xref: /openbmc/qemu/hw/timer/slavio_timer.c (revision 922d42bb)
1 /*
2  * QEMU Sparc SLAVIO timer controller emulation
3  *
4  * Copyright (c) 2003-2005 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu/timer.h"
27 #include "hw/irq.h"
28 #include "hw/ptimer.h"
29 #include "hw/qdev-properties.h"
30 #include "hw/sysbus.h"
31 #include "migration/vmstate.h"
32 #include "trace.h"
33 #include "qemu/module.h"
34 #include "qom/object.h"
35 
36 /*
37  * Registers of hardware timer in sun4m.
38  *
39  * This is the timer/counter part of chip STP2001 (Slave I/O), also
40  * produced as NCR89C105. See
41  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt
42  *
43  * The 31-bit counter is incremented every 500ns by bit 9. Bits 8..0
44  * are zero. Bit 31 is 1 when count has been reached.
45  *
46  * Per-CPU timers interrupt local CPU, system timer uses normal
47  * interrupt routing.
48  *
49  */
50 
51 #define MAX_CPUS 16
52 
53 typedef struct CPUTimerState {
54     qemu_irq irq;
55     ptimer_state *timer;
56     uint32_t count, counthigh, reached;
57     /* processor only */
58     uint32_t run;
59     uint64_t limit;
60 } CPUTimerState;
61 
62 #define TYPE_SLAVIO_TIMER "slavio_timer"
63 OBJECT_DECLARE_SIMPLE_TYPE(SLAVIO_TIMERState, SLAVIO_TIMER)
64 
65 struct SLAVIO_TIMERState {
66     SysBusDevice parent_obj;
67 
68     uint32_t num_cpus;
69     uint32_t cputimer_mode;
70     CPUTimerState cputimer[MAX_CPUS + 1];
71 };
72 
73 typedef struct TimerContext {
74     MemoryRegion iomem;
75     SLAVIO_TIMERState *s;
76     unsigned int timer_index; /* 0 for system, 1 ... MAX_CPUS for CPU timers */
77 } TimerContext;
78 
79 #define SYS_TIMER_SIZE 0x14
80 #define CPU_TIMER_SIZE 0x10
81 
82 #define TIMER_LIMIT         0
83 #define TIMER_COUNTER       1
84 #define TIMER_COUNTER_NORST 2
85 #define TIMER_STATUS        3
86 #define TIMER_MODE          4
87 
88 #define TIMER_COUNT_MASK32 0xfffffe00
89 #define TIMER_LIMIT_MASK32 0x7fffffff
90 #define TIMER_MAX_COUNT64  0x7ffffffffffffe00ULL
91 #define TIMER_MAX_COUNT32  0x7ffffe00ULL
92 #define TIMER_REACHED      0x80000000
93 #define TIMER_PERIOD       500ULL // 500ns
94 #define LIMIT_TO_PERIODS(l) (((l) >> 9) - 1)
95 #define PERIODS_TO_LIMIT(l) (((l) + 1) << 9)
96 
97 static int slavio_timer_is_user(TimerContext *tc)
98 {
99     SLAVIO_TIMERState *s = tc->s;
100     unsigned int timer_index = tc->timer_index;
101 
102     return timer_index != 0 && (s->cputimer_mode & (1 << (timer_index - 1)));
103 }
104 
105 // Update count, set irq, update expire_time
106 // Convert from ptimer countdown units
107 static void slavio_timer_get_out(CPUTimerState *t)
108 {
109     uint64_t count, limit;
110 
111     if (t->limit == 0) { /* free-run system or processor counter */
112         limit = TIMER_MAX_COUNT32;
113     } else {
114         limit = t->limit;
115     }
116     count = limit - PERIODS_TO_LIMIT(ptimer_get_count(t->timer));
117 
118     trace_slavio_timer_get_out(t->limit, t->counthigh, t->count);
119     t->count = count & TIMER_COUNT_MASK32;
120     t->counthigh = count >> 32;
121 }
122 
123 // timer callback
124 static void slavio_timer_irq(void *opaque)
125 {
126     TimerContext *tc = opaque;
127     SLAVIO_TIMERState *s = tc->s;
128     CPUTimerState *t = &s->cputimer[tc->timer_index];
129 
130     slavio_timer_get_out(t);
131     trace_slavio_timer_irq(t->counthigh, t->count);
132     /* if limit is 0 (free-run), there will be no match */
133     if (t->limit != 0) {
134         t->reached = TIMER_REACHED;
135     }
136     /* there is no interrupt if user timer or free-run */
137     if (!slavio_timer_is_user(tc) && t->limit != 0) {
138         qemu_irq_raise(t->irq);
139     }
140 }
141 
142 static uint64_t slavio_timer_mem_readl(void *opaque, hwaddr addr,
143                                        unsigned size)
144 {
