aboutsummaryrefslogtreecommitdiff
path: root/hw/arm_gic.c
blob: 58d840415c379099aadc03c8cb97b2ce58c16493 (plain)
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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
/* 
 * ARM AMBA Generic/Distributed Interrupt Controller
 *
 * Copyright (c) 2006 CodeSourcery.
 * Written by Paul Brook
 *
 * This code is licenced under the GPL.
 */

/* TODO: Some variants of this controller can handle multiple CPUs.
   Currently only single CPU operation is implemented.  */

#include "vl.h"
#include "arm_pic.h"

//#define DEBUG_GIC

#ifdef DEBUG_GIC
#define DPRINTF(fmt, args...) \
do { printf("arm_gic: " fmt , ##args); } while (0)
#else
#define DPRINTF(fmt, args...) do {} while(0)
#endif

/* Distributed interrupt controller.  */

static const uint8_t gic_id[] =
{ 0x90, 0x13, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };

#define GIC_NIRQ 96

typedef struct gic_irq_state
{
    unsigned enabled:1;
    unsigned pending:1;
    unsigned active:1;
    unsigned level:1;
    unsigned model:1; /* 0 = 1:N, 1 = N:N */
    unsigned trigger:1; /* nonzero = edge triggered.  */
} gic_irq_state;

#define GIC_SET_ENABLED(irq) s->irq_state[irq].enabled = 1
#define GIC_CLEAR_ENABLED(irq) s->irq_state[irq].enabled = 0
#define GIC_TEST_ENABLED(irq) s->irq_state[irq].enabled
#define GIC_SET_PENDING(irq) s->irq_state[irq].pending = 1
#define GIC_CLEAR_PENDING(irq) s->irq_state[irq].pending = 0
#define GIC_TEST_PENDING(irq) s->irq_state[irq].pending
#define GIC_SET_ACTIVE(irq) s->irq_state[irq].active = 1
#define GIC_CLEAR_ACTIVE(irq) s->irq_state[irq].active = 0
#define GIC_TEST_ACTIVE(irq) s->irq_state[irq].active
#define GIC_SET_MODEL(irq) s->irq_state[irq].model = 1
#define GIC_CLEAR_MODEL(irq) s->irq_state[irq].model = 0
#define GIC_TEST_MODEL(irq) s->irq_state[irq].model
#define GIC_SET_LEVEL(irq) s->irq_state[irq].level = 1
#define GIC_CLEAR_LEVEL(irq) s->irq_state[irq].level = 0
#define GIC_TEST_LEVEL(irq) s->irq_state[irq].level
#define GIC_SET_TRIGGER(irq) s->irq_state[irq].trigger = 1
#define GIC_CLEAR_TRIGGER(irq) s->irq_state[irq].trigger = 0
#define GIC_TEST_TRIGGER(irq) s->irq_state[irq].trigger

typedef struct gic_state
{
    uint32_t base;
    qemu_irq parent_irq;
    int enabled;
    int cpu_enabled;

    gic_irq_state irq_state[GIC_NIRQ];
    int irq_target[GIC_NIRQ];
    int priority[GIC_NIRQ];
    int last_active[GIC_NIRQ];

    int priority_mask;
    int running_irq;
    int running_priority;
    int current_pending;
} gic_state;

/* TODO: Many places that call this routine could be optimized.  */
/* Update interrupt status after enabled or pending bits have been changed.  */
static void gic_update(gic_state *s)
{
    int best_irq;
    int best_prio;
    int irq;

    s->current_pending = 1023;
    if (!s->enabled || !s->cpu_enabled) {
        qemu_irq_lower(s->parent_irq);
        return;
    }
    best_prio = 0x100;
    best_irq = 1023;
    for (irq = 0; irq < 96; irq++) {
        if (GIC_TEST_ENABLED(irq) && GIC_TEST_PENDING(irq)) {
            if (s->priority[irq] < best_prio) {
                best_prio = s->priority[irq];
                best_irq = irq;
            }
        }
    }
    if (best_prio > s->priority_mask) {
        qemu_irq_lower(s->parent_irq);
    } else {
        s->current_pending = best_irq;
        if (best_prio < s->running_priority) {
            DPRINTF("Raised pending IRQ %d\n", best_irq);
            qemu_irq_raise(s->parent_irq);
        }
    }
}

