xref: /openbmc/qemu/hw/timer/slavio_timer.c (revision a68694cd)
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 typedef struct SLAVIO_TIMERState SLAVIO_TIMERState;
64 DECLARE_INSTANCE_CHECKER(SLAVIO_TIMERState, SLAVIO_TIMER,
65                          TYPE_SLAVIO_TIMER)
66 
67 struct SLAVIO_TIMERState {
68     SysBusDevice parent_obj;
69 
70     uint32_t num_cpus;
71     uint32_t cputimer_mode;
72     CPUTimerState cputimer[MAX_CPUS + 1];
73 };
74 
75 typedef struct TimerContext {
76     MemoryRegion iomem;
77     SLAVIO_TIMERState *s;
78     unsigned int timer_index; /* 0 for system, 1 ... MAX_CPUS for CPU timers */
79 } TimerContext;
80 
81 #define SYS_TIMER_SIZE 0x14
82 #define CPU_TIMER_SIZE 0x10
83 
84 #define TIMER_LIMIT         0
85 #define TIMER_COUNTER       1
86 #define TIMER_COUNTER_NORST 2
87 #define TIMER_STATUS        3
88 #define TIMER_MODE          4
89 
90 #define TIMER_COUNT_MASK32 0xfffffe00
91 #define TIMER_LIMIT_MASK32 0x7fffffff
92 #define TIMER_MAX_COUNT64  0x7ffffffffffffe00ULL
93 #define TIMER_MAX_COUNT32  0x7ffffe00ULL
94 #define TIMER_REACHED      0x80000000
95 #define TIMER_PERIOD       500ULL // 500ns
96 #define LIMIT_TO_PERIODS(l) (((l) >> 9) - 1)
97 #define PERIODS_TO_LIMIT(l) (((l) + 1) << 9)
98 
99 static int slavio_timer_is_user(TimerContext *tc)
100 {
101     SLAVIO_TIMERState *s = tc->s;
102     unsigned int timer_index = tc->timer_index;
103 
104     return timer_index != 0 && (s->cputimer_mode & (1 << (timer_index - 1)));
105 }
106 
107 // Update count, set irq, update expire_time
108 // Convert from ptimer countdown units
109 static void slavio_timer_get_out(CPUTimerState *t)
110 {
111     uint64_t count, limit;
112 
113     if (t->limit == 0) { /* free-run system or processor counter */
114         limit = TIMER_MAX_COUNT32;
115     } else {
116         limit = t->limit;
117     }
118     count = limit - PERIODS_TO_LIMIT(ptimer_get_count(t->timer));
119 
120     trace_slavio_timer_get_out(t->limit, t->counthigh, t->count);
121     t->count = count & TIMER_COUNT_MASK32;
122     t->counthigh = count >> 32;
123 }
124 
125 // timer callback
126 static void slavio_timer_irq(void *opaque)
127 {
128     TimerContext *tc = opaque;
129     SLAVIO_TIMERState *s = tc->s;
130     CPUTimerState *t = &s->cputimer[tc->timer_index];
131 
132     slavio_timer_get_out(t);
133     trace_slavio_timer_irq(t->counthigh, t->count);
134     /* if limit is 0 (free-run), there will be no match */
135     if (t->limit != 0) {
136         t->reached = TIMER_REACHED;
137     }
138     /* there is no interrupt if user timer or free-run */
139     if (!slavio_timer_is_user(tc) && t->limit != 0) {
140         qemu_irq_raise(t->irq);
141     }
142 }
143 
144 static uint64_t slavio_timer_mem_readl(void *opaque, hwaddr addr,
145                                        unsigned size)
146 {
147     TimerContext *tc = opaque;
148     SLAVIO_TIMERState *s = tc->s;
149     uint32_t saddr, ret;
150     unsigned int timer_index = tc->timer_index;
151     CPUTimerState *t = &s->cputimer[timer_index];
152 
153     saddr = addr >> 2;
154     switch (saddr) {
155     case TIMER_LIMIT:
156         // read limit (system counter mode) or read most signifying
157         // part of counter (user mode)
158         if (slavio_timer_is_user(tc)) {
159             // read user timer MSW
160             slavio_timer_get_out(t);
161             ret = t->counthigh | t->reached;
162         } else {
163             // read limit
164             // clear irq
165             qemu_irq_lower(t->irq);
166             t->reached = 0;
167             ret = t->limit & TIMER_LIMIT_MASK32;
168         }
169         break;
170     case TIMER_COUNTER:
171         // read counter and reached bit (system mode) or read lsbits
172         // of counter (user mode)
173         slavio_timer_get_out(t);
174         if (slavio_timer_is_user(tc)) { // read user timer LSW
175             ret = t->count & TIMER_MAX_COUNT64;
176         } else { // read limit
177             ret = (t->count & TIMER_MAX_COUNT32) |
178                 t->reached;
179         }
180         break;
181     case TIMER_STATUS:
182         // only available in processor counter/timer
183         // read start/stop status
184         if (timer_index > 0) {
185             ret = t->run;
186         } else {
187             ret = 0;
188         }
189         break;
190     case TIMER_MODE:
191         // only available in system counter
192         // read user/system mode
193         ret = s->cputimer_mode;
194         break;
195     default:
196         trace_slavio_timer_mem_readl_invalid(addr);
197         ret = 0;
198         break;
199     }
200     trace_slavio_timer_mem_readl(addr, ret);
201     return ret;
202 }
203 
204 static void slavio_timer_mem_writel(void *opaque, hwaddr addr,