145     TimerContext *tc = opaque;
146     SLAVIO_TIMERState *s = tc->s;
147     uint32_t saddr, ret;
148     unsigned int timer_index = tc->timer_index;
149     CPUTimerState *t = &s->cputimer[timer_index];
150 
151     saddr = addr >> 2;
152     switch (saddr) {
153     case TIMER_LIMIT:
154         // read limit (system counter mode) or read most signifying
155         // part of counter (user mode)
156         if (slavio_timer_is_user(tc)) {
157             // read user timer MSW
158             slavio_timer_get_out(t);
159             ret = t->counthigh | t->reached;
160         } else {
161             // read limit
162             // clear irq
163             qemu_irq_lower(t->irq);
164             t->reached = 0;
165             ret = t->limit & TIMER_LIMIT_MASK32;
166         }
167         break;
168     case TIMER_COUNTER:
169         // read counter and reached bit (system mode) or read lsbits
170         // of counter (user mode)
171         slavio_timer_get_out(t);
172         if (slavio_timer_is_user(tc)) { // read user timer LSW
173             ret = t->count & TIMER_MAX_COUNT64;
174         } else { // read limit
175             ret = (t->count & TIMER_MAX_COUNT32) |
176                 t->reached;
177         }
178         break;
179     case TIMER_STATUS:
180         // only available in processor counter/timer
181         // read start/stop status
182         if (timer_index > 0) {
183             ret = t->run;
184         } else {
185             ret = 0;
186         }
187         break;
188     case TIMER_MODE:
189         // only available in system counter
190         // read user/system mode
191         ret = s->cputimer_mode;
192         break;
193     default:
194         trace_slavio_timer_mem_readl_invalid(addr);
195         ret = 0;
196         break;
197     }
198     trace_slavio_timer_mem_readl(addr, ret);
199     return ret;
200 }
201 
202 static void slavio_timer_mem_writel(void *opaque, hwaddr addr,
203                                     uint64_t val, unsigned size)
204 {
205     TimerContext *tc = opaque;
206     SLAVIO_TIMERState *s = tc->s;
207     uint32_t saddr;
208     unsigned int timer_index = tc->timer_index;
209     CPUTimerState *t = &s->cputimer[timer_index];
210 
211     trace_slavio_timer_mem_writel(addr, val);
212     saddr = addr >> 2;
213     switch (saddr) {
214     case TIMER_LIMIT:
215         ptimer_transaction_begin(t->timer);
216         if (slavio_timer_is_user(tc)) {
217             uint64_t count;
218 
219             // set user counter MSW, reset counter
220             t->limit = TIMER_MAX_COUNT64;
221             t->counthigh = val & (TIMER_MAX_COUNT64 >> 32);
222             t->reached = 0;
223             count = ((uint64_t)t->counthigh << 32) | t->count;
224             trace_slavio_timer_mem_writel_limit(timer_index, count);
225             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
226         } else {
227             // set limit, reset counter
228             qemu_irq_lower(t->irq);
229             t->limit = val & TIMER_MAX_COUNT32;
230             if (t->limit == 0) { /* free-run */
231                 ptimer_set_limit(t->timer,
232                                  LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
233             } else {
234                 ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1);
235             }
236         }
237         ptimer_transaction_commit(t->timer);
238         break;
239     case TIMER_COUNTER:
240         if (slavio_timer_is_user(tc)) {
241             uint64_t count;
242 
243             // set user counter LSW, reset counter
244             t->limit = TIMER_MAX_COUNT64;
245             t->count = val & TIMER_MAX_COUNT64;
246             t->reached = 0;
247             count = ((uint64_t)t->counthigh) << 32 | t->count;
248             trace_slavio_timer_mem_writel_limit(timer_index, count);
