xref: /openbmc/qemu/hw/intc/pl190.c (revision d5938f29)
1 /*
2  * Arm PrimeCell PL190 Vector Interrupt Controller
3  *
4  * Copyright (c) 2006 CodeSourcery.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the GPL.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "hw/irq.h"
12 #include "hw/sysbus.h"
13 #include "migration/vmstate.h"
14 #include "qemu/log.h"
15 #include "qemu/module.h"
16 
17 /* The number of virtual priority levels.  16 user vectors plus the
18    unvectored IRQ.  Chained interrupts would require an additional level
19    if implemented.  */
20 
21 #define PL190_NUM_PRIO 17
22 
23 #define TYPE_PL190 "pl190"
24 #define PL190(obj) OBJECT_CHECK(PL190State, (obj), TYPE_PL190)
25 
26 typedef struct PL190State {
27     SysBusDevice parent_obj;
28 
29     MemoryRegion iomem;
30     uint32_t level;
31     uint32_t soft_level;
32     uint32_t irq_enable;
33     uint32_t fiq_select;
34     uint8_t vect_control[16];
35     uint32_t vect_addr[PL190_NUM_PRIO];
36     /* Mask containing interrupts with higher priority than this one.  */
37     uint32_t prio_mask[PL190_NUM_PRIO + 1];
38     int protected;
39     /* Current priority level.  */
40     int priority;
41     int prev_prio[PL190_NUM_PRIO];
42     qemu_irq irq;
43     qemu_irq fiq;
44 } PL190State;
45 
46 static const unsigned char pl190_id[] =
47 { 0x90, 0x11, 0x04, 0x00, 0x0D, 0xf0, 0x05, 0xb1 };
48 
49 static inline uint32_t pl190_irq_level(PL190State *s)
50 {
51     return (s->level | s->soft_level) & s->irq_enable & ~s->fiq_select;
52 }
53 
54 /* Update interrupts.  */
55 static void pl190_update(PL190State *s)
56 {
57     uint32_t level = pl190_irq_level(s);
58     int set;
59 
60     set = (level & s->prio_mask[s->priority]) != 0;
61     qemu_set_irq(s->irq, set);
62     set = ((s->level | s->soft_level) & s->fiq_select) != 0;
63     qemu_set_irq(s->fiq, set);
64 }
65 
66 static void pl190_set_irq(void *opaque, int irq, int level)
67 {
68     PL190State *s = (PL190State *)opaque;
69 
70     if (level)
71         s->level |= 1u << irq;
72     else
73         s->level &= ~(1u << irq);
74     pl190_update(s);
75 }
76 
77 static void pl190_update_vectors(PL190State *s)
78 {
79     uint32_t mask;
80     int i;
81     int n;
82 
83     mask = 0;
84     for (i = 0; i < 16; i++)
85       {
86         s->prio_mask[i] = mask;
87         if (s->vect_control[i] & 0x20)
88           {
89             n = s->vect_control[i] & 0x1f;
90             mask |= 1 << n;
91           }
92       }
93     s->prio_mask[16] = mask;
94     pl190_update(s);
95 }
96 
97 static uint64_t pl190_read(void *opaque, hwaddr offset,
98                            unsigned size)
99 {
100     PL190State *s = (PL190State *)opaque;
101     int i;
102 
103     if (offset >= 0xfe0 && offset < 0x1000) {
104         return pl190_id[(offset - 0xfe0) >> 2];
105     }
106     if (offset >= 0x100 && offset < 0x140) {
107         return s->vect_addr[(offset - 0x100) >> 2];
108     }
109     if (offset >= 0x200 && offset < 0x240) {
110         return s->vect_control[(offset - 0x200) >> 2];
111     }
112     switch (offset >> 2) {
113     case 0: /* IRQSTATUS */
114         return pl190_irq_level(s);
115     case 1: /* FIQSATUS */
116         return (s->level | s->soft_level) & s->fiq_select;
117     case 2: /* RAWINTR */
118         return s->level | s->soft_level;
119     case 3: /* INTSELECT */
120         return s->fiq_select;
121     case 4: /* INTENABLE */
122         return s->irq_enable;
123     case 6: /* SOFTINT */
124         return s->soft_level;
125     case 8: /* PROTECTION */
126         return s->protected;
127     case 12: /* VECTADDR */
128         /* Read vector address at the start of an ISR.  Increases the
129          * current priority level to that of the current interrupt.
130          *
131          * Since an enabled interrupt X at priority P causes prio_mask[Y]
132          * to have bit X set for all Y > P, this loop will stop with
133          * i == the priority of the highest priority set interrupt.
134          */
135         for (i = 0; i < s->priority; i++) {
136             if ((s->level | s->soft_level) & s->prio_mask[i + 1]) {
137                 break;
138             }
139         }
140 
141         /* Reading this value with no pending interrupts is undefined.
