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