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/* $NetBSD: cpufunc_asm.S,v 1.12 2003/09/06 09:14:52 rearnsha Exp $ */
/*-
* Copyright (c) 1997,1998 Mark Brinicombe.
* Copyright (c) 1997 Causality Limited
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Causality Limited.
* 4. The name of Causality Limited may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY CAUSALITY LIMITED ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL CAUSALITY LIMITED BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* RiscBSD kernel project
*
* cpufunc.S
*
* Assembly functions for CPU / MMU / TLB specific operations
*
* Created : 30/01/97
*
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
.text
.align 2
ENTRY(cpufunc_nullop)
RET
END(cpufunc_nullop)
/*
* Generic functions to read/modify/write the internal coprocessor registers
*
*
* Currently these registers are
* c1 - CPU Control
*
* All other registers are CPU architecture specific
*/
ENTRY(cpufunc_control)
mrc CP15_SCTLR(r3) /* Read the control register */
bic r2, r3, r0 /* Clear bits */
eor r2, r2, r1 /* XOR bits */
teq r2, r3 /* Only write if there is a change */
mcrne CP15_SCTLR(r2) /* Write new control register */
mov r0, r3 /* Return old value */
RET
END(cpufunc_control)
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