249             ptimer_transaction_begin(t->timer);
250             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
251             ptimer_transaction_commit(t->timer);
252         } else {
253             trace_slavio_timer_mem_writel_counter_invalid();
254         }
255         break;
256     case TIMER_COUNTER_NORST:
257         // set limit without resetting counter
258         t->limit = val & TIMER_MAX_COUNT32;
259         ptimer_transaction_begin(t->timer);
260         if (t->limit == 0) { /* free-run */
261             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 0);
262         } else {
263             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 0);
264         }
265         ptimer_transaction_commit(t->timer);
266         break;
267     case TIMER_STATUS:
268         ptimer_transaction_begin(t->timer);
269         if (slavio_timer_is_user(tc)) {
270             // start/stop user counter
271             if (val & 1) {
272                 trace_slavio_timer_mem_writel_status_start(timer_index);
273                 ptimer_run(t->timer, 0);
274             } else {
275                 trace_slavio_timer_mem_writel_status_stop(timer_index);
276                 ptimer_stop(t->timer);
277             }
278         }
279         t->run = val & 1;
280         ptimer_transaction_commit(t->timer);
281         break;
282     case TIMER_MODE:
283         if (timer_index == 0) {
284             unsigned int i;
285 
286             for (i = 0; i < s->num_cpus; i++) {
287                 unsigned int processor = 1 << i;
288                 CPUTimerState *curr_timer = &s->cputimer[i + 1];
289 
290                 ptimer_transaction_begin(curr_timer->timer);
291                 // check for a change in timer mode for this processor
292                 if ((val & processor) != (s->cputimer_mode & processor)) {
293                     if (val & processor) { // counter -> user timer
294                         qemu_irq_lower(curr_timer->irq);
295                         // counters are always running
296                         if (!curr_timer->run) {
297                             ptimer_stop(curr_timer->timer);
298                         }
299                         // user timer limit is always the same
300                         curr_timer->limit = TIMER_MAX_COUNT64;
301                         ptimer_set_limit(curr_timer->timer,
302                                          LIMIT_TO_PERIODS(curr_timer->limit),
303                                          1);
304                         // set this processors user timer bit in config
305                         // register
306                         s->cputimer_mode |= processor;
307                         trace_slavio_timer_mem_writel_mode_user(timer_index);
308                     } else { // user timer -> counter
309                         // start the counter
310                         ptimer_run(curr_timer->timer, 0);
311                         // clear this processors user timer bit in config
312                         // register
313                         s->cputimer_mode &= ~processor;
314                         trace_slavio_timer_mem_writel_mode_counter(timer_index);
315                     }
316                 }
317                 ptimer_transaction_commit(curr_timer->timer);
318             }
319         } else {
320             trace_slavio_timer_mem_writel_mode_invalid();
321         }
322         break;
323     default:
324         trace_slavio_timer_mem_writel_invalid(addr);
325         break;
326     }
327 }
328 
329 static const MemoryRegionOps slavio_timer_mem_ops = {
330     .read = slavio_timer_mem_readl,
331     .write = slavio_timer_mem_writel,
332     .endianness = DEVICE_NATIVE_ENDIAN,
333     .valid = {
334         .min_access_size = 4,
