Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 2005 Thiemo Seufer

 * Copyright (C) 2005  MIPS Technologies, Inc.  All rights reserved.

 *      Author: Maciej W. Rozycki <macro@mips.com>

 */

#include <linux/init.h>

#include <asm/addrspace.h>

#include <asm/bug.h>

#include <asm/cacheflush.h>

#ifndef CKSEG2

#define CKSEG2 CKSSEG

#endif

#ifndef TO_PHYS_MASK

#define TO_PHYS_MASK -1

#endif

/*

 * FUNC is executed in one of the uncached segments, depending on its

 * original address as follows:

 *

 * 1. If the original address is in CKSEG0 or CKSEG1, then the uncached

 *    segment used is CKSEG1.

 * 2. If the original address is in XKPHYS, then the uncached segment

 *    used is XKPHYS(2).

 * 3. Otherwise it's a bug.

 *

 * The same remapping is done with the stack pointer.  Stack handling

 * works because we don't handle stack arguments or more complex return

 * values, so we can avoid sharing the same stack area between a cached

 * and the uncached mode.

 */

unsigned long __init run_uncached(void *func)

{

        register long sp __asm__("$sp");

        register long ret __asm__("$2");

        long lfunc = (long)func, ufunc;

        long usp;

        if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)

                usp = CKSEG1ADDR(sp);

#ifdef CONFIG_64BIT

        else if ((long long)sp >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&

                 (long long)sp < (long long)PHYS_TO_XKPHYS(8LL, 0))

                usp = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,

                                     XKPHYS_TO_PHYS((long long)sp));

#endif

        else {

                BUG();

                usp = sp;

        }

        if (lfunc >= (long)CKSEG0 && lfunc < (long)CKSEG2)

                ufunc = CKSEG1ADDR(lfunc);

#ifdef CONFIG_64BIT

        else if ((long long)lfunc >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&

                 (long long)lfunc < (long long)PHYS_TO_XKPHYS(8LL, 0))

                ufunc = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,

                                       XKPHYS_TO_PHYS((long long)lfunc));

#endif

        else {

                BUG();

                ufunc = lfunc;

        }

        __asm__ __volatile__ (

                "       move    $16, $sp\n"

                "       move    $sp, %1\n"

                "       jalr    %2\n"

                "       move    $sp, $16"

                : "=r" (ret)

                : "r" (usp), "r" (ufunc)

                : "$16", "$31");

        return ret;

}