1/*
2 * Global peripheral timer block for ARM A9MP
3 *
4 * (C) 2013 Xilinx Inc.
5 *
6 * Written by François LEGAL
7 * Written by Peter Crosthwaite <peter.crosthwaite@xilinx.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, see <http://www.gnu.org/licenses/>.
21 */
22
23#include "qemu/osdep.h"
24#include "hw/hw.h"
25#include "hw/irq.h"
26#include "hw/qdev-properties.h"
27#include "hw/timer/a9gtimer.h"
28#include "migration/vmstate.h"
29#include "qapi/error.h"
30#include "qemu/timer.h"
31#include "qemu/bitops.h"
32#include "qemu/log.h"
33#include "qemu/module.h"
34#include "hw/core/cpu.h"
35
36#ifndef A9_GTIMER_ERR_DEBUG
37#define A9_GTIMER_ERR_DEBUG 0
38#endif
39
40#define DB_PRINT_L(level, ...) do { \
41 if (A9_GTIMER_ERR_DEBUG > (level)) { \
42 fprintf(stderr, ": %s: ", __func__); \
43 fprintf(stderr, ## __VA_ARGS__); \
44 } \
45} while (0)
46
47#define DB_PRINT(...) DB_PRINT_L(0, ## __VA_ARGS__)
48
49static inline int a9_gtimer_get_current_cpu(A9GTimerState *s)
50{
51 if (current_cpu->cpu_index >= s->num_cpu) {
52 hw_error("a9gtimer: num-cpu %d but this cpu is %d!\n",
53 s->num_cpu, current_cpu->cpu_index);
54 }
55 return current_cpu->cpu_index;
56}
57
58static inline uint64_t a9_gtimer_get_conv(A9GTimerState *s)
59{
60 uint64_t prescale = extract32(s->control, R_CONTROL_PRESCALER_SHIFT,
61 R_CONTROL_PRESCALER_LEN);
62
63 return (prescale + 1) * 10;
64}
65
66static A9GTimerUpdate a9_gtimer_get_update(A9GTimerState *s)
67{
68 A9GTimerUpdate ret;
69
70 ret.now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
71 ret.new = s->ref_counter +
72 (ret.now - s->cpu_ref_time) / a9_gtimer_get_conv(s);
73 return ret;
74}
75
76static void a9_gtimer_update(A9GTimerState *s, bool sync)
77{
78
79 A9GTimerUpdate update = a9_gtimer_get_update(s);
80 int i;
81 int64_t next_cdiff = 0;
82
83 for (i = 0; i < s->num_cpu; ++i) {
84 A9GTimerPerCPU *gtb = &s->per_cpu[i];
85 int64_t cdiff = 0;
86
87 if ((s->control & R_CONTROL_TIMER_ENABLE) &&
88 (gtb->control & R_CONTROL_COMP_ENABLE)) {
89 /* R2p0+, where the compare function is >= */
90 if (gtb->compare < update.new) {
91 DB_PRINT("Compare event happened for CPU %d\n", i);
92 gtb->status = 1;
93 if (gtb->control & R_CONTROL_AUTO_INCREMENT && gtb->inc) {
94 uint64_t inc =
95 QEMU_ALIGN_UP(update.new - gtb->compare, gtb->inc);
96 DB_PRINT("Auto incrementing timer compare by %"
97 PRId64 "\n", inc);
98 gtb->compare += inc;
99 }
100 }
101 cdiff = (int64_t)gtb->compare - (int64_t)update.new + 1;
102 if (cdiff > 0 && (cdiff < next_cdiff || !next_cdiff)) {
103 next_cdiff = cdiff;
104 }
105 }
106
107 qemu_set_irq(gtb->irq,
108 gtb->status && (gtb->control & R_CONTROL_IRQ_ENABLE));
109 }
110
111 timer_del(s->timer);
112 if (next_cdiff) {
113 DB_PRINT("scheduling qemu_timer to fire again in %"
114 PRIx64 " cycles\n", next_cdiff);
115 timer_mod(s->timer, update.now + next_cdiff * a9_gtimer_get_conv(s));
