xref: /openbmc/qemu/hw/intc/pl190.c (revision 40d6ee94)
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/sysbus.h"
12 #include "qemu/log.h"
13 
14 /* The number of virtual priority levels.  16 user vectors plus the
15    unvectored IRQ.  Chained interrupts would require an additional level
16    if implemented.  */
17 
18 #define PL190_NUM_PRIO 17
19 
20 #define TYPE_PL190 "pl190"
21 #define PL190(obj) OBJECT_CHECK(PL190State, (obj), TYPE_PL190)
22 
23 typedef struct PL190State {
24     SysBusDevice parent_obj;
25 
26     MemoryRegion iomem;
27     uint32_t level;
28     uint32_t soft_level;
29     uint32_t irq_enable;
30     uint32_t fiq_select;
31     uint8_t vect_control[16];
32     uint32_t vect_addr[PL190_NUM_PRIO];
33     /* Mask containing interrupts with higher priority than this one.  */
34     uint32_t prio_mask[PL190_NUM_PRIO + 1];
35     int protected;
36     /* Current priority level.  */
37     int priority;
38     int prev_prio[PL190_NUM_PRIO];
39     qemu_irq irq;
40     qemu_irq fiq;
41 } PL190State;
42 
43 static const unsigned char pl190_id[] =
44 { 0x90, 0x11, 0x04, 0x00, 0x0D, 0xf0, 0x05, 0xb1 };
45 
46 static inline uint32_t pl190_irq_level(PL190State *s)
47 {
48     return (s->level | s->soft_level) & s->irq_enable & ~s->fiq_select;
49 }
50 
51 /* Update interrupts.  */
52 static void pl190_update(PL190State *s)
53 {
54     uint32_t level = pl190_irq_level(s);
55     int set;
56 
57     set = (level & s->prio_mask[s->priority]) != 0;
58     qemu_set_irq(s->irq, set);
59     set = ((s->level | s->soft_level) & s->fiq_select) != 0;
60     qemu_set_irq(s->fiq, set);
61 }
62 
63 static void pl190_set_irq(void *opaque, int irq, int level)
64 {
65     PL190State *s = (PL190State *)opaque;
66 
67     if (level)
68         s->level |= 1u << irq;
69     else
70         s->level &= ~(1u << irq);
71     pl190_update(s);
72 }
73 
74 static void pl190_update_vectors(PL190State *s)
75 {
76     uint32_t mask;
77     int i;
78     int n;
79 
80     mask = 0;
81     for (i = 0; i < 16; i++)
82       {
83         s->prio_mask[i] = mask;
84         if (s->vect_control[i] & 0x20)
85           {
86             n = s->vect_control[i] & 0x1f;
87             mask |= 1 << n;
88           }
89       }
90     s->prio_mask[16] = mask;
91     pl190_update(s);
92 }
93 
94 static uint64_t pl190_read(void *opaque, hwaddr offset,
95                            unsigned size)
96 {
97     PL190State *s = (PL190State *)opaque;
98     int i;
99 
100     if (offset >= 0xfe0 && offset < 0x1000) {
101         return pl190_id[(offset - 0xfe0) >> 2];
102     }
103     if (offset >= 0x100 && offset < 0x140) {
104         return s->vect_addr[(offset - 0x100) >> 2];
105     }
106     if (offset >= 0x200 && offset < 0x240) {
107         return s->vect_control[(offset - 0x200) >> 2];
108     }
109     switch (offset >> 2) {
110     case 0: /* IRQSTATUS */
111         return pl190_irq_level(s);
112     case 1: /* FIQSATUS */
113         return (s->level | s->soft_level) & s->fiq_select;
114     case 2: /* RAWINTR */
115         return s->level | s->soft_level;
116     case 3: /* INTSELECT */
117         return s->fiq_select;
118     case 4: /* INTENABLE */
119         return s->irq_enable;
120     case 6: /* SOFTINT */
121         return s->soft_level;
122     case 8: /* PROTECTION */
123         return s->protected;
124     case 12: /* VECTADDR */
125         /* Read vector address at the start of an ISR.  Increases the
126          * current priority level to that of the current interrupt.
127          *
128          * Since an enabled interrupt X at priority P causes prio_mask[Y]
129          * to have bit X set for all Y > P, this loop will stop with
130          * i == the priority of the highest priority set interrupt.
131          */
132         for (i = 0; i < s->priority; i++) {
133             if ((s->level | s->soft_level) & s->prio_mask[i + 1]) {
134                 break;
135             }
136         }
137 
138         /* Reading this value with no pending interrupts is undefined.
