hw/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 "sun4m.h"
  26 #include "qemu-timer.h"
  27 #include "sysbus.h"
  28 #include "trace.h"
  29
  30 /*
  31  * Registers of hardware timer in sun4m.
  32  *
  33  * This is the timer/counter part of chip STP2001 (Slave I/O), also
  34  * produced as NCR89C105. See
  35  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt
  36  *
  37  * The 31-bit counter is incremented every 500ns by bit 9. Bits 8..0
  38  * are zero. Bit 31 is 1 when count has been reached.
  39  *
  40  * Per-CPU timers interrupt local CPU, system timer uses normal
  41  * interrupt routing.
  42  *
  43  */
  44
  45 #define MAX_CPUS 16
  46
  47 typedef struct CPUTimerState {
  48     qemu_irq irq;
  49     ptimer_state *timer;
  50     uint32_t count, counthigh, reached;
  51     uint64_t limit;
  52     // processor only
  53     uint32_t running;
  54 } CPUTimerState;
  55
  56 typedef struct SLAVIO_TIMERState {
  57     SysBusDevice busdev;
  58     uint32_t num_cpus;
  59     CPUTimerState cputimer[MAX_CPUS + 1];
  60     uint32_t cputimer_mode;
  61 } SLAVIO_TIMERState;
  62
  63 typedef struct TimerContext {
  64     SLAVIO_TIMERState *s;
  65     unsigned int timer_index; /* 0 for system, 1 ... MAX_CPUS for CPU timers */
  66 } TimerContext;
  67
  68 #define SYS_TIMER_SIZE 0x14
  69 #define CPU_TIMER_SIZE 0x10
  70
  71 #define TIMER_LIMIT         0
  72 #define TIMER_COUNTER       1
  73 #define TIMER_COUNTER_NORST 2
  74 #define TIMER_STATUS        3
  75 #define TIMER_MODE          4
  76
  77 #define TIMER_COUNT_MASK32 0xfffffe00
  78 #define TIMER_LIMIT_MASK32 0x7fffffff
  79 #define TIMER_MAX_COUNT64  0x7ffffffffffffe00ULL
  80 #define TIMER_MAX_COUNT32  0x7ffffe00ULL
  81 #define TIMER_REACHED      0x80000000
  82 #define TIMER_PERIOD       500ULL // 500ns
  83 #define LIMIT_TO_PERIODS(l) (((l) >> 9) - 1)
  84 #define PERIODS_TO_LIMIT(l) (((l) + 1) << 9)
  85
  86 static int slavio_timer_is_user(TimerContext *tc)
  87 {
  88     SLAVIO_TIMERState *s = tc->s;
  89     unsigned int timer_index = tc->timer_index;
  90
  91     return timer_index != 0 && (s->cputimer_mode & (1 << (timer_index - 1)));
  92 }
  93
  94 // Update count, set irq, update expire_time
  95 // Convert from ptimer countdown units
  96 static void slavio_timer_get_out(CPUTimerState *t)
  97 {
  98     uint64_t count, limit;
  99
 100     if (t->limit == 0) { /* free-run system or processor counter */
 101         limit = TIMER_MAX_COUNT32;
 102     } else {
 103         limit = t->limit;
 104     }
 105     count = limit - PERIODS_TO_LIMIT(ptimer_get_count(t->timer));
 106
 107     trace_slavio_timer_get_out(t->limit, t->counthigh, t->count);
 108     t->count = count & TIMER_COUNT_MASK32;
 109     t->counthigh = count >> 32;
 110 }
 111
 112 // timer callback
 113 static void slavio_timer_irq(void *opaque)
 114 {
 115     TimerContext *tc = opaque;
 116     SLAVIO_TIMERState *s = tc->s;
 117     CPUTimerState *t = &s->cputimer[tc->timer_index];
 118
 119     slavio_timer_get_out(t);
 120     trace_slavio_timer_irq(t->counthigh, t->count);
 121     /* if limit is 0 (free-run), there will be no match */
 122     if (t->limit != 0) {
 123         t->reached = TIMER_REACHED;
 124     }
 125     /* there is no interrupt if user timer or free-run */
 126     if (!slavio_timer_is_user(tc) && t->limit != 0) {
 127         qemu_irq_raise(t->irq);
 128     }
 129 }
 130
 131 static uint32_t slavio_timer_mem_readl(void *opaque, target_phys_addr_t addr)
 132 {
 133     TimerContext *tc = opaque;
 134     SLAVIO_TIMERState *s = tc->s;
 135     uint32_t saddr, ret;
 136     unsigned int timer_index = tc->timer_index;
 137     CPUTimerState *t = &s->cputimer[timer_index];
 138
 139     saddr = addr >> 2;
 140     switch (saddr) {
 141     case TIMER_LIMIT:
 142         // read limit (system counter mode) or read most signifying
 143         // part of counter (user mode)
 144         if (slavio_timer_is_user(tc)) {
 145             // read user timer MSW
 146             slavio_timer_get_out(t);
 147             ret = t->counthigh | t->reached;
 148         } else {
 149             // read limit
 150             // clear irq
 151             qemu_irq_lower(t->irq);
 152             t->reached = 0;
 153             ret = t->limit & TIMER_LIMIT_MASK32;
 154         }
 155         break;
 156     case TIMER_COUNTER:
 157         // read counter and reached bit (system mode) or read lsbits
 158         // of counter (user mode)
 159         slavio_timer_get_out(t);
 160         if (slavio_timer_is_user(tc)) { // read user timer LSW
