xref: /openbmc/qemu/hw/intc/riscv_aclint.c (revision 142518bd)
1 /*
2  * RISC-V ACLINT (Advanced Core Local Interruptor)
3  * URL: https://github.com/riscv/riscv-aclint
4  *
5  * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
6  * Copyright (c) 2017 SiFive, Inc.
7  * Copyright (c) 2021 Western Digital Corporation or its affiliates.
8  *
9  * This provides real-time clock, timer and interprocessor interrupts.
10  *
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms and conditions of the GNU General Public License,
13  * version 2 or later, as published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope it will be useful, but WITHOUT
16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
18  * more details.
19  *
20  * You should have received a copy of the GNU General Public License along with
21  * this program.  If not, see <http://www.gnu.org/licenses/>.
22  */
23 
24 #include "qemu/osdep.h"
25 #include "qapi/error.h"
26 #include "qemu/error-report.h"
27 #include "qemu/log.h"
28 #include "qemu/module.h"
29 #include "hw/sysbus.h"
30 #include "target/riscv/cpu.h"
31 #include "hw/qdev-properties.h"
32 #include "hw/intc/riscv_aclint.h"
33 #include "qemu/timer.h"
34 #include "hw/irq.h"
35 
36 typedef struct riscv_aclint_mtimer_callback {
37     RISCVAclintMTimerState *s;
38     int num;
39 } riscv_aclint_mtimer_callback;
40 
41 static uint64_t cpu_riscv_read_rtc(uint32_t timebase_freq)
42 {
43     return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
44         timebase_freq, NANOSECONDS_PER_SECOND);
45 }
46 
47 /*
48  * Called when timecmp is written to update the QEMU timer or immediately
49  * trigger timer interrupt if mtimecmp <= current timer value.
50  */
51 static void riscv_aclint_mtimer_write_timecmp(RISCVAclintMTimerState *mtimer,
52                                               RISCVCPU *cpu,
53                                               int hartid,
54                                               uint64_t value,
55                                               uint32_t timebase_freq)
56 {
57     uint64_t next;
58     uint64_t diff;
59 
60     uint64_t rtc_r = cpu_riscv_read_rtc(timebase_freq);
61 
62     cpu->env.timecmp = value;
63     if (cpu->env.timecmp <= rtc_r) {
64         /*
65          * If we're setting an MTIMECMP value in the "past",
66          * immediately raise the timer interrupt
67          */
68         qemu_irq_raise(mtimer->timer_irqs[hartid - mtimer->hartid_base]);
69         return;
70     }
71 
72     /* otherwise, set up the future timer interrupt */
73     qemu_irq_lower(mtimer->timer_irqs[hartid - mtimer->hartid_base]);
74     diff = cpu->env.timecmp - rtc_r;
75     /* back to ns (note args switched in muldiv64) */
76     uint64_t ns_diff = muldiv64(diff, NANOSECONDS_PER_SECOND, timebase_freq);
77 
78     /*
79      * check if ns_diff overflowed and check if the addition would potentially
80      * overflow
81      */
82     if ((NANOSECONDS_PER_SECOND > timebase_freq && ns_diff < diff) ||
83         ns_diff > INT64_MAX) {
84         next = INT64_MAX;
85     } else {
86         /*
87          * as it is very unlikely qemu_clock_get_ns will return a value
88          * greater than INT64_MAX, no additional check is needed for an
89          * unsigned integer overflow.
90          */
91         next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ns_diff;
92         /*
93          * if ns_diff is INT64_MAX next may still be outside the range
94          * of a signed integer.
95          */
96         next = MIN(next, INT64_MAX);
97     }
98 
99     timer_mod(cpu->env.timer, next);
100 }
101 
102 /*
103  * Callback used when the timer set using timer_mod expires.
