hw/ptimer: Introduce timer policy feature

Some of the timer devices may behave differently from what ptimer
provides. Introduce ptimer policy feature that allows ptimer users to
change default and wrong timer behaviour, for example to continuously
trigger periodic timer when load value is equal to "0".

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 994cd608ec392da6e58f0643800dda595edb9d97.1473252818.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

24 files changed, 57 insertions, 31 deletions

diff --git a/hw/arm/musicpal.c b/hw/arm/musicpal.c
index cc50ace13d..7527037c23 100644
--- a/hw/arm/musicpal.c
+++ b/hw/arm/musicpal.c
@@ -837,7 +837,7 @@ static void mv88w8618_timer_init(SysBusDevice *dev, mv88w8618_timer_state *s,
     s->freq = freq;
 
     bh = qemu_bh_new(mv88w8618_timer_tick, s);
-    s->ptimer = ptimer_init(bh);
+    s->ptimer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
 }
 
 static uint64_t mv88w8618_pit_read(void *opaque, hwaddr offset,
diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c
index 02c313542d..00fdf157fd 100644
--- a/hw/core/ptimer.c
+++ b/hw/core/ptimer.c
@@ -21,6 +21,7 @@ struct ptimer_state
     int64_t period;
     int64_t last_event;
     int64_t next_event;
+    uint8_t policy_mask;
     QEMUBH *bh;
     QEMUTimer *timer;
 };
@@ -243,12 +244,13 @@ const VMStateDescription vmstate_ptimer = {
     }
 };
 
-ptimer_state *ptimer_init(QEMUBH *bh)
+ptimer_state *ptimer_init(QEMUBH *bh, uint8_t policy_mask)
 {
     ptimer_state *s;
 
     s = (ptimer_state *)g_malloc0(sizeof(ptimer_state));
     s->bh = bh;
     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ptimer_tick, s);
+    s->policy_mask = policy_mask;
     return s;
 }
diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
index a4753e55a2..b135a5ff12 100644
--- a/hw/dma/xilinx_axidma.c
+++ b/hw/dma/xilinx_axidma.c
@@ -548,7 +548,7 @@ static void xilinx_axidma_realize(DeviceState *dev, Error **errp)
 
         st->nr = i;
         st->bh = qemu_bh_new(timer_hit, st);
-        st->ptimer = ptimer_init(st->bh);
+        st->ptimer = ptimer_init(st->bh, PTIMER_POLICY_DEFAULT);
         ptimer_set_freq(st->ptimer, s->freqhz);
     }
     return;
diff --git a/hw/m68k/mcf5206.c b/hw/m68k/mcf5206.c
index e14896e529..b81901fdfd 100644
--- a/hw/m68k/mcf5206.c
+++ b/hw/m68k/mcf5206.c
@@ -139,7 +139,7 @@ static m5206_timer_state *m5206_timer_init(qemu_irq irq)
 
     s = (m5206_timer_state *)g_malloc0(sizeof(m5206_timer_state));
     bh = qemu_bh_new(m5206_timer_trigger, s);
-    s->timer = ptimer_init(bh);
+    s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
     s->irq = irq;
     m5206_timer_reset(s);
     return s;
diff --git a/hw/m68k/mcf5208.c b/hw/m68k/mcf5208.c
index 24155574f2..9240ebf9af 100644
--- a/hw/m68k/mcf5208.c
+++ b/hw/m68k/mcf5208.c
@@ -183,7 +183,7 @@ static void mcf5208_sys_init(MemoryRegion *address_space, qemu_irq *pic)
     for (i = 0; i < 2; i++) {
         s = (m5208_timer_state *)g_malloc0(sizeof(m5208_timer_state));
         bh = qemu_bh_new(m5208_timer_trigger, s);
-        s->timer = ptimer_init(bh);
+        s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
         memory_region_init_io(&s->iomem, NULL, &m5208_timer_ops, s,
                               "m5208-timer", 0x00004000);
         memory_region_add_subregion(address_space, 0xfc080000 + 0x4000 * i,
diff --git a/hw/net/fsl_etsec/etsec.c b/hw/net/fsl_etsec/etsec.c
index b5c777fbf6..951c5f0038 100644
--- a/hw/net/fsl_etsec/etsec.c
+++ b/hw/net/fsl_etsec/etsec.c
@@ -387,7 +387,7 @@ static void etsec_realize(DeviceState *dev, Error **errp)
 
