xref: /linux/arch/powerpc/kernel/cpu_setup_44x.S (revision ed3174d93c342b8b2eeba6bbd124707d55304a7b)
1/*
2 * This file contains low level CPU setup functions.
3 * Valentine Barshak <vbarshak@ru.mvista.com>
4 * MontaVista Software, Inc (c) 2007
5 *
6 * Based on cpu_setup_6xx code by
7 * Benjamin Herrenschmidt <benh@kernel.crashing.org>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 */
15
16#include <asm/processor.h>
17#include <asm/cputable.h>
18#include <asm/ppc_asm.h>
19
20_GLOBAL(__setup_cpu_440ep)
21	b	__init_fpu_44x
22_GLOBAL(__setup_cpu_440epx)
23	mflr	r4
24	bl	__init_fpu_44x
25	bl	__plb_disable_wrp
26	bl	__fixup_440A_mcheck
27	mtlr	r4
28	blr
29_GLOBAL(__setup_cpu_440grx)
30	mflr	r4
31	bl	__plb_disable_wrp
32	bl	__fixup_440A_mcheck
33	mtlr	r4
34	blr
35_GLOBAL(__setup_cpu_440gx)
36_GLOBAL(__setup_cpu_440spe)
37	b	__fixup_440A_mcheck
38
39 /* Temporary fixup for arch/ppc until we kill the whole thing */
40#ifndef CONFIG_PPC_MERGE
41_GLOBAL(__fixup_440A_mcheck)
42	blr
43#endif
44
45/* enable APU between CPU and FPU */
46_GLOBAL(__init_fpu_44x)
47	mfspr	r3,SPRN_CCR0
48	/* Clear DAPUIB flag in CCR0 */
49	rlwinm	r3,r3,0,12,10
50	mtspr	SPRN_CCR0,r3
51	isync
52	blr
53
54/*
55 * Workaround for the incorrect write to DDR SDRAM errata.
56 * The write address can be corrupted during writes to
57 * DDR SDRAM when write pipelining is enabled on PLB0.
58 * Disable write pipelining here.
59 */
60#define DCRN_PLB4A0_ACR	0x81
61
62_GLOBAL(__plb_disable_wrp)
63	mfdcr	r3,DCRN_PLB4A0_ACR
64	/* clear WRP bit in PLB4A0_ACR */
65	rlwinm	r3,r3,0,8,6
66	mtdcr	DCRN_PLB4A0_ACR,r3
67	isync
68	blr
69
70