1 /*
2 * ARM Nested Vectored Interrupt Controller
3 *
4 * Copyright (c) 2006-2007 CodeSourcery.
5 * Written by Paul Brook
6 *
7 * This code is licenced under the GPL.
8 *
9 * The ARMv7M System controller is fairly tightly tied in with the
10 * NVIC. Much of that is also implemented here.
11 */
12
13 #include "hw/sysbus.h"
14 #include "qemu/timer.h"
15 #include "hw/arm/arm.h"
16
17 /* 32 internal lines (16 used for system exceptions) plus 64 external
18 interrupt lines. */
19 #define GIC_NIRQ 96
20 #define NCPU 1
21 #define NVIC 1
22
23 /* Only a single "CPU" interface is present. */
24 static inline int
gic_get_current_cpu(void)25 gic_get_current_cpu(void)
26 {
27 return 0;
28 }
29
30 static uint32_t nvic_readl(void *opaque, uint32_t offset);
31 static void nvic_writel(void *opaque, uint32_t offset, uint32_t value);
32
33 #include "arm_gic.c"
34
35 typedef struct {
36 gic_state gic;
37 struct {
38 uint32_t control;
39 uint32_t reload;
40 int64_t tick;
41 QEMUTimer *timer;
42 } systick;
43 } nvic_state;
44
45 /* qemu timers run at 1GHz. We want something closer to 1MHz. */
46 #define SYSTICK_SCALE 1000ULL
47
48 #define SYSTICK_ENABLE (1 << 0)
49 #define SYSTICK_TICKINT (1 << 1)
50 #define SYSTICK_CLKSOURCE (1 << 2)
51 #define SYSTICK_COUNTFLAG (1 << 16)
52
53 int system_clock_scale;
54
55 /* Conversion factor from qemu timer to SysTick frequencies. */
systick_scale(nvic_state * s)56 static inline int64_t systick_scale(nvic_state *s)
57 {
58 if (s->systick.control & SYSTICK_CLKSOURCE)
59 return system_clock_scale;
60 else
61 return 1000;
62 }
63
systick_reload(nvic_state * s,int reset)64 static void systick_reload(nvic_state *s, int reset)
65 {
66 if (reset)
67 s->systick.tick = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
68 s->systick.tick += (s->systick.reload + 1) * systick_scale(s);
69 timer_mod(s->systick.timer, s->systick.tick);
70 }
71
systick_timer_tick(void * opaque)72 static void systick_timer_tick(void * opaque)
73 {
74 nvic_state *s = (nvic_state *)opaque;
75 s->systick.control |= SYSTICK_COUNTFLAG;
76 if (s->systick.control & SYSTICK_TICKINT) {
77 /* Trigger the interrupt. */
78 armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
79 }
80 if (s->systick.reload == 0) {
81 s->systick.control &= ~SYSTICK_ENABLE;
82 } else {
83 systick_reload(s, 0);
84 }
85 }
86
87 /* The external routines use the hardware vector numbering, ie. the first
88 IRQ is #16. The internal GIC routines use #32 as the first IRQ. */
armv7m_nvic_set_pending(void * opaque,int irq)89 void armv7m_nvic_set_pending(void *opaque, int irq)
90 {
91 nvic_state *s = (nvic_state *)opaque;
92 if (irq >= 16)
93 irq += 16;
94 gic_set_pending_private(&s->gic, 0, irq);
95 }
96
97 /* Make pending IRQ active. */
armv7m_nvic_acknowledge_irq(void * opaque)98 int armv7m_nvic_acknowledge_irq(void *opaque)
99 {
100 nvic_state *s = (nvic_state *)opaque;
101 uint32_t irq;
102
103 irq = gic_acknowledge_irq(&s->gic, 0);
104 if (irq == 1023)
105 hw_error("Interrupt but no vector\n");
106 if (irq >= 32)
107 irq -= 16;
108 return irq;
109 }
110
armv7m_nvic_complete_irq(void * opaque,int irq)111 void armv7m_nvic_complete_irq(void *opaque, int irq)
112 {
113 nvic_state *s = (nvic_state *)opaque;
114 if (irq >= 16)
115 irq += 16;
116 gic_complete_irq(&s->gic, 0, irq);
117 }
118
nvic_readl(void * opaque,uint32_t offset)119 static uint32_t nvic_readl(void *opaque, uint32_t offset)
120 {
121 nvic_state *s = (nvic_state *)opaque;
122 uint32_t val;
123 int irq;
124
125 switch (offset) {
126 case 4: /* Interrupt Control Type. */
127 return (GIC_NIRQ / 32) - 1;
128 case 0x10: /* SysTick Control and Status. */
129 val = s->systick.control;
130 s->systick.control &= ~SYSTICK_COUNTFLAG;
131 return val;
132 case 0x14: /* SysTick Reload Value. */
133 return s->systick.reload;
134 case 0x18: /* SysTick Current Value. */
135 {
136 int64_t t;
137 if ((s->systick.control & SYSTICK_ENABLE) == 0)
138 return 0;
139 t = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
140 if (t >= s->systick.tick)
141 return 0;
142 val = ((s->systick.tick - (t + 1)) / systick_scale(s)) + 1;
143 /* The interrupt in triggered when the timer reaches zero.
