cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state

[mirror_ubuntu-focal-kernel.git] / drivers / cpuidle / cpuidle-powernv.c

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 59372077ec7c1a1b7d64e5ac67880b5e625526b5..1e3ef5ec4784dcfc3b758a0d67cac25c0d33e4ba 100644 (file)
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -29,18 +29,25 @@ struct cpuidle_driver powernv_idle_driver = {
 
 static int max_idle_state;
 static struct cpuidle_state *cpuidle_state_table;
+static u64 snooze_timeout;
+static bool snooze_timeout_en;
 
 static int snooze_loop(struct cpuidle_device *dev,
                        struct cpuidle_driver *drv,
                        int index)
 {
+       u64 snooze_exit_time;
+
        local_irq_enable();
        set_thread_flag(TIF_POLLING_NRFLAG);
 
+       snooze_exit_time = get_tb() + snooze_timeout;
        ppc64_runlatch_off();
        while (!need_resched()) {
                HMT_low();
                HMT_very_low();
+               if (snooze_timeout_en && get_tb() > snooze_exit_time)
+                       break;
        }
 
        HMT_medium();
@@ -252,6 +259,11 @@ static int powernv_idle_probe(void)
                cpuidle_state_table = powernv_states;
                /* Device tree can indicate more idle states */
                max_idle_state = powernv_add_idle_states();
+               if (max_idle_state > 1) {
+                       snooze_timeout_en = true;
+                       snooze_timeout = powernv_states[1].target_residency *
+                                        tb_ticks_per_usec;
+               }
        } else
                return -ENODEV;