139            We return the default address.  */
140         if (i == PL190_NUM_PRIO)
141           return s->vect_addr[16];
142         if (i < s->priority)
143           {
144             s->prev_prio[i] = s->priority;
145             s->priority = i;
146             pl190_update(s);
147           }
148         return s->vect_addr[s->priority];
149     case 13: /* DEFVECTADDR */
150         return s->vect_addr[16];
151     default:
152         qemu_log_mask(LOG_GUEST_ERROR,
153                       "pl190_read: Bad offset %x\n", (int)offset);
154         return 0;
155     }
156 }
157 
158 static void pl190_write(void *opaque, hwaddr offset,
159                         uint64_t val, unsigned size)
160 {
161     PL190State *s = (PL190State *)opaque;
162 
163     if (offset >= 0x100 && offset < 0x140) {
164         s->vect_addr[(offset - 0x100) >> 2] = val;
165         pl190_update_vectors(s);
166         return;
167     }
168     if (offset >= 0x200 && offset < 0x240) {
169         s->vect_control[(offset - 0x200) >> 2] = val;
170         pl190_update_vectors(s);
171         return;
172     }
173     switch (offset >> 2) {
174     case 0: /* SELECT */
175         /* This is a readonly register, but linux tries to write to it
176            anyway.  Ignore the write.  */
177         break;
178     case 3: /* INTSELECT */
179         s->fiq_select = val;
180         break;
181     case 4: /* INTENABLE */
182         s->irq_enable |= val;
183         break;
184     case 5: /* INTENCLEAR */
185         s->irq_enable &= ~val;
186         break;
187     case 6: /* SOFTINT */
188         s->soft_level |= val;
189         break;
190     case 7: /* SOFTINTCLEAR */
191         s->soft_level &= ~val;
192         break;
193     case 8: /* PROTECTION */
194         /* TODO: Protection (supervisor only access) is not implemented.  */
195         s->protected = val & 1;
196         break;
197     case 12: /* VECTADDR */
198         /* Restore the previous priority level.  The value written is
199            ignored.  */
200         if (s->priority < PL190_NUM_PRIO)
201             s->priority = s->prev_prio[s->priority];
202         break;
203     case 13: /* DEFVECTADDR */
204         s->vect_addr[16] = val;
205         break;
206     case 0xc0: /* ITCR */
207         if (val) {
208             qemu_log_mask(LOG_UNIMP, "pl190: Test mode not implemented\n");
209         }
210         break;
211     default:
212         qemu_log_mask(LOG_GUEST_ERROR,
213                      "pl190_write: Bad offset %x\n", (int)offset);
214         return;
215     }
216     pl190_update(s);
217 }
218 
219 static const MemoryRegionOps pl190_ops = {
220     .read = pl190_read,
221     .write = pl190_write,
222     .endianness = DEVICE_NATIVE_ENDIAN,
223 };
224 
225 static void pl190_reset(DeviceState *d)
226 {
227     PL190State *s = PL190(d);
228     int i;
229 
230     for (i = 0; i < 16; i++) {
231         s->vect_addr[i] = 0;
232         s->vect_control[i] = 0;
233     }
234     s->vect_addr[16] = 0;
235     s->prio_mask[17] = 0xffffffff;
236     s->priority = PL190_NUM_PRIO;
237     pl190_update_vectors(s);
238 }
239 
240 static void pl190_init(Object *obj)
241 {
242     DeviceState *dev = DEVICE(obj);
243     PL190State *s = PL190(obj);
244     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
245 
246     memory_region_init_io(&s->iomem, obj, &pl190_ops, s, "pl190", 0x1000);
247     sysbus_init_mmio(sbd, &s->iomem);
248     qdev_init_gpio_in(dev, pl190_set_irq, 32);
249     sysbus_init_irq(sbd, &s->irq);
250     sysbus_init_irq(sbd, &s->fiq);
251 }
252 
253 static const VMStateDescription vmstate_pl190 = {
254     .name = "pl190",
255     .version_id = 1,
256     .minimum_version_id = 1,
257     .fields = (VMStateField[]) {
258         VMSTATE_UINT32(level, PL190State),
259         VMSTATE_UINT32(soft_level, PL190State),
260         VMSTATE_UINT32(irq_enable, PL190State),
261         VMSTATE_UINT32(fiq_select, PL190State),
262         VMSTATE_UINT8_ARRAY(vect_control, PL190State, 16),
263         VMSTATE_UINT32_ARRAY(vect_addr, PL190State, PL190_NUM_PRIO),
264         VMSTATE_UINT32_ARRAY(prio_mask, PL190State, PL190_NUM_PRIO+1),
265         VMSTATE_INT32(protected, PL190State),
266         VMSTATE_INT32(priority, PL190State),
267         VMSTATE_INT32_ARRAY(prev_prio, PL190State, PL190_NUM_PRIO),
268         VMSTATE_END_OF_LIST()
269     }
270 };
271 
272 static void pl190_class_init(ObjectClass *klass, void *data)
273 {
274     DeviceClass *dc = DEVICE_CLASS(klass);
275 
276     dc->reset = pl190_reset;
277     dc->vmsd = &vmstate_pl190;
278 }
279 
280 static const TypeInfo pl190_info = {
281     .name          = TYPE_PL190,
282     .parent        = TYPE_SYS_BUS_DEVICE,
283     .instance_size = sizeof(PL190State),
284     .instance_init = pl190_init,
285     .class_init    = pl190_class_init,
286 };
287 
288 static void pl190_register_types(void)
289 {
290     type_register_static(&pl190_info);
291 }
292 
293 type_init(pl190_register_types)
294