drm/i915/xe2hpd: Identify the memory type for SKUs with GDDR + ECC

Some SKUs of Xe2_HPD platforms (such as BMG) have GDDR memory type
with ECC enabled. We need to identify this scenario and add a new
case in xelpdp_get_dram_info() to handle it. In addition, the
derating value needs to be adjusted accordingly to compensate for
the limited bandwidth.

Bspec: 64602
Cc: Matt Roper <matthew.d.roper@intel.com>
Fixes: 3adcf97 ("drm/xe/bmg: Drop force_probe requirement")
Cc: stable@vger.kernel.org
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250324-tip-v2-1-38397de319f8@intel.com
(cherry picked from commit 327e30123cafcb45c0fc5843da0367b90332999d)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_bw.c

@@ -244,6 +244,7 @@ static int icl_get_qgv_points(struct drm_i915_private *dev_priv,
 			qi->deinterleave = 4;
 			break;
 		case INTEL_DRAM_GDDR:
+		case INTEL_DRAM_GDDR_ECC:
 			qi->channel_width = 32;
 			break;
 		default:
@@ -398,6 +399,12 @@ static const struct intel_sa_info xe2_hpd_sa_info = {
 	/* Other values not used by simplified algorithm */
 };
 
+static const struct intel_sa_info xe2_hpd_ecc_sa_info = {
+	.derating = 45,
+	.deprogbwlimit = 53,
+	/* Other values not used by simplified algorithm */
+};
+
 static int icl_get_bw_info(struct drm_i915_private *dev_priv, const struct intel_sa_info *sa)
 {
 	struct intel_qgv_info qi = {};
@@ -740,10 +747,15 @@ static unsigned int icl_qgv_bw(struct drm_i915_private *i915,
 
 void intel_bw_init_hw(struct drm_i915_private *dev_priv)
 {
+	const struct dram_info *dram_info = &dev_priv->dram_info;
+
 	if (!HAS_DISPLAY(dev_priv))
 		return;
 
-	if (DISPLAY_VERx100(dev_priv) >= 1401 && IS_DGFX(dev_priv))
+	if (DISPLAY_VERx100(dev_priv) >= 1401 && IS_DGFX(dev_priv) &&
+		 dram_info->type == INTEL_DRAM_GDDR_ECC)
+		xe2_hpd_get_bw_info(dev_priv, &xe2_hpd_ecc_sa_info);
+	else if (DISPLAY_VERx100(dev_priv) >= 1401 && IS_DGFX(dev_priv))
 		xe2_hpd_get_bw_info(dev_priv, &xe2_hpd_sa_info);
 	else if (DISPLAY_VER(dev_priv) >= 14)
 		tgl_get_bw_info(dev_priv, &mtl_sa_info);

drivers/gpu/drm/i915/i915_drv.h

@@ -305,6 +305,7 @@ struct drm_i915_private {
 			INTEL_DRAM_DDR5,
 			INTEL_DRAM_LPDDR5,
 			INTEL_DRAM_GDDR,
+			INTEL_DRAM_GDDR_ECC,
 		} type;
 		u8 num_qgv_points;
 		u8 num_psf_gv_points;

drivers/gpu/drm/i915/soc/intel_dram.c

@@ -687,6 +687,10 @@ static int xelpdp_get_dram_info(struct drm_i915_private *i915)
 		drm_WARN_ON(&i915->drm, !IS_DGFX(i915));
 		dram_info->type = INTEL_DRAM_GDDR;
 		break;
+	case 9:
+		drm_WARN_ON(&i915->drm, !IS_DGFX(i915));
+		dram_info->type = INTEL_DRAM_GDDR_ECC;
+		break;
 	default:
 		MISSING_CASE(val);
 		return -EINVAL;

drivers/gpu/drm/xe/xe_device_types.h

@@ -585,6 +585,7 @@ struct xe_device {
 			INTEL_DRAM_DDR5,
 			INTEL_DRAM_LPDDR5,
 			INTEL_DRAM_GDDR,
+			INTEL_DRAM_GDDR_ECC,
 		} type;
 		u8 num_qgv_points;
 		u8 num_psf_gv_points;