104  * Should raise the timer interrupt line
105  */
106 static void riscv_aclint_mtimer_cb(void *opaque)
107 {
108     riscv_aclint_mtimer_callback *state = opaque;
109 
110     qemu_irq_raise(state->s->timer_irqs[state->num]);
111 }
112 
113 /* CPU read MTIMER register */
114 static uint64_t riscv_aclint_mtimer_read(void *opaque, hwaddr addr,
115     unsigned size)
116 {
117     RISCVAclintMTimerState *mtimer = opaque;
118 
119     if (addr >= mtimer->timecmp_base &&
120         addr < (mtimer->timecmp_base + (mtimer->num_harts << 3))) {
121         size_t hartid = mtimer->hartid_base +
122                         ((addr - mtimer->timecmp_base) >> 3);
123         CPUState *cpu = qemu_get_cpu(hartid);
124         CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
125         if (!env) {
126             qemu_log_mask(LOG_GUEST_ERROR,
127                           "aclint-mtimer: invalid hartid: %zu", hartid);
128         } else if ((addr & 0x7) == 0) {
129             /* timecmp_lo */
130             uint64_t timecmp = env->timecmp;
131             return timecmp & 0xFFFFFFFF;
132         } else if ((addr & 0x7) == 4) {
133             /* timecmp_hi */
134             uint64_t timecmp = env->timecmp;
135             return (timecmp >> 32) & 0xFFFFFFFF;
136         } else {
137             qemu_log_mask(LOG_UNIMP,
138                           "aclint-mtimer: invalid read: %08x", (uint32_t)addr);
139             return 0;
140         }
141     } else if (addr == mtimer->time_base) {
142         /* time_lo */
143         return cpu_riscv_read_rtc(mtimer->timebase_freq) & 0xFFFFFFFF;
144     } else if (addr == mtimer->time_base + 4) {
145         /* time_hi */
146         return (cpu_riscv_read_rtc(mtimer->timebase_freq) >> 32) & 0xFFFFFFFF;
147     }
148 
149     qemu_log_mask(LOG_UNIMP,
150                   "aclint-mtimer: invalid read: %08x", (uint32_t)addr);
151     return 0;
152 }
153 
154 /* CPU write MTIMER register */
155 static void riscv_aclint_mtimer_write(void *opaque, hwaddr addr,
156     uint64_t value, unsigned size)
157 {
158     RISCVAclintMTimerState *mtimer = opaque;
159 
160     if (addr >= mtimer->timecmp_base &&
161         addr < (mtimer->timecmp_base + (mtimer->num_harts << 3))) {
162         size_t hartid = mtimer->hartid_base +
163                         ((addr - mtimer->timecmp_base) >> 3);
164         CPUState *cpu = qemu_get_cpu(hartid);
165         CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
166         if (!env) {
167             qemu_log_mask(LOG_GUEST_ERROR,
168                           "aclint-mtimer: invalid hartid: %zu", hartid);
169         } else if ((addr & 0x7) == 0) {
170             /* timecmp_lo */
171             uint64_t timecmp_hi = env->timecmp >> 32;
172             riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid,
173                 timecmp_hi << 32 | (value & 0xFFFFFFFF),
174                 mtimer->timebase_freq);
175             return;
176         } else if ((addr & 0x7) == 4) {
177             /* timecmp_hi */
178             uint64_t timecmp_lo = env->timecmp;
179             riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid,
180                 value << 32 | (timecmp_lo & 0xFFFFFFFF),
181                 mtimer->timebase_freq);
