Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 *  linux/arch/arm/lib/clear_user.S
 *
 *  Copyright (C) 1995, 1996,1997,1998 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/linkage.h>
#include <asm/assembler.h>

                .text

/* Prototype: int __clear_user(void *addr, size_t sz)
 * Purpose  : clear some user memory
 * Params   : addr - user memory address to clear
 *          : sz   - number of bytes to clear
 * Returns  : number of bytes NOT cleared
 */
ENTRY(__clear_user)
                stmfd   sp!, {r1, lr}
                mov     r2, #0
                cmp     r1, #4
                blt     2f
                ands    ip, r0, #3
                beq     1f
                cmp     ip, #2
USER(           strbt   r2, [r0], #1)
USER(           strlebt r2, [r0], #1)
USER(           strltbt r2, [r0], #1)
                rsb     ip, ip, #4
                sub     r1, r1, ip              @  7  6  5  4  3  2  1
1:              subs    r1, r1, #8              @ -1 -2 -3 -4 -5 -6 -7
USER(           strplt  r2, [r0], #4)
USER(           strplt  r2, [r0], #4)
                bpl     1b
                adds    r1, r1, #4              @  3  2  1  0 -1 -2 -3
USER(           strplt  r2, [r0], #4)
2:              tst     r1, #2                  @ 1x 1x 0x 0x 1x 1x 0x
USER(           strnebt r2, [r0], #1)
USER(           strnebt r2, [r0], #1)
                tst     r1, #1                  @ x1 x0 x1 x0 x1 x0 x1
USER(           strnebt r2, [r0], #1)
                mov     r0, #0
                ldmfd   sp!, {r1, pc}

                .section .fixup,"ax"
                .align  0
9001:           ldmfd   sp!, {r0, pc}
                .previous