205                                     uint64_t val, unsigned size)
206 {
207     TimerContext *tc = opaque;
208     SLAVIO_TIMERState *s = tc->s;
209     uint32_t saddr;
210     unsigned int timer_index = tc->timer_index;
211     CPUTimerState *t = &s->cputimer[timer_index];
212 
213     trace_slavio_timer_mem_writel(addr, val);
214     saddr = addr >> 2;
215     switch (saddr) {
216     case TIMER_LIMIT:
217         ptimer_transaction_begin(t->timer);
218         if (slavio_timer_is_user(tc)) {
219             uint64_t count;
220 
221             // set user counter MSW, reset counter
222             t->limit = TIMER_MAX_COUNT64;
223             t->counthigh = val & (TIMER_MAX_COUNT64 >> 32);
224             t->reached = 0;
225             count = ((uint64_t)t->counthigh << 32) | t->count;
226             trace_slavio_timer_mem_writel_limit(timer_index, count);
227             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
228         } else {
229             // set limit, reset counter
230             qemu_irq_lower(t->irq);
231             t->limit = val & TIMER_MAX_COUNT32;
232             if (t->limit == 0) { /* free-run */
233                 ptimer_set_limit(t->timer,
234                                  LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
235             } else {
236                 ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1);
237             }
238         }
239         ptimer_transaction_commit(t->timer);
240         break;
241     case TIMER_COUNTER:
242         if (slavio_timer_is_user(tc)) {
243             uint64_t count;
244 
245             // set user counter LSW, reset counter
246             t->limit = TIMER_MAX_COUNT64;
247             t->count = val & TIMER_MAX_COUNT64;
248             t->reached = 0;
249             count = ((uint64_t)t->counthigh) << 32 | t->count;
250             trace_slavio_timer_mem_writel_limit(timer_index, count);
251             ptimer_transaction_begin(t->timer);
252             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
253             ptimer_transaction_commit(t->timer);
254         } else {
255             trace_slavio_timer_mem_writel_counter_invalid();
256         }
257         break;
258     case TIMER_COUNTER_NORST:
259         // set limit without resetting counter
260         t->limit = val & TIMER_MAX_COUNT32;
261         ptimer_transaction_begin(t->timer);
262         if (t->limit == 0) { /* free-run */
263             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 0);
264         } else {
265             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 0);
266         }
267         ptimer_transaction_commit(t->timer);
268         break;
269     case TIMER_STATUS:
270         ptimer_transaction_begin(t->timer);
271         if (slavio_timer_is_user(tc)) {
272             // start/stop user counter
273             if (val & 1) {
274                 trace_slavio_timer_mem_writel_status_start(timer_index);
275                 ptimer_run(t->timer, 0);
276             } else {
277                 trace_slavio_timer_mem_writel_status_stop(timer_index);
278                 ptimer_stop(t->timer);
279             }
280         }
281         t->run = val & 1;
282         ptimer_transaction_commit(t->timer);
283         break;
284     case TIMER_MODE:
285         if (timer_index == 0) {
286             unsigned int i;
287 
288             for (i = 0; i < s->num_cpus; i++) {
289                 unsigned int processor = 1 << i;
290                 CPUTimerState *curr_timer = &s->cputimer[i + 1];
291 
292                 ptimer_transaction_begin(curr_timer->timer);
293                 // check for a change in timer mode for this processor
294                 if ((val & processor) != (s->cputimer_mode & processor)) {
295                     if (val & processor) { // counter -> user timer
296                         qemu_irq_lower(curr_timer->irq);
297                         // counters are always running
298                         if (!curr_timer->run) {
299                             ptimer_stop(curr_timer->timer);
300                         }
301                         // user timer limit is always the same
302                         curr_timer->limit = TIMER_MAX_COUNT64;
303                         ptimer_set_limit(curr_timer->timer,
304                                          LIMIT_TO_PERIODS(curr_timer->limit),
305                                          1);
306                         // set this processors user timer bit in config
307                         // register
308                         s->cputimer_mode |= processor;
309                         trace_slavio_timer_mem_writel_mode_user(timer_index);
310                     } else { // user timer -> counter
311                         // start the counter
