[Intel-gfx] [PATCH 04/25] drm/i915/slpc: Add enable_slpc module parameter

[tom.orourke at intel.com]

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.

slpc_enable_sanitize() converts i915.enable_slpc to either 0 or 1.
Interpretation of default value is based on HAS_SLPC(), after
slpc_version_check().  This function also enforces the requirement
that guc_submission is required for slpc.

intel_slpc_enabled() returns 1 if SLPC should be used.

v2: Add early call to sanitize enable_slpc in intel_guc_ucode_init

Suggested-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Tom O'Rourke <Tom.O'Rourke at intel.com>
---
 drivers/gpu/drm/i915/i915_params.c      |  6 ++++++
 drivers/gpu/drm/i915/i915_params.h      |  1 +
 drivers/gpu/drm/i915/intel_guc.h        |  6 ++++++
 drivers/gpu/drm/i915/intel_guc_loader.c | 19 +++++++++++++++++++
 4 files changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 1779f02..0f162a8 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -36,6 +36,7 @@ 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,
@@ -127,6 +128,11 @@ MODULE_PARM_DESC(enable_execlists,
 	"Override execlists usage. "
 	"(-1=auto [default], 0=disabled, 1=enabled)");
 
+module_param_named_unsafe(enable_slpc, i915.enable_slpc, int, 0400);
+MODULE_PARM_DESC(enable_slpc,
+	"Override single-loop-power-controller (slpc) usage. "
+	"(-1=auto, 0=disabled [default], 1=enabled)");
+
 module_param_named_unsafe(enable_psr, i915.enable_psr, int, 0600);
 MODULE_PARM_DESC(enable_psr, "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 02bc278..3f8eb82 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -39,6 +39,7 @@ struct i915_params {
 	int enable_fbc;
 	int enable_ppgtt;
 	int enable_execlists;
+	int enable_slpc;
 	int enable_psr;
 	unsigned int preliminary_hw_support;
 	int disable_power_well;
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index b18f5c3..298e243 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -110,6 +110,12 @@ struct intel_guc {
 	uint32_t last_seqno[GUC_MAX_ENGINES_NUM];
 };
 
+static inline int intel_slpc_enabled(void)
+{
+	WARN_ON(i915.enable_slpc < 0);
+	return i915.enable_slpc;
+}
+
 /* intel_guc_loader.c */
 extern void intel_guc_ucode_init(struct drm_device *dev);
 extern int intel_guc_ucode_load(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
index 00a0ffe..5dd2d9e 100644
--- a/drivers/gpu/drm/i915/intel_guc_loader.c
+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
@@ -116,6 +116,21 @@ static void direct_interrupts_to_guc(struct drm_i915_private *dev_priv)
 	I915_WRITE(GUC_WD_VECS_IER, ~irqs);
 }
 
+static void slpc_enable_sanitize(struct drm_device *dev)
+{
+	/* handle default case */
+	if (i915.enable_slpc < 0)
+		i915.enable_slpc = HAS_SLPC(dev);
+
+	/* slpc requires hardware support and compatible firmware */
+	if (!HAS_SLPC(dev))
+		i915.enable_slpc = 0;
+
+	/* slpc requires guc submission */
+	if (!i915.enable_guc_submission)
+		i915.enable_slpc = 0;
+}
+
 static void slpc_version_check(struct drm_device *dev, struct intel_guc_fw *guc_fw)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -125,6 +140,8 @@ static void slpc_version_check(struct drm_device *dev, struct intel_guc_fw *guc_
 		info = (struct intel_device_info *) &dev_priv->info;
 		info->has_slpc = 0;
 	}
+
+	slpc_enable_sanitize(dev);
 }
 
 static u32 get_gttype(struct drm_i915_private *dev_priv)
@@ -656,6 +673,8 @@ void intel_guc_ucode_init(struct drm_device *dev)
 		fw_path = "";	/* unknown device */
 	}
 
+	slpc_enable_sanitize(dev);
+
 	if (!i915.enable_guc_submission)
 		return;
 
-- 
1.9.1