sparc64: reimplement tick timers v4

sparc64 timer has tick counter which can be set and read,
and tick compare value used as deadline to fire timer interrupt.
The timer is not used as periodic timer, instead deadline
is set each time new timer interrupt is needed.

v3 -> v4:
- coding style

v2 -> v3:
- added missing timer debug output macro
- CPUTimer struct and typedef moved to cpu.h
- change CPU_SAVE_VERSION to 6, older save formats not supported

v1 -> v2:
- new conversion helpers cpu_to_timer_ticks and timer_to_cpu_ticks
- save offset from clock source to implement cpu_tick_set_count
- renamed struct sun4u_timer to CPUTimer
- load and save cpu timers

v0 -> v1:
- coding style

Signed-off-by: Igor V. Kovalenko <igor.v.kovalenko@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

1 files changed, 173 insertions, 33 deletions

diff --git a/hw/sun4u.c b/hw/sun4u.c
index c1530a6..1e01123 100644
--- a/hw/sun4u.c
+++ b/hw/sun4u.c
@@ -40,6 +40,7 @@
 
 //#define DEBUG_IRQ
 //#define DEBUG_EBUS
+//#define DEBUG_TIMER
 
 #ifdef DEBUG_IRQ
 #define CPUIRQ_DPRINTF(fmt, ...)                                \
@@ -55,6 +56,13 @@
 #define EBUS_DPRINTF(fmt, ...)
 #endif
 
+#ifdef DEBUG_TIMER
+#define TIMER_DPRINTF(fmt, ...)                                  \
+    do { printf("TIMER: " fmt , ## __VA_ARGS__); } while (0)
+#else
+#define TIMER_DPRINTF(fmt, ...)
+#endif
+
 #define KERNEL_LOAD_ADDR     0x00404000
 #define CMDLINE_ADDR         0x003ff000
 #define INITRD_LOAD_ADDR     0x00300000
@@ -282,6 +290,12 @@ void cpu_check_irqs(CPUState *env)
     }
 }
 
+static void cpu_kick_irq(CPUState *env)
+{
+    env->halted = 0;
+    cpu_check_irqs(env);
+}
+
 static void cpu_set_irq(void *opaque, int irq, int level)
 {
     CPUState *env = opaque;
@@ -303,6 +317,52 @@ typedef struct ResetData {
     uint64_t prom_addr;
 } ResetData;
 
+void cpu_put_timer(QEMUFile *f, CPUTimer *s)
+{
+    qemu_put_be32s(f, &s->frequency);
+    qemu_put_be32s(f, &s->disabled);
+    qemu_put_be64s(f, &s->disabled_mask);
+    qemu_put_sbe64s(f, &s->clock_offset);
+
+    qemu_put_timer(f, s->qtimer);
+}
+
+void cpu_get_timer(QEMUFile *f, CPUTimer *s)
+{
+    qemu_get_be32s(f, &s->frequency);
+    qemu_get_be32s(f, &s->disabled);
+    qemu_get_be64s(f, &s->disabled_mask);
+    qemu_get_sbe64s(f, &s->clock_offset);
+
+    qemu_get_timer(f, s->qtimer);
+}
+
+static CPUTimer* cpu_timer_create(const char* name, CPUState *env,
+                                  QEMUBHFunc *cb, uint32_t frequency,
+                                  uint64_t disabled_mask)
+{
+    CPUTimer *timer = qemu_mallocz(sizeof (CPUTimer));
+
+    timer->name = name;
+    timer->frequency = frequency;
+    timer->disabled_mask = disabled_mask;
+
+    timer->disabled = 1;
+    timer->clock_offset = qemu_get_clock(vm_clock);
+
+    timer->qtimer = qemu_new_timer(vm_clock, cb, env);
+
+    return timer;
+}
+
+static void cpu_timer_reset(CPUTimer *timer)
+{
+    timer->disabled = 1;
+    timer->clock_offset = qemu_get_clock(vm_clock);
+
+    qemu_del_timer(timer->qtimer);
+}
+
 static void main_cpu_reset(void *opaque)
 {
     ResetData *s = (ResetData *)opaque;
@@ -310,15 +370,11 @@ static void main_cpu_reset(void *opaque)
     static unsigned int nr_resets;
 
