[Intel-gfx] [PATCH 2/3] drm/i915/tgl: Read SAGV block time from PCODE

[James Ausmus]

Starting from TGL, we now need to read the SAGV block time via a PCODE
mailbox, rather than having a static value.

BSpec: 49326

Cc: Ville Syrjälä <ville.syrjala at intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Signed-off-by: James Ausmus <james.ausmus at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h |  1 +
 drivers/gpu/drm/i915/intel_pm.c | 20 +++++++++++++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index e752de9470bd..84ae6553485b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8865,6 +8865,7 @@ enum {
 #define     GEN9_SAGV_DISABLE			0x0
 #define     GEN9_SAGV_IS_DISABLED		0x1
 #define     GEN9_SAGV_ENABLE			0x3
+#define GEN12_PCODE_READ_SAGV_BLOCK_TIME_US	0x23
 #define GEN6_PCODE_DATA				_MMIO(0x138128)
 #define   GEN6_PCODE_FREQ_IA_RATIO_SHIFT	8
 #define   GEN6_PCODE_FREQ_RING_RATIO_SHIFT	16
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 5ad72dcb0faa..ca2bec09edb5 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3665,16 +3665,26 @@ intel_has_sagv(struct drm_i915_private *dev_priv)
 static int
 intel_get_sagv_block_time_us(struct drm_i915_private *dev_priv)
 {
-	int sagv_block_time_us = 1000; /* Default to unusable block time */
+	uint val = 0;
+	int ret, sagv_block_time_us = 1000; /* Default to unusable block time */
 
-	if (IS_GEN(dev_priv, 11))
+	if (INTEL_GEN(dev_priv) >= 12) {
+		ret = sandybridge_pcode_read(dev_priv,
+					     GEN12_PCODE_READ_SAGV_BLOCK_TIME_US,
+					     &val, NULL);
+		if (!ret)
+			sagv_block_time_us = val;
+		else
+			DRM_DEBUG_DRIVER("Couldn't read SAGV block time!\n");
+	} else if (IS_GEN(dev_priv, 11)) {
 		sagv_block_time_us = 10;
-	else if (IS_GEN(dev_priv, 10))
+	} else if (IS_GEN(dev_priv, 10)) {
 		sagv_block_time_us = 20;
-	else if (IS_GEN(dev_priv, 9))
+	} else if (IS_GEN(dev_priv, 9)) {
 		sagv_block_time_us = 30;
-	else
+	} else {
 		MISSING_CASE(INTEL_GEN(dev_priv));
+	}
 
 	return sagv_block_time_us;
 }
-- 
2.22.1