335         .max_access_size = 4,
336     },
337 };
338 
339 static const VMStateDescription vmstate_timer = {
340     .name ="timer",
341     .version_id = 3,
342     .minimum_version_id = 3,
343     .fields = (VMStateField[]) {
344         VMSTATE_UINT64(limit, CPUTimerState),
345         VMSTATE_UINT32(count, CPUTimerState),
346         VMSTATE_UINT32(counthigh, CPUTimerState),
347         VMSTATE_UINT32(reached, CPUTimerState),
348         VMSTATE_UINT32(run    , CPUTimerState),
349         VMSTATE_PTIMER(timer, CPUTimerState),
350         VMSTATE_END_OF_LIST()
351     }
352 };
353 
354 static const VMStateDescription vmstate_slavio_timer = {
355     .name ="slavio_timer",
356     .version_id = 3,
357     .minimum_version_id = 3,
358     .fields = (VMStateField[]) {
359         VMSTATE_STRUCT_ARRAY(cputimer, SLAVIO_TIMERState, MAX_CPUS + 1, 3,
360                              vmstate_timer, CPUTimerState),
361         VMSTATE_END_OF_LIST()
362     }
363 };
364 
365 static void slavio_timer_reset(DeviceState *d)
366 {
367     SLAVIO_TIMERState *s = SLAVIO_TIMER(d);
368     unsigned int i;
369     CPUTimerState *curr_timer;
370 
371     for (i = 0; i <= MAX_CPUS; i++) {
372         curr_timer = &s->cputimer[i];
373         curr_timer->limit = 0;
374         curr_timer->count = 0;
375         curr_timer->reached = 0;
376         if (i <= s->num_cpus) {
377             ptimer_transaction_begin(curr_timer->timer);
378             ptimer_set_limit(curr_timer->timer,
379                              LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
380             ptimer_run(curr_timer->timer, 0);
381             curr_timer->run = 1;
382             ptimer_transaction_commit(curr_timer->timer);
383         }
384     }
385     s->cputimer_mode = 0;
386 }
387 
388 static void slavio_timer_init(Object *obj)
389 {
390     SLAVIO_TIMERState *s = SLAVIO_TIMER(obj);
391     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
392     unsigned int i;
393     TimerContext *tc;
394 
395     for (i = 0; i <= MAX_CPUS; i++) {
396         uint64_t size;
397         char timer_name[20];
398 
399         tc = g_malloc0(sizeof(TimerContext));
400         tc->s = s;
401         tc->timer_index = i;
402 
403         s->cputimer[i].timer = ptimer_init(slavio_timer_irq, tc,
404                                            PTIMER_POLICY_DEFAULT);
405         ptimer_transaction_begin(s->cputimer[i].timer);
406         ptimer_set_period(s->cputimer[i].timer, TIMER_PERIOD);
407         ptimer_transaction_commit(s->cputimer[i].timer);
408 
409         size = i == 0 ? SYS_TIMER_SIZE : CPU_TIMER_SIZE;
410         snprintf(timer_name, sizeof(timer_name), "timer-%i", i);
411         memory_region_init_io(&tc->iomem, obj, &slavio_timer_mem_ops, tc,
412                               timer_name, size);
413         sysbus_init_mmio(dev, &tc->iomem);
414 
415         sysbus_init_irq(dev, &s->cputimer[i].irq);
416     }
417 }
418 
419 static Property slavio_timer_properties[] = {
420     DEFINE_PROP_UINT32("num_cpus",  SLAVIO_TIMERState, num_cpus,  0),
421     DEFINE_PROP_END_OF_LIST(),
422 };
423 
424 static void slavio_timer_class_init(ObjectClass *klass, void *data)
425 {
426     DeviceClass *dc = DEVICE_CLASS(klass);
427 
428     dc->reset = slavio_timer_reset;
429     dc->vmsd = &vmstate_slavio_timer;
430     device_class_set_props(dc, slavio_timer_properties);
431 }
432 
433 static const TypeInfo slavio_timer_info = {
434     .name          = TYPE_SLAVIO_TIMER,
435     .parent        = TYPE_SYS_BUS_DEVICE,
436     .instance_size = sizeof(SLAVIO_TIMERState),
437     .instance_init = slavio_timer_init,
438     .class_init    = slavio_timer_class_init,
439 };
440 
441 static void slavio_timer_register_types(void)
442 {
443     type_register_static(&slavio_timer_info);
444 }
445 
446 type_init(slavio_timer_register_types)
447