     cpu_reset(env);
-    env->tick_cmpr = TICK_INT_DIS | 0;
-    ptimer_set_limit(env->tick, TICK_MAX, 1);
-    ptimer_run(env->tick, 1);
-    env->stick_cmpr = TICK_INT_DIS | 0;
-    ptimer_set_limit(env->stick, TICK_MAX, 1);
-    ptimer_run(env->stick, 1);
-    env->hstick_cmpr = TICK_INT_DIS | 0;
-    ptimer_set_limit(env->hstick, TICK_MAX, 1);
-    ptimer_run(env->hstick, 1);
+
+    cpu_timer_reset(env->tick);
+    cpu_timer_reset(env->stick);
+    cpu_timer_reset(env->hstick);
+
     env->gregs[1] = 0; // Memory start
     env->gregs[2] = ram_size; // Memory size
     env->gregs[3] = 0; // Machine description XXX
@@ -335,44 +391,127 @@ static void tick_irq(void *opaque)
 {
     CPUState *env = opaque;
 
-    if (!(env->tick_cmpr & TICK_INT_DIS)) {
-        env->softint |= SOFTINT_TIMER;
-        cpu_interrupt(env, CPU_INTERRUPT_TIMER);
+    CPUTimer* timer = env->tick;
+
+    if (timer->disabled) {
+        CPUIRQ_DPRINTF("tick_irq: softint disabled\n");
+        return;
+    } else {
+        CPUIRQ_DPRINTF("tick: fire\n");
     }
+
+    env->softint |= SOFTINT_TIMER;
+    cpu_kick_irq(env);
 }
 
 static void stick_irq(void *opaque)
 {
     CPUState *env = opaque;
 
-    if (!(env->stick_cmpr & TICK_INT_DIS)) {
-        env->softint |= SOFTINT_STIMER;
-        cpu_interrupt(env, CPU_INTERRUPT_TIMER);
+    CPUTimer* timer = env->stick;
+
+    if (timer->disabled) {
+        CPUIRQ_DPRINTF("stick_irq: softint disabled\n");
+        return;
+    } else {
+        CPUIRQ_DPRINTF("stick: fire\n");
     }
+
+    env->softint |= SOFTINT_STIMER;
+    cpu_kick_irq(env);
 }
 
 static void hstick_irq(void *opaque)
 {
     CPUState *env = opaque;
 
-    if (!(env->hstick_cmpr & TICK_INT_DIS)) {
-        cpu_interrupt(env, CPU_INTERRUPT_TIMER);
+    CPUTimer* timer = env->hstick;
+
+    if (timer->disabled) {
+        CPUIRQ_DPRINTF("hstick_irq: softint disabled\n");
+        return;
+    } else {
+        CPUIRQ_DPRINTF("hstick: fire\n");
     }
+
+    env->softint |= SOFTINT_STIMER;
+    cpu_kick_irq(env);
+}
+
+static int64_t cpu_to_timer_ticks(int64_t cpu_ticks, uint32_t frequency)
+{
+    return muldiv64(cpu_ticks, get_ticks_per_sec(), frequency);
+}
+
+static uint64_t timer_to_cpu_ticks(int64_t timer_ticks, uint32_t frequency)
+{
+    return muldiv64(timer_ticks, frequency, get_ticks_per_sec());
 }
 
-void cpu_tick_set_count(void *opaque, uint64_t count)
+void cpu_tick_set_count(CPUTimer *timer, uint64_t count)
 {
-    ptimer_set_count(opaque, -count);
+    uint64_t real_count = count & ~timer->disabled_mask;
+    uint64_t disabled_bit = count & timer->disabled_mask;
+
+    int64_t vm_clock_offset = qemu_get_clock(vm_clock) -
+                    cpu_to_timer_ticks(real_count, timer->frequency);
+
+    TIMER_DPRINTF("%s set_count count=0x%016lx (%s) p=%p\n",
+                  timer->name, real_count,
+                  timer->disabled?"disabled":"enabled", timer);
+
+    timer->disabled = disabled_bit ? 1 : 0;
+    timer->clock_offset = vm_clock_offset;
 }
 
