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root/include/asm-cris/arch-v10/uaccess.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. __do_strncpy_from_user
  2. strnlen_user

/* 
 * Authors:    Bjorn Wesen (bjornw@axis.com)
 *             Hans-Peter Nilsson (hp@axis.com)
 *
 */
#ifndef _CRIS_ARCH_UACCESS_H
#define _CRIS_ARCH_UACCESS_H

/*
 * We don't tell gcc that we are accessing memory, but this is OK
 * because we do not write to any memory gcc knows about, so there
 * are no aliasing issues.
 *
 * Note that PC at a fault is the address *after* the faulting
 * instruction.
 */
#define __put_user_asm(x, addr, err, op)                        \
        __asm__ __volatile__(                                   \
                "       "op" %1,[%2]\n"                         \
                "2:\n"                                          \
                "       .section .fixup,\"ax\"\n"               \
                "3:     move.d %3,%0\n"                         \
                "       jump 2b\n"                              \
                "       .previous\n"                            \
                "       .section __ex_table,\"a\"\n"            \
                "       .dword 2b,3b\n"                         \
                "       .previous\n"                            \
                : "=r" (err)                                    \
                : "r" (x), "r" (addr), "g" (-EFAULT), "0" (err))

#define __put_user_asm_64(x, addr, err)                         \
        __asm__ __volatile__(                                   \
                "       move.d %M1,[%2]\n"                      \
                "2:     move.d %H1,[%2+4]\n"                    \
                "4:\n"                                          \
                "       .section .fixup,\"ax\"\n"               \
                "3:     move.d %3,%0\n"                         \
                "       jump 4b\n"                              \
                "       .previous\n"                            \
                "       .section __ex_table,\"a\"\n"            \
                "       .dword 2b,3b\n"                         \
                "       .dword 4b,3b\n"                         \
                "       .previous\n"                            \
                : "=r" (err)                                    \
                : "r" (x), "r" (addr), "g" (-EFAULT), "0" (err))

/* See comment before __put_user_asm.  */

#define __get_user_asm(x, addr, err, op)                \
        __asm__ __volatile__(                           \
                "       "op" [%2],%1\n"                 \
                "2:\n"                                  \
                "       .section .fixup,\"ax\"\n"       \
                "3:     move.d %3,%0\n"                 \
                "       moveq 0,%1\n"                   \
                "       jump 2b\n"                      \
                "       .previous\n"                    \
                "       .section __ex_table,\"a\"\n"    \
                "       .dword 2b,3b\n"                 \
                "       .previous\n"                    \
                : "=r" (err), "=r" (x)                  \
                : "r" (addr), "g" (-EFAULT), "0" (err))

#define __get_user_asm_64(x, addr, err)                 \
        __asm__ __volatile__(                           \
                "       move.d [%2],%M1\n"              \
                "2:     move.d [%2+4],%H1\n"            \
                "4:\n"                                  \
                "       .section .fixup,\"ax\"\n"       \
                "3:     move.d %3,%0\n"                 \
                "       moveq 0,%1\n"                   \
                "       jump 4b\n"                      \
                "       .previous\n"                    \
                "       .section __ex_table,\"a\"\n"    \
                "       .dword 2b,3b\n"                 \
                "       .dword 4b,3b\n"                 \
                "       .previous\n"                    \
                : "=r" (err), "=r" (x)                  \
                : "r" (addr), "g" (-EFAULT), "0" (err))

/*
 * Copy a null terminated string from userspace.
 *
 * Must return:
 * -EFAULT              for an exception
 * count                if we hit the buffer limit
 * bytes copied         if we hit a null byte
 * (without the null byte)
 */
static inline long
__do_strncpy_from_user(char *dst, const char *src, long count)
{
        long res;

        if (count == 0)
                return 0;

        /*
         * Currently, in 2.4.0-test9, most ports use a simple byte-copy loop.
         *  So do we.
         *
         *  This code is deduced from:
         *
         *      char tmp2;
         *      long tmp1, tmp3 
         *      tmp1 = count;
         *      while ((*dst++ = (tmp2 = *src++)) != 0
         *             && --tmp1)
         *        ;
         *
         *      res = count - tmp1;
         *
         *  with tweaks.
         */

        __asm__ __volatile__ (
                "       move.d %3,%0\n"
                "       move.b [%2+],$r9\n"
                "1:     beq 2f\n"
                "       move.b $r9,[%1+]\n"

