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 "hw/sparc/sun4m.h"
  26 #include "qemu/timer.h"
  27 #include "hw/ptimer.h"
  28 #include "hw/sysbus.h"
  29 #include "trace.h"
  30
  31 /*
  32  * Registers of hardware timer in sun4m.
  33  *
  34  * This is the timer/counter part of chip STP2001 (Slave I/O), also
  35  * produced as NCR89C105. See
  36  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt
  37  *
  38  * The 31-bit counter is incremented every 500ns by bit 9. Bits 8..0
  39  * are zero. Bit 31 is 1 when count has been reached.
  40  *
  41  * Per-CPU timers interrupt local CPU, system timer uses normal
  42  * interrupt routing.
  43  *
  44  */
  45
  46 #define MAX_CPUS 16
  47
  48 typedef struct CPUTimerState {
  49     qemu_irq irq;
  50     ptimer_state *timer;
  51     uint32_t count, counthigh, reached;
  52     /* processor only */
  53     uint32_t running;
  54     uint64_t limit;
  55 } CPUTimerState;
  56
  57 typedef struct SLAVIO_TIMERState {
  58     SysBusDevice busdev;
  59     uint32_t num_cpus;
  60     uint32_t cputimer_mode;
  61     CPUTimerState cputimer[MAX_CPUS + 1];
  62 } SLAVIO_TIMERState;
  63
  64 typedef struct TimerContext {
  65     MemoryRegion iomem;
  66     SLAVIO_TIMERState *s;
  67     unsigned int timer_index; /* 0 for system, 1 ... MAX_CPUS for CPU timers */
  68 } TimerContext;
  69
  70 #define SYS_TIMER_SIZE 0x14
  71 #define CPU_TIMER_SIZE 0x10
  72
  73 #define TIMER_LIMIT         0
  74 #define TIMER_COUNTER       1
  75 #define TIMER_COUNTER_NORST 2
  76 #define TIMER_STATUS        3
  77 #define TIMER_MODE          4
  78
  79 #define TIMER_COUNT_MASK32 0xfffffe00
  80 #define TIMER_LIMIT_MASK32 0x7fffffff
  81 #define TIMER_MAX_COUNT64  0x7ffffffffffffe00ULL
  82 #define TIMER_MAX_COUNT32  0x7ffffe00ULL
  83 #define TIMER_REACHED      0x80000000
  84 #define TIMER_PERIOD       500ULL // 500ns
  85 #define LIMIT_TO_PERIODS(l) (((l) >> 9) - 1)
  86 #define PERIODS_TO_LIMIT(l) (((l) + 1) << 9)
  87
  88 static int slavio_timer_is_user(TimerContext *tc)
  89 {
  90     SLAVIO_TIMERState *s = tc->s;
  91     unsigned int timer_index = tc->timer_index;
  92
  93     return timer_index != 0 && (s->cputimer_mode & (1 << (timer_index - 1)));
  94 }
  95
  96 // Update count, set irq, update expire_time
  97 // Convert from ptimer countdown units
  98 static void slavio_timer_get_out(CPUTimerState *t)
  99 {
 100     uint64_t count, limit;
 101
 102     if (t->limit == 0) { /* free-run system or processor counter */
 103         limit = TIMER_MAX_COUNT32;
 104     } else {
 105         limit = t->limit;
 106     }
 107     count = limit - PERIODS_TO_LIMIT(ptimer_get_count(t->timer));
 108
 109     trace_slavio_timer_get_out(t->limit, t->counthigh, t->count);
 110     t->count = count & TIMER_COUNT_MASK32;
 111     t->counthigh = count >> 32;
 112 }
 113
 114 // timer callback
 115 static void slavio_timer_irq(void *opaque)
 116 {
 117     TimerContext *tc = opaque;
 118     SLAVIO_TIMERState *s = tc->s;
 119     CPUTimerState *t = &s->cputimer[tc->timer_index];
 120
 121     slavio_timer_get_out(t);
 122     trace_slavio_timer_irq(t->counthigh, t->count);
 123     /* if limit is 0 (free-run), there will be no match */
 124     if (t->limit != 0) {
 125         t->reached = TIMER_REACHED;
 126     }
 127     /* there is no interrupt if user timer or free-run */
 128     if (!slavio_timer_is_user(tc) && t->limit != 0) {
 129         qemu_irq_raise(t->irq);
 130     }
 131 }
 132
 133 static uint64_t slavio_timer_mem_readl(void *opaque, hwaddr addr,
 134                                        unsigned size)
 135 {
 136     TimerContext *tc = opaque;
 137     SLAVIO_TIMERState *s = tc->s;
 138     uint32_t saddr, ret;
 139     unsigned int timer_index = tc->timer_index;
 140     CPUTimerState *t = &s->cputimer[timer_index];
 141
 142     saddr = addr >> 2;
 143     switch (saddr) {
 144     case TIMER_LIMIT:
 145         // read limit (system counter mode) or read most signifying
 146         // part of counter (user mode)
 147         if (slavio_timer_is_user(tc)) {
 148             // read user timer MSW
 149             slavio_timer_get_out(t);
 150             ret = t->counthigh | t->reached;
 151         } else {
 152             // read limit
 153             // clear irq
 154             qemu_irq_lower(t->irq);
 155             t->reached = 0;
