traps.c

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/*
 *  linux/arch/parisc/traps.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 1999, 2000  Philipp Rumpf <[e-mail]>
 */

/*
 * 'Traps.c' handles hardware traps and faults after we have saved some
 * state in 'asm.s'.
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/console.h>
#include <linux/kallsyms.h>
#include <linux/bug.h>

#include <asm/assembly.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/traps.h>
#include <asm/unaligned.h>
#include <asm/atomic.h>
#include <asm/smp.h>
#include <asm/pdc.h>
#include <asm/pdc_chassis.h>
#include <asm/unwind.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>

#include "../math-emu/math-emu.h"	/* for handle_fpe() */

#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
			  /*  dumped to the console via printk)          */

#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
DEFINE_SPINLOCK(pa_dbit_lock);
#endif

static int printbinary(char *buf, unsigned long x, int nbits)
{
	unsigned long mask = 1UL << (nbits - 1);
	while (mask != 0) {
		*buf++ = (mask & x ? '1' : '0');
		mask >>= 1;
	}
	*buf = '\0';

	return nbits;
}

#ifdef CONFIG_64BIT
#define RFMT "%016lx"
#else
#define RFMT "%08lx"
#endif
#define FFMT "%016llx"	/* fpregs are 64-bit always */

#define PRINTREGS(lvl,r,f,fmt,x)	\
	printk("%s%s%02d-%02d  " fmt " " fmt " " fmt " " fmt "\n",	\
		lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1],		\
		(r)[(x)+2], (r)[(x)+3])

static void print_gr(char *level, struct pt_regs *regs)
{
	int i;
	char buf[64];

	printk("%s\n", level);
	printk("%s     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
	printbinary(buf, regs->gr[0], 32);
	printk("%sPSW: %s %s\n", level, buf, print_tainted());

	for (i = 0; i < 32; i += 4)
		PRINTREGS(level, regs->gr, "r", RFMT, i);
}

static void print_fr(char *level, struct pt_regs *regs)
{
	int i;
	char buf[64];
	struct { u32 sw[2]; } s;

	/* FR are 64bit everywhere. Need to use asm to get the content
	 * of fpsr/fper1, and we assume that we won't have a FP Identify
	 * in our way, otherwise we're screwed.
	 * The fldd is used to restore the T-bit if there was one, as the
	 * store clears it anyway.
	 * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */
	asm volatile ("fstd %%fr0,0(%1)	\n\t"
		      "fldd 0(%1),%%fr0	\n\t"
		      : "=m" (s) : "r" (&s) : "r0");

	printk("%s\n", level);
	printk("%s      VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level);
	printbinary(buf, s.sw[0], 32);
	printk("%sFPSR: %s\n", level, buf);
	printk("%sFPER1: %08x\n", level, s.sw[1]);

	/* here we'll print fr0 again, tho it'll be meaningless */
	for (i = 0; i < 32; i += 4)
		PRINTREGS(level, regs->fr, "fr", FFMT, i);
}

void show_regs(struct pt_regs *regs)
{
	int i;
	char *level;
	unsigned long cr30, cr31;

	level = user_mode(regs) ? KERN_DEBUG : KERN_CRIT;

	print_gr(level, regs);

	for (i = 0; i < 8; i += 4)
		PRINTREGS(level, regs->sr, "sr", RFMT, i);

	if (user_mode(regs))
		print_fr(level, regs);

	cr30 = mfctl(30);
	cr31 = mfctl(31);
	printk("%s\n", level);
	printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
	       level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
	printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
	       level, regs->iir, regs->isr, regs->ior);
	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
	       level, current_thread_info()->cpu, cr30, cr31);
	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
	printk(level);
	print_symbol(" IAOQ[0]: %s\n", regs->iaoq[0]);
	printk(level);
	print_symbol(" IAOQ[1]: %s\n", regs->iaoq[1]);
	printk(level);
	print_symbol(" RP(r2): %s\n", regs->gr[2]);
}


