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1 | /* | |
2 | * SiFive CLINT (Core Local Interruptor) | |
3 | * | |
4 | * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu | |
5 | * Copyright (c) 2017 SiFive, Inc. | |
6 | * | |
7 | * This provides real-time clock, timer and interprocessor interrupts. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms and conditions of the GNU General Public License, | |
11 | * version 2 or later, as published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope it will be useful, but WITHOUT | |
14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
16 | * more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License along with | |
19 | * this program. If not, see <http://www.gnu.org/licenses/>. | |
20 | */ | |
21 | ||
22 | #include "qemu/osdep.h" | |
23 | #include "qapi/error.h" | |
24 | #include "qemu/error-report.h" | |
25 | #include "qemu/module.h" | |
26 | #include "hw/sysbus.h" | |
27 | #include "target/riscv/cpu.h" | |
28 | #include "hw/qdev-properties.h" | |
29 | #include "hw/intc/riscv_aclint.h" | |
30 | #include "qemu/timer.h" | |
31 | #include "hw/irq.h" | |
32 | ||
33 | typedef struct sifive_clint_callback { | |
34 | SiFiveCLINTState *s; | |
35 | int num; | |
36 | } sifive_clint_callback; | |
37 | ||
38 | static uint64_t cpu_riscv_read_rtc(uint32_t timebase_freq) | |
39 | { | |
40 | return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), | |
41 | timebase_freq, NANOSECONDS_PER_SECOND); | |
42 | } | |
43 | ||
44 | /* | |
45 | * Called when timecmp is written to update the QEMU timer or immediately | |
46 | * trigger timer interrupt if mtimecmp <= current timer value. | |
47 | */ | |
48 | static void sifive_clint_write_timecmp(SiFiveCLINTState *s, RISCVCPU *cpu, | |
49 | int hartid, | |
50 | uint64_t value, | |
51 | uint32_t timebase_freq) | |
52 | { | |
53 | uint64_t next; | |
54 | uint64_t diff; | |
55 | ||
56 | uint64_t rtc_r = cpu_riscv_read_rtc(timebase_freq); | |
57 | ||
58 | cpu->env.timecmp = value; | |
59 | if (cpu->env.timecmp <= rtc_r) { | |
60 | /* if we're setting an MTIMECMP value in the "past", | |
61 | immediately raise the timer interrupt */ | |
62 | qemu_irq_raise(s->timer_irqs[hartid - s->hartid_base]); | |
63 | return; | |
64 | } | |
65 | ||
66 | /* otherwise, set up the future timer interrupt */ | |
67 | qemu_irq_lower(s->timer_irqs[hartid - s->hartid_base]); | |
68 | diff = cpu->env.timecmp - rtc_r; | |
69 | /* back to ns (note args switched in muldiv64) */ | |
70 | uint64_t ns_diff = muldiv64(diff, NANOSECONDS_PER_SECOND, timebase_freq); | |
71 | ||
72 | /* | |
73 | * check if ns_diff overflowed and check if the addition would potentially | |
74 | * overflow | |
75 | */ | |
76 | if ((NANOSECONDS_PER_SECOND > timebase_freq && ns_diff < diff) || | |
77 | ns_diff > INT64_MAX) { | |
78 | next = INT64_MAX; | |
79 | } else { | |
80 | /* | |
81 | * as it is very unlikely qemu_clock_get_ns will return a value | |
82 | * greater than INT64_MAX, no additional check is needed for an | |
83 | * unsigned integer overflow. | |
84 | */ | |
