/sparc/kernel/traps.c
1da177e4 LT	3	*
4fe3ebec	4	* Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
1da177e4 LT	5	* Copyright 2000 Jakub Jelinek (jakub@redhat.com)
	6	*/
	7
	8	/*
	9	* I hate traps on the sparc, grrr...
	10	*/
	11
1da177e4 LT	12	#include <linux/sched.h> /* for jiffies */
1da177e4 LT	13	#include <linux/kernel.h>
1da177e4 LT	14	#include <linux/signal.h>
	15	#include <linux/smp.h>
	16	#include <linux/smp_lock.h>
1eeb66a1	17	#include <linux/kdebug.h>
1da177e4 LT	18
	19	#include <asm/delay.h>
	20	#include <asm/system.h>
	21	#include <asm/ptrace.h>
	22	#include <asm/oplib.h>
	23	#include <asm/page.h>
	24	#include <asm/pgtable.h>
1da177e4 LT	25	#include <asm/unistd.h>
	26	#include <asm/traps.h>
	27
8d74e32a SR	28	#include "entry.h"
8d74e32a SR	29	#include "kernel.h"
1da177e4	30
8d74e32a	31	/* #define TRAP_DEBUG */
1da177e4	32
c61c65cd	33	static void instruction_dump(unsigned long *pc)
1da177e4 LT	34	{
	35	int i;
	36
	37	if((((unsigned long) pc) & 3))
	38	return;
	39
	40	for(i = -3; i < 6; i++)
	41	printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
	42	printk("\n");
	43	}
	44
	45	#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
	46	#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
	47
	48	void die_if_kernel(char str, struct pt_regs regs)
	49	{
	50	static int die_counter;
	51	int count = 0;
	52
	53	/* Amuse the user. */
	54	printk(
	55	" \\\|/ ____ \\\|/\n"
	56	" \"@'/ ,. \\`@\"\n"
	57	" /_\| \\__/ \|_\\\n"
	58	" \\__U_/\n");
	59
19c5870c	60	printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
1da177e4	61	show_regs(regs);
bcdcd8e7	62	add_taint(TAINT_DIE);
1da177e4 LT	63
	64	__SAVE; __SAVE; __SAVE; __SAVE;
	65	__SAVE; __SAVE; __SAVE; __SAVE;
	66	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	67	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	68
	69	{
4d7b92ad	70	struct reg_window32 rw = (struct reg_window32 )regs->u_regs[UREG_FP];
1da177e4 LT	71
	72	/* Stop the back trace when we hit userland or we
	73	* find some badly aligned kernel stack. Set an upper
	74	* bound in case our stack is trashed and we loop.
	75	*/
	76	while(rw &&
	77	count++ < 30 &&
	78	(((unsigned long) rw) >= PAGE_OFFSET) &&
	79	!(((unsigned long) rw) & 0x7)) {
4fe3ebec DM	80	printk("Caller[%08lx]: %pS\n", rw->ins[7],
4fe3ebec DM	81	(void *) rw->ins[7]);
4d7b92ad	82	rw = (struct reg_window32 *)rw->ins[6];
1da177e4 LT	83	}
	84	}
	85	printk("Instruction DUMP:");
	86	instruction_dump ((unsigned long *) regs->pc);
	87	if(regs->psr & PSR_PS)
	88	do_exit(SIGKILL);
	89	do_exit(SIGSEGV);
	90	}
	91
	92	void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
	93	{
	94	siginfo_t info;
	95
	96	if(type < 0x80) {
	97	/* Sun OS's puke from bad traps, Linux survives! */
	98	printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
	99	die_if_kernel("Whee... Hello Mr. Penguin", regs);
	100	}
	101
	102	if(regs->psr & PSR_PS)
	103	die_if_kernel("Kernel bad trap", regs);
	104
	105	info.si_signo = SIGILL;
	106	info.si_errno = 0;
	107	info.si_code = ILL_ILLTRP;
	108	info.si_addr = (void __user *)regs->pc;
	109	info.si_trapno = type - 0x80;
	110	force_sig_info(SIGILL, &info, current);
	111	}
	112
	113	void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	114	unsigned long psr)
	115	{
1da177e4 LT	116	siginfo_t info;
	117
	118	if(psr & PSR_PS)
	119	die_if_kernel("Kernel illegal instruction", regs);
	120	#ifdef TRAP_DEBUG
	121	printk("Ill instr. at pc=%08lx instruction is %08lx\n",
	122	regs->pc, (unsigned long )regs->pc);
	123	#endif
	124	if (!do_user_muldiv (regs, pc))
	125	return;
	126
	127	info.si_signo = SIGILL;
	128	info.si_errno = 0;