182         } else {
183             qemu_log_mask(LOG_UNIMP,
184                           "aclint-mtimer: invalid timecmp write: %08x",
185                           (uint32_t)addr);
186         }
187         return;
188     } else if (addr == mtimer->time_base) {
189         /* time_lo */
190         qemu_log_mask(LOG_UNIMP,
191                       "aclint-mtimer: time_lo write not implemented");
192         return;
193     } else if (addr == mtimer->time_base + 4) {
194         /* time_hi */
195         qemu_log_mask(LOG_UNIMP,
196                       "aclint-mtimer: time_hi write not implemented");
197         return;
198     }
199 
200     qemu_log_mask(LOG_UNIMP,
201                   "aclint-mtimer: invalid write: %08x", (uint32_t)addr);
202 }
203 
204 static const MemoryRegionOps riscv_aclint_mtimer_ops = {
205     .read = riscv_aclint_mtimer_read,
206     .write = riscv_aclint_mtimer_write,
207     .endianness = DEVICE_LITTLE_ENDIAN,
208     .valid = {
209         .min_access_size = 4,
210         .max_access_size = 8
211     }
212 };
213 
214 static Property riscv_aclint_mtimer_properties[] = {
215     DEFINE_PROP_UINT32("hartid-base", RISCVAclintMTimerState,
216         hartid_base, 0),
217     DEFINE_PROP_UINT32("num-harts", RISCVAclintMTimerState, num_harts, 1),
218     DEFINE_PROP_UINT32("timecmp-base", RISCVAclintMTimerState,
219         timecmp_base, RISCV_ACLINT_DEFAULT_MTIMECMP),
220     DEFINE_PROP_UINT32("time-base", RISCVAclintMTimerState,
221         time_base, RISCV_ACLINT_DEFAULT_MTIME),
222     DEFINE_PROP_UINT32("aperture-size", RISCVAclintMTimerState,
223         aperture_size, RISCV_ACLINT_DEFAULT_MTIMER_SIZE),
224     DEFINE_PROP_UINT32("timebase-freq", RISCVAclintMTimerState,
225         timebase_freq, 0),
226     DEFINE_PROP_END_OF_LIST(),
227 };
228 
229 static void riscv_aclint_mtimer_realize(DeviceState *dev, Error **errp)
230 {
231     RISCVAclintMTimerState *s = RISCV_ACLINT_MTIMER(dev);
232     int i;
233 
234     memory_region_init_io(&s->mmio, OBJECT(dev), &riscv_aclint_mtimer_ops,
235                           s, TYPE_RISCV_ACLINT_MTIMER, s->aperture_size);
236     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
237 
238     s->timer_irqs = g_malloc(sizeof(qemu_irq) * s->num_harts);
239     qdev_init_gpio_out(dev, s->timer_irqs, s->num_harts);
240 
241     /* Claim timer interrupt bits */
242     for (i = 0; i < s->num_harts; i++) {
243         RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(s->hartid_base + i));
244         if (riscv_cpu_claim_interrupts(cpu, MIP_MTIP) < 0) {
245             error_report("MTIP already claimed");
246             exit(1);
247         }
248     }
249 }
250 
251 static void riscv_aclint_mtimer_class_init(ObjectClass *klass, void *data)
252 {
253     DeviceClass *dc = DEVICE_CLASS(klass);
254     dc->realize = riscv_aclint_mtimer_realize;
255     device_class_set_props(dc, riscv_aclint_mtimer_properties);
256 }
257 
258 static const TypeInfo riscv_aclint_mtimer_info = {
259     .name          = TYPE_RISCV_ACLINT_MTIMER,
260     .parent        = TYPE_SYS_BUS_DEVICE,
261     .instance_size = sizeof(RISCVAclintMTimerState),
262     .class_init    = riscv_aclint_mtimer_class_init,
263 };
264 
265 /*
266  * Create ACLINT MTIMER device.