 
     etsec->bh     = qemu_bh_new(etsec_timer_hit, etsec);
-    etsec->ptimer = ptimer_init(etsec->bh);
+    etsec->ptimer = ptimer_init(etsec->bh, PTIMER_POLICY_DEFAULT);
     ptimer_set_freq(etsec->ptimer, 100);
 }
 
diff --git a/hw/net/lan9118.c b/hw/net/lan9118.c
index 4615d873b1..3db8937cac 100644
--- a/hw/net/lan9118.c
+++ b/hw/net/lan9118.c
@@ -1345,7 +1345,7 @@ static int lan9118_init1(SysBusDevice *sbd)
     s->txp = &s->tx_packet;
 
     bh = qemu_bh_new(lan9118_tick, s);
-    s->timer = ptimer_init(bh);
+    s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
     ptimer_set_freq(s->timer, 10000);
     ptimer_set_limit(s->timer, 0xffff, 1);
 
diff --git a/hw/timer/allwinner-a10-pit.c b/hw/timer/allwinner-a10-pit.c
index 3385e5dc35..22ceabe1d4 100644
--- a/hw/timer/allwinner-a10-pit.c
+++ b/hw/timer/allwinner-a10-pit.c
@@ -267,7 +267,7 @@ static void a10_pit_init(Object *obj)
         tc->container = s;
         tc->index = i;
         bh[i] = qemu_bh_new(a10_pit_timer_cb, tc);
-        s->timer[i] = ptimer_init(bh[i]);
+        s->timer[i] = ptimer_init(bh[i], PTIMER_POLICY_DEFAULT);
     }
 }
 
diff --git a/hw/timer/arm_timer.c b/hw/timer/arm_timer.c
index 111a16db37..98fddd7ac1 100644
--- a/hw/timer/arm_timer.c
+++ b/hw/timer/arm_timer.c
@@ -171,7 +171,7 @@ static arm_timer_state *arm_timer_init(uint32_t freq)
     s->control = TIMER_CTRL_IE;
 
     bh = qemu_bh_new(arm_timer_tick, s);
-    s->timer = ptimer_init(bh);
+    s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
     vmstate_register(NULL, -1, &vmstate_arm_timer, s);
     return s;
 }
diff --git a/hw/timer/digic-timer.c b/hw/timer/digic-timer.c
index 0f21faf876..e1fcf73c3e 100644
--- a/hw/timer/digic-timer.c
+++ b/hw/timer/digic-timer.c
@@ -127,7 +127,7 @@ static void digic_timer_init(Object *obj)
 {
     DigicTimerState *s = DIGIC_TIMER(obj);
 
-    s->ptimer = ptimer_init(NULL);
+    s->ptimer = ptimer_init(NULL, PTIMER_POLICY_DEFAULT);
 
     /*
      * FIXME: there is no documentation on Digic timer
diff --git a/hw/timer/etraxfs_timer.c b/hw/timer/etraxfs_timer.c
index 36d8f462c4..8e18236c5a 100644
--- a/hw/timer/etraxfs_timer.c
+++ b/hw/timer/etraxfs_timer.c
@@ -322,9 +322,9 @@ static int etraxfs_timer_init(SysBusDevice *dev)
     t->bh_t0 = qemu_bh_new(timer0_hit, t);
     t->bh_t1 = qemu_bh_new(timer1_hit, t);
     t->bh_wd = qemu_bh_new(watchdog_hit, t);
-    t->ptimer_t0 = ptimer_init(t->bh_t0);
-    t->ptimer_t1 = ptimer_init(t->bh_t1);
-    t->ptimer_wd = ptimer_init(t->bh_wd);
+    t->ptimer_t0 = ptimer_init(t->bh_t0, PTIMER_POLICY_DEFAULT);
+    t->ptimer_t1 = ptimer_init(t->bh_t1, PTIMER_POLICY_DEFAULT);
+    t->ptimer_wd = ptimer_init(t->bh_wd, PTIMER_POLICY_DEFAULT);
 
