[PATCH 14/15] drm/i915/dg1: Double memory bandwidth available

[Matthew Auld]

From: Clint Taylor <clinton.a.taylor at intel.com>

Use MCHBAR Gear_type information to compute memory bandwidth available
during MCHBAR calculations.

v2 by Jani:
- switch to intel_uncore_read/intel_uncore_write

Tested-by: Swati Sharma <swati2.sharma at intel.com>
Cc: Swati Sharma <swati2.sharma at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Clint Taylor <clinton.a.taylor at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/display/intel_bw.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index 7558b343a99f..98485053d435 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -41,6 +41,9 @@ struct intel_qgv_info {
 #define  DG1_DRAM_T_RP_MASK (0x7F << 0)
 #define  DG1_DRAM_T_RP_SHIFT 0
 
+#define  ICL_GEAR_TYPE_MASK (0x01 << 16)
+#define  ICL_GEAR_TYPE_SHIFT 16
+
 static int dg1_mchbar_read_qgv_point_info(struct drm_i915_private *dev_priv,
 					  struct intel_qgv_point *sp,
 					  int point)
@@ -55,6 +58,11 @@ static int dg1_mchbar_read_qgv_point_info(struct drm_i915_private *dev_priv,
 	else
 		dclk_reference = 8; /* 8 * 16.666 MHz = 133 MHz */
 	sp->dclk = dclk_ratio * dclk_reference;
+
+	val = intel_uncore_read(&dev_priv->uncore, SKL_MC_BIOS_DATA_0_0_0_MCHBAR_PCU);
+	if ((val & ICL_GEAR_TYPE_MASK) >> ICL_GEAR_TYPE_SHIFT)
+		sp->dclk *= 2;
+
 	if (sp->dclk == 0)
 		return -EINVAL;
 
-- 
2.26.3