source: mainline/kernel/arch/sparc64/src/asm.S

/*
 * Copyright (c) 2005 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <abi/asmtool.h>
#include <arch/arch.h>
#include <arch/stack.h>

.text

.register %g2, #scratch
.register %g3, #scratch

/*
 * Almost the same as memcpy() except the loads are from userspace.
 */
FUNCTION_BEGIN(memcpy_from_uspace)
        mov %o0, %o3  /* save dst */
        add %o1, 7, %g1
        and %g1, -8, %g1
        cmp %o1, %g1
        be,pn %xcc, 3f
        add %o0, 7, %g1
        mov 0, %g3

        0:

                brz,pn %o2, 2f
                mov 0, %g2

        1:

                lduba [%g3 + %o1] ASI_AIUS, %g1
                add %g2, 1, %g2
                cmp %o2, %g2
                stb %g1, [%g3 + %o0]
                bne,pt %xcc, 1b
                mov %g2, %g3

        2:

                jmp %o7 + 8  /* exit point */
                mov %o3, %o0

        3:

                and %g1, -8, %g1
                cmp %o0, %g1
                bne,pt %xcc, 0b
                mov 0, %g3
                srlx %o2, 3, %g4
                brz,pn %g4, 5f
                mov 0, %g5

        4:

                sllx %g3, 3, %g2
                add %g5, 1, %g3
                ldxa [%o1 + %g2] ASI_AIUS, %g1
                mov %g3, %g5
                cmp %g4, %g3
                bne,pt %xcc, 4b
                stx %g1, [%o0 + %g2]

        5:

                and %o2, 7, %o2
                brz,pn %o2, 2b
                sllx %g4, 3, %g1
                mov 0, %g2
                add %g1, %o0, %o0
                add %g1, %o1, %g4
                mov 0, %g3

        6:

                lduba [%g2 + %g4] ASI_AIUS, %g1
                stb %g1, [%g2 + %o0]
                add %g3, 1, %g2
                cmp %o2, %g2
                bne,pt %xcc, 6b
                mov %g2, %g3

                jmp %o7 + 8  /* exit point */
                mov %o3, %o0
FUNCTION_END(memcpy_from_uspace)

/*
 * Almost the same as memcpy() except the stores are to userspace.
 */
FUNCTION_BEGIN(memcpy_to_uspace)
        mov %o0, %o3  /* save dst */
        add %o1, 7, %g1
        and %g1, -8, %g1
        cmp %o1, %g1
        be,pn %xcc, 3f
        add %o0, 7, %g1
        mov 0, %g3

        0:

                brz,pn %o2, 2f
                mov 0, %g2

        1:

                ldub [%g3 + %o1], %g1
                add %g2, 1, %g2
                cmp %o2, %g2
                stba %g1, [%g3 + %o0] ASI_AIUS
                bne,pt %xcc, 1b
                mov %g2, %g3

        2:

                jmp %o7 + 8  /* exit point */
                mov %o3, %o0

        3:

                and %g1, -8, %g1
                cmp %o0, %g1
                bne,pt %xcc, 0b
                mov 0, %g3
                srlx %o2, 3, %g4
                brz,pn %g4, 5f
                mov 0, %g5

        4:

                sllx %g3, 3, %g2
                add %g5, 1, %g3
                ldx [%o1 + %g2], %g1
                mov %g3, %g5
                cmp %g4, %g3
                bne,pt %xcc, 4b
                stxa %g1, [%o0 + %g2] ASI_AIUS

        5:

                and %o2, 7, %o2
                brz,pn %o2, 2b
                sllx %g4, 3, %g1
                mov 0, %g2
                add %g1, %o0, %o0
                add %g1, %o1, %g4
                mov 0, %g3

        6:

                ldub [%g2 + %g4], %g1
                stba %g1, [%g2 + %o0] ASI_AIUS
                add %g3, 1, %g2
                cmp %o2, %g2
                bne,pt %xcc, 6b
                mov %g2, %g3

                jmp     %o7 + 8  /* exit point */
                mov     %o3, %o0
FUNCTION_END(memcpy_to_uspace)

SYMBOL(memcpy_from_uspace_failover_address)
SYMBOL(memcpy_to_uspace_failover_address)
        jmp %o7 + 8   /* exit point */
        mov %g0, %o0  /* return 0 on failure */

FUNCTION_BEGIN(early_putuchar)
        retl
        nop
FUNCTION_END(early_putuchar)