	129	info.si_code = ILL_ILLOPC;
	130	info.si_addr = (void __user *)pc;
	131	info.si_trapno = 0;
	132	send_sig_info(SIGILL, &info, current);
	133	}
	134
	135	void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	136	unsigned long psr)
	137	{
	138	siginfo_t info;
	139
	140	if(psr & PSR_PS)
	141	die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
	142	info.si_signo = SIGILL;
	143	info.si_errno = 0;
	144	info.si_code = ILL_PRVOPC;
	145	info.si_addr = (void __user *)pc;
	146	info.si_trapno = 0;
	147	send_sig_info(SIGILL, &info, current);
	148	}
	149
	150	/* XXX User may want to be allowed to do this. XXX */
	151
	152	void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	153	unsigned long psr)
	154	{
	155	siginfo_t info;
	156
	157	if(regs->psr & PSR_PS) {
	158	printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
	159	regs->u_regs[UREG_RETPC]);
	160	die_if_kernel("BOGUS", regs);
	161	/* die_if_kernel("Kernel MNA access", regs); */
	162	}
	163	#if 0
	164	show_regs (regs);
	165	instruction_dump ((unsigned long *) regs->pc);
	166	printk ("do_MNA!\n");
	167	#endif
	168	info.si_signo = SIGBUS;
	169	info.si_errno = 0;
	170	info.si_code = BUS_ADRALN;
	171	info.si_addr = /* FIXME: Should dig out mna address / (void )0;
	172	info.si_trapno = 0;
	173	send_sig_info(SIGBUS, &info, current);
	174	}
	175
1da177e4 LT	176	static unsigned long init_fsr = 0x0UL;
	177	static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
	178	{ ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	179	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	180	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	181	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
	182
	183	void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	184	unsigned long psr)
	185	{
	186	/* Sanity check... */
	187	if(psr & PSR_PS)
	188	die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
	189
	190	put_psr(get_psr() \| PSR_EF); /* Allow FPU ops. */
	191	regs->psr \|= PSR_EF;
	192	#ifndef CONFIG_SMP
	193	if(last_task_used_math == current)
	194	return;
	195	if(last_task_used_math) {
	196	/* Other processes fpu state, save away */
	197	struct task_struct *fptask = last_task_used_math;
	198	fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
	199	&fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
	200	}
	201	last_task_used_math = current;
	202	if(used_math()) {
	203	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	204	} else {
	205	/* Set initial sane state. */
	206	fpload(&init_fregs[0], &init_fsr);
	207	set_used_math();
	208	}
	209	#else
	210	if(!used_math()) {
	211	fpload(&init_fregs[0], &init_fsr);
	212	set_used_math();
	213	} else {
	214	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	215	}
54f565ea	216	set_thread_flag(TIF_USEDFPU);
1da177e4 LT	217	#endif
	218	}
	219
	220	static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
	221	static unsigned long fake_fsr;
	222	static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
	223	static unsigned long fake_depth;
	224
	225	extern int do_mathemu(struct pt_regs , struct task_struct );
	226
	227	void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	228	unsigned long psr)
	229	{
	230	static int calls;
	231	siginfo_t info;
	232	unsigned long fsr;
	233	int ret = 0;
	234	#ifndef CONFIG_SMP
	235	struct task_struct *fpt = last_task_used_math;
	236	#else
	237	struct task_struct *fpt = current;
	238	#endif
	239	put_psr(get_psr() \| PSR_EF);
	240	/* If nobody owns the fpu right now, just clear the
	241	* error into our fake static buffer and hope it don't
	242	* happen again. Thank you crashme...
