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1/*
2 * linux/arch/arm/mm/proc-v7m.S
3 *
4 * Copyright (C) 2008 ARM Ltd.
5 * Copyright (C) 2001 Deep Blue Solutions Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This is the "shell" of the ARMv7-M processor support.
12 */
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15#include <asm/memory.h>
16#include <asm/v7m.h>
17#include "proc-macros.S"
18
19ENTRY(cpu_v7m_proc_init)
20 ret lr
21ENDPROC(cpu_v7m_proc_init)
22
23ENTRY(cpu_v7m_proc_fin)
24 ret lr
25ENDPROC(cpu_v7m_proc_fin)
26
27/*
28 * cpu_v7m_reset(loc)
29 *
30 * Perform a soft reset of the system. Put the CPU into the
31 * same state as it would be if it had been reset, and branch
32 * to what would be the reset vector.
33 *
34 * - loc - location to jump to for soft reset
35 */
36 .align 5
37ENTRY(cpu_v7m_reset)
38 ret r0
39ENDPROC(cpu_v7m_reset)
40
41/*
42 * cpu_v7m_do_idle()
43 *
44 * Idle the processor (eg, wait for interrupt).
45 *
46 * IRQs are already disabled.
47 */
48ENTRY(cpu_v7m_do_idle)
49 wfi
50 ret lr
51ENDPROC(cpu_v7m_do_idle)
52
53ENTRY(cpu_v7m_dcache_clean_area)
54 ret lr
55ENDPROC(cpu_v7m_dcache_clean_area)
56
57/*
58 * There is no MMU, so here is nothing to do.
59 */
60ENTRY(cpu_v7m_switch_mm)
61 ret lr
62ENDPROC(cpu_v7m_switch_mm)
63
64.globl cpu_v7m_suspend_size
65.equ cpu_v7m_suspend_size, 0
66
67#ifdef CONFIG_ARM_CPU_SUSPEND
68ENTRY(cpu_v7m_do_suspend)
69 ret lr
70ENDPROC(cpu_v7m_do_suspend)
71
72ENTRY(cpu_v7m_do_resume)
73 ret lr
74ENDPROC(cpu_v7m_do_resume)
75#endif
76
77ENTRY(cpu_cm7_dcache_clean_area)
78 dcache_line_size r2, r3
79 movw r3, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
80 movt r3, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
81
821: str r0, [r3] @ clean D entry
83 add r0, r0, r2
84 subs r1, r1, r2
85 bhi 1b
86 dsb
87 ret lr
88ENDPROC(cpu_cm7_dcache_clean_area)
89
90ENTRY(cpu_cm7_proc_fin)
91 movw r2, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
92 movt r2, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
93 ldr r0, [r2]
94 bic r0, r0, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC)
95 str r0, [r2]
96 ret lr
97ENDPROC(cpu_cm7_proc_fin)
98
99 .section ".init.text", #alloc, #execinstr
100
101__v7m_cm7_setup:
102 mov r8, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC| V7M_SCB_CCR_BP)
103 b __v7m_setup_cont
104/*
105 * __v7m_setup
106 *
107 * This should be able to cover all ARMv7-M cores.
108 */
109__v7m_setup:
110 mov r8, 0
111
112__v7m_setup_cont:
113 @ Configure the vector table base address
114 ldr r0, =BASEADDR_V7M_SCB
115 ldr r12, =vector_table
116 str r12, [r0, V7M_SCB_VTOR]
117
118 @ enable UsageFault, BusFault and MemManage fault.
119 ldr r5, [r0, #V7M_SCB_SHCSR]
120 orr r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
121 str r5, [r0, #V7M_SCB_SHCSR]
122
123 @ Lower the priority of the SVC and PendSV exceptions
124 mov r5, #0x80000000
125 str r5, [r0, V7M_SCB_SHPR2] @ set SVC priority
126 mov r5, #0x00800000
127 str r5, [r0, V7M_SCB_SHPR3] @ set PendSV priority
128
129 @ SVC to switch to handler mode. Notice that this requires sp to
130 @ point to writeable memory because the processor saves
131 @ some registers to the stack.
132 badr r1, 1f
133 ldr r5, [r12, #11 * 4] @ read the SVC vector entry
134 str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
135 dsb
136 mov r6, lr @ save LR
137 ldr sp, =init_thread_union + THREAD_START_SP
138 stmia sp, {r0-r3, r12}
139 cpsie i
140 svc #0
1411: cpsid i
142 ldmia sp, {r0-r3, r12}
143 str r5, [r12, #11 * 4] @ restore the original SVC vector entry
144 mov lr, r6 @ restore LR
145
146 @ Special-purpose control register
147 mov r1, #1
148 msr control, r1 @ Thread mode has unpriviledged access
149
150 @ Configure caches (if implemented)
151 teq r8, #0
152 stmneia sp, {r0-r6, lr} @ v7m_invalidate_l1 touches r0-r6
153 blne v7m_invalidate_l1
154 teq r8, #0 @ re-evalutae condition
155 ldmneia sp, {r0-r6, lr}
156
157 @ Configure the System Control Register to ensure 8-byte stack alignment
158 @ Note the STKALIGN bit is either RW or RAO.
