+static void pnv_alloc_idle_core_states(void)
+{
+ int i, j;
+ int nr_cores = cpu_nr_cores();
+ u32 *core_idle_state;
+
+ /*
+ * core_idle_state - First 8 bits track the idle state of each thread
+ * of the core. The 8th bit is the lock bit. Initially all thread bits
+ * are set. They are cleared when the thread enters deep idle state
+ * like sleep and winkle. Initially the lock bit is cleared.
+ * The lock bit has 2 purposes
+ * a. While the first thread is restoring core state, it prevents
+ * other threads in the core from switching to process context.
+ * b. While the last thread in the core is saving the core state, it
+ * prevents a different thread from waking up.
+ */
+ for (i = 0; i < nr_cores; i++) {
+ int first_cpu = i * threads_per_core;
+ int node = cpu_to_node(first_cpu);
+
+ core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
+ *core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
+
+ for (j = 0; j < threads_per_core; j++) {
+ int cpu = first_cpu + j;
+
+ paca[cpu].core_idle_state_ptr = core_idle_state;
+ paca[cpu].thread_idle_state = PNV_THREAD_RUNNING;
+ paca[cpu].thread_mask = 1 << j;
+ }
+ }
+}
+