 161             ret = t->count & TIMER_MAX_COUNT64;
 162         } else { // read limit
 163             ret = (t->count & TIMER_MAX_COUNT32) |
 164                 t->reached;
 165         }
 166         break;
 167     case TIMER_STATUS:
 168         // only available in processor counter/timer
 169         // read start/stop status
 170         if (timer_index > 0) {
 171             ret = t->running;
 172         } else {
 173             ret = 0;
 174         }
 175         break;
 176     case TIMER_MODE:
 177         // only available in system counter
 178         // read user/system mode
 179         ret = s->cputimer_mode;
 180         break;
 181     default:
 182         trace_slavio_timer_mem_readl_invalid(addr);
 183         ret = 0;
 184         break;
 185     }
 186     trace_slavio_timer_mem_readl(addr, ret);
 187     return ret;
 188 }
 189
 190 static void slavio_timer_mem_writel(void *opaque, target_phys_addr_t addr,
 191                                     uint32_t val)
 192 {
 193     TimerContext *tc = opaque;
 194     SLAVIO_TIMERState *s = tc->s;
 195     uint32_t saddr;
 196     unsigned int timer_index = tc->timer_index;
 197     CPUTimerState *t = &s->cputimer[timer_index];
 198
 199     trace_slavio_timer_mem_writel(addr, val);
 200     saddr = addr >> 2;
 201     switch (saddr) {
 202     case TIMER_LIMIT:
 203         if (slavio_timer_is_user(tc)) {
 204             uint64_t count;
 205
 206             // set user counter MSW, reset counter
 207             t->limit = TIMER_MAX_COUNT64;
 208             t->counthigh = val & (TIMER_MAX_COUNT64 >> 32);
 209             t->reached = 0;
 210             count = ((uint64_t)t->counthigh << 32) | t->count;
 211             trace_slavio_timer_mem_writel_limit(timer_index, count);
 212             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
 213         } else {
 214             // set limit, reset counter
 215             qemu_irq_lower(t->irq);
 216             t->limit = val & TIMER_MAX_COUNT32;
 217             if (t->timer) {
 218                 if (t->limit == 0) { /* free-run */
 219                     ptimer_set_limit(t->timer,
 220                                      LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
 221                 } else {
 222                     ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1);
 223                 }
 224             }
 225         }
 226         break;
 227     case TIMER_COUNTER:
 228         if (slavio_timer_is_user(tc)) {
 229             uint64_t count;
 230
 231             // set user counter LSW, reset counter
 232             t->limit = TIMER_MAX_COUNT64;
 233             t->count = val & TIMER_MAX_COUNT64;
 234             t->reached = 0;
 235             count = ((uint64_t)t->counthigh) << 32 | t->count;
 236             trace_slavio_timer_mem_writel_limit(timer_index, count);
 237             ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
 238         } else {
 239             trace_slavio_timer_mem_writel_counter_invalid();
 240         }
 241         break;
 242     case TIMER_COUNTER_NORST:
 243         // set limit without resetting counter
 244         t->limit = val & TIMER_MAX_COUNT32;
 245         if (t->limit == 0) { /* free-run */
 246             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 0);
 247         } else {
 248             ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 0);
 249         }
 250         break;
 251     case TIMER_STATUS:
 252         if (slavio_timer_is_user(tc)) {
 253             // start/stop user counter
 254             if ((val & 1) && !t->running) {
 255                 trace_slavio_timer_mem_writel_status_start(timer_index);
 256                 ptimer_run(t->timer, 0);
 257                 t->running = 1;
 258             } else if (!(val & 1) && t->running) {
 259                 trace_slavio_timer_mem_writel_status_stop(timer_index);
 260                 ptimer_stop(t->timer);
 261                 t->running = 0;
 262             }
 263         }
 264         break;
 265     case TIMER_MODE:
 266         if (timer_index == 0) {
 267             unsigned int i;
 268
 269             for (i = 0; i < s->num_cpus; i++) {
 270                 unsigned int processor = 1 << i;
 271                 CPUTimerState *curr_timer = &s->cputimer[i + 1];
 272
 273                 // check for a change in timer mode for this processor
 274                 if ((val & processor) != (s->cputimer_mode & processor)) {
 275                     if (val & processor) { // counter -> user timer