 156             ret = t->limit & TIMER_LIMIT_MASK32;
 157         }
 158         break;
 159     case TIMER_COUNTER:
 160         // read counter and reached bit (system mode) or read lsbits
 161         // of counter (user mode)
 162         slavio_timer_get_out(t);
 163         if (slavio_timer_is_user(tc)) { // read user timer LSW
 164             ret = t->count & TIMER_MAX_COUNT64;
 165         } else { // read limit
 166             ret = (t->count & TIMER_MAX_COUNT32) |
 167                 t->reached;
 168         }
 169         break;
 170     case TIMER_STATUS:
 171         // only available in processor counter/timer
 172         // read start/stop status
 173         if (timer_index > 0) {
 174             ret = t->running;
 175         } else {
 176             ret = 0;
 177         }
 178         break;
 179     case TIMER_MODE:
 180         // only available in system counter
 181         // read user/system mode
 182         ret = s->cputimer_mode;
 183         break;
 184     default:
 185         trace_slavio_timer_mem_readl_invalid(addr);
 186         ret = 0;
 187         break;
 188     }
 189     trace_slavio_timer_mem_readl(addr, ret);
 190     return ret;
 191 }
 192
 193 static void slavio_timer_mem_writel(void *opaque, hwaddr addr,
 194                                     uint64_t val, unsigned size)
 195 {
 196     TimerContext *tc = opaque;
 197     SLAVIO_TIMERState *s = tc->s;
 198     uint32_t saddr;
 199     unsigned int timer_index = tc->timer_index;
 200     CPUTimerState *t = &s->cputimer[timer_index];
 201
 202     trace_slavio_timer_mem_writel(addr, val);
 203     saddr = addr >> 2;
 204     switch (saddr) {
 205     case TIMER_LIMIT:
 206         if (slavio_timer_is_user(tc)) {
 207             uint64_t count;
 208
 209             // set user counter MSW, reset counter
 210             t->limit = TIMER_MAX_COUNT64;
 211             t->counthigh = val & (TIMER_MAX_COUNT64 >> 32);
 212             t->reached = 0;
 213             count = ((uint64_t)t->counthigh << 32) | t->count;
 214             trace_slavio_timer_mem_writel_limit(timer_index, count);
 215             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
 216         } else {
 217             // set limit, reset counter
 218             qemu_irq_lower(t->irq);
 219             t->limit = val & TIMER_MAX_COUNT32;
 220             if (t->timer) {
 221                 if (t->limit == 0) { /* free-run */
 222                     ptimer_set_limit(t->timer,
 223                                      LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
 224                 } else {
 225                     ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1);
 226                 }
 227             }
 228         }
 229         break;
 230     case TIMER_COUNTER:
 231         if (slavio_timer_is_user(tc)) {
 232             uint64_t count;
 233
 234             // set user counter LSW, reset counter
 235             t->limit = TIMER_MAX_COUNT64;
 236             t->count = val & TIMER_MAX_COUNT64;
 237             t->reached = 0;
 238             count = ((uint64_t)t->counthigh) << 32 | t->count;
 239             trace_slavio_timer_mem_writel_limit(timer_index, count);
 240             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
 241         } else {
 242             trace_slavio_timer_mem_writel_counter_invalid();
 243         }
 244         break;
 245     case TIMER_COUNTER_NORST:
 246         // set limit without resetting counter
 247         t->limit = val & TIMER_MAX_COUNT32;
 248         if (t->limit == 0) { /* free-run */
 249             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 0);
 250         } else {
 251             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 0);
 252         }
 253         break;
 254     case TIMER_STATUS:
 255         if (slavio_timer_is_user(tc)) {
 256             // start/stop user counter
 257             if ((val & 1) && !t->running) {
 258                 trace_slavio_timer_mem_writel_status_start(timer_index);
 259                 ptimer_run(t->timer, 0);
 260                 t->running = 1;
 261             } else if (!(val & 1) && t->running) {
 262                 trace_slavio_timer_mem_writel_status_stop(timer_index);
 263                 ptimer_stop(t->timer);
 264                 t->running = 0;
 265             }
 266         }