267  */
268 DeviceState *riscv_aclint_mtimer_create(hwaddr addr, hwaddr size,
269     uint32_t hartid_base, uint32_t num_harts,
270     uint32_t timecmp_base, uint32_t time_base, uint32_t timebase_freq,
271     bool provide_rdtime)
272 {
273     int i;
274     DeviceState *dev = qdev_new(TYPE_RISCV_ACLINT_MTIMER);
275 
276     assert(num_harts <= RISCV_ACLINT_MAX_HARTS);
277     assert(!(addr & 0x7));
278     assert(!(timecmp_base & 0x7));
279     assert(!(time_base & 0x7));
280 
281     qdev_prop_set_uint32(dev, "hartid-base", hartid_base);
282     qdev_prop_set_uint32(dev, "num-harts", num_harts);
283     qdev_prop_set_uint32(dev, "timecmp-base", timecmp_base);
284     qdev_prop_set_uint32(dev, "time-base", time_base);
285     qdev_prop_set_uint32(dev, "aperture-size", size);
286     qdev_prop_set_uint32(dev, "timebase-freq", timebase_freq);
287     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
288     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
289 
290     for (i = 0; i < num_harts; i++) {
291         CPUState *cpu = qemu_get_cpu(hartid_base + i);
292         RISCVCPU *rvcpu = RISCV_CPU(cpu);
293         CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
294         riscv_aclint_mtimer_callback *cb =
295             g_malloc0(sizeof(riscv_aclint_mtimer_callback));
296 
297         if (!env) {
298             g_free(cb);
299             continue;
300         }
301         if (provide_rdtime) {
302             riscv_cpu_set_rdtime_fn(env, cpu_riscv_read_rtc, timebase_freq);
303         }
304 
305         cb->s = RISCV_ACLINT_MTIMER(dev);
306         cb->num = i;
307         env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
308                                   &riscv_aclint_mtimer_cb, cb);
309         env->timecmp = 0;
310 
311         qdev_connect_gpio_out(dev, i,
312                               qdev_get_gpio_in(DEVICE(rvcpu), IRQ_M_TIMER));
313     }
314 
315     return dev;
316 }
317 
318 /* CPU read [M|S]SWI register */
319 static uint64_t riscv_aclint_swi_read(void *opaque, hwaddr addr,
320     unsigned size)
321 {
322     RISCVAclintSwiState *swi = opaque;
323 
324     if (addr < (swi->num_harts << 2)) {
325         size_t hartid = swi->hartid_base + (addr >> 2);
326         CPUState *cpu = qemu_get_cpu(hartid);
327         CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
328         if (!env) {
329             qemu_log_mask(LOG_GUEST_ERROR,
330                           "aclint-swi: invalid hartid: %zu", hartid);
331         } else if ((addr & 0x3) == 0) {
332             return (swi->sswi) ? 0 : ((env->mip & MIP_MSIP) > 0);
333         }
334     }
335 
336     qemu_log_mask(LOG_UNIMP,
337                   "aclint-swi: invalid read: %08x", (uint32_t)addr);
338     return 0;
339 }
340 
341 /* CPU write [M|S]SWI register */
342 static void riscv_aclint_swi_write(void *opaque, hwaddr addr, uint64_t value,
343         unsigned size)
344 {
345     RISCVAclintSwiState *swi = opaque;
346 
347     if (addr < (swi->num_harts << 2)) {
348         size_t hartid = swi->hartid_base + (addr >> 2);
349         CPUState *cpu = qemu_get_cpu(hartid);
350         CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
351         if (!env) {
352             qemu_log_mask(LOG_GUEST_ERROR,
353                           "aclint-swi: invalid hartid: %zu", hartid);
354         } else if ((addr & 0x3) == 0) {
355             if (value & 0x1) {
356                 qemu_irq_raise(swi->soft_irqs[hartid - swi->hartid_base]);
357             } else {
358                 if (!swi->sswi) {
359                     qemu_irq_lower(swi->soft_irqs[hartid - swi->hartid_base]);