-uint64_t cpu_tick_get_count(void *opaque)
+uint64_t cpu_tick_get_count(CPUTimer *timer)
 {
-    return -ptimer_get_count(opaque);
+    uint64_t real_count = timer_to_cpu_ticks(
+                    qemu_get_clock(vm_clock) - timer->clock_offset,
+                    timer->frequency);
+
+    TIMER_DPRINTF("%s get_count count=0x%016lx (%s) p=%p\n",
+           timer->name, real_count,
+           timer->disabled?"disabled":"enabled", timer);
+
+    if (timer->disabled)
+        real_count |= timer->disabled_mask;
+
+    return real_count;
 }
 
-void cpu_tick_set_limit(void *opaque, uint64_t limit)
+void cpu_tick_set_limit(CPUTimer *timer, uint64_t limit)
 {
-    ptimer_set_limit(opaque, -limit, 0);
+    int64_t now = qemu_get_clock(vm_clock);
+
+    uint64_t real_limit = limit & ~timer->disabled_mask;
+    timer->disabled = (limit & timer->disabled_mask) ? 1 : 0;
+
+    int64_t expires = cpu_to_timer_ticks(real_limit, timer->frequency) +
+                    timer->clock_offset;
+
+    if (expires < now) {
+        expires = now + 1;
+    }
+
+    TIMER_DPRINTF("%s set_limit limit=0x%016lx (%s) p=%p "
+                  "called with limit=0x%016lx at 0x%016lx (delta=0x%016lx)\n",
+                  timer->name, real_limit,
+                  timer->disabled?"disabled":"enabled",
+                  timer, limit,
+                  timer_to_cpu_ticks(now - timer->clock_offset,
+                                     timer->frequency),
+                  timer_to_cpu_ticks(expires - now, timer->frequency));
+
+    if (!real_limit) {
+        TIMER_DPRINTF("%s set_limit limit=ZERO - not starting timer\n",
+                timer->name);
+        qemu_del_timer(timer->qtimer);
+    } else if (timer->disabled) {
+        qemu_del_timer(timer->qtimer);
+    } else {
+        qemu_mod_timer(timer->qtimer, expires);
+    }
 }
 
 static void ebus_mmio_mapfunc(PCIDevice *pci_dev, int region_num,
@@ -559,9 +698,12 @@ device_init(ram_register_devices);
 static CPUState *cpu_devinit(const char *cpu_model, const struct hwdef *hwdef)
 {
     CPUState *env;
-    QEMUBH *bh;
     ResetData *reset_info;
 
+    uint32_t   tick_frequency = 100*1000000;
+    uint32_t  stick_frequency = 100*1000000;
+    uint32_t hstick_frequency = 100*1000000;
+
     if (!cpu_model)
         cpu_model = hwdef->default_cpu_model;
     env = cpu_init(cpu_model);
@@ -569,17 +711,15 @@ static CPUState *cpu_devinit(const char *cpu_model, const struct hwdef *hwdef)
         fprintf(stderr, "Unable to find Sparc CPU definition\n");
         exit(1);
     }
-    bh = qemu_bh_new(tick_irq, env);
-    env->tick = ptimer_init(bh);
-    ptimer_set_period(env->tick, 1ULL);
 
-    bh = qemu_bh_new(stick_irq, env);
-    env->stick = ptimer_init(bh);
-    ptimer_set_period(env->stick, 1ULL);
+    env->tick = cpu_timer_create("tick", env, tick_irq,
+                                  tick_frequency, TICK_NPT_MASK);
+
+    env->stick = cpu_timer_create("stick", env, stick_irq,
+                                   stick_frequency, TICK_INT_DIS);
 
-    bh = qemu_bh_new(hstick_irq, env);
-    env->hstick = ptimer_init(bh);
-    ptimer_set_period(env->hstick, 1ULL);
+    env->hstick = cpu_timer_create("hstick", env, hstick_irq,
+                                    hstick_frequency, TICK_INT_DIS);
 
     reset_info = qemu_mallocz(sizeof(ResetData));
     reset_info->env = env;