hw/timer/mips_gictimer.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2016 Imagination Technologies
   7  */
   8
   9 #include "qemu/osdep.h"
  10 #include "hw/hw.h"
  11 #include "hw/sysbus.h"
  12 #include "qemu/timer.h"
  13 #include "hw/timer/mips_gictimer.h"
  14
  15 #define TIMER_PERIOD 10 /* 10 ns period for 100 Mhz frequency */
  16
  17 static void gic_vptimer_update(MIPSGICTimerState *gictimer,
  18                                    uint32_t vp_index, uint64_t now)
  19 {
  20     uint64_t next;
  21     uint32_t wait;
  22
  23     wait = gictimer->vptimers[vp_index].comparelo - gictimer->sh_counterlo -
  24            (uint32_t)(now / TIMER_PERIOD);
  25     next = now + (uint64_t)wait * TIMER_PERIOD;
  26
  27     timer_mod(gictimer->vptimers[vp_index].qtimer, next);
  28 }
  29
  30 static void gic_vptimer_expire(MIPSGICTimerState *gictimer, uint32_t vp_index,
  31                                uint64_t now)
  32 {
  33     if (gictimer->countstop) {
  34         /* timer stopped */
  35         return;
  36     }
  37     gictimer->cb(gictimer->opaque, vp_index);
  38     gic_vptimer_update(gictimer, vp_index, now);
  39 }
  40
  41 static void gic_vptimer_cb(void *opaque)
  42 {
  43     MIPSGICTimerVPState *vptimer = opaque;
  44     MIPSGICTimerState *gictimer = vptimer->gictimer;
  45     gic_vptimer_expire(gictimer, vptimer->vp_index,
  46                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
  47 }
  48
  49 uint32_t mips_gictimer_get_sh_count(MIPSGICTimerState *gictimer)
  50 {
  51     int i;
  52     if (gictimer->countstop) {
  53         return gictimer->sh_counterlo;
  54     } else {
  55         uint64_t now;
  56         now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  57         for (i = 0; i < gictimer->num_vps; i++) {
  58             if (timer_pending(gictimer->vptimers[i].qtimer)
  59                 && timer_expired(gictimer->vptimers[i].qtimer, now)) {
  60                 /* The timer has already expired.  */
  61                 gic_vptimer_expire(gictimer, i, now);
  62             }
  63         }
  64         return gictimer->sh_counterlo + (uint32_t)(now / TIMER_PERIOD);
  65     }
  66 }
  67
  68 void mips_gictimer_store_sh_count(MIPSGICTimerState *gictimer, uint64_t count)
  69 {
  70     int i;
  71     uint64_t now;
  72
  73     if (gictimer->countstop || !gictimer->vptimers[0].qtimer) {
  74         gictimer->sh_counterlo = count;
  75     } else {
  76         /* Store new count register */
  77         now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  78         gictimer->sh_counterlo = count - (uint32_t)(now / TIMER_PERIOD);
  79         /* Update timer timer */
  80         for (i = 0; i < gictimer->num_vps; i++) {
  81             gic_vptimer_update(gictimer, i, now);
  82         }
  83     }
  84 }
  85
  86 uint32_t mips_gictimer_get_vp_compare(MIPSGICTimerState *gictimer,
  87                                       uint32_t vp_index)
  88 {
  89     return gictimer->vptimers[vp_index].comparelo;
  90 }
  91
  92 void mips_gictimer_store_vp_compare(MIPSGICTimerState *gictimer,
  93                                     uint32_t vp_index, uint64_t compare)
  94 {
  95     gictimer->vptimers[vp_index].comparelo = (uint32_t) compare;
  96     gic_vptimer_update(gictimer, vp_index,
  97                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
  98 }
  99
 100 uint8_t mips_gictimer_get_countstop(MIPSGICTimerState *gictimer)
 101 {
 102     return gictimer->countstop;
 103 }
 104
 105 void mips_gictimer_start_count(MIPSGICTimerState *gictimer)
 106 {
 107     gictimer->countstop = 0;
 108     mips_gictimer_store_sh_count(gictimer, gictimer->sh_counterlo);
 109 }
 110
 111 void mips_gictimer_stop_count(MIPSGICTimerState *gictimer)
 112 {
 113     int i;
 114
 115     gictimer->countstop = 1;
 116     /* Store the current value */
 117     gictimer->sh_counterlo +=
 118         (uint32_t)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / TIMER_PERIOD);
 119     for (i = 0; i < gictimer->num_vps; i++) {
 120         timer_del(gictimer->vptimers[i].qtimer);
 121     }
 122 }
 123
 124 MIPSGICTimerState *mips_gictimer_init(void *opaque, uint32_t nvps,
 125                                       MIPSGICTimerCB *cb)
 126 {
 127     int i;
 128     MIPSGICTimerState *gictimer = g_new(MIPSGICTimerState, 1);
 129     gictimer->vptimers = g_new(MIPSGICTimerVPState, nvps);
 130     gictimer->countstop = 1;
 131     gictimer->num_vps = nvps;
 132     gictimer->opaque = opaque;
 133     gictimer->cb = cb;
 134     for (i = 0; i < nvps; i++) {
 135         gictimer->vptimers[i].gictimer = gictimer;
 136         gictimer->vptimers[i].vp_index = i;
 137         gictimer->vptimers[i].qtimer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
 138                                             &gic_vptimer_cb,
 139                                             &gictimer->vptimers[i]);
 140     }
 141     return gictimer;
 142 }