360                 }
361             }
362             return;
363         }
364     }
365 
366     qemu_log_mask(LOG_UNIMP,
367                   "aclint-swi: invalid write: %08x", (uint32_t)addr);
368 }
369 
370 static const MemoryRegionOps riscv_aclint_swi_ops = {
371     .read = riscv_aclint_swi_read,
372     .write = riscv_aclint_swi_write,
373     .endianness = DEVICE_LITTLE_ENDIAN,
374     .valid = {
375         .min_access_size = 4,
376         .max_access_size = 4
377     }
378 };
379 
380 static Property riscv_aclint_swi_properties[] = {
381     DEFINE_PROP_UINT32("hartid-base", RISCVAclintSwiState, hartid_base, 0),
382     DEFINE_PROP_UINT32("num-harts", RISCVAclintSwiState, num_harts, 1),
383     DEFINE_PROP_UINT32("sswi", RISCVAclintSwiState, sswi, false),
384     DEFINE_PROP_END_OF_LIST(),
385 };
386 
387 static void riscv_aclint_swi_realize(DeviceState *dev, Error **errp)
388 {
389     RISCVAclintSwiState *swi = RISCV_ACLINT_SWI(dev);
390     int i;
391 
392     memory_region_init_io(&swi->mmio, OBJECT(dev), &riscv_aclint_swi_ops, swi,
393                           TYPE_RISCV_ACLINT_SWI, RISCV_ACLINT_SWI_SIZE);
394     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &swi->mmio);
395 
396     swi->soft_irqs = g_malloc(sizeof(qemu_irq) * swi->num_harts);
397     qdev_init_gpio_out(dev, swi->soft_irqs, swi->num_harts);
398 
399     /* Claim software interrupt bits */
400     for (i = 0; i < swi->num_harts; i++) {
401         RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(swi->hartid_base + i));
402         /* We don't claim mip.SSIP because it is writeable by software */
403         if (riscv_cpu_claim_interrupts(cpu, swi->sswi ? 0 : MIP_MSIP) < 0) {
404             error_report("MSIP already claimed");
405             exit(1);
406         }
407     }
408 }
409 
410 static void riscv_aclint_swi_class_init(ObjectClass *klass, void *data)
411 {
412     DeviceClass *dc = DEVICE_CLASS(klass);
413     dc->realize = riscv_aclint_swi_realize;
414     device_class_set_props(dc, riscv_aclint_swi_properties);
415 }
416 
417 static const TypeInfo riscv_aclint_swi_info = {
418     .name          = TYPE_RISCV_ACLINT_SWI,
419     .parent        = TYPE_SYS_BUS_DEVICE,
420     .instance_size = sizeof(RISCVAclintSwiState),
421     .class_init    = riscv_aclint_swi_class_init,
422 };
423 
424 /*
425  * Create ACLINT [M|S]SWI device.
426  */
427 DeviceState *riscv_aclint_swi_create(hwaddr addr, uint32_t hartid_base,
428     uint32_t num_harts, bool sswi)
429 {
430     int i;
431     DeviceState *dev = qdev_new(TYPE_RISCV_ACLINT_SWI);
432 
433     assert(num_harts <= RISCV_ACLINT_MAX_HARTS);
434     assert(!(addr & 0x3));
435 
436     qdev_prop_set_uint32(dev, "hartid-base", hartid_base);
437     qdev_prop_set_uint32(dev, "num-harts", num_harts);
438     qdev_prop_set_uint32(dev, "sswi", sswi ? true : false);
439     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
440     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
441 
442     for (i = 0; i < num_harts; i++) {
443         CPUState *cpu = qemu_get_cpu(hartid_base + i);
444         RISCVCPU *rvcpu = RISCV_CPU(cpu);
445 
446         qdev_connect_gpio_out(dev, i,
447                               qdev_get_gpio_in(DEVICE(rvcpu),
448                                   (sswi) ? IRQ_S_SOFT : IRQ_M_SOFT));
449     }
450 
451     return dev;
452 }
453 
454 static void riscv_aclint_register_types(void)
455 {
456     type_register_static(&riscv_aclint_mtimer_info);
457     type_register_static(&riscv_aclint_swi_info);
458 }
459 
460 type_init(riscv_aclint_register_types)
461