xref: /openbmc/linux/arch/powerpc/kernel/cpu_setup_44x.S (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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	mtlr	r4
27	blr
28_GLOBAL(__setup_cpu_440grx)
29	b	__plb_disable_wrp
30
31
32/* enable APU between CPU and FPU */
33_GLOBAL(__init_fpu_44x)
34	mfspr	r3,SPRN_CCR0
35	/* Clear DAPUIB flag in CCR0 */
36	rlwinm	r3,r3,0,12,10
37	mtspr	SPRN_CCR0,r3
38	isync
39	blr
40
41/*
42 * Workaround for the incorrect write to DDR SDRAM errata.
43 * The write address can be corrupted during writes to
44 * DDR SDRAM when write pipelining is enabled on PLB0.
45 * Disable write pipelining here.
46 */
47#define DCRN_PLB4A0_ACR	0x81
48
49_GLOBAL(__plb_disable_wrp)
50	mfdcr	r3,DCRN_PLB4A0_ACR
51	/* clear WRP bit in PLB4A0_ACR */
52	rlwinm	r3,r3,0,8,6
53	mtdcr	DCRN_PLB4A0_ACR,r3
54	isync
55	blr
56
57