cpufreq: powernv: Remove global pstate ramp-down timer in POWER9

POWER9 does not support global pstate requests for the chip. So remove
the timer logic which slowly ramps down the global pstate in P9
platforms.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[mpe: Drop NULL check before kfree(policy->driver_data)]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 54edaec1e60837dfcc515430012979482652271a..bf6519cf64bc2e040b6e004f1771e47e5691c7e0 100644 (file)
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -758,8 +758,13 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
 
        cur_msec = jiffies_to_msecs(get_jiffies_64());
 
-       spin_lock(&gpstates->gpstate_lock);
        freq_data.pstate_id = idx_to_pstate(new_index);
+       if (!gpstates) {
+               freq_data.gpstate_id = freq_data.pstate_id;
+               goto no_gpstate;
+       }
+
+       spin_lock(&gpstates->gpstate_lock);
 
        if (!gpstates->last_sampled_time) {
                gpstate_idx = new_index;
@@ -809,6 +814,7 @@ gpstates_done:
 
        spin_unlock(&gpstates->gpstate_lock);
 
+no_gpstate:
        /*
         * Use smp_call_function to send IPI and execute the
         * mtspr on target CPU.  We could do that without IPI
@@ -843,6 +849,13 @@ static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
                kernfs_put(kn);
        }
 
+       policy->freq_table = powernv_freqs;
+       policy->fast_switch_possible = true;
+
+       if (pvr_version_is(PVR_POWER9))
+               return 0;
+
+       /* Initialise Gpstate ramp-down timer only on POWER8 */
        gpstates =  kzalloc(sizeof(*gpstates), GFP_KERNEL);
        if (!gpstates)
                return -ENOMEM;
@@ -857,8 +870,6 @@ static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
                                msecs_to_jiffies(GPSTATE_TIMER_INTERVAL);
        spin_lock_init(&gpstates->gpstate_lock);
 
-       policy->freq_table = powernv_freqs;
-       policy->fast_switch_possible = true;
        return 0;
 }
 
@@ -998,7 +1009,8 @@ static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy)
        freq_data.pstate_id = idx_to_pstate(powernv_pstate_info.min);
        freq_data.gpstate_id = idx_to_pstate(powernv_pstate_info.min);
        smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1);
-       del_timer_sync(&gpstates->timer);
+       if (gpstates)
+               del_timer_sync(&gpstates->timer);
 }
 
 static unsigned int powernv_fast_switch(struct cpufreq_policy *policy,