/* SPDX-License-Identifier: GPL-2.0 */
/* copy_in_user.S: Copy from userspace to userspace.
 *
 * Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com)
 */

#include <linux/export.h>
#include <linux/linkage.h>
#include <asm/asi.h>

#define XCC xcc

#define EX(x,y,z)               \
98:     x,y;                    \
        .section __ex_table,"a";\
        .align 4;               \
        .word 98b, z;           \
        .text;                  \
        .align 4;

#define EX_O4(x,y) EX(x,y,__retl_o4_plus_8)
#define EX_O2_4(x,y) EX(x,y,__retl_o2_plus_4)
#define EX_O2_1(x,y) EX(x,y,__retl_o2_plus_1)

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

        .text
__retl_o4_plus_8:
        add     %o4, %o2, %o4
        retl
         add    %o4, 8, %o0
__retl_o2_plus_4:
        retl
         add    %o2, 4, %o0
__retl_o2_plus_1:
        retl
         add    %o2, 1, %o0

        .align  32

        /* Don't try to get too fancy here, just nice and
         * simple.  This is predominantly used for well aligned
         * small copies in the compat layer.  It is also used
         * to copy register windows around during thread cloning.
         */

ENTRY(raw_copy_in_user) /* %o0=dst, %o1=src, %o2=len */
        cmp             %o2, 0
        be,pn           %XCC, 85f
         or             %o0, %o1, %o3
        cmp             %o2, 16
        bleu,a,pn       %XCC, 80f
         or             %o3, %o2, %o3

        /* 16 < len <= 64 */
        andcc           %o3, 0x7, %g0
        bne,pn          %XCC, 90f
         nop

        andn            %o2, 0x7, %o4
        and             %o2, 0x7, %o2
1:      subcc           %o4, 0x8, %o4
        EX_O4(ldxa [%o1] %asi, %o5)
        EX_O4(stxa %o5, [%o0] %asi)
        add             %o1, 0x8, %o1
        bgu,pt          %XCC, 1b
         add            %o0, 0x8, %o0
        andcc           %o2, 0x4, %g0
        be,pt           %XCC, 1f
         nop
        sub             %o2, 0x4, %o2
        EX_O2_4(lduwa [%o1] %asi, %o5)
        EX_O2_4(stwa %o5, [%o0] %asi)
        add             %o1, 0x4, %o1
        add             %o0, 0x4, %o0
1:      cmp             %o2, 0
        be,pt           %XCC, 85f
         nop
        ba,pt           %xcc, 90f
         nop

80:     /* 0 < len <= 16 */
        andcc           %o3, 0x3, %g0
        bne,pn          %XCC, 90f
         nop

82:
        subcc           %o2, 4, %o2
        EX_O2_4(lduwa [%o1] %asi, %g1)
        EX_O2_4(stwa %g1, [%o0] %asi)
        add             %o1, 4, %o1
        bgu,pt          %XCC, 82b
         add            %o0, 4, %o0

85:     retl
         clr            %o0

        .align  32
90:
        subcc           %o2, 1, %o2
        EX_O2_1(lduba [%o1] %asi, %g1)
        EX_O2_1(stba %g1, [%o0] %asi)
        add             %o1, 1, %o1
        bgu,pt          %XCC, 90b
         add            %o0, 1, %o0
        retl
         clr            %o0
ENDPROC(raw_copy_in_user)
EXPORT_SYMBOL(raw_copy_in_user)