hw/timer/slavio_timer.c

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