                "       subq 1,%0\n"
                "       bne 1b\n"
                "       move.b [%2+],$r9\n"

                "2:     sub.d %3,%0\n"
                "       neg.d %0,%0\n"
                "3:\n"
                "       .section .fixup,\"ax\"\n"
                "4:     move.d %7,%0\n"
                "       jump 3b\n"

                /* There's one address for a fault at the first move, and
                   two possible PC values for a fault at the second move,
                   being a delay-slot filler.  However, the branch-target
                   for the second move is the same as the first address.
                   Just so you don't get confused...  */
                "       .previous\n"
                "       .section __ex_table,\"a\"\n"
                "       .dword 1b,4b\n"
                "       .dword 2b,4b\n"
                "       .previous"
                : "=r" (res), "=r" (dst), "=r" (src), "=r" (count)
                : "3" (count), "1" (dst), "2" (src), "g" (-EFAULT)
                : "r9");

        return res;
}

/* A few copy asms to build up the more complex ones from.

   Note again, a post-increment is performed regardless of whether a bus
   fault occurred in that instruction, and PC for a faulted insn is the
   address *after* the insn.  */

#define __asm_copy_user_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm__ __volatile__ (                          \
                        COPY                            \
                "1:\n"                                  \
                "       .section .fixup,\"ax\"\n"       \
                        FIXUP                           \
                "       jump 1b\n"                      \
                "       .previous\n"                    \
                "       .section __ex_table,\"a\"\n"    \
                        TENTRY                          \
                "       .previous\n"                    \
                : "=r" (to), "=r" (from), "=r" (ret)    \
                : "0" (to), "1" (from), "2" (ret)       \
                : "r9", "memory")

#define __asm_copy_from_user_1(to, from, ret) \
        __asm_copy_user_cont(to, from, ret,     \
                "       move.b [%1+],$r9\n"     \
                "2:     move.b $r9,[%0+]\n",    \
                "3:     addq 1,%2\n"            \
                "       clear.b [%0+]\n",       \
                "       .dword 2b,3b\n")

#define __asm_copy_from_user_2x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_user_cont(to, from, ret,             \
                "       move.w [%1+],$r9\n"             \
                "2:     move.w $r9,[%0+]\n" COPY,       \
                "3:     addq 2,%2\n"                    \
                "       clear.w [%0+]\n" FIXUP,         \
                "       .dword 2b,3b\n" TENTRY)

#define __asm_copy_from_user_2(to, from, ret) \
        __asm_copy_from_user_2x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_3(to, from, ret)           \
        __asm_copy_from_user_2x_cont(to, from, ret,     \
                "       move.b [%1+],$r9\n"             \
                "4:     move.b $r9,[%0+]\n",            \
                "5:     addq 1,%2\n"                    \
                "       clear.b [%0+]\n",               \
                "       .dword 4b,5b\n")

#define __asm_copy_from_user_4x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_user_cont(to, from, ret,             \
                "       move.d [%1+],$r9\n"             \
                "2:     move.d $r9,[%0+]\n" COPY,       \
                "3:     addq 4,%2\n"                    \
                "       clear.d [%0+]\n" FIXUP,         \
                "       .dword 2b,3b\n" TENTRY)

#define __asm_copy_from_user_4(to, from, ret) \
        __asm_copy_from_user_4x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_5(to, from, ret) \
        __asm_copy_from_user_4x_cont(to, from, ret,     \
                "       move.b [%1+],$r9\n"             \
                "4:     move.b $r9,[%0+]\n",            \
                "5:     addq 1,%2\n"                    \
                "       clear.b [%0+]\n",               \
                "       .dword 4b,5b\n")

#define __asm_copy_from_user_6x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_4x_cont(to, from, ret,     \
                "       move.w [%1+],$r9\n"             \
                "4:     move.w $r9,[%0+]\n" COPY,       \
                "5:     addq 2,%2\n"                    \
                "       clear.w [%0+]\n" FIXUP,         \
                "       .dword 4b,5b\n" TENTRY)

#define __asm_copy_from_user_6(to, from, ret) \
        __asm_copy_from_user_6x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_7(to, from, ret) \
        __asm_copy_from_user_6x_cont(to, from, ret,     \
                "       move.b [%1+],$r9\n"             \
                "6:     move.b $r9,[%0+]\n",            \
                "7:     addq 1,%2\n"                    \
                "       clear.b [%0+]\n",               \
                "       .dword 6b,7b\n")

