1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * This file contains low level CPU setup functions.
4 * Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org)
5 */
6
7#include <asm/processor.h>
8#include <asm/page.h>
9#include <asm/cputable.h>
10#include <asm/ppc_asm.h>
11#include <asm/asm-offsets.h>
12#include <asm/cache.h>
13
14_GLOBAL(__cpu_preinit_ppc970)
15 /* Do nothing if not running in HV mode */
16 mfmsr r0
17 rldicl. r0,r0,4,63
18 beqlr
19
20 /* Make sure HID4:rm_ci is off before MMU is turned off, that large
21 * pages are enabled with HID4:61 and clear HID5:DCBZ_size and
22 * HID5:DCBZ32_ill
23 */
24 li r0,0
25 mfspr r3,SPRN_HID4
26 rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
27 rldimi r3,r0,2,61 /* clear bit 61 (lg_pg_en) */
28 sync
29 mtspr SPRN_HID4,r3
30 isync
31 sync
32 mfspr r3,SPRN_HID5
33 rldimi r3,r0,6,56 /* clear bits 56 & 57 (DCBZ*) */
34 sync
35 mtspr SPRN_HID5,r3
36 isync
37 sync
38
39 /* Setup some basic HID1 features */
40 mfspr r0,SPRN_HID1
41 li r3,0x1200 /* enable i-fetch cacheability */
42 sldi r3,r3,44 /* and prefetch */
43 or r0,r0,r3
44 mtspr SPRN_HID1,r0
45 mtspr SPRN_HID1,r0
46 isync
47
48 /* Clear HIOR */
49 li r0,0
50 sync
51 mtspr SPRN_HIOR,0 /* Clear interrupt prefix */
52 isync
53 blr
54
55/* Definitions for the table use to save CPU states */
56#define CS_HID0 0
57#define CS_HID1 8
58#define CS_HID4 16
59#define CS_HID5 24
60#define CS_SIZE 32
61
62 .data
63 .balign L1_CACHE_BYTES,0
64cpu_state_storage:
65 .space CS_SIZE
66 .balign L1_CACHE_BYTES,0
67 .text
68
69
70_GLOBAL(__setup_cpu_ppc970)
71 /* Do nothing if not running in HV mode */
72 mfmsr r0
73 rldicl. r0,r0,4,63
74 beq no_hv_mode
75
76 mfspr r0,SPRN_HID0
77 li r11,5 /* clear DOZE and SLEEP */
78 rldimi r0,r11,52,8 /* set NAP and DPM */
79 li r11,0
80 rldimi r0,r11,32,31 /* clear EN_ATTN */
81 b load_hids /* Jump to shared code */
82
83
84_GLOBAL(__setup_cpu_ppc970MP)
85 /* Do nothing if not running in HV mode */
86 mfmsr r0
87 rldicl. r0,r0,4,63
88 beq no_hv_mode
89
90 mfspr r0,SPRN_HID0
91 li r11,0x15 /* clear DOZE and SLEEP */
92 rldimi r0,r11,52,6 /* set DEEPNAP, NAP and DPM */
93 li r11,0
94 rldimi r0,r11,32,31 /* clear EN_ATTN */
95
96load_hids:
97 mtspr SPRN_HID0,r0
98 mfspr r0,SPRN_HID0
99 mfspr r0,SPRN_HID0
100 mfspr r0,SPRN_HID0
101 mfspr r0,SPRN_HID0
102 mfspr r0,SPRN_HID0
103 mfspr r0,SPRN_HID0
104 sync
105 isync
106
107 /* Try to set LPES = 01 in HID4 */
108 mfspr r0,SPRN_HID4
109 clrldi r0,r0,1 /* clear LPES0 */
110 ori r0,r0,HID4_LPES1 /* set LPES1 */
111 sync
112 mtspr SPRN_HID4,r0
113 isync
114
115 /* Save away cpu state */
116 LOAD_REG_ADDR(r5,cpu_state_storage)
117
118 /* Save HID0,1,4 and 5 */
119 mfspr r3,SPRN_HID0
120 std r3,CS_HID0(r5)
121 mfspr r3,SPRN_HID1
122 std r3,CS_HID1(r5)
123 mfspr r4,SPRN_HID4
124 std r4,CS_HID4(r5)
125 mfspr r3,SPRN_HID5
126 std r3,CS_HID5(r5)
127
128 /* See if we successfully set LPES1 to 1; if not we are in Apple mode */
129 andi. r4,r4,HID4_LPES1
130 bnelr
131
132no_hv_mode:
133 /* Disable CPU_FTR_HVMODE and exit, since we don't have HV mode */
134 ld r5,CPU_SPEC_FEATURES(r4)
135 LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE)
136 andc r5,r5,r6
137 std r5,CPU_SPEC_FEATURES(r4)
138 blr
139
140/* Called with no MMU context (typically MSR:IR/DR off) to
141 * restore CPU state as backed up by the previous
142 * function. This does not include cache setting
143 */
144_GLOBAL(__restore_cpu_ppc970)
145 /* Do nothing if not running in HV mode */
146 mfmsr r0
147 rldicl. r0,r0,4,63
148 beqlr
149
150 LOAD_REG_ADDR(r5,cpu_state_storage)
151 /* Before accessing memory, we make sure rm_ci is clear */
152 li r0,0
153 mfspr r3,SPRN_HID4
154 rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
155 sync
156 mtspr SPRN_HID4,r3
157 isync
158 sync
159
160 /* Clear interrupt prefix */
161 li r0,0
162 sync
163 mtspr SPRN_HIOR,0
164 isync
165
166 /* Restore HID0 */
167 ld r3,CS_HID0(r5)
168 sync
169 isync
170 mtspr SPRN_HID0,r3
171 mfspr r3,SPRN_HID0
172 mfspr r3,SPRN_HID0
173 mfspr r3,SPRN_HID0
174 mfspr r3,SPRN_HID0
175 mfspr r3,SPRN_HID0
176 mfspr r3,SPRN_HID0
177 sync
178 isync
179
180 /* Restore HID1 */
181 ld r3,CS_HID1(r5)
182 sync
183 isync
184 mtspr SPRN_HID1,r3
185 mtspr SPRN_HID1,r3
186 sync
187 isync
188
189 /* Restore HID4 */
190 ld r3,CS_HID4(r5)
191 sync
192 isync
193 mtspr SPRN_HID4,r3
194 sync
195 isync
196
197 /* Restore HID5 */
198 ld r3,CS_HID5(r5)
199 sync
200 isync
201 mtspr SPRN_HID5,r3
202 sync
203 isync
204 blr
205
206

source code of linux/arch/powerpc/kernel/cpu_setup_ppc970.S