xref: /openbmc/qemu/hw/timer/slavio_timer.c (revision 650d103d)
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/sysbus.h"
30 #include "migration/vmstate.h"
31 #include "trace.h"
32 #include "qemu/main-loop.h"
33 #include "qemu/module.h"
34 
35 /*
36  * Registers of hardware timer in sun4m.
37  *
38  * This is the timer/counter part of chip STP2001 (Slave I/O), also
39  * produced as NCR89C105. See
40  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt
41  *
42  * The 31-bit counter is incremented every 500ns by bit 9. Bits 8..0
43  * are zero. Bit 31 is 1 when count has been reached.
44  *
45  * Per-CPU timers interrupt local CPU, system timer uses normal
46  * interrupt routing.
47  *
48  */
49 
50 #define MAX_CPUS 16
51 
52 typedef struct CPUTimerState {
53     qemu_irq irq;
54     ptimer_state *timer;
55     uint32_t count, counthigh, reached;
56     /* processor only */
57     uint32_t run;
58     uint64_t limit;
59 } CPUTimerState;
60 
61 #define TYPE_SLAVIO_TIMER "slavio_timer"
62 #define SLAVIO_TIMER(obj) \
63     OBJECT_CHECK(SLAVIO_TIMERState, (obj), TYPE_SLAVIO_TIMER)
64 
65 typedef 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 } SLAVIO_TIMERState;
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         if (slavio_timer_is_user(tc)) {
216             uint64_t count;
217 
218             // set user counter MSW, reset counter
219             t->limit = TIMER_MAX_COUNT64;
220             t->counthigh = val & (TIMER_MAX_COUNT64 >> 32);
221             t->reached = 0;
222             count = ((uint64_t)t->counthigh << 32) | t->count;
223             trace_slavio_timer_mem_writel_limit(timer_index, count);
224             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
225         } else {
226             // set limit, reset counter
227             qemu_irq_lower(t->irq);
228             t->limit = val & TIMER_MAX_COUNT32;
229             if (t->timer) {
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         }
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_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
250         } else {
251             trace_slavio_timer_mem_writel_counter_invalid();
252         }
253         break;
254     case TIMER_COUNTER_NORST:
255         // set limit without resetting counter
256         t->limit = val & TIMER_MAX_COUNT32;
257         if (t->limit == 0) { /* free-run */
258             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 0);
259         } else {
260             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 0);
261         }
262         break;
263     case TIMER_STATUS:
264         if (slavio_timer_is_user(tc)) {
265             // start/stop user counter
266             if (val & 1) {
267                 trace_slavio_timer_mem_writel_status_start(timer_index);
268                 ptimer_run(t->timer, 0);
269             } else {
270                 trace_slavio_timer_mem_writel_status_stop(timer_index);
271                 ptimer_stop(t->timer);
272             }
273         }
274         t->run = val & 1;
275         break;
276     case TIMER_MODE:
277         if (timer_index == 0) {
278             unsigned int i;
279 
280             for (i = 0; i < s->num_cpus; i++) {
281                 unsigned int processor = 1 << i;
282                 CPUTimerState *curr_timer = &s->cputimer[i + 1];
283 
284                 // check for a change in timer mode for this processor
285                 if ((val & processor) != (s->cputimer_mode & processor)) {
286                     if (val & processor) { // counter -> user timer
287                         qemu_irq_lower(curr_timer->irq);
288                         // counters are always running
289                         if (!curr_timer->run) {
290                             ptimer_stop(curr_timer->timer);
291                         }
292                         // user timer limit is always the same
293                         curr_timer->limit = TIMER_MAX_COUNT64;
294                         ptimer_set_limit(curr_timer->timer,
295                                          LIMIT_TO_PERIODS(curr_timer->limit),
296                                          1);
297                         // set this processors user timer bit in config
298                         // register
299                         s->cputimer_mode |= processor;
300                         trace_slavio_timer_mem_writel_mode_user(timer_index);
301                     } else { // user timer -> counter