#define __asm_copy_from_user_8x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_4x_cont(to, from, ret,     \
                "       move.d [%1+],$r9\n"             \
                "4:     move.d $r9,[%0+]\n" COPY,       \
                "5:     addq 4,%2\n"                    \
                "       clear.d [%0+]\n" FIXUP,         \
                "       .dword 4b,5b\n" TENTRY)

#define __asm_copy_from_user_8(to, from, ret) \
        __asm_copy_from_user_8x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_9(to, from, ret) \
        __asm_copy_from_user_8x_cont(to, from, ret,     \
                "       move.b [%1+],$r9\n"             \
                "6:     move.b $r9,[%0+]\n",            \
                "7:     addq 1,%2\n"                    \
                "       clear.b [%0+]\n",               \
                "       .dword 6b,7b\n")

#define __asm_copy_from_user_10x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_8x_cont(to, from, ret,     \
                "       move.w [%1+],$r9\n"             \
                "6:     move.w $r9,[%0+]\n" COPY,       \
                "7:     addq 2,%2\n"                    \
                "       clear.w [%0+]\n" FIXUP,         \
                "       .dword 6b,7b\n" TENTRY)

#define __asm_copy_from_user_10(to, from, ret) \
        __asm_copy_from_user_10x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_11(to, from, ret)          \
        __asm_copy_from_user_10x_cont(to, from, ret,    \
                "       move.b [%1+],$r9\n"             \
                "8:     move.b $r9,[%0+]\n",            \
                "9:     addq 1,%2\n"                    \
                "       clear.b [%0+]\n",               \
                "       .dword 8b,9b\n")

#define __asm_copy_from_user_12x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_8x_cont(to, from, ret,     \
                "       move.d [%1+],$r9\n"             \
                "6:     move.d $r9,[%0+]\n" COPY,       \
                "7:     addq 4,%2\n"                    \
                "       clear.d [%0+]\n" FIXUP,         \
                "       .dword 6b,7b\n" TENTRY)

#define __asm_copy_from_user_12(to, from, ret) \
        __asm_copy_from_user_12x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_13(to, from, ret) \
        __asm_copy_from_user_12x_cont(to, from, ret,    \
                "       move.b [%1+],$r9\n"             \
                "8:     move.b $r9,[%0+]\n",            \
                "9:     addq 1,%2\n"                    \
                "       clear.b [%0+]\n",               \
                "       .dword 8b,9b\n")

#define __asm_copy_from_user_14x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_12x_cont(to, from, ret,    \
                "       move.w [%1+],$r9\n"             \
                "8:     move.w $r9,[%0+]\n" COPY,       \
                "9:     addq 2,%2\n"                    \
                "       clear.w [%0+]\n" FIXUP,         \
                "       .dword 8b,9b\n" TENTRY)

#define __asm_copy_from_user_14(to, from, ret) \
        __asm_copy_from_user_14x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_15(to, from, ret) \
        __asm_copy_from_user_14x_cont(to, from, ret,    \
                "       move.b [%1+],$r9\n"             \
                "10:    move.b $r9,[%0+]\n",            \
                "11:    addq 1,%2\n"                    \
                "       clear.b [%0+]\n",               \
                "       .dword 10b,11b\n")

#define __asm_copy_from_user_16x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_12x_cont(to, from, ret,    \
                "       move.d [%1+],$r9\n"             \
                "8:     move.d $r9,[%0+]\n" COPY,       \
                "9:     addq 4,%2\n"                    \
                "       clear.d [%0+]\n" FIXUP,         \
                "       .dword 8b,9b\n" TENTRY)

#define __asm_copy_from_user_16(to, from, ret) \
        __asm_copy_from_user_16x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_20x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_16x_cont(to, from, ret,    \
                "       move.d [%1+],$r9\n"             \
                "10:    move.d $r9,[%0+]\n" COPY,       \
                "11:    addq 4,%2\n"                    \
                "       clear.d [%0+]\n" FIXUP,         \
                "       .dword 10b,11b\n" TENTRY)

#define __asm_copy_from_user_20(to, from, ret) \
        __asm_copy_from_user_20x_cont(to, from, ret, "", "", "")

