[Intel-gfx] [PATCH v8 3/3] drm/i915: Predictive governor to control slice/subslice/eu

[Ankit Navik]

Load classification is used for predictive governor to control
eu/slice/subslice based on workloads.

sysfs is provided to enable/disable the feature

V2:
 * Fix code style.
 * Move predictive_load_timer into a drm_i915_private
   structure.
 * Make generic function to set optimum config. (Tvrtko Ursulin)

V3:
 * Rebase.
 * Fix race condition for predictive load set.
 * Add slack to start hrtimer for more power efficient. (Tvrtko Ursulin)

V4:
 * Fix data type and initialization of mutex to protect predictive load
   state.
 * Move predictive timer init to i915_gem_init_early. (Tvrtko Ursulin)
 * Move debugfs to kernel parameter.

V5:
 * Rebase.
 * Remove mutex for pred_timer

V6:
 * Rebase.
 * Fix warnings.

V7:
 * Drop timer and move logic to __execlists_update_reg_state. (Tvrtko Ursulin)
 * Remove kernel boot param and make it to sysfs entry. (Jani Nikula)

v8:
 * Rebase.

Cc: Vipin Anand <vipin.anand at intel.com>
Signed-off-by: Ankit Navik <ankit.p.navik at intel.com>
---
 drivers/gpu/drm/i915/i915_sysfs.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index 45d32ef42787..5d76e4992c8d 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -433,12 +433,43 @@ static ssize_t gt_min_freq_mhz_store(struct device *kdev,
 	return ret ?: count;
 }
 
+static ssize_t deu_enable_show(struct device *kdev, struct device_attribute *attr, char *buf)
+{
+	struct drm_i915_private *i915 = kdev_minor_to_i915(kdev);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", i915->predictive_load_enable);
+}
+
+static ssize_t deu_enable_store(struct device *kdev,
+				struct device_attribute *attr,
+				const char *buf,
+				size_t count)
+{
+	struct drm_i915_private *i915 = kdev_minor_to_i915(kdev);
+	ssize_t ret;
+	u32 val;
+
+	ret = kstrtou32(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	/* Check invalid values */
+	if (val != 0 && val != 1)
+		ret = -EINVAL;
+
+	i915->predictive_load_enable = val;
+
+	return count;
+}
+
 static DEVICE_ATTR_RO(gt_act_freq_mhz);
 static DEVICE_ATTR_RO(gt_cur_freq_mhz);
 static DEVICE_ATTR_RW(gt_boost_freq_mhz);
 static DEVICE_ATTR_RW(gt_max_freq_mhz);
 static DEVICE_ATTR_RW(gt_min_freq_mhz);
 
+static DEVICE_ATTR_RW(deu_enable);
+
 static DEVICE_ATTR_RO(vlv_rpe_freq_mhz);
 
 static ssize_t gt_rp_mhz_show(struct device *kdev, struct device_attribute *attr, char *buf);
@@ -474,6 +505,7 @@ static const struct attribute * const gen6_attrs[] = {
 	&dev_attr_gt_RP0_freq_mhz.attr,
 	&dev_attr_gt_RP1_freq_mhz.attr,
 	&dev_attr_gt_RPn_freq_mhz.attr,
+	&dev_attr_deu_enable.attr,
 	NULL,
 };
 
-- 
2.7.4