85 | next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ns_diff; | |
86 | /* | |
87 | * if ns_diff is INT64_MAX next may still be outside the range | |
88 | * of a signed integer. | |
89 | */ | |
90 | next = MIN(next, INT64_MAX); | |
91 | } | |
92 | ||
93 | timer_mod(cpu->env.timer, next); | |
94 | } | |
95 | ||
96 | /* | |
97 | * Callback used when the timer set using timer_mod expires. | |
98 | * Should raise the timer interrupt line | |
99 | */ | |
100 | static void sifive_clint_timer_cb(void *opaque) | |
101 | { | |
102 | sifive_clint_callback *state = opaque; | |
103 | ||
104 | qemu_irq_raise(state->s->timer_irqs[state->num]); | |
105 | } | |
106 | ||
107 | /* CPU wants to read rtc or timecmp register */ | |
108 | static uint64_t sifive_clint_read(void *opaque, hwaddr addr, unsigned size) | |
109 | { | |
110 | SiFiveCLINTState *clint = opaque; | |
111 | if (addr >= clint->sip_base && | |
112 | addr < clint->sip_base + (clint->num_harts << 2)) { | |
113 | size_t hartid = clint->hartid_base + ((addr - clint->sip_base) >> 2); | |
114 | CPUState *cpu = qemu_get_cpu(hartid); | |
115 | CPURISCVState *env = cpu ? cpu->env_ptr : NULL; | |
116 | if (!env) { | |
117 | error_report("clint: invalid timecmp hartid: %zu", hartid); | |
118 | } else if ((addr & 0x3) == 0) { | |
119 | return (env->mip & MIP_MSIP) > 0; | |
120 | } else { | |
121 | error_report("clint: invalid read: %08x", (uint32_t)addr); | |
122 | return 0; | |
123 | } | |
124 | } else if (addr >= clint->timecmp_base && | |
125 | addr < clint->timecmp_base + (clint->num_harts << 3)) { | |
126 | size_t hartid = clint->hartid_base + | |
127 | ((addr - clint->timecmp_base) >> 3); | |
128 | CPUState *cpu = qemu_get_cpu(hartid); | |
129 | CPURISCVState *env = cpu ? cpu->env_ptr : NULL; | |
130 | if (!env) { | |
131 | error_report("clint: invalid timecmp hartid: %zu", hartid); | |
132 | } else if ((addr & 0x7) == 0) { | |
133 | /* timecmp_lo */ | |
134 | uint64_t timecmp = env->timecmp; | |
135 | return timecmp & 0xFFFFFFFF; | |
136 | } else if ((addr & 0x7) == 4) { | |
137 | /* timecmp_hi */ | |
138 | uint64_t timecmp = env->timecmp; | |
139 | return (timecmp >> 32) & 0xFFFFFFFF; | |
140 | } else { | |
141 | error_report("clint: invalid read: %08x", (uint32_t)addr); | |
142 | return 0; | |
143 | } | |
144 | } else if (addr == clint->time_base) { | |
145 | /* time_lo */ | |
146 | return cpu_riscv_read_rtc(clint->timebase_freq) & 0xFFFFFFFF; | |
147 | } else if (addr == clint->time_base + 4) { | |
148 | /* time_hi */ | |
149 | return (cpu_riscv_read_rtc(clint->timebase_freq) >> 32) & 0xFFFFFFFF; | |
150 | } | |
151 | ||
152 | error_report("clint: invalid read: %08x", (uint32_t)addr); | |
153 | return 0; | |
154 | } | |
155 | ||
156 | /* CPU wrote to rtc or timecmp register */ | |
157 | static void sifive_clint_write(void *opaque, hwaddr addr, uint64_t value, | |
158 | unsigned size) | |
159 | { | |
160 | SiFiveCLINTState *clint = opaque; | |
161 | ||
162 | if (addr >= clint->sip_base && | |
163 | addr < clint->sip_base + (clint->num_harts << 2)) { | |
164 | size_t hartid = clint->hartid_base + ((addr - clint->sip_base) >> 2); | |