#define __asm_copy_from_user_24x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_from_user_20x_cont(to, from, ret,    \
                "       move.d [%1+],$r9\n"             \
                "12:    move.d $r9,[%0+]\n" COPY,       \
                "13:    addq 4,%2\n"                    \
                "       clear.d [%0+]\n" FIXUP,         \
                "       .dword 12b,13b\n" TENTRY)

#define __asm_copy_from_user_24(to, from, ret) \
        __asm_copy_from_user_24x_cont(to, from, ret, "", "", "")

/* And now, the to-user ones.  */

#define __asm_copy_to_user_1(to, from, ret)     \
        __asm_copy_user_cont(to, from, ret,     \
                "       move.b [%1+],$r9\n"     \
                "       move.b $r9,[%0+]\n2:\n",        \
                "3:     addq 1,%2\n",           \
                "       .dword 2b,3b\n")

#define __asm_copy_to_user_2x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_user_cont(to, from, ret,             \
                "       move.w [%1+],$r9\n"             \
                "       move.w $r9,[%0+]\n2:\n" COPY,   \
                "3:     addq 2,%2\n" FIXUP,             \
                "       .dword 2b,3b\n" TENTRY)

#define __asm_copy_to_user_2(to, from, ret) \
        __asm_copy_to_user_2x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_3(to, from, ret) \
        __asm_copy_to_user_2x_cont(to, from, ret,       \
                "       move.b [%1+],$r9\n"             \
                "       move.b $r9,[%0+]\n4:\n",                \
                "5:     addq 1,%2\n",                   \
                "       .dword 4b,5b\n")

#define __asm_copy_to_user_4x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_user_cont(to, from, ret,             \
                "       move.d [%1+],$r9\n"             \
                "       move.d $r9,[%0+]\n2:\n" COPY,   \
                "3:     addq 4,%2\n" FIXUP,             \
                "       .dword 2b,3b\n" TENTRY)

#define __asm_copy_to_user_4(to, from, ret) \
        __asm_copy_to_user_4x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_5(to, from, ret) \
        __asm_copy_to_user_4x_cont(to, from, ret,       \
                "       move.b [%1+],$r9\n"             \
                "       move.b $r9,[%0+]\n4:\n",                \
                "5:     addq 1,%2\n",                   \
                "       .dword 4b,5b\n")

#define __asm_copy_to_user_6x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_4x_cont(to, from, ret,       \
                "       move.w [%1+],$r9\n"             \
                "       move.w $r9,[%0+]\n4:\n" COPY,   \
                "5:     addq 2,%2\n" FIXUP,             \
                "       .dword 4b,5b\n" TENTRY)

#define __asm_copy_to_user_6(to, from, ret) \
        __asm_copy_to_user_6x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_7(to, from, ret) \
        __asm_copy_to_user_6x_cont(to, from, ret,       \
                "       move.b [%1+],$r9\n"             \
                "       move.b $r9,[%0+]\n6:\n",                \
                "7:     addq 1,%2\n",                   \
                "       .dword 6b,7b\n")

#define __asm_copy_to_user_8x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_4x_cont(to, from, ret,       \
                "       move.d [%1+],$r9\n"             \
                "       move.d $r9,[%0+]\n4:\n" COPY,   \
                "5:     addq 4,%2\n"  FIXUP,            \
                "       .dword 4b,5b\n" TENTRY)

#define __asm_copy_to_user_8(to, from, ret) \
        __asm_copy_to_user_8x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_9(to, from, ret) \
        __asm_copy_to_user_8x_cont(to, from, ret,       \
                "       move.b [%1+],$r9\n"             \
                "       move.b $r9,[%0+]\n6:\n",                \
                "7:     addq 1,%2\n",                   \
                "       .dword 6b,7b\n")

#define __asm_copy_to_user_10x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_8x_cont(to, from, ret,       \
                "       move.w [%1+],$r9\n"             \
                "       move.w $r9,[%0+]\n6:\n" COPY,   \
                "7:     addq 2,%2\n" FIXUP,             \
                "       .dword 6b,7b\n" TENTRY)

#define __asm_copy_to_user_10(to, from, ret) \
        __asm_copy_to_user_10x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_11(to, from, ret) \
        __asm_copy_to_user_10x_cont(to, from, ret,      \
                "       move.b [%1+],$r9\n"             \
                "       move.b $r9,[%0+]\n8:\n",                \
                "9:     addq 1,%2\n",                   \
                "       .dword 8b,9b\n")