116 }
117
118 if (s->control & R_CONTROL_TIMER_ENABLE) {
119 s->counter = update.new;
120 }
121
122 if (sync) {
123 s->cpu_ref_time = update.now;
124 s->ref_counter = s->counter;
125 }
126}
127
128static void a9_gtimer_update_no_sync(void *opaque)
129{
130 A9GTimerState *s = A9_GTIMER(opaque);
131
132 a9_gtimer_update(s, false);
133}
134
135static uint64_t a9_gtimer_read(void *opaque, hwaddr addr, unsigned size)
136{
137 A9GTimerPerCPU *gtb = (A9GTimerPerCPU *)opaque;
138 A9GTimerState *s = gtb->parent;
139 A9GTimerUpdate update;
140 uint64_t ret = 0;
141 int shift = 0;
142
143 switch (addr) {
144 case R_COUNTER_HI:
145 shift = 32;
146 /* fallthrough */
147 case R_COUNTER_LO:
148 update = a9_gtimer_get_update(s);
149 ret = extract64(update.new, shift, 32);
150 break;
151 case R_CONTROL:
152 ret = s->control | gtb->control;
153 break;
154 case R_INTERRUPT_STATUS:
155 ret = gtb->status;
156 break;
157 case R_COMPARATOR_HI:
158 shift = 32;
159 /* fallthrough */
160 case R_COMPARATOR_LO:
161 ret = extract64(gtb->compare, shift, 32);
162 break;
163 case R_AUTO_INCREMENT:
164 ret = gtb->inc;
165 break;
166 default:
167 qemu_log_mask(LOG_GUEST_ERROR, "bad a9gtimer register: %x\n",
168 (unsigned)addr);
169 return 0;
170 }
171
172 DB_PRINT("addr:%#x data:%#08" PRIx64 "\n", (unsigned)addr, ret);
173 return ret;
174}
175
176static void a9_gtimer_write(void *opaque, hwaddr addr, uint64_t value,
177 unsigned size)
178{
179 A9GTimerPerCPU *gtb = (A9GTimerPerCPU *)opaque;
180 A9GTimerState *s = gtb->parent;
181 int shift = 0;
182
183 DB_PRINT("addr:%#x data:%#08" PRIx64 "\n", (unsigned)addr, value);
184
185 switch (addr) {
186 case R_COUNTER_HI:
187 shift = 32;
188 /* fallthrough */
189 case R_COUNTER_LO:
190 /*
191 * Keep it simple - ARM docco explicitly says to disable timer before
192 * modding it, so don't bother trying to do all the difficult on the fly
193 * timer modifications - (if they even work in real hardware??).
194 */
195 if (s->control & R_CONTROL_TIMER_ENABLE) {
196 qemu_log_mask(LOG_GUEST_ERROR, "Cannot mod running ARM gtimer\n");
197 return;
198 }
199 s->counter = deposit64(s->counter, shift, 32, value);
200 return;
201 case R_CONTROL:
202 a9_gtimer_update(s, (value ^ s->control) & R_CONTROL_NEEDS_SYNC);
203 gtb->control = value & R_CONTROL_BANKED;
204 s->control = value & ~R_CONTROL_BANKED;
205 break;
206 case R_INTERRUPT_STATUS:
207 a9_gtimer_update(s, false);
208 gtb->status &= ~value;
209 break;
210 case R_COMPARATOR_HI:
211 shift = 32;
212 /* fallthrough */
213 case R_COMPARATOR_LO:
214 a9_gtimer_update(s, false);
215 gtb->compare = deposit64(gtb->compare, shift, 32, value);
216 break;
217 case R_AUTO_INCREMENT:
218 gtb->inc = value;
219 return;
220 default:
221 return;
222 }
223
224 a9_gtimer_update(s, false);
225}
226
227/* Wrapper functions to implement the "read global timer for
228 * the current CPU" memory regions.