	243	*/
	244	#ifndef CONFIG_SMP
	245	if(!fpt) {
	246	#else
54f565ea	247	if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
1da177e4 LT	248	#endif
	249	fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
	250	regs->psr &= ~PSR_EF;
	251	return;
	252	}
	253	fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
	254	&fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
	255	#ifdef DEBUG_FPU
	256	printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
	257	#endif
	258
	259	switch ((fpt->thread.fsr & 0x1c000)) {
	260	/* switch on the contents of the ftt [floating point trap type] field */
	261	#ifdef DEBUG_FPU
	262	case (1 << 14):
	263	printk("IEEE_754_exception\n");
	264	break;
	265	#endif
	266	case (2 << 14): /* unfinished_FPop (underflow & co) */
	267	case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */
	268	ret = do_mathemu(regs, fpt);
	269	break;
	270	#ifdef DEBUG_FPU
	271	case (4 << 14):
	272	printk("sequence_error (OS bug...)\n");
	273	break;
	274	case (5 << 14):
	275	printk("hardware_error (uhoh!)\n");
	276	break;
	277	case (6 << 14):
	278	printk("invalid_fp_register (user error)\n");
	279	break;
	280	#endif /* DEBUG_FPU */
	281	}
	282	/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
	283	if (ret) {
	284	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	285	return;
	286	}
	287	/* nope, better SIGFPE the offending process... */
	288
	289	#ifdef CONFIG_SMP
54f565ea	290	clear_tsk_thread_flag(fpt, TIF_USEDFPU);
1da177e4 LT	291	#endif
	292	if(psr & PSR_PS) {
	293	/* The first fsr store/load we tried trapped,
	294	* the second one will not (we hope).
	295	*/
	296	printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
	297	regs->pc);
	298	regs->pc = regs->npc;
	299	regs->npc += 4;
	300	calls++;
	301	if(calls > 2)
	302	die_if_kernel("Too many Penguin-FPU traps from kernel mode",
	303	regs);
	304	return;
	305	}
	306
	307	fsr = fpt->thread.fsr;
	308	info.si_signo = SIGFPE;
	309	info.si_errno = 0;
	310	info.si_addr = (void __user *)pc;
	311	info.si_trapno = 0;
	312	info.si_code = __SI_FAULT;
	313	if ((fsr & 0x1c000) == (1 << 14)) {
	314	if (fsr & 0x10)
	315	info.si_code = FPE_FLTINV;
	316	else if (fsr & 0x08)
	317	info.si_code = FPE_FLTOVF;
	318	else if (fsr & 0x04)
	319	info.si_code = FPE_FLTUND;
	320	else if (fsr & 0x02)
	321	info.si_code = FPE_FLTDIV;
	322	else if (fsr & 0x01)
	323	info.si_code = FPE_FLTRES;
	324	}
	325	send_sig_info(SIGFPE, &info, fpt);
	326	#ifndef CONFIG_SMP
	327	last_task_used_math = NULL;
	328	#endif
	329	regs->psr &= ~PSR_EF;
	330	if(calls > 0)
	331	calls=0;
	332	}
	333
	334	void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	335	unsigned long psr)
	336	{
	337	siginfo_t info;
	338
	339	if(psr & PSR_PS)
	340	die_if_kernel("Penguin overflow trap from kernel mode", regs);
	341	info.si_signo = SIGEMT;
	342	info.si_errno = 0;
	343	info.si_code = EMT_TAGOVF;
	344	info.si_addr = (void __user *)pc;
	345	info.si_trapno = 0;
	346	send_sig_info(SIGEMT, &info, current);
	347	}
	348
	349	void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	350	unsigned long psr)
	351	{
	352	#ifdef TRAP_DEBUG
	353	printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
	354	pc, npc, psr);
355	#endif
356	if(psr & PSR_PS)
357	panic("Tell me what a watchpoint trap is, and I'll then deal "
