[Qemu-devel] [RFC v1 1/2] timer: arm_mp: Factor out timer value calculation

[Peter Crosthwaite <crosthwaitepeter@gmail.com>]

Factor out the code that calculates the runtime value of the timer.
Updates tb->count to the calculated value. Prepares support for pausing
the timer where the timer disable event should sync the counter to its
current value.

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
---
 hw/timer/arm_mptimer.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/hw/timer/arm_mptimer.c b/hw/timer/arm_mptimer.c
index 8b93b3c..04dfb63 100644
--- a/hw/timer/arm_mptimer.c
+++ b/hw/timer/arm_mptimer.c
@@ -72,25 +72,32 @@ static void timerblock_tick(void *opaque)
     timerblock_update_irq(tb);
 }
 
+static void timerblock_sync(TimerBlock *tb)
+{
+    int64_t val;
+
+    if (((tb->control & 1) == 0) || (tb->count == 0)) {
+        return;
+    }
+    /* Slow and ugly, but hopefully won't happen too often.  */
+    val = tb->tick - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+    val /= timerblock_scale(tb);
+    if (val < 0) {
+        val = 0;
+    }
+    tb->count = val;
+}
+
 static uint64_t timerblock_read(void *opaque, hwaddr addr,
                                 unsigned size)
 {
     TimerBlock *tb = (TimerBlock *)opaque;
-    int64_t val;
     switch (addr) {
     case 0: /* Load */
         return tb->load;
     case 4: /* Counter.  */
-        if (((tb->control & 1) == 0) || (tb->count == 0)) {
-            return 0;
-        }
-        /* Slow and ugly, but hopefully won't happen too often.  */
-        val = tb->tick - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
-        val /= timerblock_scale(tb);
-        if (val < 0) {
-            val = 0;
-        }
-        return val;
+        timerblock_sync(tb);
+        return tb->count;
     case 8: /* Control.  */
         return tb->control;
     case 12: /* Interrupt status.  */
-- 
1.9.1