quoted hunk ↗ jump to hunk
+ * We must write a positive value to the decrementer to clear
+ * the interrupt on the IBM 970 CPU series. In periodic mode,
+ * this happens when the decrementer gets reloaded later, but
+ * in one-shot mode, we have to do it here since an event handler
+ * may skip loading the new value...
Nothing special about 970 here -- on *every* PowerPC,
a decrementer exception exists as long as the high
bit of the decrementer equals 1. BookE is different
of course. Some other CPUs might deviate from the
architecture as well.
Segher