Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 * __get_user functions.
 *
 * (C) Copyright 1998 Linus Torvalds
 *
 * These functions have a non-standard call interface
 * to make them more efficient, especially as they
 * return an error value in addition to the "real"
 * return value.
 */
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/thread_info.h>


/*
 * __get_user_X
 *
 * Inputs:      %eax contains the address
 *
 * Outputs:     %eax is error code (0 or -EFAULT)
 *              %edx contains zero-extended value
 *
 * These functions should not modify any other registers,
 * as they get called from within inline assembly.
 */

.text
ENTRY(__get_user_1)
        CFI_STARTPROC
        GET_THREAD_INFO(%edx)
        cmpl TI_addr_limit(%edx),%eax
        jae bad_get_user
1:      movzbl (%eax),%edx
        xorl %eax,%eax
        ret
        CFI_ENDPROC
ENDPROC(__get_user_1)

ENTRY(__get_user_2)
        CFI_STARTPROC
        addl $1,%eax
        jc bad_get_user
        GET_THREAD_INFO(%edx)
        cmpl TI_addr_limit(%edx),%eax
        jae bad_get_user
2:      movzwl -1(%eax),%edx
        xorl %eax,%eax
        ret
        CFI_ENDPROC
ENDPROC(__get_user_2)

ENTRY(__get_user_4)
        CFI_STARTPROC
        addl $3,%eax
        jc bad_get_user
        GET_THREAD_INFO(%edx)
        cmpl TI_addr_limit(%edx),%eax
        jae bad_get_user
3:      movl -3(%eax),%edx
        xorl %eax,%eax
        ret
        CFI_ENDPROC
ENDPROC(__get_user_4)

bad_get_user:
        CFI_STARTPROC
        xorl %edx,%edx
        movl $-14,%eax
        ret
        CFI_ENDPROC
END(bad_get_user)

.section __ex_table,"a"
        .long 1b,bad_get_user
        .long 2b,bad_get_user
        .long 3b,bad_get_user
.previous