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 #include "hw.h"
  25 #include "sun4m.h"
  26 #include "qemu-timer.h"
  27
  28 //#define DEBUG_TIMER
  29
  30 #ifdef DEBUG_TIMER
  31 #define DPRINTF(fmt, args...) \
  32 do { printf("TIMER: " fmt , ##args); } while (0)
  33 #else
  34 #define DPRINTF(fmt, args...) do {} while (0)
  35 #endif
  36
  37 /*
  38  * Registers of hardware timer in sun4m.
  39  *
  40  * This is the timer/counter part of chip STP2001 (Slave I/O), also
  41  * produced as NCR89C105. See
  42  * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt
  43  *
  44  * The 31-bit counter is incremented every 500ns by bit 9. Bits 8..0
  45  * are zero. Bit 31 is 1 when count has been reached.
  46  *
  47  * Per-CPU timers interrupt local CPU, system timer uses normal
  48  * interrupt routing.
  49  *
  50  */
  51
  52 #define MAX_CPUS 16
  53
  54 typedef struct SLAVIO_TIMERState {
  55     qemu_irq irq;
  56     ptimer_state *timer;
  57     uint32_t count, counthigh, reached;
  58     uint64_t limit;
  59     // processor only
  60     uint32_t running;
  61     struct SLAVIO_TIMERState *master;
  62     uint32_t slave_index;
  63     // system only
  64     uint32_t num_slaves;
  65     struct SLAVIO_TIMERState *slave[MAX_CPUS];
  66     uint32_t slave_mode;
  67 } SLAVIO_TIMERState;
  68
  69 #define SYS_TIMER_SIZE 0x14
  70 #define CPU_TIMER_SIZE 0x10
  71
  72 #define SYS_TIMER_OFFSET      0x10000ULL
  73 #define CPU_TIMER_OFFSET(cpu) (0x1000ULL * cpu)
  74
  75 #define TIMER_LIMIT         0
  76 #define TIMER_COUNTER       1
  77 #define TIMER_COUNTER_NORST 2
  78 #define TIMER_STATUS        3
  79 #define TIMER_MODE          4
  80
  81 #define TIMER_COUNT_MASK32 0xfffffe00
  82 #define TIMER_LIMIT_MASK32 0x7fffffff
  83 #define TIMER_MAX_COUNT64  0x7ffffffffffffe00ULL
  84 #define TIMER_MAX_COUNT32  0x7ffffe00ULL
  85 #define TIMER_REACHED      0x80000000
  86 #define TIMER_PERIOD       500ULL // 500ns
  87 #define LIMIT_TO_PERIODS(l) ((l) >> 9)
  88 #define PERIODS_TO_LIMIT(l) ((l) << 9)
  89
  90 static int slavio_timer_is_user(SLAVIO_TIMERState *s)
  91 {
  92     return s->master && (s->master->slave_mode & (1 << s->slave_index));
  93 }
  94
  95 // Update count, set irq, update expire_time
  96 // Convert from ptimer countdown units
  97 static void slavio_timer_get_out(SLAVIO_TIMERState *s)
  98 {
  99     uint64_t count, limit;
 100
 101     if (s->limit == 0) /* free-run processor or system counter */
 102         limit = TIMER_MAX_COUNT32;
 103     else
 104         limit = s->limit;
 105
 106     if (s->timer)
 107         count = limit - PERIODS_TO_LIMIT(ptimer_get_count(s->timer));
 108     else
 109         count = 0;
 110
 111     DPRINTF("get_out: limit %" PRIx64 " count %x%08x\n", s->limit,
 112             s->counthigh, s->count);
 113     s->count = count & TIMER_COUNT_MASK32;
 114     s->counthigh = count >> 32;
 115 }
 116
 117 // timer callback
 118 static void slavio_timer_irq(void *opaque)
 119 {
 120     SLAVIO_TIMERState *s = opaque;
 121
 122     slavio_timer_get_out(s);
 123     DPRINTF("callback: count %x%08x\n", s->counthigh, s->count);
 124     s->reached = TIMER_REACHED;
 125     if (!slavio_timer_is_user(s))
 126         qemu_irq_raise(s->irq);
 127 }
 128
 129 static uint32_t slavio_timer_mem_readl(void *opaque, target_phys_addr_t addr)
 130 {
 131     SLAVIO_TIMERState *s = opaque;
 132     uint32_t saddr, ret;
 133
 134     saddr = addr >> 2;
 135     switch (saddr) {
 136     case TIMER_LIMIT:
 137         // read limit (system counter mode) or read most signifying
 138         // part of counter (user mode)