165 | CPUState *cpu = qemu_get_cpu(hartid); | |
166 | CPURISCVState *env = cpu ? cpu->env_ptr : NULL; | |
167 | if (!env) { | |
168 | error_report("clint: invalid timecmp hartid: %zu", hartid); | |
169 | } else if ((addr & 0x3) == 0) { | |
170 | qemu_set_irq(clint->soft_irqs[hartid - clint->hartid_base], value); | |
171 | } else { | |
172 | error_report("clint: invalid sip write: %08x", (uint32_t)addr); | |
173 | } | |
174 | return; | |
175 | } else if (addr >= clint->timecmp_base && | |
176 | addr < clint->timecmp_base + (clint->num_harts << 3)) { | |
177 | size_t hartid = clint->hartid_base + | |
178 | ((addr - clint->timecmp_base) >> 3); | |
179 | CPUState *cpu = qemu_get_cpu(hartid); | |
180 | CPURISCVState *env = cpu ? cpu->env_ptr : NULL; | |
181 | if (!env) { | |
182 | error_report("clint: invalid timecmp hartid: %zu", hartid); | |
183 | } else if ((addr & 0x7) == 0) { | |
184 | /* timecmp_lo */ | |
185 | uint64_t timecmp_hi = env->timecmp >> 32; | |
186 | sifive_clint_write_timecmp(clint, RISCV_CPU(cpu), hartid, | |
187 | timecmp_hi << 32 | (value & 0xFFFFFFFF), clint->timebase_freq); | |
188 | return; | |
189 | } else if ((addr & 0x7) == 4) { | |
190 | /* timecmp_hi */ | |
191 | uint64_t timecmp_lo = env->timecmp; | |
192 | sifive_clint_write_timecmp(clint, RISCV_CPU(cpu), hartid, | |
193 | value << 32 | (timecmp_lo & 0xFFFFFFFF), clint->timebase_freq); | |
194 | } else { | |
195 | error_report("clint: invalid timecmp write: %08x", (uint32_t)addr); | |
196 | } | |
197 | return; | |
198 | } else if (addr == clint->time_base) { | |
199 | /* time_lo */ | |
200 | error_report("clint: time_lo write not implemented"); | |
201 | return; | |
202 | } else if (addr == clint->time_base + 4) { | |
203 | /* time_hi */ | |
204 | error_report("clint: time_hi write not implemented"); | |
205 | return; | |
206 | } | |
207 | ||
208 | error_report("clint: invalid write: %08x", (uint32_t)addr); | |
209 | } | |
210 | ||
211 | static const MemoryRegionOps sifive_clint_ops = { | |
212 | .read = sifive_clint_read, | |
213 | .write = sifive_clint_write, | |
214 | .endianness = DEVICE_LITTLE_ENDIAN, | |
215 | .valid = { | |
216 | .min_access_size = 4, | |
217 | .max_access_size = 8 | |
218 | } | |
219 | }; | |
220 | ||
221 | static Property sifive_clint_properties[] = { | |
222 | DEFINE_PROP_UINT32("hartid-base", SiFiveCLINTState, hartid_base, 0), | |
223 | DEFINE_PROP_UINT32("num-harts", SiFiveCLINTState, num_harts, 0), | |
224 | DEFINE_PROP_UINT32("sip-base", SiFiveCLINTState, sip_base, 0), | |
225 | DEFINE_PROP_UINT32("timecmp-base", SiFiveCLINTState, timecmp_base, 0), | |
226 | DEFINE_PROP_UINT32("time-base", SiFiveCLINTState, time_base, 0), | |
227 | DEFINE_PROP_UINT32("aperture-size", SiFiveCLINTState, aperture_size, 0), | |
228 | DEFINE_PROP_UINT32("timebase-freq", SiFiveCLINTState, timebase_freq, 0), | |
229 | DEFINE_PROP_END_OF_LIST(), | |
230 | }; | |
231 | ||
232 | static void sifive_clint_realize(DeviceState *dev, Error **errp) | |
233 | { | |
234 | SiFiveCLINTState *s = SIFIVE_CLINT(dev); | |
235 | memory_region_init_io(&s->mmio, OBJECT(dev), &sifive_clint_ops, s, | |