144 However the counter is not reloaded until the next clock
145 tick. This is a hack to return zero during the first tick. */
146 if (val > s->systick.reload)
147 val = 0;
148 return val;
149 }
150 case 0x1c: /* SysTick Calibration Value. */
151 return 10000;
152 case 0xd00: /* CPUID Base. */
153 return cpu_single_env->cp15.c0_cpuid;
154 case 0xd04: /* Interrypt Control State. */
155 /* VECTACTIVE */
156 val = s->gic.running_irq[0];
157 if (val == 1023) {
158 val = 0;
159 } else if (val >= 32) {
160 val -= 16;
161 }
162 /* RETTOBASE */
163 if (s->gic.running_irq[0] == 1023
164 || s->gic.last_active[s->gic.running_irq[0]][0] == 1023) {
165 val |= (1 << 11);
166 }
167 /* VECTPENDING */
168 if (s->gic.current_pending[0] != 1023)
169 val |= (s->gic.current_pending[0] << 12);
170 /* ISRPENDING */
171 for (irq = 32; irq < GIC_NIRQ; irq++) {
172 if (s->gic.irq_state[irq].pending) {
173 val |= (1 << 22);
174 break;
175 }
176 }
177 /* PENDSTSET */
178 if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending)
179 val |= (1 << 26);
180 /* PENDSVSET */
181 if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending)
182 val |= (1 << 28);
183 /* NMIPENDSET */
184 if (s->gic.irq_state[ARMV7M_EXCP_NMI].pending)
185 val |= (1 << 31);
186 return val;
187 case 0xd08: /* Vector Table Offset. */
188 return cpu_single_env->v7m.vecbase;
189 case 0xd0c: /* Application Interrupt/Reset Control. */
190 return 0xfa05000;
191 case 0xd10: /* System Control. */
192 /* TODO: Implement SLEEPONEXIT. */
193 return 0;
194 case 0xd14: /* Configuration Control. */
195 /* TODO: Implement Configuration Control bits. */
196 return 0;
197 case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority. */
198 irq = offset - 0xd14;
199 val = 0;
200 val = s->gic.priority1[irq++][0];
201 val = s->gic.priority1[irq++][0] << 8;
202 val = s->gic.priority1[irq++][0] << 16;
203 val = s->gic.priority1[irq][0] << 24;
204 return val;
205 case 0xd24: /* System Handler Status. */
206 val = 0;
207 if (s->gic.irq_state[ARMV7M_EXCP_MEM].active) val |= (1 << 0);
208 if (s->gic.irq_state[ARMV7M_EXCP_BUS].active) val |= (1 << 1);
209 if (s->gic.irq_state[ARMV7M_EXCP_USAGE].active) val |= (1 << 3);
210 if (s->gic.irq_state[ARMV7M_EXCP_SVC].active) val |= (1 << 7);
211 if (s->gic.irq_state[ARMV7M_EXCP_DEBUG].active) val |= (1 << 8);
212 if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].active) val |= (1 << 10);
213 if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].active) val |= (1 << 11);
214 if (s->gic.irq_state[ARMV7M_EXCP_USAGE].pending) val |= (1 << 12);
215 if (s->gic.irq_state[ARMV7M_EXCP_MEM].pending) val |= (1 << 13);
216 if (s->gic.irq_state[ARMV7M_EXCP_BUS].pending) val |= (1 << 14);
217 if (s->gic.irq_state[ARMV7M_EXCP_SVC].pending) val |= (1 << 15);
218 if (s->gic.irq_state[ARMV7M_EXCP_MEM].enabled) val |= (1 << 16);
219 if (s->gic.irq_state[ARMV7M_EXCP_BUS].enabled) val |= (1 << 17);
220 if (s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled) val |= (1 << 18);
221 return val;