229 */
230static uint64_t a9_gtimer_this_read(void *opaque, hwaddr addr,
231 unsigned size)
232{
233 A9GTimerState *s = A9_GTIMER(opaque);
234 int id = a9_gtimer_get_current_cpu(s);
235
236 /* no \n so concatenates with message from read fn */
237 DB_PRINT("CPU:%d:", id);
238
239 return a9_gtimer_read(&s->per_cpu[id], addr, size);
240}
241
242static void a9_gtimer_this_write(void *opaque, hwaddr addr,
243 uint64_t value, unsigned size)
244{
245 A9GTimerState *s = A9_GTIMER(opaque);
246 int id = a9_gtimer_get_current_cpu(s);
247
248 /* no \n so concatenates with message from write fn */
249 DB_PRINT("CPU:%d:", id);
250
251 a9_gtimer_write(&s->per_cpu[id], addr, value, size);
252}
253
254static const MemoryRegionOps a9_gtimer_this_ops = {
255 .read = a9_gtimer_this_read,
256 .write = a9_gtimer_this_write,
257 .valid = {
258 .min_access_size = 4,
259 .max_access_size = 4,
260 },
261 .endianness = DEVICE_NATIVE_ENDIAN,
262};
263
264static const MemoryRegionOps a9_gtimer_ops = {
265 .read = a9_gtimer_read,
266 .write = a9_gtimer_write,
267 .valid = {
268 .min_access_size = 4,
269 .max_access_size = 4,
270 },
271 .endianness = DEVICE_NATIVE_ENDIAN,
272};
273
274static void a9_gtimer_reset(DeviceState *dev)
275{
276 A9GTimerState *s = A9_GTIMER(dev);
277 int i;
278
279 s->counter = 0;
280 s->control = 0;
281
282 for (i = 0; i < s->num_cpu; i++) {
283 A9GTimerPerCPU *gtb = &s->per_cpu[i];
284
285 gtb->control = 0;
286 gtb->status = 0;
287 gtb->compare = 0;
288 gtb->inc = 0;
289 }
290 a9_gtimer_update(s, false);
291}
292
293static void a9_gtimer_realize(DeviceState *dev, Error **errp)
294{
295 A9GTimerState *s = A9_GTIMER(dev);
296 SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
297 int i;
298
299 if (s->num_cpu < 1 || s->num_cpu > A9_GTIMER_MAX_CPUS) {
300 error_setg(errp, "%s: num-cpu must be between 1 and %d",
301 __func__, A9_GTIMER_MAX_CPUS);
302 return;
303 }
304
305 memory_region_init_io(&s->iomem, OBJECT(dev), &a9_gtimer_this_ops, s,
306 "a9gtimer shared", 0x20);
307 sysbus_init_mmio(sbd, &s->iomem);
308 s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, a9_gtimer_update_no_sync, s);
309
310 for (i = 0; i < s->num_cpu; i++) {
311 A9GTimerPerCPU *gtb = &s->per_cpu[i];
312
313 gtb->parent = s;
314 sysbus_init_irq(sbd, &gtb->irq);
315 memory_region_init_io(&gtb->iomem, OBJECT(dev), &a9_gtimer_ops, gtb,
316 "a9gtimer per cpu", 0x20);
317 sysbus_init_mmio(sbd, &gtb->iomem);
318 }
319}
320
321static const VMStateDescription vmstate_a9_gtimer_per_cpu = {
322 .name = "arm.cortex-a9-global-timer.percpu",
323 .version_id = 1,
324 .minimum_version_id = 1,
325 .fields = (VMStateField[]) {
326 VMSTATE_UINT32(control, A9GTimerPerCPU),
327 VMSTATE_UINT64(compare, A9GTimerPerCPU),
328 VMSTATE_UINT32(status, A9GTimerPerCPU),
329 VMSTATE_UINT32(inc, A9GTimerPerCPU),
330 VMSTATE_END_OF_LIST()
331 }
332};
333
334static const VMStateDescription vmstate_a9_gtimer = {
335 .name = "arm.cortex-a9-global-timer",
336 .version_id = 1,
337 .minimum_version_id = 1,
338 .fields = (VMStateField[]) {
339 VMSTATE_TIMER_PTR(timer, A9GTimerState),
340 VMSTATE_UINT64(counter, A9GTimerState),
341 VMSTATE_UINT64(ref_counter, A9GTimerState),
342 VMSTATE_UINT64(cpu_ref_time, A9GTimerState),
343 VMSTATE_STRUCT_VARRAY_UINT32(per_cpu, A9GTimerState, num_cpu,
344 1, vmstate_a9_gtimer_per_cpu,
345 A9GTimerPerCPU),
346 VMSTATE_END_OF_LIST()
347 }
348};
349
350static Property a9_gtimer_properties[] = {
351 DEFINE_PROP_UINT32("num-cpu", A9GTimerState, num_cpu, 0),
352 DEFINE_PROP_END_OF_LIST()
353};
354
355static void a9_gtimer_class_init(ObjectClass *klass, void *data)
356{
357 DeviceClass *dc = DEVICE_CLASS(klass);
358
359 dc->realize = a9_gtimer_realize;
360 dc->vmsd = &vmstate_a9_gtimer;
361 dc->reset = a9_gtimer_reset;
362 dc->props = a9_gtimer_properties;
363}
364
365static const TypeInfo a9_gtimer_info = {
366 .name = TYPE_A9_GTIMER,
367 .parent = TYPE_SYS_BUS_DEVICE,
368 .instance_size = sizeof(A9GTimerState),
369 .class_init = a9_gtimer_class_init,
370};
371
372static void a9_gtimer_register_types(void)
373{
374 type_register_static(&a9_gtimer_info);
375}
376
377type_init(a9_gtimer_register_types)
378