db_asm.s   [plain text]

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */

#include <debug.h>
#include <ppc/asm.h>
#include <ppc/proc_reg.h>
#include <mach/ppc/vm_param.h>
#include <assym.s>


/* void
 * db_phys_cmp(src_a, src_b, bytecount)
 *      vm_offset_t     src_a;
 *      vm_offset_t     src_b;
 *      int             bytecount
 *
 * This routine will compare bytecount bytes from physical address src_a and physical
 * address src_b. 
 */

#warning THIS IS BROKEN FOR 64-BIT

	/* Switch off data translations */
	lis		r7,hi16(MASK(MSR_VEC))
	ori		r7,r7,lo16(MASK(MSR_FP))
	mfmsr	r6
	andc	r6,r6,r7			; Force FP and vec off
	ori		r7,r7,lo16(MASK(MSR_DR))	; Set the DR bit
	andc	r7,r6,r7			; Force DR off
	mtmsr	r7
	isync			/* Ensure data translations are off */

	subi	r3,	r3,	4
	subi	r4,	r4,	4

	cmpwi	r5,	3
	ble-	.L_db_phys_cmp_bytes
.L_db_phys_cmp_loop:
	lwz	r0,	4(r3)
	lwz	r7,	4(r4)
	addi	r3,	r3,	4
	addi	r4,	r4,	4
	subi	r5,	r5,	4
	cmpw	r0,	r7
	bne	.L_db_phys_cmp_false
	cmpwi	r5,	3
	bgt+	.L_db_phys_cmp_loop

	/* If no leftover bytes, we're done now */
	cmpwi	r5,	0
	beq+	.L_db_phys_cmp_true
	
.L_db_phys_cmp_bytes:
	addi	r3,	r3,	3
	addi	r4,	r4,	3
.L_db_phys_cmp_byte_loop:	
	lbz	r0,	1(r3)
	lbz	r7,	1(r4)
	addi	r3,	r3,	1
	addi	r4,	r4,	1
	subi	r5,	r5,	1
	cmpw	r0,	r7
	bne	.L_db_phys_cmp_false
	cmpwi	r5,	0
	bne+	.L_db_phys_cmp_loop

.L_db_phys_cmp_true:
	li	r3,	1
	b	.L_db_phys_cmp_done

.L_db_phys_cmp_false:
	li	r3,	0

.L_db_phys_cmp_done:
	mtmsr	r6		/* Restore original translations */
	isync			/* Ensure data translations are off */

	blr