[PATCH 3/6] drm/i915: Add enable_sagv option

[Lyude]

This option allows us to manually control the SAGV at module load time.
This can be useful in situations such as trying to debug watermark
changes, since enabled SAGV + incorrect watermarks = total GPU
annihilation.

Signed-off-by: Lyude <cpaul@xxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Ville SyrjÃlà <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
---
 drivers/gpu/drm/i915/i915_params.c   |  5 +++++
 drivers/gpu/drm/i915/i915_params.h   |  1 +
 drivers/gpu/drm/i915/intel_display.c | 16 +++++++++++++---
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 768ad89..f462cd4 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -62,6 +62,7 @@ struct i915_params i915 __read_mostly = {
 	.inject_load_failure = 0,
 	.enable_dpcd_backlight = false,
 	.enable_gvt = false,
+	.enable_sagv = -1,
 };
 
 module_param_named(modeset, i915.modeset, int, 0400);
@@ -233,3 +234,7 @@ MODULE_PARM_DESC(enable_dpcd_backlight,
 module_param_named(enable_gvt, i915.enable_gvt, bool, 0400);
 MODULE_PARM_DESC(enable_gvt,
 	"Enable support for Intel GVT-g graphics virtualization host support(default:false)");
+
+module_param_named_unsafe(enable_sagv, i915.enable_sagv, int, 0400);
+MODULE_PARM_DESC(enable_sagv,
+	"Enable the SAGV (gen9+ only)(1=enabled, 0=disabled, -1=driver discretion [default])");
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index 3a0dd78..a7db125 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -65,6 +65,7 @@ struct i915_params {
 	bool enable_dp_mst;
 	bool enable_dpcd_backlight;
 	bool enable_gvt;
+	int enable_sagv;
 };
 
 extern struct i915_params i915 __read_mostly;
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a71d05a..dd15ae2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -16904,12 +16904,22 @@ intel_modeset_setup_hw_state(struct drm_device *dev)
 		pll->on = false;
 	}
 
-	if (IS_VALLEYVIEW(dev) || IS_CHERRYVIEW(dev))
+	if (IS_VALLEYVIEW(dev) || IS_CHERRYVIEW(dev)) {
 		vlv_wm_get_hw_state(dev);
-	else if (IS_GEN9(dev))
+	} else if (IS_GEN9(dev)) {
 		skl_wm_get_hw_state(dev);
-	else if (HAS_PCH_SPLIT(dev))
+
+		if (i915.enable_sagv != -1) {
+			if (i915.enable_sagv)
+				intel_enable_sagv(dev_priv);
+			else
+				intel_disable_sagv(dev_priv);
+
+			dev_priv->sagv_status = I915_SAGV_NOT_CONTROLLED;
+		}
+	} else if (HAS_PCH_SPLIT(dev)) {
 		ilk_wm_get_hw_state(dev);
+	}
 
 	for_each_intel_crtc(dev, crtc) {
 		unsigned long put_domains;
-- 
2.7.4