159 ldr r0, [r0, V7M_SCB_CCR] @ system control register
160 orr r0, #V7M_SCB_CCR_STKALIGN
161 orr r0, r0, r8
162
163 ret lr
164ENDPROC(__v7m_setup)
165
166/*
167 * Cortex-M7 processor functions
168 */
169 globl_equ cpu_cm7_proc_init, cpu_v7m_proc_init
170 globl_equ cpu_cm7_reset, cpu_v7m_reset
171 globl_equ cpu_cm7_do_idle, cpu_v7m_do_idle
172 globl_equ cpu_cm7_switch_mm, cpu_v7m_switch_mm
173
174 define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
175 define_processor_functions cm7, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
176
177 .section ".rodata"
178 string cpu_arch_name, "armv7m"
179 string cpu_elf_name "v7m"
180 string cpu_v7m_name "ARMv7-M"
181
182 .section ".proc.info.init", #alloc
183
184.macro __v7m_proc name, initfunc, cache_fns = nop_cache_fns, hwcaps = 0, proc_fns = v7m_processor_functions
185 .long 0 /* proc_info_list.__cpu_mm_mmu_flags */
186 .long 0 /* proc_info_list.__cpu_io_mmu_flags */
187 initfn \initfunc, \name
188 .long cpu_arch_name
189 .long cpu_elf_name
190 .long HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \hwcaps
191 .long cpu_v7m_name
192 .long \proc_fns
193 .long 0 /* proc_info_list.tlb */
194 .long 0 /* proc_info_list.user */
195 .long \cache_fns
196.endm
197
198 /*
199 * Match ARM Cortex-M7 processor.
200 */
201 .type __v7m_cm7_proc_info, #object
202__v7m_cm7_proc_info:
203 .long 0x410fc270 /* ARM Cortex-M7 0xC27 */
204 .long 0xff0ffff0 /* Mask off revision, patch release */
205 __v7m_proc __v7m_cm7_proc_info, __v7m_cm7_setup, hwcaps = HWCAP_EDSP, cache_fns = v7m_cache_fns, proc_fns = cm7_processor_functions
206 .size __v7m_cm7_proc_info, . - __v7m_cm7_proc_info
207
208 /*
209 * Match ARM Cortex-M4 processor.
210 */
211 .type __v7m_cm4_proc_info, #object
212__v7m_cm4_proc_info:
213 .long 0x410fc240 /* ARM Cortex-M4 0xC24 */
214 .long 0xff0ffff0 /* Mask off revision, patch release */
215 __v7m_proc __v7m_cm4_proc_info, __v7m_setup, hwcaps = HWCAP_EDSP
216 .size __v7m_cm4_proc_info, . - __v7m_cm4_proc_info
217
218 /*
219 * Match ARM Cortex-M3 processor.
220 */
221 .type __v7m_cm3_proc_info, #object
222__v7m_cm3_proc_info:
223 .long 0x410fc230 /* ARM Cortex-M3 0xC23 */
224 .long 0xff0ffff0 /* Mask off revision, patch release */
225 __v7m_proc __v7m_cm3_proc_info, __v7m_setup
226 .size __v7m_cm3_proc_info, . - __v7m_cm3_proc_info
227
228 /*
229 * Match any ARMv7-M processor core.
230 */
231 .type __v7m_proc_info, #object
232__v7m_proc_info:
233 .long 0x000f0000 @ Required ID value
234 .long 0x000f0000 @ Mask for ID
235 __v7m_proc __v7m_proc_info, __v7m_setup
236 .size __v7m_proc_info, . - __v7m_proc_info
237
1/*
2 * linux/arch/arm/mm/proc-v7m.S
3 *
4 * Copyright (C) 2008 ARM Ltd.
5 * Copyright (C) 2001 Deep Blue Solutions Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This is the "shell" of the ARMv7-M processor support.
12 */
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15#include <asm/v7m.h>
16#include "proc-macros.S"
17
18ENTRY(cpu_v7m_proc_init)
19 mov pc, lr
20ENDPROC(cpu_v7m_proc_init)
21
22ENTRY(cpu_v7m_proc_fin)
23 mov pc, lr
24ENDPROC(cpu_v7m_proc_fin)
25
26/*
27 * cpu_v7m_reset(loc)
28 *
29 * Perform a soft reset of the system. Put the CPU into the
30 * same state as it would be if it had been reset, and branch
31 * to what would be the reset vector.