222 case 0xd28: /* Configurable Fault Status. */
223 /* TODO: Implement Fault Status. */
224 hw_error("Not implemented: Configurable Fault Status.");
225 return 0;
226 case 0xd2c: /* Hard Fault Status. */
227 case 0xd30: /* Debug Fault Status. */
228 case 0xd34: /* Mem Manage Address. */
229 case 0xd38: /* Bus Fault Address. */
230 case 0xd3c: /* Aux Fault Status. */
231 /* TODO: Implement fault status registers. */
232 goto bad_reg;
233 case 0xd40: /* PFR0. */
234 return 0x00000030;
235 case 0xd44: /* PRF1. */
236 return 0x00000200;
237 case 0xd48: /* DFR0. */
238 return 0x00100000;
239 case 0xd4c: /* AFR0. */
240 return 0x00000000;
241 case 0xd50: /* MMFR0. */
242 return 0x00000030;
243 case 0xd54: /* MMFR1. */
244 return 0x00000000;
245 case 0xd58: /* MMFR2. */
246 return 0x00000000;
247 case 0xd5c: /* MMFR3. */
248 return 0x00000000;
249 case 0xd60: /* ISAR0. */
250 return 0x01141110;
251 case 0xd64: /* ISAR1. */
252 return 0x02111000;
253 case 0xd68: /* ISAR2. */
254 return 0x21112231;
255 case 0xd6c: /* ISAR3. */
256 return 0x01111110;
257 case 0xd70: /* ISAR4. */
258 return 0x01310102;
259 /* TODO: Implement debug registers. */
260 default:
261 bad_reg:
262 hw_error("NVIC: Bad read offset 0x%x\n", offset);
263 }
264 }
265
nvic_writel(void * opaque,uint32_t offset,uint32_t value)266 static void nvic_writel(void *opaque, uint32_t offset, uint32_t value)
267 {
268 nvic_state *s = (nvic_state *)opaque;
269 uint32_t oldval;
270 switch (offset) {
271 case 0x10: /* SysTick Control and Status. */
272 oldval = s->systick.control;
273 s->systick.control &= 0xfffffff8;
274 s->systick.control |= value & 7;
275 if ((oldval ^ value) & SYSTICK_ENABLE) {
276 int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
277 if (value & SYSTICK_ENABLE) {
278 if (s->systick.tick) {
279 s->systick.tick += now;
280 timer_mod(s->systick.timer, s->systick.tick);
281 } else {
282 systick_reload(s, 1);
283 }
284 } else {
285 timer_del(s->systick.timer);
286 s->systick.tick -= now;
287 if (s->systick.tick < 0)
288 s->systick.tick = 0;
289 }
290 } else if ((oldval ^ value) & SYSTICK_CLKSOURCE) {
291 /* This is a hack. Force the timer to be reloaded
292 when the reference clock is changed. */
293 systick_reload(s, 1);
294 }
295 break;
296 case 0x14: /* SysTick Reload Value. */
297 s->systick.reload = value;
298 break;
299 case 0x18: /* SysTick Current Value. Writes reload the timer. */
300 systick_reload(s, 1);
301 s->systick.control &= ~SYSTICK_COUNTFLAG;
302 break;
303 case 0xd04: /* Interrupt Control State. */
304 if (value & (1 << 31)) {
305 armv7m_nvic_set_pending(s, ARMV7M_EXCP_NMI);
306 }
307 if (value & (1 << 28)) {
308 armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV);
309 } else if (value & (1 << 27)) {
310 s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending = 0;
311 gic_update(&s->gic);
312 }
313 if (value & (1 << 26)) {
314 armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
315 } else if (value & (1 << 25)) {
316 s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending = 0;
