devfreq: remove throughput hints from podgov

The CONFIG_TEGRA_THROUGHPUT-dependent throughput hint feature is dead,
so remove the code from podgov that used it.

Bug 1853519

Change-Id: Icb36eb0b2baa98757b3ce419080b43978384bbc9
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/1454591
(cherry picked from linux-4.9 commit 96fcf87d98618ddf9a1e23a017294d201040859b)
Reviewed-on: https://git-master.nvidia.com/r/1770147
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Timo Alho <talho@nvidia.com>
Tested-by: Timo Alho <talho@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 7 insertions, 152 deletions

diff --git a/drivers/devfreq/governor_pod_scaling.c b/drivers/devfreq/governor_pod_scaling.c
index cca369997..351cfd6ee 100644
--- a/drivers/devfreq/governor_pod_scaling.c
+++ b/drivers/devfreq/governor_pod_scaling.c
@@ -22,13 +22,9 @@
  * Power-on-demand clock scaling for nvhost devices
  *
  * devfreq calls nvhost_pod_estimate_freq() for estimating the new
- * frequency for the device. The clocking is done using two properties:
- *
- *  (1) Usually the governor receives actively throughput hints that indicate
- *      whether scaling up or down is required.
- *  (2) The load of the device is estimated using the busy times from the
- *      device profile. This information indicates if the device frequency
- *      should be altered.
+ * frequency for the device. The clocking is done using the load of the device
+ * is estimated using the busy times from the device profile. This information
+ * indicates if the device frequency should be altered.
  *
  */
 
@@ -42,12 +38,6 @@
 #include <linux/tegra-soc.h>
 #include <linux/module.h>
 
-#include <linux/notifier.h>
-#include <linux/tegra-throughput.h>
-
-#include <linux/notifier.h>
-#include <linux/tegra-throughput.h>
-
 #define CREATE_TRACE_POINTS
 #include <trace/events/nvhost_podgov.h>
 
@@ -58,16 +48,10 @@
 
 #define GET_TARGET_FREQ_DONTSCALE       1
 
-/* time frame for load and hint tracking - when events come in at a larger
- * interval, this probably indicates the current estimates are stale
- */
-#define GR3D_TIMEFRAME 1000000 /* 1 sec */
-
-/* the number of frames to use in the running average of load estimates and
- * throughput hints. Choosing 6 frames targets a window of about 100 msec.
- * Large flucutuations in frame times require a window that's large enough to
- * prevent spiky scaling behavior, which in turn exacerbates frame rate
- * instability.
+/* the number of frames to use in the running average of load estimates.
+ * Choosing 6 frames targets a window of about 100 msec.  Large flucutuations
+ * in frame times require a window that's large enough to prevent spiky scaling
+ * behavior, which in turn exacerbates frame rate instability.
  */
 
 static void podgov_enable(struct devfreq *df, int enable);
@@ -84,14 +68,12 @@ struct podgov_info_rec {
         int                     enable;
         int                     init;
 
-        ktime_t                 last_throughput_hint;
         ktime_t                 last_scale;
 
         struct delayed_work     idle_timer;
 
         unsigned int            p_slowdown_delay;
         unsigned int            p_block_window;
-        unsigned int            p_use_throughput_hint;
         unsigned int            p_hint_lo_limit;
         unsigned int            p_hint_hi_limit;
         unsigned int            p_scaleup_limit;
@@ -124,8 +106,6 @@ struct podgov_info_rec {
         struct kobj_attribute   enable_3d_scaling_attr;
         struct kobj_attribute   user_attr;
         struct kobj_attribute   freq_request_attr;
-
-        struct notifier_block   throughput_hint_notifier;
 };
 
 /*******************************************************************************
@@ -437,110 +417,6 @@ static void podgov_idle_handler(struct work_struct *work)
         mutex_unlock(&df->lock);
 }
 
