traps.c

上传linux-jx2410的源代码

/*
 * Architecture-specific trap handling.
 *
 * Copyright (C) 1998-2001 Hewlett-Packard Co
 *	David Mosberger-Tang <[e-mail]>
 *
 * 05/12/00 grao <[e-mail]> : added isr in siginfo for SIGFPE
 */

/*
 * fp_emulate() needs to be able to access and update all floating point registers.  Those
 * saved in pt_regs can be accessed through that structure, but those not saved, will be
 * accessed directly.  To make this work, we need to ensure that the compiler does not end
 * up using a preserved floating point register on its own.  The following achieves this
 * by declaring preserved registers that are not marked as "fixed" as global register
 * variables.
 */
register double f2 asm ("f2"); register double f3 asm ("f3");
register double f4 asm ("f4"); register double f5 asm ("f5");

register long f16 asm ("f16"); register long f17 asm ("f17");
register long f18 asm ("f18"); register long f19 asm ("f19");
register long f20 asm ("f20"); register long f21 asm ("f21");
register long f22 asm ("f22"); register long f23 asm ("f23");

register double f24 asm ("f24"); register double f25 asm ("f25");
register double f26 asm ("f26"); register double f27 asm ("f27");
register double f28 asm ("f28"); register double f29 asm ("f29");
register double f30 asm ("f30"); register double f31 asm ("f31");

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/vt_kern.h>		/* For unblank_screen() */

#include <asm/hardirq.h>
#include <asm/ia32.h>
#include <asm/processor.h>
#include <asm/uaccess.h>

#include <asm/fpswa.h>

extern spinlock_t timerlist_lock;

static fpswa_interface_t *fpswa_interface;

void __init
trap_init (void)
{
	printk("fpswa interface at %lx\n", ia64_boot_param->fpswa);
	if (ia64_boot_param->fpswa)
		/* FPSWA fixup: make the interface pointer a kernel virtual address: */
		fpswa_interface = __va(ia64_boot_param->fpswa);
}

/*
 * Unlock any spinlocks which will prevent us from getting the message out (timerlist_lock
 * is acquired through the console unblank code)
 */
void
bust_spinlocks (int yes)
{
	spin_lock_init(&timerlist_lock);
	if (yes) {
		oops_in_progress = 1;
#ifdef CONFIG_SMP
		global_irq_lock = 0;	/* Many serial drivers do __global_cli() */
#endif
	} else {
		int loglevel_save = console_loglevel;
#ifdef CONFIG_VT
		unblank_screen();
#endif
		oops_in_progress = 0;
		/*
		 * OK, the message is on the console.  Now we call printk() without
		 * oops_in_progress set so that printk will give klogd a poke.  Hold onto
		 * your hats...
		 */
		console_loglevel = 15;		/* NMI oopser may have shut the console up */
		printk(" ");
		console_loglevel = loglevel_save;
	}
}

void
die (const char *str, struct pt_regs *regs, long err)
{
	static struct {
		spinlock_t lock;
		int lock_owner;
		int lock_owner_depth;
	} die = {
		lock:			SPIN_LOCK_UNLOCKED,
		lock_owner:		-1,
		lock_owner_depth:	0
	};

	if (die.lock_owner != smp_processor_id()) {
		console_verbose();
		spin_lock_irq(&die.lock);
		die.lock_owner = smp_processor_id();
		die.lock_owner_depth = 0;
		bust_spinlocks(1);
	}

	if (++die.lock_owner_depth < 3) {
		printk("%s[%d]: %s %ld\n", current->comm, current->pid, str, err);
		show_regs(regs);
  	} else
		printk(KERN_ERR "Recursive die() failure, output suppressed\n");

	bust_spinlocks(0);
	die.lock_owner = -1;
	spin_unlock_irq(&die.lock);
  	do_exit(SIGSEGV);
}

void
die_if_kernel (char *str, struct pt_regs *regs, long err)
{
	if (!user_mode(regs))
		die(str, regs, err);
}

void
ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
{
	siginfo_t siginfo;
	int sig, code;