 276                         qemu_irq_lower(curr_timer->irq);
 277                         // counters are always running
 278                         ptimer_stop(curr_timer->timer);
 279                         curr_timer->running = 0;
 280                         // user timer limit is always the same
 281                         curr_timer->limit = TIMER_MAX_COUNT64;
 282                         ptimer_set_limit(curr_timer->timer,
 283                                          LIMIT_TO_PERIODS(curr_timer->limit),
 284                                          1);
 285                         // set this processors user timer bit in config
 286                         // register
 287                         s->cputimer_mode |= processor;
 288                         trace_slavio_timer_mem_writel_mode_user(timer_index);
 289                     } else { // user timer -> counter
 290                         // stop the user timer if it is running
 291                         if (curr_timer->running) {
 292                             ptimer_stop(curr_timer->timer);
 293                         }
 294                         // start the counter
 295                         ptimer_run(curr_timer->timer, 0);
 296                         curr_timer->running = 1;
 297                         // clear this processors user timer bit in config
 298                         // register
 299                         s->cputimer_mode &= ~processor;
 300                         trace_slavio_timer_mem_writel_mode_counter(timer_index);
 301                     }
 302                 }
 303             }
 304         } else {
 305             trace_slavio_timer_mem_writel_mode_invalid();
 306         }
 307         break;
 308     default:
 309         trace_slavio_timer_mem_writel_invalid(addr);
 310         break;
 311     }
 312 }
 313
 314 static CPUReadMemoryFunc * const slavio_timer_mem_read[3] = {
 315     NULL,
 316     NULL,
 317     slavio_timer_mem_readl,
 318 };
 319
 320 static CPUWriteMemoryFunc * const slavio_timer_mem_write[3] = {
 321     NULL,
 322     NULL,
 323     slavio_timer_mem_writel,
 324 };
 325
 326 static const VMStateDescription vmstate_timer = {
 327     .name ="timer",
 328     .version_id = 3,
 329     .minimum_version_id = 3,
 330     .minimum_version_id_old = 3,
 331     .fields      = (VMStateField []) {
 332         VMSTATE_UINT64(limit, CPUTimerState),
 333         VMSTATE_UINT32(count, CPUTimerState),
 334         VMSTATE_UINT32(counthigh, CPUTimerState),
 335         VMSTATE_UINT32(reached, CPUTimerState),
 336         VMSTATE_UINT32(running, CPUTimerState),
 337         VMSTATE_PTIMER(timer, CPUTimerState),
 338         VMSTATE_END_OF_LIST()
 339     }
 340 };
 341
 342 static const VMStateDescription vmstate_slavio_timer = {
 343     .name ="slavio_timer",
 344     .version_id = 3,
 345     .minimum_version_id = 3,
 346     .minimum_version_id_old = 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 = container_of(d, SLAVIO_TIMERState, busdev.qdev);
 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->running = 1;
 370         }
 371     }
 372     s->cputimer_mode = 0;
 373 }
 374
 375 static int slavio_timer_init1(SysBusDevice *dev)
 376 {
 377     int io;
 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         tc = qemu_mallocz(sizeof(TimerContext));
 385         tc->s = s;
 386         tc->timer_index = i;
 387
 388         bh = qemu_bh_new(slavio_timer_irq, tc);
 389         s->cputimer[i].timer = ptimer_init(bh);
 390         ptimer_set_period(s->cputimer[i].timer, TIMER_PERIOD);
 391
 392         io = cpu_register_io_memory(slavio_timer_mem_read,
 393                                     slavio_timer_mem_write, tc);
 394         if (i == 0) {
 395             sysbus_init_mmio(dev, SYS_TIMER_SIZE, io);
 396         } else {
 397             sysbus_init_mmio(dev, CPU_TIMER_SIZE, io);
 398         }
 399
 400         sysbus_init_irq(dev, &s->cputimer[i].irq);
 401     }
 402
 403     return 0;
 404 }
 405
 406 static SysBusDeviceInfo slavio_timer_info = {
 407     .init = slavio_timer_init1,
 408     .qdev.name  = "slavio_timer",
 409     .qdev.size  = sizeof(SLAVIO_TIMERState),
 410     .qdev.vmsd  = &vmstate_slavio_timer,
 411     .qdev.reset = slavio_timer_reset,
 412     .qdev.props = (Property[]) {
 413         DEFINE_PROP_UINT32("num_cpus",  SLAVIO_TIMERState, num_cpus,  0),
 414         DEFINE_PROP_END_OF_LIST(),
 415     }
 416 };
 417
 418 static void slavio_timer_register_devices(void)
 419 {
 420     sysbus_register_withprop(&slavio_timer_info);
 421 }
 422
 423 device_init(slavio_timer_register_devices)