-#ifdef CONFIG_TEGRA_THROUGHPUT
-/*******************************************************************************
- * freqlist_down(podgov, target, steps)
- *
- * This function determines the frequency that is "steps" frequency steps
- * lower compared to the target frequency.
- ******************************************************************************/
-
-static int freqlist_down(struct podgov_info_rec *podgov, unsigned long target,
-                  int steps)
-{
-        int i, pos;
-
-        for (i = podgov->freq_count - 1; i >= 0; i--)
-                if (podgov->freqlist[i] <= target)
-                        break;
-
-        pos = max(0, i - steps);
-        return podgov->freqlist[pos];
-}
-
-/*******************************************************************************
- * nvhost_scale_emc_set_throughput_hint(hint)
- *
- * This function can be used to request scaling up or down based on the
- * required throughput
- ******************************************************************************/
-
-static int nvhost_scale_emc_set_throughput_hint(struct notifier_block *nb,
-                                              unsigned long action, void *data)
-{
-        struct podgov_info_rec *podgov =
-                container_of(nb, struct podgov_info_rec,
-                             throughput_hint_notifier);
-        struct devfreq *df = podgov->power_manager;
-        struct device *dev = df->dev.parent;
-        int hint = tegra_throughput_get_hint();
-        long idle;
-        unsigned long curr, target;
-        int avg_idle, avg_hint, scale_score;
-        unsigned int smooth;
-
-        /* make sure the device is alive before doing any scaling */
-        pm_runtime_get_noresume(dev);
-        if (!pm_runtime_active(dev)) {
-                pm_runtime_put(dev);
-                return 0;
-        }
-
-        mutex_lock(&df->lock);
-
-        podgov->block--;
-
-        if (!podgov->enable ||
-                !podgov->p_use_throughput_hint ||
-                podgov->block > 0)
-                goto exit_unlock;
-
-        trace_podgov_hint(df->dev.parent, podgov->idle, hint);
-        podgov->last_throughput_hint = ktime_get();
-
-        curr = df->previous_freq;
-        idle = podgov->idle;
-        avg_idle = podgov->idle_avg;
-        smooth = podgov->p_smooth;
-
-        /* compute averages usings exponential-moving-average */
-        avg_hint = ((smooth*podgov->hint_avg + hint)/(smooth+1));
-        podgov->hint_avg = avg_hint;
-
-        /* set the target using avg_hint and avg_idle */
-        target = curr;
-        if (avg_hint < podgov->p_hint_lo_limit) {
-                target = freqlist_up(podgov, curr, 1);
-        } else {
-                scale_score = avg_idle + avg_hint;
-                if (scale_score > podgov->p_scaledown_limit)
-                        target = freqlist_down(podgov, curr, 1);
-                else if (scale_score < podgov->p_scaleup_limit
-                                && hint < podgov->p_hint_hi_limit)
-                        target = freqlist_up(podgov, curr, 1);
-        }
-
-        /* clamp and apply target */
-        scaling_limit(df, &target);
-        if (target != curr) {
-                podgov->block = podgov->p_smooth;
-                trace_podgov_do_scale(df->dev.parent,
-                                      df->previous_freq, target);
-                podgov->adjustment_frequency = target;
-                podgov->adjustment_type = ADJUSTMENT_LOCAL;
-                update_devfreq(df);
-        }
-
-        trace_podgov_print_target(df->dev.parent, idle, avg_idle,
-                                  curr / 1000000, target, hint, avg_hint);
-
-exit_unlock:
-        mutex_unlock(&df->lock);
-        pm_runtime_put(dev);
-        return NOTIFY_OK;
-}
-#endif
-
 /*******************************************************************************
  * debugfs interface for controlling 3d clock scaling on the fly
  ******************************************************************************/
@@ -580,7 +456,6 @@ static void nvhost_scale_emc_debug_init(struct devfreq *df)
         CREATE_PODGOV_FILE(load_target);
         CREATE_PODGOV_FILE(bias);
         CREATE_PODGOV_FILE(damp);
-        CREATE_PODGOV_FILE(use_throughput_hint);
         CREATE_PODGOV_FILE(hint_hi_limit);
         CREATE_PODGOV_FILE(hint_lo_limit);
         CREATE_PODGOV_FILE(scaleup_limit);
@@ -784,11 +659,6 @@ static int nvhost_pod_estimate_freq(struct devfreq *df,
                 podgov->idle;
         podgov->idle_avg = podgov->idle_avg / (podgov->p_smooth + 1);
 
-        /* if throughput hint enabled, and last hint is recent enough, return */
-        if (podgov->p_use_throughput_hint &&
-                ktime_us_delta(now, podgov->last_throughput_hint) < 1000000)
-                return GET_TARGET_FREQ_DONTSCALE;
-
         if (dev_stat.busy) {
                 cancel_delayed_work(&podgov->idle_timer);
                 *freq = scaling_state_check(df, now);
@@ -842,7 +712,6 @@ static int nvhost_pod_init(struct devfreq *df)
         /* Set scaling parameter defaults */
         podgov->enable = 1;
         podgov->block = 0;
-        podgov->p_use_throughput_hint = 1;
 
         if (!strcmp(d->name, "vic03.0")) {
                 podgov->p_load_max = 990;
@@ -871,7 +740,6 @@ static int nvhost_pod_init(struct devfreq *df)
                         podgov->p_scaledown_limit = 1300;
                         podgov->p_smooth = 10;
                         podgov->p_damp = 7;
-                        podgov->p_use_throughput_hint = 0;
                         break;
                 default:
                         pr_err("%s: un-supported chip id\n", __func__);
@@ -886,7 +754,6 @@ static int nvhost_pod_init(struct devfreq *df)
         podgov->p_user = 0;
 
         /* Reset clock counters */
-        podgov->last_throughput_hint = now;
         podgov->last_scale = now;
 
         podgov->power_manager = df;
@@ -937,14 +804,6 @@ static int nvhost_pod_init(struct devfreq *df)
 
         nvhost_scale_emc_debug_init(df);
 
-        /* register the governor to throughput hint notifier chain */
-#ifdef CONFIG_TEGRA_THROUGHPUT
-        podgov->throughput_hint_notifier.notifier_call =
-                &nvhost_scale_emc_set_throughput_hint;
-        blocking_notifier_chain_register(&throughput_notifier_list,
-                                         &podgov->throughput_hint_notifier);
-#endif
-
         return 0;
 
 err_get_freqs:
@@ -973,10 +832,6 @@ static void nvhost_pod_exit(struct devfreq *df)
 {
         struct podgov_info_rec *podgov = df->data;
 
-#ifdef CONFIG_TEGRA_THROUGHPUT
-        blocking_notifier_chain_unregister(&throughput_notifier_list,
-                                           &podgov->throughput_hint_notifier);
-#endif
         cancel_delayed_work(&podgov->idle_timer);
 
         sysfs_remove_file(&df->dev.parent->kobj, &podgov->user_attr.attr);