     sysbus_init_irq(dev, &t->irq);
     sysbus_init_irq(dev, &t->nmi);
diff --git a/hw/timer/exynos4210_mct.c b/hw/timer/exynos4210_mct.c
index ae69345f0d..0c189348ae 100644
--- a/hw/timer/exynos4210_mct.c
+++ b/hw/timer/exynos4210_mct.c
@@ -1431,15 +1431,16 @@ static void exynos4210_mct_init(Object *obj)
 
     /* Global timer */
     bh[0] = qemu_bh_new(exynos4210_gfrc_event, s);
-    s->g_timer.ptimer_frc = ptimer_init(bh[0]);
+    s->g_timer.ptimer_frc = ptimer_init(bh[0], PTIMER_POLICY_DEFAULT);
     memset(&s->g_timer.reg, 0, sizeof(struct gregs));
 
     /* Local timers */
     for (i = 0; i < 2; i++) {
         bh[0] = qemu_bh_new(exynos4210_ltick_event, &s->l_timer[i]);
         bh[1] = qemu_bh_new(exynos4210_lfrc_event, &s->l_timer[i]);
-        s->l_timer[i].tick_timer.ptimer_tick = ptimer_init(bh[0]);
-        s->l_timer[i].ptimer_frc = ptimer_init(bh[1]);
+        s->l_timer[i].tick_timer.ptimer_tick =
+                                   ptimer_init(bh[0], PTIMER_POLICY_DEFAULT);
+        s->l_timer[i].ptimer_frc = ptimer_init(bh[1], PTIMER_POLICY_DEFAULT);
         s->l_timer[i].id = i;
     }
 
diff --git a/hw/timer/exynos4210_pwm.c b/hw/timer/exynos4210_pwm.c
index 0e9e2e9bf5..f5765075c7 100644
--- a/hw/timer/exynos4210_pwm.c
+++ b/hw/timer/exynos4210_pwm.c
@@ -390,7 +390,7 @@ static void exynos4210_pwm_init(Object *obj)
     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
         bh = qemu_bh_new(exynos4210_pwm_tick, &s->timer[i]);
         sysbus_init_irq(dev, &s->timer[i].irq);
-        s->timer[i].ptimer = ptimer_init(bh);
+        s->timer[i].ptimer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
         s->timer[i].id = i;
         s->timer[i].parent = s;
     }
diff --git a/hw/timer/exynos4210_rtc.c b/hw/timer/exynos4210_rtc.c
index da4dd451b9..1a648c5d9e 100644
--- a/hw/timer/exynos4210_rtc.c
+++ b/hw/timer/exynos4210_rtc.c
@@ -555,12 +555,12 @@ static void exynos4210_rtc_init(Object *obj)
     QEMUBH *bh;
 
     bh = qemu_bh_new(exynos4210_rtc_tick, s);
-    s->ptimer = ptimer_init(bh);
+    s->ptimer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
     ptimer_set_freq(s->ptimer, RTC_BASE_FREQ);
     exynos4210_rtc_update_freq(s, 0);
 
     bh = qemu_bh_new(exynos4210_rtc_1Hz_tick, s);
-    s->ptimer_1Hz = ptimer_init(bh);
+    s->ptimer_1Hz = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
     ptimer_set_freq(s->ptimer_1Hz, RTC_BASE_FREQ);
 
     sysbus_init_irq(dev, &s->alm_irq);
diff --git a/hw/timer/grlib_gptimer.c b/hw/timer/grlib_gptimer.c
index dd000f5afa..712d1aece5 100644
--- a/hw/timer/grlib_gptimer.c
+++ b/hw/timer/grlib_gptimer.c
@@ -363,7 +363,7 @@ static int grlib_gptimer_init(SysBusDevice *dev)
 
         timer->unit   = unit;
         timer->bh     = qemu_bh_new(grlib_gptimer_hit, timer);
-        timer->ptimer = ptimer_init(timer->bh);
+        timer->ptimer = ptimer_init(timer->bh, PTIMER_POLICY_DEFAULT);
         timer->id     = i;
 