	/* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
	siginfo.si_addr = (void *) (regs->cr_iip + ia64_psr(regs)->ri);
	siginfo.si_imm = break_num;

	switch (break_num) {
	      case 0: /* unknown error */
		sig = SIGILL; code = ILL_ILLOPC;
		break;

	      case 1: /* integer divide by zero */
		sig = SIGFPE; code = FPE_INTDIV;
		break;

	      case 2: /* integer overflow */
		sig = SIGFPE; code = FPE_INTOVF;
		break;

	      case 3: /* range check/bounds check */
		sig = SIGFPE; code = FPE_FLTSUB;
		break;

	      case 4: /* null pointer dereference */
		sig = SIGSEGV; code = SEGV_MAPERR;
		break;

	      case 5: /* misaligned data */
		sig = SIGSEGV; code = BUS_ADRALN;
		break;

	      case 6: /* decimal overflow */
		sig = SIGFPE; code = __FPE_DECOVF;
		break;

	      case 7: /* decimal divide by zero */
		sig = SIGFPE; code = __FPE_DECDIV;
		break;

	      case 8: /* packed decimal error */
		sig = SIGFPE; code = __FPE_DECERR;
		break;

	      case 9: /* invalid ASCII digit */
		sig = SIGFPE; code = __FPE_INVASC;
		break;

	      case 10: /* invalid decimal digit */
		sig = SIGFPE; code = __FPE_INVDEC;
		break;

	      case 11: /* paragraph stack overflow */
		sig = SIGSEGV; code = __SEGV_PSTKOVF;
		break;

	      default:
		if (break_num < 0x40000 || break_num > 0x100000)
			die_if_kernel("Bad break", regs, break_num);

		if (break_num < 0x80000) {
			sig = SIGILL; code = __ILL_BREAK;
		} else {
			sig = SIGTRAP; code = TRAP_BRKPT;
		}
	}
	siginfo.si_signo = sig;
	siginfo.si_errno = 0;
	siginfo.si_code = code;
	force_sig_info(sig, &siginfo, current);
}

/*
 * Unimplemented system calls.  This is called only for stuff that
 * we're supposed to implement but haven't done so yet.  Everything
 * else goes to sys_ni_syscall.
 */
asmlinkage long
ia64_ni_syscall (unsigned long arg0, unsigned long arg1, unsigned long arg2, unsigned long arg3,
		 unsigned long arg4, unsigned long arg5, unsigned long arg6, unsigned long arg7,
		 unsigned long stack)
{
	struct pt_regs *regs = (struct pt_regs *) &stack;

	printk("<sc%ld(%lx,%lx,%lx,%lx)>\n", regs->r15, arg0, arg1, arg2, arg3);
	return -ENOSYS;
}

/*
 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127
 * and it doesn't own the fp-high register partition.  When this happens, we save the
 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load
 * the fp-high partition of the current task (if necessary).  Note that the kernel has
 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes
 * care of clearing psr.dfh.
 */
static inline void
disabled_fph_fault (struct pt_regs *regs)
{
	struct ia64_psr *psr = ia64_psr(regs);

	/* first, grant user-level access to fph partition: */
	psr->dfh = 0;
#ifndef CONFIG_SMP
	{
		struct task_struct *fpu_owner = ia64_get_fpu_owner();

		if (fpu_owner == current)
			return;

		if (fpu_owner)
			ia64_flush_fph(fpu_owner);

		ia64_set_fpu_owner(current);
	}
#endif /* !CONFIG_SMP */
	if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) {
		__ia64_load_fpu(current->thread.fph);
		psr->mfh = 0;
	} else {
		__ia64_init_fpu();
		/*
		 * Set mfh because the state in thread.fph does not match the state in
		 * the fph partition.
		 */
		psr->mfh = 1;
	}
}

static inline int
fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
	    struct pt_regs *regs)
{
	struct ia64_fpreg f6_11[6];
	fp_state_t fp_state;
	fpswa_ret_t ret;

	if (!fpswa_interface)
		return -1;

	memset(&fp_state, 0, sizeof(fp_state_t));

	/*
	 * compute fp_state.  only FP registers f6 - f11 are used by the
	 * kernel, so set those bits in the mask and set the low volatile
	 * pointer to point to these registers.
	 */
	fp_state.bitmask_low64 = 0xfc0;  /* bit6..bit11 */
	f6_11[0] = regs->f6; f6_11[1] = regs->f7;
	f6_11[2] = regs->f8; f6_11[3] = regs->f9;
	__asm__ ("stf.spill %0=f10%P0" : "=m"(f6_11[4]));
	__asm__ ("stf.spill %0=f11%P0" : "=m"(f6_11[5]));
	fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) f6_11;
	/*
	 * unsigned long (*EFI_FPSWA) (
	 *      unsigned long    trap_type,
	 *	void             *Bundle,
	 *	unsigned long    *pipsr,
	 *	unsigned long    *pfsr,
	 *	unsigned long    *pisr,
	 *	unsigned long    *ppreds,