32 *
33 * - loc - location to jump to for soft reset
34 */
35 .align 5
36ENTRY(cpu_v7m_reset)
37 mov pc, r0
38ENDPROC(cpu_v7m_reset)
39
40/*
41 * cpu_v7m_do_idle()
42 *
43 * Idle the processor (eg, wait for interrupt).
44 *
45 * IRQs are already disabled.
46 */
47ENTRY(cpu_v7m_do_idle)
48 wfi
49 mov pc, lr
50ENDPROC(cpu_v7m_do_idle)
51
52ENTRY(cpu_v7m_dcache_clean_area)
53 mov pc, lr
54ENDPROC(cpu_v7m_dcache_clean_area)
55
56/*
57 * There is no MMU, so here is nothing to do.
58 */
59ENTRY(cpu_v7m_switch_mm)
60 mov pc, lr
61ENDPROC(cpu_v7m_switch_mm)
62
63.globl cpu_v7m_suspend_size
64.equ cpu_v7m_suspend_size, 0
65
66#ifdef CONFIG_ARM_CPU_SUSPEND
67ENTRY(cpu_v7m_do_suspend)
68 mov pc, lr
69ENDPROC(cpu_v7m_do_suspend)
70
71ENTRY(cpu_v7m_do_resume)
72 mov pc, lr
73ENDPROC(cpu_v7m_do_resume)
74#endif
75
76 .section ".text.init", #alloc, #execinstr
77
78/*
79 * __v7m_setup
80 *
81 * This should be able to cover all ARMv7-M cores.
82 */
83__v7m_setup:
84 @ Configure the vector table base address
85 ldr r0, =BASEADDR_V7M_SCB
86 ldr r12, =vector_table
87 str r12, [r0, V7M_SCB_VTOR]
88
89 @ enable UsageFault, BusFault and MemManage fault.
90 ldr r5, [r0, #V7M_SCB_SHCSR]
91 orr r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
92 str r5, [r0, #V7M_SCB_SHCSR]
93
94 @ Lower the priority of the SVC and PendSV exceptions
95 mov r5, #0x80000000
96 str r5, [r0, V7M_SCB_SHPR2] @ set SVC priority
97 mov r5, #0x00800000
98 str r5, [r0, V7M_SCB_SHPR3] @ set PendSV priority
99
100 @ SVC to run the kernel in this mode
101 adr r1, BSYM(1f)
102 ldr r5, [r12, #11 * 4] @ read the SVC vector entry
103 str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
104 mov r6, lr @ save LR
105 mov r7, sp @ save SP
106 ldr sp, =__v7m_setup_stack_top
107 cpsie i
108 svc #0
1091: cpsid i
110 str r5, [r12, #11 * 4] @ restore the original SVC vector entry
111 mov lr, r6 @ restore LR
112 mov sp, r7 @ restore SP
113
114 @ Special-purpose control register
115 mov r1, #1
116 msr control, r1 @ Thread mode has unpriviledged access
117
118 @ Configure the System Control Register to ensure 8-byte stack alignment
119 @ Note the STKALIGN bit is either RW or RAO.
120 ldr r12, [r0, V7M_SCB_CCR] @ system control register
121 orr r12, #V7M_SCB_CCR_STKALIGN
122 str r12, [r0, V7M_SCB_CCR]
123 mov pc, lr
124ENDPROC(__v7m_setup)
125
126 .align 2
127__v7m_setup_stack:
128 .space 4 * 8 @ 8 registers
129__v7m_setup_stack_top:
130
131 define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
132
133 .section ".rodata"
134 string cpu_arch_name, "armv7m"
135 string cpu_elf_name "v7m"
136 string cpu_v7m_name "ARMv7-M"
137
138 .section ".proc.info.init", #alloc, #execinstr
139
140 /*
141 * Match any ARMv7-M processor core.
142 */
143 .type __v7m_proc_info, #object
144__v7m_proc_info:
145 .long 0x000f0000 @ Required ID value
146 .long 0x000f0000 @ Mask for ID
147 .long 0 @ proc_info_list.__cpu_mm_mmu_flags
148 .long 0 @ proc_info_list.__cpu_io_mmu_flags
149 b __v7m_setup @ proc_info_list.__cpu_flush
150 .long cpu_arch_name
151 .long cpu_elf_name
152 .long HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT
153 .long cpu_v7m_name
154 .long v7m_processor_functions @ proc_info_list.proc
155 .long 0 @ proc_info_list.tlb
156 .long 0 @ proc_info_list.user
157 .long nop_cache_fns @ proc_info_list.cache
158 .size __v7m_proc_info, . - __v7m_proc_info
159