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19c4d593 UKK |
1 | /* |
2 | * linux/arch/arm/kernel/entry-v7m.S | |
3 | * | |
4 | * Copyright (C) 2008 ARM Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * Low-level vector interface routines for the ARMv7-M architecture | |
11 | */ | |
12 | #include <asm/memory.h> | |
13 | #include <asm/glue.h> | |
14 | #include <asm/thread_notify.h> | |
15 | #include <asm/v7m.h> | |
16 | ||
19c4d593 UKK |
17 | #include "entry-header.S" |
18 | ||
19 | #ifdef CONFIG_TRACE_IRQFLAGS | |
20 | #error "CONFIG_TRACE_IRQFLAGS not supported on the current ARMv7M implementation" | |
21 | #endif | |
22 | ||
23 | __invalid_entry: | |
24 | v7m_exception_entry | |
ed460925 | 25 | #ifdef CONFIG_PRINTK |
19c4d593 UKK |
26 | adr r0, strerr |
27 | mrs r1, ipsr | |
28 | mov r2, lr | |
29 | bl printk | |
ed460925 | 30 | #endif |
19c4d593 UKK |
31 | mov r0, sp |
32 | bl show_regs | |
33 | 1: b 1b | |
34 | ENDPROC(__invalid_entry) | |
35 | ||
36 | strerr: .asciz "\nUnhandled exception: IPSR = %08lx LR = %08lx\n" | |
37 | ||
38 | .align 2 | |
39 | __irq_entry: | |
40 | v7m_exception_entry | |
41 | ||
42 | @ | |
43 | @ Invoke the IRQ handler | |
44 | @ | |
45 | mrs r0, ipsr | |
46 | ldr r1, =V7M_xPSR_EXCEPTIONNO | |
47 | and r0, r1 | |
48 | sub r0, #16 | |
49 | mov r1, sp | |
50 | stmdb sp!, {lr} | |
51 | @ routine called with r0 = irq number, r1 = struct pt_regs * | |
bed859c1 | 52 | bl nvic_handle_irq |
19c4d593 UKK |
53 | |
54 | pop {lr} | |
55 | @ | |
56 | @ Check for any pending work if returning to user | |
57 | @ | |
58 | ldr r1, =BASEADDR_V7M_SCB | |
59 | ldr r0, [r1, V7M_SCB_ICSR] | |
60 | tst r0, V7M_SCB_ICSR_RETTOBASE | |
61 | beq 2f | |
62 | ||
63 | get_thread_info tsk | |
64 | ldr r2, [tsk, #TI_FLAGS] | |
65 | tst r2, #_TIF_WORK_MASK | |
66 | beq 2f @ no work pending | |
67 | mov r0, #V7M_SCB_ICSR_PENDSVSET | |
68 | str r0, [r1, V7M_SCB_ICSR] @ raise PendSV | |
69 | ||
70 | 2: | |
71 | @ registers r0-r3 and r12 are automatically restored on exception | |
72 | @ return. r4-r7 were not clobbered in v7m_exception_entry so for | |
73 | @ correctness they don't need to be restored. So only r8-r11 must be | |
74 | @ restored here. The easiest way to do so is to restore r0-r7, too. | |
75 | ldmia sp!, {r0-r11} | |
76 | add sp, #S_FRAME_SIZE-S_IP | |
77 | cpsie i | |
78 | bx lr | |
79 | ENDPROC(__irq_entry) | |
80 | ||
81 | __pendsv_entry: | |
82 | v7m_exception_entry | |
83 | ||
84 | ldr r1, =BASEADDR_V7M_SCB | |
85 | mov r0, #V7M_SCB_ICSR_PENDSVCLR | |
86 | str r0, [r1, V7M_SCB_ICSR] @ clear PendSV | |
87 | ||
88 | @ execute the pending work, including reschedule | |
89 | get_thread_info tsk | |
90 | mov why, #0 | |
440ee365 | 91 | b ret_to_user_from_irq |
19c4d593 UKK |
92 | ENDPROC(__pendsv_entry) |
93 | ||
94 | /* | |
95 | * Register switch for ARMv7-M processors. | |
96 | * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info | |
97 | * previous and next are guaranteed not to be the same. | |
98 | */ | |
99 | ENTRY(__switch_to) | |
100 | .fnstart | |
101 | .cantunwind | |
102 | add ip, r1, #TI_CPU_SAVE | |
103 | stmia ip!, {r4 - r11} @ Store most regs on stack | |
104 | str sp, [ip], #4 | |
105 | str lr, [ip], #4 | |
106 | mov r5, r0 | |
107 | add r4, r2, #TI_CPU_SAVE | |
108 | ldr r0, =thread_notify_head | |
109 | mov r1, #THREAD_NOTIFY_SWITCH | |
110 | bl atomic_notifier_call_chain | |
111 | mov ip, r4 | |
112 | mov r0, r5 | |
113 | ldmia ip!, {r4 - r11} @ Load all regs saved previously | |
114 | ldr sp, [ip] | |
115 | ldr pc, [ip, #4]! | |
116 | .fnend | |
117 | ENDPROC(__switch_to) | |
118 | ||
119 | .data | |
6b1814cd MC |
120 | #if CONFIG_CPU_V7M_NUM_IRQ <= 112 |
121 | .align 9 | |
122 | #else | |
123 | .align 10 | |
124 | #endif | |
125 | ||
19c4d593 | 126 | /* |
6b1814cd | 127 | * Vector table (Natural alignment need to be ensured) |
19c4d593 UKK |
128 | */ |
129 | ENTRY(vector_table) | |
130 | .long 0 @ 0 - Reset stack pointer | |
131 | .long __invalid_entry @ 1 - Reset | |
132 | .long __invalid_entry @ 2 - NMI | |
133 | .long __invalid_entry @ 3 - HardFault | |
134 | .long __invalid_entry @ 4 - MemManage | |
135 | .long __invalid_entry @ 5 - BusFault | |
136 | .long __invalid_entry @ 6 - UsageFault | |
137 | .long __invalid_entry @ 7 - Reserved | |
138 | .long __invalid_entry @ 8 - Reserved | |
139 | .long __invalid_entry @ 9 - Reserved | |
140 | .long __invalid_entry @ 10 - Reserved | |
141 | .long vector_swi @ 11 - SVCall | |
142 | .long __invalid_entry @ 12 - Debug Monitor | |
143 | .long __invalid_entry @ 13 - Reserved | |
144 | .long __pendsv_entry @ 14 - PendSV | |
145 | .long __invalid_entry @ 15 - SysTick | |
6b1814cd MC |
146 | .rept CONFIG_CPU_V7M_NUM_IRQ |
147 | .long __irq_entry @ External Interrupts | |
19c4d593 | 148 | .endr |