358	"with such a beast...");
359	}
360
361	void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
362	unsigned long psr)
363	{
364	siginfo_t info;
365
366	#ifdef TRAP_DEBUG
367	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
368	pc, npc, psr);
369	#endif
370	info.si_signo = SIGBUS;
371	info.si_errno = 0;
372	info.si_code = BUS_OBJERR;
373	info.si_addr = (void __user *)pc;
374	info.si_trapno = 0;
375	force_sig_info(SIGBUS, &info, current);
376	}
377
378	void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
379	unsigned long psr)
380	{
381	siginfo_t info;
382
383	info.si_signo = SIGILL;
384	info.si_errno = 0;
385	info.si_code = ILL_COPROC;
386	info.si_addr = (void __user *)pc;
387	info.si_trapno = 0;
388	send_sig_info(SIGILL, &info, current);
389	}
390
391	void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
392	unsigned long psr)
393	{
394	siginfo_t info;
395
396	#ifdef TRAP_DEBUG
397	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
398	pc, npc, psr);
399	#endif
400	info.si_signo = SIGILL;
401	info.si_errno = 0;
402	info.si_code = ILL_COPROC;
403	info.si_addr = (void __user *)pc;
404	info.si_trapno = 0;
405	send_sig_info(SIGILL, &info, current);
406	}
407
408	void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
409	unsigned long psr)
410	{
411	siginfo_t info;
412
413	info.si_signo = SIGFPE;
414	info.si_errno = 0;
415	info.si_code = FPE_INTDIV;
416	info.si_addr = (void __user *)pc;
417	info.si_trapno = 0;
418	send_sig_info(SIGFPE, &info, current);
419	}
420
421	#ifdef CONFIG_DEBUG_BUGVERBOSE
422	void do_BUG(const char *file, int line)
423	{
424	// bust_spinlocks(1); XXX Not in our original BUG()
425	printk("kernel BUG at %s:%d!\n", file, line);
426	}
427	#endif
428
429	/* Since we have our mappings set up, on multiprocessors we can spin them
430	* up here so that timer interrupts work during initialization.
431	*/
432
1da177e4 LT	433	void trap_init(void)
	434	{
	435	extern void thread_info_offsets_are_bolixed_pete(void);
	436
	437	/* Force linker to barf if mismatched */
	438	if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) \|\|
	439	TI_TASK != offsetof(struct thread_info, task) \|\|
	440	TI_EXECDOMAIN != offsetof(struct thread_info, exec_domain) \|\|
	441	TI_FLAGS != offsetof(struct thread_info, flags) \|\|
	442	TI_CPU != offsetof(struct thread_info, cpu) \|\|
	443	TI_PREEMPT != offsetof(struct thread_info, preempt_count) \|\|
	444	TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) \|\|
	445	TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) \|\|
	446	TI_KSP != offsetof(struct thread_info, ksp) \|\|
	447	TI_KPC != offsetof(struct thread_info, kpc) \|\|
	448	TI_KPSR != offsetof(struct thread_info, kpsr) \|\|
	449	TI_KWIM != offsetof(struct thread_info, kwim) \|\|
	450	TI_REG_WINDOW != offsetof(struct thread_info, reg_window) \|\|
	451	TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) \|\|
	452	TI_W_SAVED != offsetof(struct thread_info, w_saved))
	453	thread_info_offsets_are_bolixed_pete();
	454
	455	/* Attach to the address space of init_task. */
	456	atomic_inc(&init_mm.mm_count);
	457	current->active_mm = &init_mm;
	458
	459	/* NOTE: Other cpus have this done as they are started
	460	* up on SMP.
	461	*/
	462	}