void dump_stack(void)
{
	show_stack(NULL, NULL);
}

EXPORT_SYMBOL(dump_stack);

static void do_show_stack(struct unwind_frame_info *info)
{
	int i = 1;

	printk(KERN_CRIT "Backtrace:\n");
	while (i <= 16) {
		if (unwind_once(info) < 0 || info->ip == 0)
			break;

		if (__kernel_text_address(info->ip)) {
			printk("%s [<" RFMT ">] ", (i&0x3)==1 ? KERN_CRIT : "", info->ip);
#ifdef CONFIG_KALLSYMS
			print_symbol("%s\n", info->ip);
#else
			if ((i & 0x03) == 0)
				printk("\n");
#endif
			i++;
		}
	}
	printk("\n");
}

void show_stack(struct task_struct *task, unsigned long *s)
{
	struct unwind_frame_info info;

	if (!task) {
		unsigned long sp;

HERE:
		asm volatile ("copy %%r30, %0" : "=r"(sp));
		{
			struct pt_regs r;

			memset(&r, 0, sizeof(struct pt_regs));
			r.iaoq[0] = (unsigned long)&&HERE;
			r.gr[2] = (unsigned long)__builtin_return_address(0);
			r.gr[30] = sp;

			unwind_frame_init(&info, current, &r);
		}
	} else {
		unwind_frame_init_from_blocked_task(&info, task);
	}

	do_show_stack(&info);
}

int is_valid_bugaddr(unsigned long iaoq)
{
	return 1;
}

void die_if_kernel(char *str, struct pt_regs *regs, long err)
{
	if (user_mode(regs)) {
		if (err == 0)
			return; /* STFU */

		printk(KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
			current->comm, task_pid_nr(current), str, err, regs->iaoq[0]);
#ifdef PRINT_USER_FAULTS
		/* XXX for debugging only */
		show_regs(regs);
#endif
		return;
	}

	oops_in_progress = 1;

	/* Amuse the user in a SPARC fashion */
	if (err) printk(
KERN_CRIT "      _______________________________ \n"
KERN_CRIT "     < Your System ate a SPARC! Gah! >\n"
KERN_CRIT "      ------------------------------- \n"
KERN_CRIT "             \\   ^__^\n"
KERN_CRIT "              \\  (xx)\\_______\n"
KERN_CRIT "                 (__)\\       )\\/\\\n"
KERN_CRIT "                  U  ||----w |\n"
KERN_CRIT "                     ||     ||\n");
	
	/* unlock the pdc lock if necessary */
	pdc_emergency_unlock();

	/* maybe the kernel hasn't booted very far yet and hasn't been able 
	 * to initialize the serial or STI console. In that case we should 
	 * re-enable the pdc console, so that the user will be able to 
	 * identify the problem. */
	if (!console_drivers)
		pdc_console_restart();
	
	if (err)
		printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
			current->comm, task_pid_nr(current), str, err);

	/* Wot's wrong wif bein' racy? */
	if (current->thread.flags & PARISC_KERNEL_DEATH) {
		printk(KERN_CRIT "%s() recursion detected.\n", __FUNCTION__);
		local_irq_enable();
		while (1);
	}
	current->thread.flags |= PARISC_KERNEL_DEATH;

	show_regs(regs);
	dump_stack();
	add_taint(TAINT_DIE);

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops) {
		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
		ssleep(5);
		panic("Fatal exception");
	}

	do_exit(SIGSEGV);
}

int syscall_ipi(int (*syscall) (struct pt_regs *), struct pt_regs *regs)
{
	return syscall(regs);
}