#define __asm_copy_to_user_12x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_8x_cont(to, from, ret,       \
                "       move.d [%1+],$r9\n"             \
                "       move.d $r9,[%0+]\n6:\n" COPY,   \
                "7:     addq 4,%2\n" FIXUP,             \
                "       .dword 6b,7b\n" TENTRY)

#define __asm_copy_to_user_12(to, from, ret) \
        __asm_copy_to_user_12x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_13(to, from, ret) \
        __asm_copy_to_user_12x_cont(to, from, ret,      \
                "       move.b [%1+],$r9\n"             \
                "       move.b $r9,[%0+]\n8:\n",                \
                "9:     addq 1,%2\n",                   \
                "       .dword 8b,9b\n")

#define __asm_copy_to_user_14x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_12x_cont(to, from, ret,      \
                "       move.w [%1+],$r9\n"             \
                "       move.w $r9,[%0+]\n8:\n" COPY,   \
                "9:     addq 2,%2\n" FIXUP,             \
                "       .dword 8b,9b\n" TENTRY)

#define __asm_copy_to_user_14(to, from, ret)    \
        __asm_copy_to_user_14x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_15(to, from, ret) \
        __asm_copy_to_user_14x_cont(to, from, ret,      \
                "       move.b [%1+],$r9\n"             \
                "       move.b $r9,[%0+]\n10:\n",               \
                "11:    addq 1,%2\n",                   \
                "       .dword 10b,11b\n")

#define __asm_copy_to_user_16x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_12x_cont(to, from, ret,      \
                "       move.d [%1+],$r9\n"             \
                "       move.d $r9,[%0+]\n8:\n" COPY,   \
                "9:     addq 4,%2\n" FIXUP,             \
                "       .dword 8b,9b\n" TENTRY)

#define __asm_copy_to_user_16(to, from, ret) \
        __asm_copy_to_user_16x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_20x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_16x_cont(to, from, ret,      \
                "       move.d [%1+],$r9\n"             \
                "       move.d $r9,[%0+]\n10:\n" COPY,  \
                "11:    addq 4,%2\n" FIXUP,             \
                "       .dword 10b,11b\n" TENTRY)

#define __asm_copy_to_user_20(to, from, ret) \
        __asm_copy_to_user_20x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_24x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
        __asm_copy_to_user_20x_cont(to, from, ret,      \
                "       move.d [%1+],$r9\n"             \
                "       move.d $r9,[%0+]\n12:\n" COPY,  \
                "13:    addq 4,%2\n" FIXUP,             \
                "       .dword 12b,13b\n" TENTRY)

#define __asm_copy_to_user_24(to, from, ret)    \
        __asm_copy_to_user_24x_cont(to, from, ret, "", "", "")

/* Define a few clearing asms with exception handlers.  */

/* This frame-asm is like the __asm_copy_user_cont one, but has one less
   input.  */

#define __asm_clear(to, ret, CLEAR, FIXUP, TENTRY) \
        __asm__ __volatile__ (                          \
                        CLEAR                           \
                "1:\n"                                  \
                "       .section .fixup,\"ax\"\n"       \
                        FIXUP                           \
                "       jump 1b\n"                      \
                "       .previous\n"                    \
                "       .section __ex_table,\"a\"\n"    \
                        TENTRY                          \
                "       .previous"                      \
                : "=r" (to), "=r" (ret)                 \
                : "0" (to), "1" (ret)                   \
                : "memory")

#define __asm_clear_1(to, ret) \
        __asm_clear(to, ret,                    \
                "       clear.b [%0+]\n2:\n",   \
                "3:     addq 1,%1\n",           \
                "       .dword 2b,3b\n")

#define __asm_clear_2(to, ret) \
        __asm_clear(to, ret,                    \
                "       clear.w [%0+]\n2:\n",   \
                "3:     addq 2,%1\n",           \
                "       .dword 2b,3b\n")

#define __asm_clear_3(to, ret) \
     __asm_clear(to, ret,                       \
                 "      clear.w [%0+]\n"        \
                 "2:    clear.b [%0+]\n3:\n",   \
                 "4:    addq 2,%1\n"            \
                 "5:    addq 1,%1\n",           \
                 "      .dword 2b,4b\n"         \
                 "      .dword 3b,5b\n")

