[Intel-gfx] [PATCH v2 2/2] 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

v2: Fix up pcode val data type (Ville), tighten variable scope (Ville)

Cc: Ville Syrjälä <ville.syrjala at linux.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>
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h |  1 +
 drivers/gpu/drm/i915/intel_pm.c | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 058aa5ca8b73..6a45df9dad9c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8869,6 +8869,7 @@ 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 b413a7f3bc5d..13721ba44013 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3645,7 +3645,20 @@ intel_has_sagv(struct drm_i915_private *dev_priv)
 static void
 skl_setup_sagv_block_time(struct drm_i915_private *dev_priv)
 {
-	if (IS_GEN(dev_priv, 11)) {
+	if (INTEL_GEN(dev_priv) >= 12) {
+		u32 val = 0;
+		int ret;
+
+		ret = sandybridge_pcode_read(dev_priv,
+					     GEN12_PCODE_READ_SAGV_BLOCK_TIME_US,
+					     &val, NULL);
+		if (!ret) {
+			dev_priv->sagv_block_time_us = val;
+			return;
+		}
+
+		DRM_DEBUG_DRIVER("Couldn't read SAGV block time!\n");
+	} else if (IS_GEN(dev_priv, 11)) {
 		dev_priv->sagv_block_time_us = 10;
 		return;
 	} else if (IS_GEN(dev_priv, 10)) {
-- 
2.22.1