static void gic_set_irq(void *opaque, int irq, int level)
{
    gic_state *s = (gic_state *)opaque;
    /* The first external input line is internal interrupt 32.  */
    irq += 32;
    if (level == GIC_TEST_LEVEL(irq)) 
        return;

    if (level) {
        GIC_SET_LEVEL(irq);
        if (GIC_TEST_TRIGGER(irq) || GIC_TEST_ENABLED(irq)) {
            DPRINTF("Set %d pending\n", irq);
            GIC_SET_PENDING(irq);
        }
    } else {
        GIC_CLEAR_LEVEL(irq);
    }
    gic_update(s);
}

static void gic_set_running_irq(gic_state *s, int irq)
{
    s->running_irq = irq;
    if (irq == 1023)
        s->running_priority = 0x100;
    else
        s->running_priority = s->priority[irq];
    gic_update(s);
}

static uint32_t gic_acknowledge_irq(gic_state *s)
{
    int new_irq;
    new_irq = s->current_pending;
    if (new_irq == 1023 || s->priority[new_irq] >= s->running_priority) {
        DPRINTF("ACK no pending IRQ\n");
        return 1023;
    }
    qemu_irq_lower(s->parent_irq);
    s->last_active[new_irq] = s->running_irq;
    /* For level triggered interrupts we clear the pending bit while
       the interrupt is active.  */
    GIC_CLEAR_PENDING(new_irq);
    gic_set_running_irq(s, new_irq);
    DPRINTF("ACK %d\n", new_irq);
    return new_irq;
}

static void gic_complete_irq(gic_state * s, int irq)
{
    int update = 0;
    DPRINTF("EOI %d\n", irq);
    if (s->running_irq == 1023)
        return; /* No active IRQ.  */
    if (irq != 1023) {
        /* Mark level triggered interrupts as pending if they are still
           raised.  */
        if (!GIC_TEST_TRIGGER(irq) && GIC_TEST_ENABLED(irq)
                && GIC_TEST_LEVEL(irq)) {
            GIC_SET_PENDING(irq);
            update = 1;
        }
    }
    if (irq != s->running_irq) {
        /* Complete an IRQ that is not currently running.  */
        int tmp = s->running_irq;
        while (s->last_active[tmp] != 1023) {
            if (s->last_active[tmp] == irq) {
                s->last_active[tmp] = s->last_active[irq];
                break;
            }
            tmp = s->last_active[tmp];
        }
        if (update) {
            gic_update(s);
        }
    } else {
        /* Complete the current running IRQ.  */
        gic_set_running_irq(s, s->last_active[s->running_irq]);
    }
}

static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
{
    gic_state *s = (gic_state *)opaque;
    uint32_t res;
    int irq;
    int i;

    offset -= s->base + 0x1000;
    if (offset < 0x100) {
        if (offset == 0)
            return s->enabled;
        if (offset == 4)
            return (GIC_NIRQ / 32) - 1;
        if (offset < 0x08)
            return 0;
        goto bad_reg;
    } else if (offset < 0x200) {
        /* Interrupt Set/Clear Enable.  */
        if (offset < 0x180)
            irq = (offset - 0x100) * 8;
        else
            irq = (offset - 0x180) * 8;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        res = 0;
        for (i = 0; i < 8; i++) {
            if (GIC_TEST_ENABLED(irq + i)) {
                res |= (1 << i);
            }
        }
    } else if (offset < 0x300) {
        /* Interrupt Set/Clear Pending.  */
        if (offset < 0x280)
            irq = (offset - 0x200) * 8;
        else
            irq = (offset - 0x280) * 8;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        res = 0;
        for (i = 0; i < 8; i++) {
            if (GIC_TEST_PENDING(irq + i)) {
                res |= (1 << i);
            }
        }
    } else if (offset < 0x400) {
        /* Interrupt Active.  */
        irq = (offset - 0x300) * 8;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        res = 0;
        for (i = 0; i < 8; i++) {
            if (GIC_TEST_ACTIVE(irq + i)) {
                res |= (1 << i);
            }
        }
    } else if (offset < 0x800) {
        /* Interrupt Priority.  */
        irq = offset - 0x400;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        res = s->priority[irq];
    } else if (offset < 0xc00) {
        /* Interrupt CPU Target.  */
        irq = offset - 0x800;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        res = s->irq_target[irq];
    } else if (offset < 0xf00) {
        /* Interrupt Configuration.  */
        irq = (offset - 0xc00) * 2;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        res = 0;
        for (i = 0; i < 4; i++) {
            if (GIC_TEST_MODEL(irq + i))
                res |= (1 << (i * 2));
            if (GIC_TEST_TRIGGER(irq + i))
                res |= (2 << (i * 2));
        }
    } else if (offset < 0xfe0) {
        goto bad_reg;
    } else /* offset >= 0xfe0 */ {
        if (offset & 3) {
            res = 0;
        } else {
            res = gic_id[(offset - 0xfe0) >> 2];
        }
    }
    return res;
bad_reg:
    cpu_abort (cpu_single_env, "gic_dist_readb: Bad offset %x\n", offset);
    return 0;
}