302                         // start the counter
303                         ptimer_run(curr_timer->timer, 0);
304                         // clear this processors user timer bit in config
305                         // register
306                         s->cputimer_mode &= ~processor;
307                         trace_slavio_timer_mem_writel_mode_counter(timer_index);
308                     }
309                 }
310             }
311         } else {
312             trace_slavio_timer_mem_writel_mode_invalid();
313         }
314         break;
315     default:
316         trace_slavio_timer_mem_writel_invalid(addr);
317         break;
318     }
319 }
320 
321 static const MemoryRegionOps slavio_timer_mem_ops = {
322     .read = slavio_timer_mem_readl,
323     .write = slavio_timer_mem_writel,
324     .endianness = DEVICE_NATIVE_ENDIAN,
325     .valid = {
326         .min_access_size = 4,
327         .max_access_size = 4,
328     },
329 };
330 
331 static const VMStateDescription vmstate_timer = {
332     .name ="timer",
333     .version_id = 3,
334     .minimum_version_id = 3,
335     .fields = (VMStateField[]) {
336         VMSTATE_UINT64(limit, CPUTimerState),
337         VMSTATE_UINT32(count, CPUTimerState),
338         VMSTATE_UINT32(counthigh, CPUTimerState),
339         VMSTATE_UINT32(reached, CPUTimerState),
340         VMSTATE_UINT32(run    , CPUTimerState),
341         VMSTATE_PTIMER(timer, CPUTimerState),
342         VMSTATE_END_OF_LIST()
343     }
344 };
345 
346 static const VMStateDescription vmstate_slavio_timer = {
347     .name ="slavio_timer",
348     .version_id = 3,
349     .minimum_version_id = 3,
350     .fields = (VMStateField[]) {
351         VMSTATE_STRUCT_ARRAY(cputimer, SLAVIO_TIMERState, MAX_CPUS + 1, 3,
352                              vmstate_timer, CPUTimerState),
353         VMSTATE_END_OF_LIST()
354     }
355 };
356 
357 static void slavio_timer_reset(DeviceState *d)
358 {
359     SLAVIO_TIMERState *s = SLAVIO_TIMER(d);
360     unsigned int i;
361     CPUTimerState *curr_timer;
362 
363     for (i = 0; i <= MAX_CPUS; i++) {
364         curr_timer = &s->cputimer[i];
365         curr_timer->limit = 0;
366         curr_timer->count = 0;
367         curr_timer->reached = 0;
368         if (i <= s->num_cpus) {
369             ptimer_set_limit(curr_timer->timer,
370                              LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
371             ptimer_run(curr_timer->timer, 0);
372             curr_timer->run = 1;
373         }
374     }
375     s->cputimer_mode = 0;
376 }
377 
378 static void slavio_timer_init(Object *obj)
379 {
380     SLAVIO_TIMERState *s = SLAVIO_TIMER(obj);
381     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
382     QEMUBH *bh;
383     unsigned int i;
384     TimerContext *tc;
385 
386     for (i = 0; i <= MAX_CPUS; i++) {
387         uint64_t size;
388         char timer_name[20];
389 
390         tc = g_malloc0(sizeof(TimerContext));
391         tc->s = s;
392         tc->timer_index = i;
393 
394         bh = qemu_bh_new(slavio_timer_irq, tc);
395         s->cputimer[i].timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
396         ptimer_set_period(s->cputimer[i].timer, TIMER_PERIOD);
397 
398         size = i == 0 ? SYS_TIMER_SIZE : CPU_TIMER_SIZE;
399         snprintf(timer_name, sizeof(timer_name), "timer-%i", i);
400         memory_region_init_io(&tc->iomem, obj, &slavio_timer_mem_ops, tc,
401                               timer_name, size);
402         sysbus_init_mmio(dev, &tc->iomem);
403 
404         sysbus_init_irq(dev, &s->cputimer[i].irq);
405     }
406 }
407 
408 static Property slavio_timer_properties[] = {
409     DEFINE_PROP_UINT32("num_cpus",  SLAVIO_TIMERState, num_cpus,  0),
410     DEFINE_PROP_END_OF_LIST(),
411 };
412 
413 static void slavio_timer_class_init(ObjectClass *klass, void *data)
414 {
415     DeviceClass *dc = DEVICE_CLASS(klass);
416 
417     dc->reset = slavio_timer_reset;
418     dc->vmsd = &vmstate_slavio_timer;
419     dc->props = slavio_timer_properties;
420 }
421 
422 static const TypeInfo slavio_timer_info = {
423     .name          = TYPE_SLAVIO_TIMER,
424     .parent        = TYPE_SYS_BUS_DEVICE,
425     .instance_size = sizeof(SLAVIO_TIMERState),
426     .instance_init = slavio_timer_init,
427     .class_init    = slavio_timer_class_init,
428 };
429 
430 static void slavio_timer_register_types(void)
431 {
432     type_register_static(&slavio_timer_info);
433 }
434 
435 type_init(slavio_timer_register_types)
436