 139         if (slavio_timer_is_user(s)) {
 140             // read user timer MSW
 141             slavio_timer_get_out(s);
 142             ret = s->counthigh | s->reached;
 143         } else {
 144             // read limit
 145             // clear irq
 146             qemu_irq_lower(s->irq);
 147             s->reached = 0;
 148             ret = s->limit & TIMER_LIMIT_MASK32;
 149         }
 150         break;
 151     case TIMER_COUNTER:
 152         // read counter and reached bit (system mode) or read lsbits
 153         // of counter (user mode)
 154         slavio_timer_get_out(s);
 155         if (slavio_timer_is_user(s)) // read user timer LSW
 156             ret = s->count & TIMER_MAX_COUNT64;
 157         else // read limit
 158             ret = (s->count & TIMER_MAX_COUNT32) | s->reached;
 159         break;
 160     case TIMER_STATUS:
 161         // only available in processor counter/timer
 162         // read start/stop status
 163         ret = s->running;
 164         break;
 165     case TIMER_MODE:
 166         // only available in system counter
 167         // read user/system mode
 168         ret = s->slave_mode;
 169         break;
 170     default:
 171         DPRINTF("invalid read address " TARGET_FMT_plx "\n", addr);
 172         ret = 0;
 173         break;
 174     }
 175     DPRINTF("read " TARGET_FMT_plx " = %08x\n", addr, ret);
 176
 177     return ret;
 178 }
 179
 180 static void slavio_timer_mem_writel(void *opaque, target_phys_addr_t addr,
 181                                     uint32_t val)
 182 {
 183     SLAVIO_TIMERState *s = opaque;
 184     uint32_t saddr;
 185
 186     DPRINTF("write " TARGET_FMT_plx " %08x\n", addr, val);
 187     saddr = addr >> 2;
 188     switch (saddr) {
 189     case TIMER_LIMIT:
 190         if (slavio_timer_is_user(s)) {
 191             uint64_t count;
 192
 193             // set user counter MSW, reset counter
 194             s->limit = TIMER_MAX_COUNT64;
 195             s->counthigh = val & (TIMER_MAX_COUNT64 >> 32);
 196             s->reached = 0;
 197             count = ((uint64_t)s->counthigh << 32) | s->count;
 198             DPRINTF("processor %d user timer set to %016llx\n", s->slave_index,
 199                     count);
 200             if (s->timer)
 201                 ptimer_set_count(s->timer, LIMIT_TO_PERIODS(s->limit - count));
 202         } else {
 203             // set limit, reset counter
 204             qemu_irq_lower(s->irq);
 205             s->limit = val & TIMER_MAX_COUNT32;
 206             if (s->timer) {
 207                 if (s->limit == 0) /* free-run */
 208                     ptimer_set_limit(s->timer,
 209                                      LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
 210                 else
 211                     ptimer_set_limit(s->timer, LIMIT_TO_PERIODS(s->limit), 1);
 212             }
 213         }
 214         break;
 215     case TIMER_COUNTER:
 216         if (slavio_timer_is_user(s)) {
 217             uint64_t count;
 218
 219             // set user counter LSW, reset counter
 220             s->limit = TIMER_MAX_COUNT64;
 221             s->count = val & TIMER_MAX_COUNT64;
 222             s->reached = 0;
 223             count = ((uint64_t)s->counthigh) << 32 | s->count;
 224             DPRINTF("processor %d user timer set to %016llx\n", s->slave_index,
 225                     count);
 226             if (s->timer)
 227                 ptimer_set_count(s->timer, LIMIT_TO_PERIODS(s->limit - count));
 228         } else
 229             DPRINTF("not user timer\n");
 230         break;
 231     case TIMER_COUNTER_NORST:
 232         // set limit without resetting counter
 233         s->limit = val & TIMER_MAX_COUNT32;
 234         if (s->timer) {
 235             if (s->limit == 0)  /* free-run */
 236                 ptimer_set_limit(s->timer,
 237                                  LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 0);
 238             else
 239                 ptimer_set_limit(s->timer, LIMIT_TO_PERIODS(s->limit), 0);
 240         }
 241         break;
 242     case TIMER_STATUS:
 243         if (slavio_timer_is_user(s)) {
 244             // start/stop user counter
 245             if ((val & 1) && !s->running) {
 246                 DPRINTF("processor %d user timer started\n", s->slave_index);
 247                 if (s->timer)
 248                     ptimer_run(s->timer, 0);
 249                 s->running = 1;
 250             } else if (!(val & 1) && s->running) {
 251                 DPRINTF("processor %d user timer stopped\n", s->slave_index);
 252                 if (s->timer)
 253                     ptimer_stop(s->timer);
 254                 s->running = 0;
 255             }
 256         }
 257         break;
 258     case TIMER_MODE:
 259         if (s->master == NULL) {
 260             unsigned int i;
 261
 262             for (i = 0; i < s->num_slaves; i++) {
 263                 unsigned int processor = 1 << i;
 264
 265                 // check for a change in timer mode for this processor
 266                 if ((val & processor) != (s->slave_mode & processor)) {
 267                     if (val & processor) { // counter -> user timer
 268                         qemu_irq_lower(s->slave[i]->irq);
 269                         // counters are always running
 270                         ptimer_stop(s->slave[i]->timer);
 271                         s->slave[i]->running = 0;
 272                         // user timer limit is always the same
 273                         s->slave[i]->limit = TIMER_MAX_COUNT64;
 274                         ptimer_set_limit(s->slave[i]->timer,
 275                                          LIMIT_TO_PERIODS(s->slave[i]->limit),
 276                                          1);
 277                         // set this processors user timer bit in config
 278                         // register
 279                         s->slave_mode |= processor;
 280                         DPRINTF("processor %d changed from counter to user "
 281                                 "timer\n", s->slave[i]->slave_index);
 282                     } else { // user timer -> counter
 283                         // stop the user timer if it is running
 284                         if (s->slave[i]->running)
 285                             ptimer_stop(s->slave[i]->timer);
 286                         // start the counter
 287                         ptimer_run(s->slave[i]->timer, 0);
 288                         s->slave[i]->running = 1;
 289                         // clear this processors user timer bit in config
 290                         // register
 291                         s->slave_mode &= ~processor;
 292                         DPRINTF("processor %d changed from user timer to "
 293                                 "counter\n", s->slave[i]->slave_index);
 294                     }
 295                 }
 296             }
 297         } else
 298             DPRINTF("not system timer\n");
 299         break;
 300     default:
 301         DPRINTF("invalid write address " TARGET_FMT_plx "\n", addr);
 302         break;
 303     }
 304 }
 305
 306 static CPUReadMemoryFunc *slavio_timer_mem_read[3] = {
 307     NULL,
 308     NULL,