static uint32_t gic_dist_readw(void *opaque, target_phys_addr_t offset)
{
    uint32_t val;
    val = gic_dist_readb(opaque, offset);
    val |= gic_dist_readb(opaque, offset + 1) << 8;
    return val;
}

static uint32_t gic_dist_readl(void *opaque, target_phys_addr_t offset)
{
    uint32_t val;
    val = gic_dist_readw(opaque, offset);
    val |= gic_dist_readw(opaque, offset + 2) << 16;
    return val;
}

static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
                            uint32_t value)
{
    gic_state *s = (gic_state *)opaque;
    int irq;
    int i;

    offset -= s->base + 0x1000;
    if (offset < 0x100) {
        if (offset == 0) {
            s->enabled = (value & 1);
            DPRINTF("Distribution %sabled\n", s->enabled ? "En" : "Dis");
        } else if (offset < 4) {
            /* ignored.  */
        } else {
            goto bad_reg;
        }
    } else if (offset < 0x180) {
        /* Interrupt Set Enable.  */
        irq = (offset - 0x100) * 8;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        for (i = 0; i < 8; i++) {
            if (value & (1 << i)) {
                if (!GIC_TEST_ENABLED(irq + i))
                    DPRINTF("Enabled IRQ %d\n", irq + i);
                GIC_SET_ENABLED(irq + i);
                /* If a raised level triggered IRQ enabled then mark
                   is as pending.  */
                if (GIC_TEST_LEVEL(irq + i) && !GIC_TEST_TRIGGER(irq + i))
                    GIC_SET_PENDING(irq + i);
            }
        }
    } else if (offset < 0x200) {
        /* Interrupt Clear Enable.  */
        irq = (offset - 0x180) * 8;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        for (i = 0; i < 8; i++) {
            if (value & (1 << i)) {
                if (GIC_TEST_ENABLED(irq + i))
                    DPRINTF("Disabled IRQ %d\n", irq + i);
                GIC_CLEAR_ENABLED(irq + i);
            }
        }
    } else if (offset < 0x280) {
        /* Interrupt Set Pending.  */
        irq = (offset - 0x200) * 8;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        for (i = 0; i < 8; i++) {
            if (value & (1 << i)) {
                GIC_SET_PENDING(irq + i);
            }
        }
    } else if (offset < 0x300) {
        /* Interrupt Clear Pending.  */
        irq = (offset - 0x280) * 8;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        for (i = 0; i < 8; i++) {
            if (value & (1 << i)) {
                GIC_CLEAR_PENDING(irq + i);
            }
        }
    } else if (offset < 0x400) {
        /* Interrupt Active.  */
        goto bad_reg;
    } else if (offset < 0x800) {
        /* Interrupt Priority.  */
        irq = offset - 0x400;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        s->priority[irq] = value;
    } else if (offset < 0xc00) {
        /* Interrupt CPU Target.  */
        irq = offset - 0x800;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        s->irq_target[irq] = value;
    } else if (offset < 0xf00) {
        /* Interrupt Configuration.  */
        irq = (offset - 0xc00) * 4;
        if (irq >= GIC_NIRQ)
            goto bad_reg;
        for (i = 0; i < 4; i++) {
            if (value & (1 << (i * 2))) {
                GIC_SET_MODEL(irq + i);
            } else {
                GIC_CLEAR_MODEL(irq + i);
            }
            if (value & (2 << (i * 2))) {
                GIC_SET_TRIGGER(irq + i);
            } else {
                GIC_CLEAR_TRIGGER(irq + i);
            }
        }
    } else {
        /* 0xf00 is only handled for word writes.  */
        goto bad_reg;
    }
    gic_update(s);
    return;
bad_reg:
    cpu_abort (cpu_single_env, "gic_dist_writeb: Bad offset %x\n", offset);
}

