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
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/kernel/entry-v7m.S
*
* Copyright (C) 2008 ARM Ltd.
*
* Low-level vector interface routines for the ARMv7-M architecture
*/
#include <asm/memory.h>
#include <asm/glue.h>
#include <asm/thread_notify.h>
#include <asm/v7m.h>
#include "entry-header.S"
#ifdef CONFIG_TRACE_IRQFLAGS
#error "CONFIG_TRACE_IRQFLAGS not supported on the current ARMv7M implementation"
#endif
__invalid_entry:
v7m_exception_entry
#ifdef CONFIG_PRINTK
adr r0, strerr
mrs r1, ipsr
mov r2, lr
bl printk
#endif
mov r0, sp
bl show_regs
1: b 1b
ENDPROC(__invalid_entry)
strerr: .asciz "\nUnhandled exception: IPSR = %08lx LR = %08lx\n"
.align 2
__irq_entry:
v7m_exception_entry
@
@ Invoke the IRQ handler
@
mrs r0, ipsr
ldr r1, =V7M_xPSR_EXCEPTIONNO
and r0, r1
sub r0, #16
mov r1, sp
stmdb sp!, {lr}
@ routine called with r0 = irq number, r1 = struct pt_regs *
bl nvic_handle_irq
pop {lr}
@
@ Check for any pending work if returning to user
@
ldr r1, =BASEADDR_V7M_SCB
ldr r0, [r1, V7M_SCB_ICSR]
tst r0, V7M_SCB_ICSR_RETTOBASE
beq 2f
get_thread_info tsk
ldr r2, [tsk, #TI_FLAGS]
tst r2, #_TIF_WORK_MASK
beq 2f @ no work pending
mov r0, #V7M_SCB_ICSR_PENDSVSET
str r0, [r1, V7M_SCB_ICSR] @ raise PendSV
2:
@ registers r0-r3 and r12 are automatically restored on exception
@ return. r4-r7 were not clobbered in v7m_exception_entry so for
@ correctness they don't need to be restored. So only r8-r11 must be
@ restored here. The easiest way to do so is to restore r0-r7, too.
ldmia sp!, {r0-r11}
add sp, #PT_REGS_SIZE-S_IP
cpsie i
bx lr
ENDPROC(__irq_entry)
__pendsv_entry:
v7m_exception_entry
ldr r1, =BASEADDR_V7M_SCB
mov r0, #V7M_SCB_ICSR_PENDSVCLR
str r0, [r1, V7M_SCB_ICSR] @ clear PendSV
@ execute the pending work, including reschedule
get_thread_info tsk
mov why, #0
b ret_to_user_from_irq
ENDPROC(__pendsv_entry)
/*
* Register switch for ARMv7-M processors.
* r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
* previous and next are guaranteed not to be the same.
*/
ENTRY(__switch_to)
.fnstart
.cantunwind
add ip, r1, #TI_CPU_SAVE
stmia ip!, {r4 - r11} @ Store most regs on stack
str sp, [ip], #4
str lr, [ip], #4
mov r5, r0
add r4, r2, #TI_CPU_SAVE
ldr r0, =thread_notify_head
mov r1, #THREAD_NOTIFY_SWITCH
bl atomic_notifier_call_chain
mov ip, r4
mov r0, r5
ldmia ip!, {r4 - r11} @ Load all regs saved previously
ldr sp, [ip]
ldr pc, [ip, #4]!
.fnend
ENDPROC(__switch_to)
.data
#if CONFIG_CPU_V7M_NUM_IRQ <= 112
.align 9
#else
.align 10
#endif
/*
* Vector table (Natural alignment need to be ensured)
*/
ENTRY(vector_table)
.long 0 @ 0 - Reset stack pointer
.long __invalid_entry @ 1 - Reset
.long __invalid_entry @ 2 - NMI
.long __invalid_entry @ 3 - HardFault
.long __invalid_entry @ 4 - MemManage
.long __invalid_entry @ 5 - BusFault
.long __invalid_entry @ 6 - UsageFault
.long __invalid_entry @ 7 - Reserved
.long __invalid_entry @ 8 - Reserved
.long __invalid_entry @ 9 - Reserved
.long __invalid_entry @ 10 - Reserved
.long vector_swi @ 11 - SVCall
.long __invalid_entry @ 12 - Debug Monitor
.long __invalid_entry @ 13 - Reserved
.long __pendsv_entry @ 14 - PendSV
.long __invalid_entry @ 15 - SysTick
.rept CONFIG_CPU_V7M_NUM_IRQ
.long __irq_entry @ External Interrupts
.endr
.align 2
.globl exc_ret
exc_ret:
.space 4
|