236 | TYPE_SIFIVE_CLINT, s->aperture_size); | |
237 | sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio); | |
238 | ||
239 | s->timer_irqs = g_malloc(sizeof(qemu_irq) * s->num_harts); | |
240 | qdev_init_gpio_out(dev, s->timer_irqs, s->num_harts); | |
241 | ||
242 | s->soft_irqs = g_malloc(sizeof(qemu_irq) * s->num_harts); | |
243 | qdev_init_gpio_out(dev, s->soft_irqs, s->num_harts); | |
244 | } | |
245 | ||
246 | static void sifive_clint_class_init(ObjectClass *klass, void *data) | |
247 | { | |
248 | DeviceClass *dc = DEVICE_CLASS(klass); | |
249 | dc->realize = sifive_clint_realize; | |
250 | device_class_set_props(dc, sifive_clint_properties); | |
251 | } | |
252 | ||
253 | static const TypeInfo sifive_clint_info = { | |
254 | .name = TYPE_SIFIVE_CLINT, | |
255 | .parent = TYPE_SYS_BUS_DEVICE, | |
256 | .instance_size = sizeof(SiFiveCLINTState), | |
257 | .class_init = sifive_clint_class_init, | |
258 | }; | |
259 | ||
260 | static void sifive_clint_register_types(void) | |
261 | { | |
262 | type_register_static(&sifive_clint_info); | |
263 | } | |
264 | ||
265 | type_init(sifive_clint_register_types) | |
266 | ||
267 | /* | |
268 | * Create CLINT device. | |
269 | */ | |
270 | DeviceState *sifive_clint_create(hwaddr addr, hwaddr size, | |
271 | uint32_t hartid_base, uint32_t num_harts, uint32_t sip_base, | |
272 | uint32_t timecmp_base, uint32_t time_base, uint32_t timebase_freq, | |
273 | bool provide_rdtime) | |
274 | { | |
275 | int i; | |
276 | ||
277 | DeviceState *dev = qdev_new(TYPE_SIFIVE_CLINT); | |
278 | qdev_prop_set_uint32(dev, "hartid-base", hartid_base); | |
279 | qdev_prop_set_uint32(dev, "num-harts", num_harts); | |
280 | qdev_prop_set_uint32(dev, "sip-base", sip_base); | |
281 | qdev_prop_set_uint32(dev, "timecmp-base", timecmp_base); | |
282 | qdev_prop_set_uint32(dev, "time-base", time_base); | |
283 | qdev_prop_set_uint32(dev, "aperture-size", size); | |
284 | qdev_prop_set_uint32(dev, "timebase-freq", timebase_freq); | |
285 | sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal); | |
286 | sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr); | |
287 | ||
288 | for (i = 0; i < num_harts; i++) { | |
289 | CPUState *cpu = qemu_get_cpu(hartid_base + i); | |
290 | RISCVCPU *rvcpu = RISCV_CPU(cpu); | |
291 | CPURISCVState *env = cpu ? cpu->env_ptr : NULL; | |
292 | sifive_clint_callback *cb = g_malloc0(sizeof(sifive_clint_callback)); | |
293 | ||
294 | if (!env) { | |
295 | g_free(cb); | |
296 | continue; | |
297 | } | |
298 | if (provide_rdtime) { | |
299 | riscv_cpu_set_rdtime_fn(env, cpu_riscv_read_rtc, timebase_freq); | |
300 | } | |
301 | ||
302 | cb->s = SIFIVE_CLINT(dev); | |
303 | cb->num = i; | |
304 | env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, | |
305 | &sifive_clint_timer_cb, cb); | |
306 | env->timecmp = 0; | |
307 | ||
308 | qdev_connect_gpio_out(dev, i, | |
309 | qdev_get_gpio_in(DEVICE(rvcpu), IRQ_M_TIMER)); | |
310 | qdev_connect_gpio_out(dev, num_harts + i, | |
311 | qdev_get_gpio_in(DEVICE(rvcpu), IRQ_M_SOFT)); | |
312 | } | |
313 | ||
314 | return dev; | |
315 | } |