static void gic_dist_writew(void *opaque, target_phys_addr_t offset,
                            uint32_t value)
{
    gic_state *s = (gic_state *)opaque;
    if (offset - s->base == 0xf00) {
        GIC_SET_PENDING(value & 0x3ff);
        gic_update(s);
        return;
    }
    gic_dist_writeb(opaque, offset, value & 0xff);
    gic_dist_writeb(opaque, offset + 1, value >> 8);
}

static void gic_dist_writel(void *opaque, target_phys_addr_t offset,
                            uint32_t value)
{
    gic_dist_writew(opaque, offset, value & 0xffff);
    gic_dist_writew(opaque, offset + 2, value >> 16);
}

static CPUReadMemoryFunc *gic_dist_readfn[] = {
   gic_dist_readb,
   gic_dist_readw,
   gic_dist_readl
};

static CPUWriteMemoryFunc *gic_dist_writefn[] = {
   gic_dist_writeb,
   gic_dist_writew,
   gic_dist_writel
};

static uint32_t gic_cpu_read(void *opaque, target_phys_addr_t offset)
{
    gic_state *s = (gic_state *)opaque;
    offset -= s->base;
    switch (offset) {
    case 0x00: /* Control */
        return s->cpu_enabled;
    case 0x04: /* Priority mask */
        return s->priority_mask;
    case 0x08: /* Binary Point */
        /* ??? Not implemented.  */
        return 0;
    case 0x0c: /* Acknowledge */
        return gic_acknowledge_irq(s);
    case 0x14: /* Runing Priority */
        return s->running_priority;
    case 0x18: /* Highest Pending Interrupt */
        return s->current_pending;
    default:
        cpu_abort (cpu_single_env, "gic_cpu_read: Bad offset %x\n", offset);
        return 0;
    }
}

static void gic_cpu_write(void *opaque, target_phys_addr_t offset,
                          uint32_t value)
{
    gic_state *s = (gic_state *)opaque;
    offset -= s->base;
    switch (offset) {
    case 0x00: /* Control */
        s->cpu_enabled = (value & 1);
        DPRINTF("CPU %sabled\n", s->cpu_enabled ? "En" : "Dis");
        break;
    case 0x04: /* Priority mask */
        s->priority_mask = (value & 0x3ff);
        break;
    case 0x08: /* Binary Point */
        /* ??? Not implemented.  */
        break;
    case 0x10: /* End Of Interrupt */
        return gic_complete_irq(s, value & 0x3ff);
    default:
        cpu_abort (cpu_single_env, "gic_cpu_write: Bad offset %x\n", offset);
        return;
    }
    gic_update(s);
}

static CPUReadMemoryFunc *gic_cpu_readfn[] = {
   gic_cpu_read,
   gic_cpu_read,
   gic_cpu_read
};

static CPUWriteMemoryFunc *gic_cpu_writefn[] = {
   gic_cpu_write,
   gic_cpu_write,
   gic_cpu_write
};

static void gic_reset(gic_state *s)
{
    int i;
    memset(s->irq_state, 0, GIC_NIRQ * sizeof(gic_irq_state));
    s->priority_mask = 0xf0;
    s->current_pending = 1023;
    s->running_irq = 1023;
    s->running_priority = 0x100;
    for (i = 0; i < 15; i++) {
        GIC_SET_ENABLED(i);
        GIC_SET_TRIGGER(i);
    }
    s->enabled = 0;
    s->cpu_enabled = 0;
}

qemu_irq *arm_gic_init(uint32_t base, qemu_irq parent_irq)
{
    gic_state *s;
    qemu_irq *qi;
    int iomemtype;

    s = (gic_state *)qemu_mallocz(sizeof(gic_state));
    if (!s)
        return NULL;
    qi = qemu_allocate_irqs(gic_set_irq, s, GIC_NIRQ);
    s->parent_irq = parent_irq;
    if (base != 0xffffffff) {
        iomemtype = cpu_register_io_memory(0, gic_cpu_readfn,
                                           gic_cpu_writefn, s);
        cpu_register_physical_memory(base, 0x00001000, iomemtype);
        iomemtype = cpu_register_io_memory(0, gic_dist_readfn,
                                           gic_dist_writefn, s);
        cpu_register_physical_memory(base + 0x1000, 0x00001000, iomemtype);
        s->base = base;
    } else {
        s->base = 0;
    }
    gic_reset(s);
    return qi;
}