 267         break;
 268     case TIMER_MODE:
 269         if (timer_index == 0) {
 270             unsigned int i;
 271
 272             for (i = 0; i < s->num_cpus; i++) {
 273                 unsigned int processor = 1 << i;
 274                 CPUTimerState *curr_timer = &s->cputimer[i + 1];
 275
 276                 // check for a change in timer mode for this processor
 277                 if ((val & processor) != (s->cputimer_mode & processor)) {
 278                     if (val & processor) { // counter -> user timer
 279                         qemu_irq_lower(curr_timer->irq);
 280                         // counters are always running
 281                         ptimer_stop(curr_timer->timer);
 282                         curr_timer->running = 0;
 283                         // user timer limit is always the same
 284                         curr_timer->limit = TIMER_MAX_COUNT64;
 285                         ptimer_set_limit(curr_timer->timer,
 286                                          LIMIT_TO_PERIODS(curr_timer->limit),
 287                                          1);
 288                         // set this processors user timer bit in config
 289                         // register
 290                         s->cputimer_mode |= processor;
 291                         trace_slavio_timer_mem_writel_mode_user(timer_index);
 292                     } else { // user timer -> counter
 293                         // stop the user timer if it is running
 294                         if (curr_timer->running) {
 295                             ptimer_stop(curr_timer->timer);
 296                         }
 297                         // start the counter
 298                         ptimer_run(curr_timer->timer, 0);
 299                         curr_timer->running = 1;
 300                         // clear this processors user timer bit in config
 301                         // register
 302                         s->cputimer_mode &= ~processor;
 303                         trace_slavio_timer_mem_writel_mode_counter(timer_index);
 304                     }
 305                 }
 306             }
 307         } else {
 308             trace_slavio_timer_mem_writel_mode_invalid();
 309         }
 310         break;
 311     default:
 312         trace_slavio_timer_mem_writel_invalid(addr);
 313         break;
 314     }
 315 }
 316
 317 static const MemoryRegionOps slavio_timer_mem_ops = {
 318     .read = slavio_timer_mem_readl,
 319     .write = slavio_timer_mem_writel,
 320     .endianness = DEVICE_NATIVE_ENDIAN,
 321     .valid = {
 322         .min_access_size = 4,
 323         .max_access_size = 4,
 324     },
 325 };
 326
 327 static const VMStateDescription vmstate_timer = {
 328     .name ="timer",
 329     .version_id = 3,
 330     .minimum_version_id = 3,
 331     .minimum_version_id_old = 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(running, 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     .minimum_version_id_old = 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 = container_of(d, SLAVIO_TIMERState, busdev.qdev);
 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->running = 1;
 371         }
 372     }
 373     s->cputimer_mode = 0;
 374 }
 375
 376 static int slavio_timer_init1(SysBusDevice *dev)
 377 {
 378     SLAVIO_TIMERState *s = FROM_SYSBUS(SLAVIO_TIMERState, dev);
 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);
 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, NULL, &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     return 0;
 405 }
 406
 407 static Property slavio_timer_properties[] = {
 408     DEFINE_PROP_UINT32("num_cpus",  SLAVIO_TIMERState, num_cpus,  0),
 409     DEFINE_PROP_END_OF_LIST(),
 410 };
 411
 412 static void slavio_timer_class_init(ObjectClass *klass, void *data)
 413 {
 414     DeviceClass *dc = DEVICE_CLASS(klass);
 415     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 416
 417     k->init = slavio_timer_init1;
 418     dc->reset = slavio_timer_reset;
 419     dc->vmsd = &vmstate_slavio_timer;
 420     dc->props = slavio_timer_properties;
 421 }
 422
 423 static const TypeInfo slavio_timer_info = {
 424     .name          = "slavio_timer",
 425     .parent        = TYPE_SYS_BUS_DEVICE,
 426     .instance_size = sizeof(SLAVIO_TIMERState),
 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)