312                         ptimer_run(curr_timer->timer, 0);
313                         // clear this processors user timer bit in config
314                         // register
315                         s->cputimer_mode &= ~processor;
316                         trace_slavio_timer_mem_writel_mode_counter(timer_index);
317                     }
318                 }
319                 ptimer_transaction_commit(curr_timer->timer);
320             }
321         } else {
322             trace_slavio_timer_mem_writel_mode_invalid();
323         }
324         break;
325     default:
326         trace_slavio_timer_mem_writel_invalid(addr);
327         break;
328     }
329 }
330 
331 static const MemoryRegionOps slavio_timer_mem_ops = {
332     .read = slavio_timer_mem_readl,
333     .write = slavio_timer_mem_writel,
334     .endianness = DEVICE_NATIVE_ENDIAN,
335     .valid = {
336         .min_access_size = 4,
337         .max_access_size = 4,
338     },
339 };
340 
341 static const VMStateDescription vmstate_timer = {
342     .name ="timer",
343     .version_id = 3,
344     .minimum_version_id = 3,
345     .fields = (VMStateField[]) {
346         VMSTATE_UINT64(limit, CPUTimerState),
347         VMSTATE_UINT32(count, CPUTimerState),
348         VMSTATE_UINT32(counthigh, CPUTimerState),
349         VMSTATE_UINT32(reached, CPUTimerState),
350         VMSTATE_UINT32(run    , CPUTimerState),
351         VMSTATE_PTIMER(timer, CPUTimerState),
352         VMSTATE_END_OF_LIST()
353     }
354 };
355 
356 static const VMStateDescription vmstate_slavio_timer = {
357     .name ="slavio_timer",
358     .version_id = 3,
359     .minimum_version_id = 3,
360     .fields = (VMStateField[]) {
361         VMSTATE_STRUCT_ARRAY(cputimer, SLAVIO_TIMERState, MAX_CPUS + 1, 3,
362                              vmstate_timer, CPUTimerState),
363         VMSTATE_END_OF_LIST()
364     }
365 };
366 
367 static void slavio_timer_reset(DeviceState *d)
368 {
369     SLAVIO_TIMERState *s = SLAVIO_TIMER(d);
370     unsigned int i;
371     CPUTimerState *curr_timer;
372 
373     for (i = 0; i <= MAX_CPUS; i++) {
374         curr_timer = &s->cputimer[i];
375         curr_timer->limit = 0;
376         curr_timer->count = 0;
377         curr_timer->reached = 0;
378         if (i <= s->num_cpus) {
379             ptimer_transaction_begin(curr_timer->timer);
380             ptimer_set_limit(curr_timer->timer,
381                              LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
382             ptimer_run(curr_timer->timer, 0);
383             curr_timer->run = 1;
384             ptimer_transaction_commit(curr_timer->timer);
385         }
386     }
387     s->cputimer_mode = 0;
388 }
389 
390 static void slavio_timer_init(Object *obj)
391 {
392     SLAVIO_TIMERState *s = SLAVIO_TIMER(obj);
393     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
394     unsigned int i;
395     TimerContext *tc;
396 
397     for (i = 0; i <= MAX_CPUS; i++) {
398         uint64_t size;
399         char timer_name[20];
400 
401         tc = g_malloc0(sizeof(TimerContext));
402         tc->s = s;
403         tc->timer_index = i;
404 
405         s->cputimer[i].timer = ptimer_init(slavio_timer_irq, tc,
406                                            PTIMER_POLICY_DEFAULT);
407         ptimer_transaction_begin(s->cputimer[i].timer);
408         ptimer_set_period(s->cputimer[i].timer, TIMER_PERIOD);
409         ptimer_transaction_commit(s->cputimer[i].timer);
410 
411         size = i == 0 ? SYS_TIMER_SIZE : CPU_TIMER_SIZE;
412         snprintf(timer_name, sizeof(timer_name), "timer-%i", i);
413         memory_region_init_io(&tc->iomem, obj, &slavio_timer_mem_ops, tc,
414                               timer_name, size);
415         sysbus_init_mmio(dev, &tc->iomem);
416 
417         sysbus_init_irq(dev, &s->cputimer[i].irq);
418     }
419 }
420 
421 static Property slavio_timer_properties[] = {
422     DEFINE_PROP_UINT32("num_cpus",  SLAVIO_TIMERState, num_cpus,  0),
423     DEFINE_PROP_END_OF_LIST(),
424 };
425 
426 static void slavio_timer_class_init(ObjectClass *klass, void *data)
427 {
428     DeviceClass *dc = DEVICE_CLASS(klass);
429 
430     dc->reset = slavio_timer_reset;
431     dc->vmsd = &vmstate_slavio_timer;
432     device_class_set_props(dc, slavio_timer_properties);
433 }
434 
435 static const TypeInfo slavio_timer_info = {
436     .name          = TYPE_SLAVIO_TIMER,
437     .parent        = TYPE_SYS_BUS_DEVICE,
438     .instance_size = sizeof(SLAVIO_TIMERState),
439     .instance_init = slavio_timer_init,
440     .class_init    = slavio_timer_class_init,
441 };
442 
443 static void slavio_timer_register_types(void)
444 {
445     type_register_static(&slavio_timer_info);
446 }
447 
448 type_init(slavio_timer_register_types)
449