 309     slavio_timer_mem_readl,
 310 };
 311
 312 static CPUWriteMemoryFunc *slavio_timer_mem_write[3] = {
 313     NULL,
 314     NULL,
 315     slavio_timer_mem_writel,
 316 };
 317
 318 static void slavio_timer_save(QEMUFile *f, void *opaque)
 319 {
 320     SLAVIO_TIMERState *s = opaque;
 321
 322     qemu_put_be64s(f, &s->limit);
 323     qemu_put_be32s(f, &s->count);
 324     qemu_put_be32s(f, &s->counthigh);
 325     qemu_put_be32s(f, &s->reached);
 326     qemu_put_be32s(f, &s->running);
 327     if (s->timer)
 328         qemu_put_ptimer(f, s->timer);
 329 }
 330
 331 static int slavio_timer_load(QEMUFile *f, void *opaque, int version_id)
 332 {
 333     SLAVIO_TIMERState *s = opaque;
 334
 335     if (version_id != 3)
 336         return -EINVAL;
 337
 338     qemu_get_be64s(f, &s->limit);
 339     qemu_get_be32s(f, &s->count);
 340     qemu_get_be32s(f, &s->counthigh);
 341     qemu_get_be32s(f, &s->reached);
 342     qemu_get_be32s(f, &s->running);
 343     if (s->timer)
 344         qemu_get_ptimer(f, s->timer);
 345
 346     return 0;
 347 }
 348
 349 static void slavio_timer_reset(void *opaque)
 350 {
 351     SLAVIO_TIMERState *s = opaque;
 352
 353     s->limit = 0;
 354     s->count = 0;
 355     s->reached = 0;
 356     s->slave_mode = 0;
 357     if (!s->master || s->slave_index < s->master->num_slaves) {
 358         ptimer_set_limit(s->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
 359         ptimer_run(s->timer, 0);
 360     }
 361     s->running = 1;
 362     qemu_irq_lower(s->irq);
 363 }
 364
 365 static SLAVIO_TIMERState *slavio_timer_init(target_phys_addr_t addr,
 366                                             qemu_irq irq,
 367                                             SLAVIO_TIMERState *master,
 368                                             uint32_t slave_index)
 369 {
 370     int slavio_timer_io_memory;
 371     SLAVIO_TIMERState *s;
 372     QEMUBH *bh;
 373
 374     s = qemu_mallocz(sizeof(SLAVIO_TIMERState));
 375     s->irq = irq;
 376     s->master = master;
 377     s->slave_index = slave_index;
 378     if (!master || slave_index < master->num_slaves) {
 379         bh = qemu_bh_new(slavio_timer_irq, s);
 380         s->timer = ptimer_init(bh);
 381         ptimer_set_period(s->timer, TIMER_PERIOD);
 382     }
 383
 384     slavio_timer_io_memory = cpu_register_io_memory(0, slavio_timer_mem_read,
 385                                                     slavio_timer_mem_write, s);
 386     if (master)
 387         cpu_register_physical_memory(addr, CPU_TIMER_SIZE,
 388                                      slavio_timer_io_memory);
 389     else
 390         cpu_register_physical_memory(addr, SYS_TIMER_SIZE,
 391                                      slavio_timer_io_memory);
 392     register_savevm("slavio_timer", addr, 3, slavio_timer_save,
 393                     slavio_timer_load, s);
 394     qemu_register_reset(slavio_timer_reset, s);
 395     slavio_timer_reset(s);
 396
 397     return s;
 398 }
 399
 400 void slavio_timer_init_all(target_phys_addr_t base, qemu_irq master_irq,
 401                            qemu_irq *cpu_irqs, unsigned int num_cpus)
 402 {
 403     SLAVIO_TIMERState *master;
 404     unsigned int i;
 405
 406     master = slavio_timer_init(base + SYS_TIMER_OFFSET, master_irq, NULL, 0);
 407
 408     master->num_slaves = num_cpus;
 409
 410     for (i = 0; i < MAX_CPUS; i++) {
 411         master->slave[i] = slavio_timer_init(base + (target_phys_addr_t)
 412                                              CPU_TIMER_OFFSET(i),
 413                                              cpu_irqs[i], master, i);
 414     }
 415 }