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

source code of linux/arch/powerpc/kernel/cpu_setup_44x.S