1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
/*
* linux/arch/arm/mm/proc-v6.S
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
* Modified by Catalin Marinas for noMMU support
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This is the "shell" of the ARMv6 processor support.
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/hwcap.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include "proc-macros.S"
#define D_CACHE_LINE_SIZE 32
#define TTB_C (1 << 0)
#define TTB_S (1 << 1)
#define TTB_IMP (1 << 2)
#define TTB_RGN_NC (0 << 3)
#define TTB_RGN_WBWA (1 << 3)
#define TTB_RGN_WT (2 << 3)
#define TTB_RGN_WB (3 << 3)
#ifndef CONFIG_SMP
#define TTB_FLAGS TTB_RGN_WBWA
#define PMD_FLAGS PMD_SECT_WB
#else
#define TTB_FLAGS TTB_RGN_WBWA|TTB_S
#define PMD_FLAGS PMD_SECT_WBWA|PMD_SECT_S
#endif
ENTRY(cpu_v6_proc_init)
mov pc, lr
ENTRY(cpu_v6_proc_fin)
stmfd sp!, {lr}
cpsid if @ disable interrupts
bl v6_flush_kern_cache_all
mrc p15, 0, r0, c1, c0, 0 @ ctrl register
bic r0, r0, #0x1000 @ ...i............
bic r0, r0, #0x0006 @ .............ca.
mcr p15, 0, r0, c1, c0, 0 @ disable caches
ldmfd sp!, {pc}
/*
* cpu_v6_reset(loc)
*
* Perform a soft reset of the system. Put the CPU into the
* same state as it would be if it had been reset, and branch
* to what would be the reset vector.
*
* - loc - location to jump to for soft reset
*/
.align 5
ENTRY(cpu_v6_reset)
mov pc, r0
/*
* cpu_v6_do_idle()
*
* Idle the processor (eg, wait for interrupt).
*
* IRQs are already disabled.
*/
ENTRY(cpu_v6_do_idle)
mov r1, #0
mcr p15, 0, r1, c7, c10, 4 @ DWB - WFI may enter a low-power mode
mcr p15, 0, r1, c7, c0, 4 @ wait for interrupt
mov pc, lr
ENTRY(cpu_v6_dcache_clean_area)
#ifndef TLB_CAN_READ_FROM_L1_CACHE
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #D_CACHE_LINE_SIZE
subs r1, r1, #D_CACHE_LINE_SIZE
bhi 1b
#endif
mov pc, lr
/*
* cpu_arm926_switch_mm(pgd_phys, tsk)
*
* Set the translation table base pointer to be pgd_phys
*
* - pgd_phys - physical address of new TTB
*
* It is assumed that:
* - we are not using split page tables
*/
ENTRY(cpu_v6_switch_mm)
#ifdef CONFIG_MMU
mov r2, #0
ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id
orr r0, r0, #TTB_FLAGS
mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
mcr p15, 0, r2, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
mcr p15, 0, r1, c13, c0, 1 @ set context ID
#endif
mov pc, lr
/*
* cpu_v6_set_pte_ext(ptep, pte, ext)
*
* Set a level 2 translation table entry.
*
* - ptep - pointer to level 2 translation table entry
* (hardware version is stored at -1024 bytes)
* - pte - PTE value to store
* - ext - value for extended PTE bits
*/
armv6_mt_table cpu_v6
ENTRY(cpu_v6_set_pte_ext)
#ifdef CONFIG_MMU
armv6_set_pte_ext cpu_v6
#endif
mov pc, lr
cpu_v6_name:
.asciz "ARMv6-compatible processor"
.align
__INIT
/*
* __v6_setup
*
* Initialise TLB, Caches, and MMU state ready to switch the MMU
* on. Return in r0 the new CP15 C1 control register setting.
*
* We automatically detect if we have a Harvard cache, and use the
* Harvard cache control instructions insead of the unified cache
* control instructions.
*
* This should be able to cover all ARMv6 cores.
*
* It is assumed that:
* - cache type register is implemented
*/
__v6_setup:
#ifdef CONFIG_SMP
mrc p15, 0, r0, c1, c0, 1 @ Enable SMP/nAMP mode
orr r0, r0, #0x20
mcr p15, 0, r0, c1, c0, 1
#endif
mov r0, #0
mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
#ifdef CONFIG_MMU
mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
mcr p15, 0, r0, c2, c0, 2 @ TTB control register
orr r4, r4, #TTB_FLAGS
mcr p15, 0, r4, c2, c0, 1 @ load TTB1
#endif /* CONFIG_MMU */
adr r5, v6_crval
ldmia r5, {r5, r6}
#ifdef CONFIG_CPU_ENDIAN_BE8
orr r6, r6, #1 << 25 @ big-endian page tables
#endif
mrc p15, 0, r0, c1, c0, 0 @ read control register
bic r0, r0, r5 @ clear bits them
orr r0, r0, r6 @ set them
mov pc, lr @ return to head.S:__ret
/*
* V X F I D LR
* .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM
* rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced
* 0 110 0011 1.00 .111 1101 < we want
*/
.type v6_crval, #object
v6_crval:
crval clear=0x01e0fb7f, mmuset=0x00c0387d, ucset=0x00c0187c
.type v6_processor_functions, #object
ENTRY(v6_processor_functions)
.word v6_early_abort
.word v6_pabort
.word cpu_v6_proc_init
.word cpu_v6_proc_fin
.word cpu_v6_reset
.word cpu_v6_do_idle
.word cpu_v6_dcache_clean_area
.word cpu_v6_switch_mm
.word cpu_v6_set_pte_ext
.size v6_processor_functions, . - v6_processor_functions
.type cpu_arch_name, #object
cpu_arch_name:
.asciz "armv6"
.size cpu_arch_name, . - cpu_arch_name
.type cpu_elf_name, #object
cpu_elf_name:
.asciz "v6"
.size cpu_elf_name, . - cpu_elf_name
.align
.section ".proc.info.init", #alloc, #execinstr
/*
* Match any ARMv6 processor core.
*/
.type __v6_proc_info, #object
__v6_proc_info:
.long 0x0007b000
.long 0x0007f000
.long PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ | \
PMD_FLAGS
.long PMD_TYPE_SECT | \
PMD_SECT_XN | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
b __v6_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA
.long cpu_v6_name
.long v6_processor_functions
.long v6wbi_tlb_fns
.long v6_user_fns
.long v6_cache_fns
.size __v6_proc_info, . - __v6_proc_info
|