         /* One IRQ line for each timer */
diff --git a/hw/timer/imx_epit.c b/hw/timer/imx_epit.c
index eddf3481e8..f34d7f7c77 100644
--- a/hw/timer/imx_epit.c
+++ b/hw/timer/imx_epit.c
@@ -314,10 +314,10 @@ static void imx_epit_realize(DeviceState *dev, Error **errp)
                           0x00001000);
     sysbus_init_mmio(sbd, &s->iomem);
 
-    s->timer_reload = ptimer_init(NULL);
+    s->timer_reload = ptimer_init(NULL, PTIMER_POLICY_DEFAULT);
 
     bh = qemu_bh_new(imx_epit_cmp, s);
-    s->timer_cmp = ptimer_init(bh);
+    s->timer_cmp = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
 }
 
 static void imx_epit_class_init(ObjectClass *klass, void *data)
diff --git a/hw/timer/imx_gpt.c b/hw/timer/imx_gpt.c
index 82bc73cb86..f034d65036 100644
--- a/hw/timer/imx_gpt.c
+++ b/hw/timer/imx_gpt.c
@@ -461,7 +461,7 @@ static void imx_gpt_realize(DeviceState *dev, Error **errp)
     sysbus_init_mmio(sbd, &s->iomem);
 
     bh = qemu_bh_new(imx_gpt_timeout, s);
-    s->timer = ptimer_init(bh);
+    s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
 }
 
 static void imx_gpt_class_init(ObjectClass *klass, void *data)
diff --git a/hw/timer/lm32_timer.c b/hw/timer/lm32_timer.c
index e45a65bb9d..2a07b59524 100644
--- a/hw/timer/lm32_timer.c
+++ b/hw/timer/lm32_timer.c
@@ -184,7 +184,7 @@ static void lm32_timer_init(Object *obj)
     sysbus_init_irq(dev, &s->irq);
 
     s->bh = qemu_bh_new(timer_hit, s);
-    s->ptimer = ptimer_init(s->bh);
+    s->ptimer = ptimer_init(s->bh, PTIMER_POLICY_DEFAULT);
 
     memory_region_init_io(&s->iomem, obj, &timer_ops, s,
                           "timer", R_MAX * 4);
diff --git a/hw/timer/milkymist-sysctl.c b/hw/timer/milkymist-sysctl.c
index 21948328ce..44885907c9 100644
--- a/hw/timer/milkymist-sysctl.c
+++ b/hw/timer/milkymist-sysctl.c
@@ -281,8 +281,8 @@ static void milkymist_sysctl_init(Object *obj)
 
     s->bh0 = qemu_bh_new(timer0_hit, s);
     s->bh1 = qemu_bh_new(timer1_hit, s);
-    s->ptimer0 = ptimer_init(s->bh0);
-    s->ptimer1 = ptimer_init(s->bh1);
+    s->ptimer0 = ptimer_init(s->bh0, PTIMER_POLICY_DEFAULT);
+    s->ptimer1 = ptimer_init(s->bh1, PTIMER_POLICY_DEFAULT);
 
     memory_region_init_io(&s->regs_region, obj, &sysctl_mmio_ops, s,
             "milkymist-sysctl", R_MAX * 4);
diff --git a/hw/timer/puv3_ost.c b/hw/timer/puv3_ost.c
index 93650b7990..0b3d717e60 100644
--- a/hw/timer/puv3_ost.c
+++ b/hw/timer/puv3_ost.c
@@ -125,7 +125,7 @@ static int puv3_ost_init(SysBusDevice *dev)
     sysbus_init_irq(dev, &s->irq);
 
     s->bh = qemu_bh_new(puv3_ost_tick, s);
-    s->ptimer = ptimer_init(s->bh);
+    s->ptimer = ptimer_init(s->bh, PTIMER_POLICY_DEFAULT);
     ptimer_set_freq(s->ptimer, 50 * 1000 * 1000);
 
