xref: /linux/arch/powerpc/kernel/cpu_setup_44x.S (revision a4eb44a6435d6d8f9e642407a4a06f65eb90ca04)
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * This file contains low level CPU setup functions.
4 * Valentine Barshak <vbarshak@ru.mvista.com>
5 * MontaVista Software, Inc (c) 2007
6 *
7 * Based on cpu_setup_6xx code by
8 * Benjamin Herrenschmidt <benh@kernel.crashing.org>
9 */
10
11#include <asm/processor.h>
12#include <asm/cputable.h>
13#include <asm/ppc_asm.h>
14
15_GLOBAL(__setup_cpu_440ep)
16	b	__init_fpu_44x
17_GLOBAL(__setup_cpu_440epx)
18	mflr	r4
19	bl	__init_fpu_44x
20	bl	__plb_disable_wrp
21	bl	__fixup_440A_mcheck
22	mtlr	r4
23	blr
24_GLOBAL(__setup_cpu_440grx)
25	mflr	r4
26	bl	__plb_disable_wrp
27	bl	__fixup_440A_mcheck
28	mtlr	r4
29	blr
30_GLOBAL(__setup_cpu_460ex)
31_GLOBAL(__setup_cpu_460gt)
32_GLOBAL(__setup_cpu_460sx)
33_GLOBAL(__setup_cpu_apm821xx)
34	mflr	r4
35	bl	__init_fpu_44x
36	bl	__fixup_440A_mcheck
37	mtlr	r4
38	blr
39
40_GLOBAL(__setup_cpu_440x5)
41_GLOBAL(__setup_cpu_440gx)
42_GLOBAL(__setup_cpu_440spe)
43	b	__fixup_440A_mcheck
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