[Intel-gfx] [PATCH 14/31] drm/i915/slpc: Add enable_slpc module parameter

[Sagar Arun Kamble]

From: Tom O'Rourke <Tom.O'Rourke at intel.com>

i915.enable_slpc is used to override the default for slpc usage.
The expected values are -1=auto, 0=disabled [default], 1=enabled.

Sanitize i915.enable_slpc to either 0 or 1 based on HAS_SLPC() and
GuC load and submission options.

v1: Add early call to sanitize enable_slpc in intel_guc_ucode_init
    Remove sanitize enable_slpc call before firmware version check
    is performed. (ChrisW)
    Version check is added in next patch and that will be done as
    part of slpc_enable_sanitize function in the next patch. (Sagar)
    Updated slpc option sanitize function call for platforms without
    GuC support. This was caught by CI BAT.

v2: Changed parameter to dev_priv for HAS_SLPC macro. (David)
    Code indentation based on checkpatch.

v3: Rebase.

v4: Moved sanitization of SLPC option post GuC load.

v5: Removed function intel_slpc_enabled. Planning to rely only on
    kernel parameter. Moved sanitization prior to GuC load to use the
    parameter during SLPC state setup during to GuC load. (Sagar)

v6: Commit message update. Rebase.

v7: Moved SLPC option sanitization to intel_uc_sanitize_options.

v8: Clearing SLPC option on GuC load failure. Change moved from later
patch. (Sagar)

Suggested-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Tom O'Rourke <Tom.O'Rourke at intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/i915_params.c |  5 +++++
 drivers/gpu/drm/i915/i915_params.h |  1 +
 drivers/gpu/drm/i915/intel_uc.c    | 15 +++++++++++++++
 3 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index d32d761..a14db53 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -43,6 +43,7 @@ struct i915_params i915 __read_mostly = {
 	.enable_dc = -1,
 	.enable_fbc = -1,
 	.enable_execlists = -1,
+	.enable_slpc = 0,
 	.enable_hangcheck = true,
 	.enable_ppgtt = -1,
 	.enable_psr = -1,
@@ -139,6 +140,10 @@ struct i915_params i915 __read_mostly = {
 	"Override execlists usage. "
 	"(-1=auto [default], 0=disabled, 1=enabled)");
 
+i915_param_named_unsafe(enable_slpc, int, 0400,
+	"Override single-loop-power-controller (slpc) usage. "
+	"(-1=auto, 0=disabled [default], 1=enabled)");
+
 i915_param_named_unsafe(enable_psr, int, 0600,
 	"Enable PSR "
 	"(0=disabled, 1=enabled - link mode chosen per-platform, 2=force link-standby mode, 3=force link-off mode) "
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index ac84470..d5c7bfb 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -41,6 +41,7 @@
 	func(int, enable_ppgtt); \
 	func(int, enable_execlists); \
 	func(int, enable_psr); \
+	func(int, enable_slpc); \
 	func(int, disable_power_well); \
 	func(int, enable_ips); \
 	func(int, invert_brightness); \
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index bb31243..eeec986 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -69,6 +69,7 @@ void intel_uc_sanitize_options(struct drm_i915_private *dev_priv)
 
 		i915.enable_guc_loading = 0;
 		i915.enable_guc_submission = 0;
+		i915.enable_slpc = 0;
 		return;
 	}
 
@@ -92,6 +93,18 @@ void intel_uc_sanitize_options(struct drm_i915_private *dev_priv)
 	/* A negative value means "use platform default" */
 	if (i915.enable_guc_submission < 0)
 		i915.enable_guc_submission = HAS_GUC_SCHED(dev_priv);
+
+	/* slpc requires hardware support and compatible firmware */
+	if (!HAS_SLPC(dev_priv))
+		i915.enable_slpc = 0;
+
+	/* slpc requires guc loaded */
+	if (!i915.enable_guc_loading)
+		i915.enable_slpc = 0;
+
+	/* slpc requires guc submission */
+	if (!i915.enable_guc_submission)
+		i915.enable_slpc = 0;
 }
 
 void intel_uc_init_early(struct drm_i915_private *dev_priv)
@@ -400,6 +413,8 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 	i915.enable_guc_loading = 0;
 	DRM_NOTE("GuC firmware loading disabled\n");
 
+	i915.enable_slpc = 0;
+
 	return ret;
 }
 
-- 
1.9.1