1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * "Indirect" DCR access
4 *
5 * Copyright (c) 2004 Eugene Surovegin <ebs@ebshome.net>
6 */
7
8#include <linux/export.h>
9#include <asm/ppc_asm.h>
10#include <asm/processor.h>
11#include <asm/bug.h>
12
13#define DCR_ACCESS_PROLOG(table) \
14	cmplwi	cr0,r3,1024;	 \
15	rlwinm  r3,r3,4,18,27;   \
16	lis     r5,table@h;      \
17	ori     r5,r5,table@l;   \
18	add     r3,r3,r5;        \
19	bge-	1f;		 \
20	mtctr   r3;              \
21	bctr;			 \
221:	trap;			 \
23	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0;	\
24	blr
25
26_GLOBAL(__mfdcr)
27	DCR_ACCESS_PROLOG(__mfdcr_table)
28EXPORT_SYMBOL(__mfdcr)
29
30_GLOBAL(__mtdcr)
31	DCR_ACCESS_PROLOG(__mtdcr_table)
32EXPORT_SYMBOL(__mtdcr)
33
34__mfdcr_table:
35	mfdcr  r3,0; blr
36__mtdcr_table:
37	mtdcr  0,r4; blr
38
39dcr     = 1
40        .rept   1023
41	mfdcr   r3,dcr; blr
42	mtdcr   dcr,r4; blr
43	dcr     = dcr + 1
44	.endr
45