Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 * __put_user functions.
 *
 * (C) Copyright 1998 Linus Torvalds
 * (C) Copyright 2005 Andi Kleen
 *
 * 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.
 */

/*
 * __put_user_X
 *
 * Inputs:      %rcx contains the address
 *              %rdx contains new value
 *
 * Outputs:     %rax is error code (0 or -EFAULT)
 *
 * %r8 is destroyed.
 *
 * These functions should not modify any other registers,
 * as they get called from within inline assembly.
 */

#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/page.h>
#include <asm/errno.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>

        .text
ENTRY(__put_user_1)
        CFI_STARTPROC
        GET_THREAD_INFO(%r8)
        cmpq threadinfo_addr_limit(%r8),%rcx
        jae bad_put_user
1:      movb %dl,(%rcx)
        xorl %eax,%eax
        ret
        CFI_ENDPROC
ENDPROC(__put_user_1)

ENTRY(__put_user_2)
        CFI_STARTPROC
        GET_THREAD_INFO(%r8)
        addq $1,%rcx
        jc 20f
        cmpq threadinfo_addr_limit(%r8),%rcx
        jae 20f
        decq %rcx
2:      movw %dx,(%rcx)
        xorl %eax,%eax
        ret
20:     decq %rcx
        jmp bad_put_user
        CFI_ENDPROC
ENDPROC(__put_user_2)

ENTRY(__put_user_4)
        CFI_STARTPROC
        GET_THREAD_INFO(%r8)
        addq $3,%rcx
        jc 30f
        cmpq threadinfo_addr_limit(%r8),%rcx
        jae 30f
        subq $3,%rcx
3:      movl %edx,(%rcx)
        xorl %eax,%eax
        ret
30:     subq $3,%rcx
        jmp bad_put_user
        CFI_ENDPROC
ENDPROC(__put_user_4)

ENTRY(__put_user_8)
        CFI_STARTPROC
        GET_THREAD_INFO(%r8)
        addq $7,%rcx
        jc 40f
        cmpq threadinfo_addr_limit(%r8),%rcx
        jae 40f
        subq $7,%rcx
4:      movq %rdx,(%rcx)
        xorl %eax,%eax
        ret
40:     subq $7,%rcx
        jmp bad_put_user
        CFI_ENDPROC
ENDPROC(__put_user_8)

bad_put_user:
        CFI_STARTPROC
        movq $(-EFAULT),%rax
        ret
        CFI_ENDPROC
END(bad_put_user)

.section __ex_table,"a"
        .quad 1b,bad_put_user
        .quad 2b,bad_put_user
        .quad 3b,bad_put_user
        .quad 4b,bad_put_user
.previous