142            We return the default address.  */
143         if (i == PL190_NUM_PRIO)
144           return s->vect_addr[16];
145         if (i < s->priority)
146           {
147             s->prev_prio[i] = s->priority;
148             s->priority = i;
149             pl190_update(s);
150           }
151         return s->vect_addr[s->priority];
152     case 13: /* DEFVECTADDR */
153         return s->vect_addr[16];
154     default:
155         qemu_log_mask(LOG_GUEST_ERROR,
156                       "pl190_read: Bad offset %x\n", (int)offset);
157         return 0;
158     }
159 }
160 
161 static void pl190_write(void *opaque, hwaddr offset,
162                         uint64_t val, unsigned size)
163 {
164     PL190State *s = (PL190State *)opaque;
165 
166     if (offset >= 0x100 && offset < 0x140) {
167         s->vect_addr[(offset - 0x100) >> 2] = val;
168         pl190_update_vectors(s);
169         return;
170     }
171     if (offset >= 0x200 && offset < 0x240) {
172         s->vect_control[(offset - 0x200) >> 2] = val;
173         pl190_update_vectors(s);
174         return;
175     }
176     switch (offset >> 2) {
177     case 0: /* SELECT */
178         /* This is a readonly register, but linux tries to write to it
179            anyway.  Ignore the write.  */
180         break;
181     case 3: /* INTSELECT */
182         s->fiq_select = val;
183         break;
184     case 4: /* INTENABLE */
185         s->irq_enable |= val;
186         break;
187     case 5: /* INTENCLEAR */
188         s->irq_enable &= ~val;
189         break;
190     case 6: /* SOFTINT */
191         s->soft_level |= val;
192         break;
193     case 7: /* SOFTINTCLEAR */
194         s->soft_level &= ~val;
195         break;
196     case 8: /* PROTECTION */
197         /* TODO: Protection (supervisor only access) is not implemented.  */
198         s->protected = val & 1;
199         break;
200     case 12: /* VECTADDR */
201         /* Restore the previous priority level.  The value written is
202            ignored.  */
203         if (s->priority < PL190_NUM_PRIO)
204             s->priority = s->prev_prio[s->priority];
205         break;
206     case 13: /* DEFVECTADDR */
207         s->vect_addr[16] = val;
208         break;
209     case 0xc0: /* ITCR */
210         if (val) {
211             qemu_log_mask(LOG_UNIMP, "pl190: Test mode not implemented\n");
212         }
213         break;
214     default:
215         qemu_log_mask(LOG_GUEST_ERROR,
216                      "pl190_write: Bad offset %x\n", (int)offset);
217         return;
218     }
219     pl190_update(s);
220 }
221 
222 static const MemoryRegionOps pl190_ops = {
223     .read = pl190_read,
224     .write = pl190_write,
225     .endianness = DEVICE_NATIVE_ENDIAN,
226 };
227 
228 static void pl190_reset(DeviceState *d)
229 {
230     PL190State *s = PL190(d);
231     int i;
232 
233     for (i = 0; i < 16; i++) {
234         s->vect_addr[i] = 0;
235         s->vect_control[i] = 0;
236     }
237     s->vect_addr[16] = 0;
238     s->prio_mask[17] = 0xffffffff;
239     s->priority = PL190_NUM_PRIO;
240     pl190_update_vectors(s);
241 }
242 
243 static void pl190_init(Object *obj)
244 {
245     DeviceState *dev = DEVICE(obj);
246     PL190State *s = PL190(obj);
247     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
248 
249     memory_region_init_io(&s->iomem, obj, &pl190_ops, s, "pl190", 0x1000);
250     sysbus_init_mmio(sbd, &s->iomem);
251     qdev_init_gpio_in(dev, pl190_set_irq, 32);
252     sysbus_init_irq(sbd, &s->irq);
253     sysbus_init_irq(sbd, &s->fiq);
254 }
255 
256 static const VMStateDescription vmstate_pl190 = {
257     .name = "pl190",
258     .version_id = 1,
259     .minimum_version_id = 1,
260     .fields = (VMStateField[]) {
261         VMSTATE_UINT32(level, PL190State),
262         VMSTATE_UINT32(soft_level, PL190State),
263         VMSTATE_UINT32(irq_enable, PL190State),
264         VMSTATE_UINT32(fiq_select, PL190State),
265         VMSTATE_UINT8_ARRAY(vect_control, PL190State, 16),
266         VMSTATE_UINT32_ARRAY(vect_addr, PL190State, PL190_NUM_PRIO),
267         VMSTATE_UINT32_ARRAY(prio_mask, PL190State, PL190_NUM_PRIO+1),
268         VMSTATE_INT32(protected, PL190State),
269         VMSTATE_INT32(priority, PL190State),
270         VMSTATE_INT32_ARRAY(prev_prio, PL190State, PL190_NUM_PRIO),
271         VMSTATE_END_OF_LIST()
272     }
273 };
274 
275 static void pl190_class_init(ObjectClass *klass, void *data)
276 {
277     DeviceClass *dc = DEVICE_CLASS(klass);
278 
279     dc->reset = pl190_reset;
280     dc->vmsd = &vmstate_pl190;
281 }
282 
283 static const TypeInfo pl190_info = {
284     .name          = TYPE_PL190,
285     .parent        = TYPE_SYS_BUS_DEVICE,
286     .instance_size = sizeof(PL190State),
287     .instance_init = pl190_init,
288     .class_init    = pl190_class_init,
289 };
290 
291 static void pl190_register_types(void)
292 {
293     type_register_static(&pl190_info);
294 }
295 
296 type_init(pl190_register_types)
297