/* gdb uses break 4,8 */
#define GDB_BREAK_INSN 0x10004
static void handle_gdb_break(struct pt_regs *regs, int wot)
{
	struct siginfo si;

	si.si_signo = SIGTRAP;
	si.si_errno = 0;
	si.si_code = wot;
	si.si_addr = (void __user *) (regs->iaoq[0] & ~3);
	force_sig_info(SIGTRAP, &si, current);
}

static void handle_break(struct pt_regs *regs)
{
	unsigned iir = regs->iir;

	if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) {
		/* check if a BUG() or WARN() trapped here.  */
		enum bug_trap_type tt;
		tt = report_bug(regs->iaoq[0] & ~3, regs);
		if (tt == BUG_TRAP_TYPE_WARN) {
			regs->iaoq[0] += 4;
			regs->iaoq[1] += 4;
			return; /* return to next instruction when WARN_ON().  */
		}
		die_if_kernel("Unknown kernel breakpoint", regs,
			(tt == BUG_TRAP_TYPE_NONE) ? 9 : 0);
	}

#ifdef PRINT_USER_FAULTS
	if (unlikely(iir != GDB_BREAK_INSN)) {
		printk(KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
			iir & 31, (iir>>13) & ((1<<13)-1),
			task_pid_nr(current), current->comm);
		show_regs(regs);
	}
#endif

	/* send standard GDB signal */
	handle_gdb_break(regs, TRAP_BRKPT);
}

static void default_trap(int code, struct pt_regs *regs)
{
	printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
	show_regs(regs);
}

void (*cpu_lpmc) (int code, struct pt_regs *regs) __read_mostly = default_trap;


void transfer_pim_to_trap_frame(struct pt_regs *regs)
{
    register int i;
    extern unsigned int hpmc_pim_data[];
    struct pdc_hpmc_pim_11 *pim_narrow;
    struct pdc_hpmc_pim_20 *pim_wide;

    if (boot_cpu_data.cpu_type >= pcxu) {

	pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;

	/*
	 * Note: The following code will probably generate a
	 * bunch of truncation error warnings from the compiler.
	 * Could be handled with an ifdef, but perhaps there
	 * is a better way.
	 */

	regs->gr[0] = pim_wide->cr[22];

	for (i = 1; i < 32; i++)
	    regs->gr[i] = pim_wide->gr[i];

	for (i = 0; i < 32; i++)
	    regs->fr[i] = pim_wide->fr[i];

	for (i = 0; i < 8; i++)
	    regs->sr[i] = pim_wide->sr[i];

	regs->iasq[0] = pim_wide->cr[17];
	regs->iasq[1] = pim_wide->iasq_back;
	regs->iaoq[0] = pim_wide->cr[18];
	regs->iaoq[1] = pim_wide->iaoq_back;

	regs->sar  = pim_wide->cr[11];
	regs->iir  = pim_wide->cr[19];
	regs->isr  = pim_wide->cr[20];
	regs->ior  = pim_wide->cr[21];
    }
    else {
	pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;

	regs->gr[0] = pim_narrow->cr[22];

	for (i = 1; i < 32; i++)
	    regs->gr[i] = pim_narrow->gr[i];

	for (i = 0; i < 32; i++)
	    regs->fr[i] = pim_narrow->fr[i];

	for (i = 0; i < 8; i++)
	    regs->sr[i] = pim_narrow->sr[i];

	regs->iasq[0] = pim_narrow->cr[17];
	regs->iasq[1] = pim_narrow->iasq_back;
	regs->iaoq[0] = pim_narrow->cr[18];
	regs->iaoq[1] = pim_narrow->iaoq_back;

	regs->sar  = pim_narrow->cr[11];
	regs->iir  = pim_narrow->cr[19];
	regs->isr  = pim_narrow->cr[20];
	regs->ior  = pim_narrow->cr[21];
    }

    /*
     * The following fields only have meaning if we came through
     * another path. So just zero them here.
     */

    regs->ksp = 0;
    regs->kpc = 0;
    regs->orig_r28 = 0;
}


/*
 * This routine is called as a last resort when everything else
 * has gone clearly wrong. We get called for faults in kernel space,
 * and HPMC's.
 */
void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
{
	static DEFINE_SPINLOCK(terminate_lock);

	oops_in_progress = 1;

	set_eiem(0);
	local_irq_disable();
	spin_lock(&terminate_lock);

	/* unlock the pdc lock if necessary */
	pdc_emergency_unlock();

	/* restart pdc console if necessary */