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comparison src/device/picirq.c @ 0:53676d1f5817 default tip

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author tobaru
date Sun, 04 Feb 2018 17:54:49 +0900
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1 // Support of ARM PrimeCell Vectored Interrrupt Controller (PL190)
2 #include "types.h"
3 #include "defs.h"
4 #include "param.h"
5 #include "arm.h"
6 #include "memlayout.h"
7 #include "mmu.h"
8
9 // PL190 supports the vectored interrupts and non-vectored interrupts.
10 // In this code, we use non-vected interrupts (aka. simple interrupt).
11 // The flow to handle simple interrupts is as the following:
12 // 1. an interrupt (IRQ) occurs, trap.c branches to our IRQ handler
13 // 2. read the VICIRQStatus register, for each source generating
14 // the interrrupt:
15 // 2.1 locate the correct ISR
16 // 2.2 execute the ISR
17 // 2.3 clear the interrupt
18 // 3 return to trap.c, which will resume interrupted routines
19 // Note: must not read VICVectorAddr
20
21
22 // define the register offsets (in the unit of 4 bytes). The base address
23 // of the VIC depends on the board
24 static volatile uint* vic_base;
25
26 #define VIC_IRQSTATUS 0 // status of interrupts after masking by ENABLE and SEL
27 #define VIC_FIQSTATUS 1 // status of interrupts after masking
28 #define VIC_RAWINTR 2 // status of interrupts before masking
29 #define VIC_INTSEL 3 // interrupt select (IRQ or FIQ), by default IRQ
30 #define VIC_INTENABLE 4 // enable interrupts (1 - enabled, 0 - disabled)
31 #define VIC_INTCLEAR 5 // clear bits in ENABLE register (1 - clear it)
32 #define VIC_PROTECTIOIN 8 // who can access: user or privileged
33
34 #define NUM_INTSRC 32 // numbers of interrupt source supported
35
36 static ISR isrs[NUM_INTSRC];
37
38 static void default_isr (struct trapframe *tf, int n)
39 {
40 cprintf ("unhandled interrupt: %d\n", n);
41 }
42
43 // initialize the PL190 VIC
44 void pic_init (void * base)
45 {
46 int i;
47
48 // set the base for the controller and disable all interrupts
49 vic_base = base;
50 vic_base[VIC_INTCLEAR] = 0xFFFFFFFF;
51
52 for (i = 0; i < NUM_INTSRC; i++) {
53 isrs[i] = default_isr;
54 }
55 }
56
57 // enable an interrupt (with the ISR)
58 void pic_enable (int n, ISR isr)
59 {
60 if ((n<0) || (n >= NUM_INTSRC)) {
61 panic ("invalid interrupt source");
62 }
63
64 // write 1 bit enable the interrupt, 0 bit has no effect
65 isrs[n] = isr;
66 vic_base[VIC_INTENABLE] = (1 << n);
67 }
68
69 // disable an interrupt
70 void pic_disable (int n)
71 {
72 if ((n<0) || (n >= NUM_INTSRC)) {
73 panic ("invalid interrupt source");
74 }
75
76 vic_base[VIC_INTCLEAR] = (1 << n);
77 isrs[n] = default_isr;
78 }
79
80 // dispatch the interrupt
81 void pic_dispatch (struct trapframe *tp)
82 {
83 uint intstatus;
84 int i;
85
86 intstatus = vic_base[VIC_IRQSTATUS];
87
88 for (i = 0; i < NUM_INTSRC; i++) {
89 if (intstatus & (1<<i)) {
90 isrs[i](tp, i);
91 }
92 }
93
94 intstatus = vic_base[VIC_IRQSTATUS];
95 }
96