Add a tunable to set forcewake hysteresis timer for those
who want explore the perf/power impacts.

Signed-off-by: Mika Kuoppala <mika.kuopp...@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 44 +++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_drv.h     |  8 +++++++
 drivers/gpu/drm/i915/intel_uncore.c | 19 +++++++++++++++-
 3 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c 
b/drivers/gpu/drm/i915/i915_debugfs.c
index 2ad4c48..3c55d40 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1301,6 +1301,9 @@ static int i915_forcewake_domains(struct seq_file *m, 
void *data)
                seq_printf(m, "%s.wake_count = %u\n",
                           intel_uncore_forcewake_domain_to_str(i),
                           fw_domain->wake_count);
+               seq_printf(m, "%s.hyst_ms = %u\n",
+                          intel_uncore_forcewake_domain_to_str(i),
+                          jiffies_to_msecs(fw_domain->hyst_jiffies));
        }
        spin_unlock_irq(&dev_priv->uncore.lock);
 
@@ -4321,6 +4324,46 @@ DEFINE_SIMPLE_ATTRIBUTE(i915_cache_sharing_fops,
                        i915_cache_sharing_get, i915_cache_sharing_set,
                        "%llu\n");
 
+static int i915_forcewake_hysteresis_get(void *data, u64 *val)
+{
+       struct drm_device *dev = data;
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       struct intel_uncore_forcewake_domain *d;
+       enum forcewake_domain_id id;
+
+       spin_lock_irq(&dev_priv->uncore.lock);
+       /* Same hysteresis for all */
+       for_each_fw_domain(d, dev_priv, id) {
+               *val = fw_domain_get_hysteresis(d);
+               break;
+       }
+       spin_unlock_irq(&dev_priv->uncore.lock);
+
+       return 0;
+}
+
+static int i915_forcewake_hysteresis_set(void *data, u64 val)
+{
+       struct drm_device *dev = data;
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       struct intel_uncore_forcewake_domain *d;
+       enum forcewake_domain_id id;
+
+       spin_lock_irq(&dev_priv->uncore.lock);
+       /* Same hysteresis for all */
+       for_each_fw_domain(d, dev_priv, id)
+               fw_domain_set_hysteresis(d, val);
+
+       spin_unlock_irq(&dev_priv->uncore.lock);
+
+       return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(i915_forcewake_hysteresis_fops,
+                       i915_forcewake_hysteresis_get,
+                       i915_forcewake_hysteresis_set,
+                       "%llu\n");
+
 static int i915_forcewake_open(struct inode *inode, struct file *file)
 {
        struct drm_device *dev = inode->i_private;
@@ -4455,6 +4498,7 @@ static const struct i915_debugfs_files {
        {"i915_spr_wm_latency", &i915_spr_wm_latency_fops},
        {"i915_cur_wm_latency", &i915_cur_wm_latency_fops},
        {"i915_fbc_false_color", &i915_fbc_fc_fops},
+       {"i915_forcewake_hysteresis", &i915_forcewake_hysteresis_fops},
 };
 
 void intel_display_crc_init(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0d67b17..6b10dc1 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -630,6 +630,7 @@ struct intel_uncore {
                enum forcewake_domain_id id;
                unsigned wake_count;
                struct timer_list timer;
+               unsigned long hyst_jiffies;
                u32 reg_set;
                u32 val_set;
                u32 val_clear;
@@ -2578,6 +2579,13 @@ void intel_uncore_forcewake_put(struct drm_i915_private 
*dev_priv,
 void assert_forcewakes_inactive(struct drm_i915_private *dev_priv);
 
 void
+fw_domain_set_hysteresis(struct intel_uncore_forcewake_domain *d,
+                             unsigned hyst_ms);
+unsigned
+fw_domain_get_hysteresis(const struct intel_uncore_forcewake_domain *d);
+
+
+void
 i915_enable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
                     u32 status_mask);
 
diff --git a/drivers/gpu/drm/i915/intel_uncore.c 
b/drivers/gpu/drm/i915/intel_uncore.c
index b3951f2..723698c 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -62,6 +62,22 @@ intel_uncore_forcewake_domain_to_str(const enum 
forcewake_domain_id id)
        return "unknown";
 }
 
+void
+fw_domain_set_hysteresis(struct intel_uncore_forcewake_domain *d,
+                        unsigned hyst_ms)
+{
+       d->hyst_jiffies = msecs_to_jiffies_timeout(hyst_ms);
+
+       if (d->hyst_jiffies == 0)
+               d->hyst_jiffies = 1;
+}
+
+unsigned
+fw_domain_get_hysteresis(const struct intel_uncore_forcewake_domain *d)
+{
+       return jiffies_to_msecs(d->hyst_jiffies);
+}
+
 static void
 assert_device_not_suspended(struct drm_i915_private *dev_priv)
 {
@@ -78,7 +94,7 @@ fw_domain_reset(const struct intel_uncore_forcewake_domain *d)
 static inline void
 fw_domain_arm_timer(struct intel_uncore_forcewake_domain *d)
 {
-       mod_timer_pinned(&d->timer, jiffies + 1);
+       mod_timer_pinned(&d->timer, jiffies + d->hyst_jiffies);
 }
 
 static inline void
@@ -956,6 +972,7 @@ static void fw_domain_init(struct drm_i915_private 
*dev_priv,
        WARN_ON(d->wake_count);
 
        d->wake_count = 0;
+       d->hyst_jiffies = 1;
        d->reg_set = reg_set;
        d->reg_ack = reg_ack;
 
-- 
1.9.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to