#define __asm_clear_4x_cont(to, ret, CLEAR, FIXUP, TENTRY) \
        __asm_clear(to, ret,                            \
                "       clear.d [%0+]\n2:\n" CLEAR,     \
                "3:     addq 4,%1\n" FIXUP,             \
                "       .dword 2b,3b\n" TENTRY)

#define __asm_clear_4(to, ret) \
        __asm_clear_4x_cont(to, ret, "", "", "")

#define __asm_clear_8x_cont(to, ret, CLEAR, FIXUP, TENTRY) \
        __asm_clear_4x_cont(to, ret,                    \
                "       clear.d [%0+]\n4:\n" CLEAR,     \
                "5:     addq 4,%1\n" FIXUP,             \
                "       .dword 4b,5b\n" TENTRY)

#define __asm_clear_8(to, ret) \
        __asm_clear_8x_cont(to, ret, "", "", "")

#define __asm_clear_12x_cont(to, ret, CLEAR, FIXUP, TENTRY) \
        __asm_clear_8x_cont(to, ret,                    \
                "       clear.d [%0+]\n6:\n" CLEAR,     \
                "7:     addq 4,%1\n" FIXUP,             \
                "       .dword 6b,7b\n" TENTRY)

#define __asm_clear_12(to, ret) \
        __asm_clear_12x_cont(to, ret, "", "", "")

#define __asm_clear_16x_cont(to, ret, CLEAR, FIXUP, TENTRY) \
        __asm_clear_12x_cont(to, ret,                   \
                "       clear.d [%0+]\n8:\n" CLEAR,     \
                "9:     addq 4,%1\n" FIXUP,             \
                "       .dword 8b,9b\n" TENTRY)

#define __asm_clear_16(to, ret) \
        __asm_clear_16x_cont(to, ret, "", "", "")

#define __asm_clear_20x_cont(to, ret, CLEAR, FIXUP, TENTRY) \
        __asm_clear_16x_cont(to, ret,                   \
                "       clear.d [%0+]\n10:\n" CLEAR,    \
                "11:    addq 4,%1\n" FIXUP,             \
                "       .dword 10b,11b\n" TENTRY)

#define __asm_clear_20(to, ret) \
        __asm_clear_20x_cont(to, ret, "", "", "")

#define __asm_clear_24x_cont(to, ret, CLEAR, FIXUP, TENTRY) \
        __asm_clear_20x_cont(to, ret,                   \
                "       clear.d [%0+]\n12:\n" CLEAR,    \
                "13:    addq 4,%1\n" FIXUP,             \
                "       .dword 12b,13b\n" TENTRY)

#define __asm_clear_24(to, ret) \
        __asm_clear_24x_cont(to, ret, "", "", "")

/*
 * Return the size of a string (including the ending 0)
 *
 * Return length of string in userspace including terminating 0
 * or 0 for error.  Return a value greater than N if too long.
 */

static inline long
strnlen_user(const char *s, long n)
{
        long res, tmp1;

        if (!access_ok(VERIFY_READ, s, 0))
                return 0;

        /*
         * This code is deduced from:
         *
         *      tmp1 = n;
         *      while (tmp1-- > 0 && *s++)
         *        ;
         *
         *      res = n - tmp1;
         *
         *  (with tweaks).
         */

        __asm__ __volatile__ (
                "       move.d %1,$r9\n"
                "0:\n"
                "       ble 1f\n"
                "       subq 1,$r9\n"

                "       test.b [%0+]\n"
                "       bne 0b\n"
                "       test.d $r9\n"
                "1:\n"
                "       move.d %1,%0\n"
                "       sub.d $r9,%0\n"
                "2:\n"
                "       .section .fixup,\"ax\"\n"

                "3:     clear.d %0\n"
                "       jump 2b\n"

                /* There's one address for a fault at the first move, and
                   two possible PC values for a fault at the second move,
                   being a delay-slot filler.  However, the branch-target
                   for the second move is the same as the first address.
                   Just so you don't get confused...  */
                "       .previous\n"
                "       .section __ex_table,\"a\"\n"
                "       .dword 0b,3b\n"
                "       .dword 1b,3b\n"
                "       .previous\n"
                : "=r" (res), "=r" (tmp1)
                : "0" (s), "1" (n)
                : "r9");

        return res;
}

#endif

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