317 gic_update(&s->gic);
318 }
319 break;
320 case 0xd08: /* Vector Table Offset. */
321 cpu_single_env->v7m.vecbase = value & 0xffffff80;
322 break;
323 case 0xd0c: /* Application Interrupt/Reset Control. */
324 if ((value >> 16) == 0x05fa) {
325 if (value & 2) {
326 hw_error("VECTCLRACTIVE not implemented");
327 }
328 if (value & 5) {
329 hw_error("System reset");
330 }
331 }
332 break;
333 case 0xd10: /* System Control. */
334 case 0xd14: /* Configuration Control. */
335 /* TODO: Implement control registers. */
336 goto bad_reg;
337 case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority. */
338 {
339 int irq;
340 irq = offset - 0xd14;
341 s->gic.priority1[irq++][0] = value & 0xff;
342 s->gic.priority1[irq++][0] = (value >> 8) & 0xff;
343 s->gic.priority1[irq++][0] = (value >> 16) & 0xff;
344 s->gic.priority1[irq][0] = (value >> 24) & 0xff;
345 gic_update(&s->gic);
346 }
347 break;
348 case 0xd24: /* System Handler Control. */
349 /* TODO: Real hardware allows you to set/clear the active bits
350 under some circumstances. We don't implement this. */
351 s->gic.irq_state[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0;
352 s->gic.irq_state[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0;
353 s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0;
354 break;
355 case 0xd28: /* Configurable Fault Status. */
356 case 0xd2c: /* Hard Fault Status. */
357 case 0xd30: /* Debug Fault Status. */
358 case 0xd34: /* Mem Manage Address. */
359 case 0xd38: /* Bus Fault Address. */
360 case 0xd3c: /* Aux Fault Status. */
361 goto bad_reg;
362 default:
363 bad_reg:
364 hw_error("NVIC: Bad write offset 0x%x\n", offset);
365 }
366 }
367
nvic_save(QEMUFile * f,void * opaque)368 static void nvic_save(QEMUFile *f, void *opaque)
369 {
370 nvic_state *s = (nvic_state *)opaque;
371
372 qemu_put_be32(f, s->systick.control);
373 qemu_put_be32(f, s->systick.reload);
374 qemu_put_be64(f, s->systick.tick);
375 timer_put(f, s->systick.timer);
376 }
377
nvic_load(QEMUFile * f,void * opaque,int version_id)378 static int nvic_load(QEMUFile *f, void *opaque, int version_id)
379 {
380 nvic_state *s = (nvic_state *)opaque;
381
382 if (version_id != 1)
383 return -EINVAL;
384
385 s->systick.control = qemu_get_be32(f);
386 s->systick.reload = qemu_get_be32(f);
387 s->systick.tick = qemu_get_be64(f);
388 timer_get(f, s->systick.timer);
389
390 return 0;
391 }
392
armv7m_nvic_init(SysBusDevice * dev)393 static void armv7m_nvic_init(SysBusDevice *dev)
394 {
395 nvic_state *s= FROM_SYSBUSGIC(nvic_state, dev);
396
397 gic_init(&s->gic);
398 cpu_register_physical_memory(0xe000e000, 0x1000, s->gic.iomemtype);
399 s->systick.timer = timer_new(QEMU_CLOCK_VIRTUAL, SCALE_NS, systick_timer_tick, s);
400 register_savevm(NULL, "armv7m_nvic", -1, 1, nvic_save, nvic_load, s);
401 }
402
armv7m_nvic_register_devices(void)403 static void armv7m_nvic_register_devices(void)
404 {
405 sysbus_register_dev("armv7m_nvic", sizeof(nvic_state), armv7m_nvic_init);
406 }
407
408 device_init(armv7m_nvic_register_devices)
409