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/*
 *  arch/s390/lib/uaccess.S
 *    __copy_{from|to}_user functions.
 *
 *  s390
 *    Copyright (C) 2000,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Authors(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 *  These functions have standard call interface
 */

#include <asm/lowcore.h>

        .text
        .align 4
        .globl __copy_from_user_asm
__copy_from_user_asm:
        lr      %r5,%r3
        sacf    512
0:      mvcle   %r2,%r4,0
        jo      0b
1:      sacf    0
        lr      %r2,%r5
        br      %r14
2:      lhi     %r1,-4096
        lr      %r3,%r4
        slr     %r3,%r1      # %r3 = %r4 + 4096
        nr      %r3,%r1      # %r3 = (%r4 + 4096) & -4096
        slr     %r3,%r4      # %r3 = #bytes to next user page boundary
        clr     %r5,%r3      # copy crosses next page boundary ?
        jnh     1b           # no, this page fauled
        # The page after the current user page might have faulted.
        # We cant't find out which page because the program check handler
        # might have callled schedule, destroying all lowcore information.
        # We retry with the shortened length.
3:      mvcle   %r2,%r4,0
        jo      3b
        j       1b
        .section __ex_table,"a"
        .long   0b,2b
        .long   3b,1b
        .previous

        .align 4
        .text
        .globl __copy_to_user_asm
__copy_to_user_asm:
        lr      %r5,%r3
        sacf    512
0:      mvcle   %r4,%r2,0
        jo      0b
1:      sacf    0
        lr      %r2,%r3
        br      %r14
2:      lhi     %r1,-4096
        lr      %r5,%r4
        slr     %r5,%r1      # %r5 = %r4 + 4096
        nr      %r5,%r1      # %r5 = (%r4 + 4096) & -4096
        slr     %r5,%r4      # %r5 = #bytes to next user page boundary
        clr     %r3,%r5      # copy crosses next page boundary ?
        jnh     1b           # no, the current page fauled
        # The page after the current user page might have faulted.
        # We cant't find out which page because the program check handler
        # might have callled schedule, destroying all lowcore information.
        # We retry with the shortened length.
3:      mvcle   %r4,%r2,0
        jo      3b
        j       1b
        .section __ex_table,"a"
        .long   0b,2b
        .long   3b,1b
        .previous

        .align 4
        .text
        .globl __clear_user_asm
__clear_user_asm:
        lr      %r4,%r2
        lr      %r5,%r3
        sr      %r2,%r2
        sr      %r3,%r3
        sacf    512
0:      mvcle   %r4,%r2,0
        jo      0b
1:      sacf    0
        br      %r14
2:      lr      %r2,%r5
        lhi     %r1,-4096
        slr     %r5,%r1      # %r5 = %r4 + 4096
        nr      %r5,%r1      # %r5 = (%r4 + 4096) & -4096
        slr     %r5,%r4      # %r5 = #bytes to next user page boundary
        clr     %r2,%r5      # copy crosses next page boundary ?
        jnh     1b           # no, the current page fauled
        # The page after the current user page might have faulted.
        # We cant't find out which page because the program check handler
        # might have callled schedule, destroying all lowcore information.
        # We retry with the shortened length.
        slr     %r2,%r5
3:      mvcle   %r4,%r2,0
        jo      3b
        j       1b
4:      alr     %r2,%r5
        j       1b
        .section __ex_table,"a"
        .long   0b,2b
        .long   3b,4b
        .previous