     memory_region_init_io(&s->iomem, OBJECT(s), &puv3_ost_ops, s, "puv3_ost",
diff --git a/hw/timer/sh_timer.c b/hw/timer/sh_timer.c
index 255b2fc910..9afb2d048c 100644
--- a/hw/timer/sh_timer.c
+++ b/hw/timer/sh_timer.c
@@ -203,7 +203,7 @@ static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
     s->irq = irq;
 
     bh = qemu_bh_new(sh_timer_tick, s);
-    s->timer = ptimer_init(bh);
+    s->timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
 
     sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
     sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
diff --git a/hw/timer/slavio_timer.c b/hw/timer/slavio_timer.c
index fb3e08bedc..bfee1f3027 100644
--- a/hw/timer/slavio_timer.c
+++ b/hw/timer/slavio_timer.c
@@ -389,7 +389,7 @@ static int slavio_timer_init1(SysBusDevice *dev)
         tc->timer_index = i;
 
         bh = qemu_bh_new(slavio_timer_irq, tc);
-        s->cputimer[i].timer = ptimer_init(bh);
+        s->cputimer[i].timer = ptimer_init(bh, PTIMER_POLICY_DEFAULT);
         ptimer_set_period(s->cputimer[i].timer, TIMER_PERIOD);
 
         size = i == 0 ? SYS_TIMER_SIZE : CPU_TIMER_SIZE;
diff --git a/hw/timer/xilinx_timer.c b/hw/timer/xilinx_timer.c
index 2ea970dc9d..59439c05be 100644
--- a/hw/timer/xilinx_timer.c
+++ b/hw/timer/xilinx_timer.c
@@ -218,7 +218,7 @@ static void xilinx_timer_realize(DeviceState *dev, Error **errp)
         xt->parent = t;
         xt->nr = i;
         xt->bh = qemu_bh_new(timer_hit, xt);
-        xt->ptimer = ptimer_init(xt->bh);
+        xt->ptimer = ptimer_init(xt->bh, PTIMER_POLICY_DEFAULT);
         ptimer_set_freq(xt->ptimer, t->freq_hz);
     }
 
diff --git a/include/hw/ptimer.h b/include/hw/ptimer.h
index e397db5bdb..26c7fdcd75 100644
--- a/include/hw/ptimer.h
+++ b/include/hw/ptimer.h
@@ -12,11 +12,34 @@
 #include "qemu/timer.h"
 #include "migration/vmstate.h"
 
+/* The default ptimer policy retains backward compatibility with the legacy
+ * timers. Custom policies are adjusting the default one. Consider providing
+ * a correct policy for your timer.
+ *
+ * The rough edges of the default policy:
+ *  - Starting to run with a period = 0 emits error message and stops the
+ *    timer without a trigger.
+ *
+ *  - Setting period to 0 of the running timer emits error message and
+ *    stops the timer without a trigger.
+ *
+ *  - Starting to run with counter = 0 or setting it to "0" while timer
+ *    is running causes a trigger and reloads counter with a limit value.
+ *    If limit = 0, ptimer emits error message and stops the timer.
+ *
+ *  - Counter value of the running timer is one less than the actual value.
+ *
+ *  - Changing period/frequency of the running timer loses time elapsed
+ *    since the last period, effectively restarting the timer with a
+ *    counter = counter value at the moment of change (.i.e. one less).
+ */
+#define PTIMER_POLICY_DEFAULT               0
+
 /* ptimer.c */
 typedef struct ptimer_state ptimer_state;
 typedef void (*ptimer_cb)(void *opaque);
 
-ptimer_state *ptimer_init(QEMUBH *bh);
+ptimer_state *ptimer_init(QEMUBH *bh, uint8_t policy_mask);
 void ptimer_set_period(ptimer_state *s, int64_t period);
 void ptimer_set_freq(ptimer_state *s, uint32_t freq);
 uint64_t ptimer_get_limit(ptimer_state *s);