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/*

 * Kernel exception handling table support.  Derived from arch/alpha/mm/extable.c.

 *

 * Copyright (C) 1998, 1999, 2001-2002 Hewlett-Packard Co

 *      David Mosberger-Tang <davidm@hpl.hp.com>

 */

#include <linux/config.h>

#include <asm/uaccess.h>

#include <asm/module.h>

extern const struct exception_table_entry __start___ex_table[];

extern const struct exception_table_entry __stop___ex_table[];

static inline const struct exception_table_entry *

search_one_table (const struct exception_table_entry *first,

                  const struct exception_table_entry *last,

                  unsigned long ip, unsigned long gp)

{

        while (first <= last) {

                const struct exception_table_entry *mid;

                long diff;

                mid = &first[(last - first)/2];

                diff = (mid->addr + gp) - ip;

                if (diff == 0)

                        return mid;

                else if (diff < 0)

                        first = mid + 1;

                else

                        last = mid - 1;

        }

        return 0;

}

#ifndef CONFIG_MODULES

register unsigned long main_gp __asm__("gp");

#endif

extern spinlock_t modlist_lock;

struct exception_fixup

search_exception_table (unsigned long addr)

{

        const struct exception_table_entry *entry;

        struct exception_fixup fix = { 0 };

#ifndef CONFIG_MODULES

        /* There is only the kernel to search.  */

        entry = search_one_table(__start___ex_table, __stop___ex_table - 1, addr, main_gp);

        if (entry)

                fix.cont = entry->cont + main_gp;

        return fix;

#else

        struct archdata *archdata;

        unsigned long flags;

        struct module *mp;

        /* The kernel is the last "module" -- no need to treat it special. */

        spin_lock_irqsave(&modlist_lock, flags);

        for (mp = module_list; mp; mp = mp->next) {

                if (!mp->ex_table_start)

                        continue;

                archdata = (struct archdata *) mp->archdata_start;

                if (!archdata)

                        continue;

                entry = search_one_table(mp->ex_table_start, mp->ex_table_end - 1,

                                         addr, (unsigned long) archdata->gp);

                if (entry) {

                        fix.cont = entry->cont + (unsigned long) archdata->gp;

                        break;

                }

        }

        spin_unlock_irqrestore(&modlist_lock, flags);

#endif

        return fix;

}

void

handle_exception (struct pt_regs *regs, struct exception_fixup fix)

{

        regs->r8 = -EFAULT;

        if (fix.cont & 4)

                regs->r9 = 0;

        regs->cr_iip = (long) fix.cont & ~0xf;

        ia64_psr(regs)->ri = fix.cont & 0x3;            /* set continuation slot number */

}