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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 | |
25 | adr r0, strerr | |
26 | mrs r1, ipsr | |
27 | mov r2, lr | |
28 | bl printk | |
29 | mov r0, sp | |
30 | bl show_regs | |
31 | 1: b 1b | |
32 | ENDPROC(__invalid_entry) | |
33 | ||
34 | strerr: .asciz "\nUnhandled exception: IPSR = %08lx LR = %08lx\n" | |
35 | ||
36 | .align 2 | |
37 | __irq_entry: | |
38 | v7m_exception_entry | |
39 | ||
40 | @ | |
41 | @ Invoke the IRQ handler | |
42 | @ | |
43 | mrs r0, ipsr | |
44 | ldr r1, =V7M_xPSR_EXCEPTIONNO | |
45 | and r0, r1 | |
46 | sub r0, #16 | |
47 | mov r1, sp | |
48 | stmdb sp!, {lr} | |
49 | @ routine called with r0 = irq number, r1 = struct pt_regs * | |
bed859c1 | 50 | bl nvic_handle_irq |
19c4d593 UKK |
51 | |
52 | pop {lr} | |
53 | @ | |
54 | @ Check for any pending work if returning to user | |
55 | @ | |
56 | ldr r1, =BASEADDR_V7M_SCB | |
57 | ldr r0, [r1, V7M_SCB_ICSR] | |
58 | tst r0, V7M_SCB_ICSR_RETTOBASE | |
59 | beq 2f | |
60 | ||
61 | get_thread_info tsk | |
62 | ldr r2, [tsk, #TI_FLAGS] | |
63 | tst r2, #_TIF_WORK_MASK | |
64 | beq 2f @ no work pending | |
65 | mov r0, #V7M_SCB_ICSR_PENDSVSET | |
66 | str r0, [r1, V7M_SCB_ICSR] @ raise PendSV | |
67 | ||
68 | 2: | |
69 | @ registers r0-r3 and r12 are automatically restored on exception | |
70 | @ return. r4-r7 were not clobbered in v7m_exception_entry so for | |
71 | @ correctness they don't need to be restored. So only r8-r11 must be | |
72 | @ restored here. The easiest way to do so is to restore r0-r7, too. | |
73 | ldmia sp!, {r0-r11} | |
74 | add sp, #S_FRAME_SIZE-S_IP | |
75 | cpsie i | |
76 | bx lr | |
77 | ENDPROC(__irq_entry) | |
78 | ||
79 | __pendsv_entry: | |
80 | v7m_exception_entry | |
81 | ||
82 | ldr r1, =BASEADDR_V7M_SCB | |
83 | mov r0, #V7M_SCB_ICSR_PENDSVCLR | |
84 | str r0, [r1, V7M_SCB_ICSR] @ clear PendSV | |
85 | ||
86 | @ execute the pending work, including reschedule | |
87 | get_thread_info tsk | |
88 | mov why, #0 | |
89 | b ret_to_user | |
90 | ENDPROC(__pendsv_entry) | |
91 | ||
92 | /* | |
93 | * Register switch for ARMv7-M processors. | |
94 | * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info | |
95 | * previous and next are guaranteed not to be the same. | |
96 | */ | |
97 | ENTRY(__switch_to) | |
98 | .fnstart | |
99 | .cantunwind | |
100 | add ip, r1, #TI_CPU_SAVE | |
101 | stmia ip!, {r4 - r11} @ Store most regs on stack | |
102 | str sp, [ip], #4 | |
103 | str lr, [ip], #4 | |
104 | mov r5, r0 | |
105 | add r4, r2, #TI_CPU_SAVE | |
106 | ldr r0, =thread_notify_head | |
107 | mov r1, #THREAD_NOTIFY_SWITCH | |
108 | bl atomic_notifier_call_chain | |
109 | mov ip, r4 | |
110 | mov r0, r5 | |
111 | ldmia ip!, {r4 - r11} @ Load all regs saved previously | |
112 | ldr sp, [ip] | |
113 | ldr pc, [ip, #4]! | |
114 | .fnend | |
115 | ENDPROC(__switch_to) | |
116 | ||
117 | .data | |
118 | .align 8 | |
119 | /* | |
120 | * Vector table (64 words => 256 bytes natural alignment) | |
121 | */ | |
122 | ENTRY(vector_table) | |
123 | .long 0 @ 0 - Reset stack pointer | |
124 | .long __invalid_entry @ 1 - Reset | |
125 | .long __invalid_entry @ 2 - NMI | |
126 | .long __invalid_entry @ 3 - HardFault | |
127 | .long __invalid_entry @ 4 - MemManage | |
128 | .long __invalid_entry @ 5 - BusFault | |
129 | .long __invalid_entry @ 6 - UsageFault | |
130 | .long __invalid_entry @ 7 - Reserved | |
131 | .long __invalid_entry @ 8 - Reserved | |
132 | .long __invalid_entry @ 9 - Reserved | |
133 | .long __invalid_entry @ 10 - Reserved | |
134 | .long vector_swi @ 11 - SVCall | |
135 | .long __invalid_entry @ 12 - Debug Monitor | |
136 | .long __invalid_entry @ 13 - Reserved | |
137 | .long __pendsv_entry @ 14 - PendSV | |
138 | .long __invalid_entry @ 15 - SysTick | |
139 | .rept 64 - 16 | |
140 | .long __irq_entry @ 16..64 - External Interrupts | |
141 | .endr |