[PATCH v6 2/2] drm/xe/guc: Eliminate RPa frequency caching

[Sk Anirban <sk.anirban@intel.com>]

Remove the cached pc->rpa_freq field and refactor RPA frequency handling
to fetch values directly from hardware registers on each request.

v2: Check graphics version instead of platform (Rodrigo)
v3: Fix graphics version check (Badal)

Suggested-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Suggested-by: Badal Nilawar <badal.nilawar@intel.com>
Signed-off-by: Sk Anirban <sk.anirban@intel.com>
---
 drivers/gpu/drm/xe/xe_guc_pc.c       | 55 +++++++++++++---------------
 drivers/gpu/drm/xe/xe_guc_pc_types.h |  2 -
 2 files changed, 26 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c
index efa9318c4587..ea9925cdc107 100644
--- a/drivers/gpu/drm/xe/xe_guc_pc.c
+++ b/drivers/gpu/drm/xe/xe_guc_pc.c
@@ -363,7 +363,7 @@ static int pc_set_max_freq(struct xe_guc_pc *pc, u32 freq)
 				   freq);
 }
 
-static void mtl_update_rpa_value(struct xe_guc_pc *pc)
+static u32 mtl_get_rpa_freq(struct xe_guc_pc *pc)
 {
 	struct xe_gt *gt = pc_to_gt(pc);
 	u32 reg;
@@ -373,7 +373,7 @@ static void mtl_update_rpa_value(struct xe_guc_pc *pc)
 	else
 		reg = xe_mmio_read32(&gt->mmio, MTL_GT_RPA_FREQUENCY);
 
-	pc->rpa_freq = decode_freq(REG_FIELD_GET(MTL_RPA_MASK, reg));
+	return decode_freq(REG_FIELD_GET(MTL_RPA_MASK, reg));
 }
 
 static u32 mtl_get_rpe_freq(struct xe_guc_pc *pc)
@@ -389,24 +389,28 @@ static u32 mtl_get_rpe_freq(struct xe_guc_pc *pc)
 	return decode_freq(REG_FIELD_GET(MTL_RPE_MASK, reg));
 }
 
-static void tgl_update_rpa_value(struct xe_guc_pc *pc)
+static u32 pvc_get_rpa_freq(struct xe_guc_pc *pc)
 {
-	struct xe_gt *gt = pc_to_gt(pc);
-	struct xe_device *xe = gt_to_xe(gt);
-	u32 reg;
-
 	/*
 	 * For PVC we still need to use fused RP0 as the approximation for RPa
 	 * For other platforms than PVC we get the resolved RPa directly from
 	 * PCODE at a different register
 	 */
-	if (xe->info.platform == XE_PVC) {
-		reg = xe_mmio_read32(&gt->mmio, PVC_RP_STATE_CAP);
-		pc->rpa_freq = REG_FIELD_GET(RP0_MASK, reg) * GT_FREQUENCY_MULTIPLIER;
-	} else {
-		reg = xe_mmio_read32(&gt->mmio, FREQ_INFO_REC);
-		pc->rpa_freq = REG_FIELD_GET(RPA_MASK, reg) * GT_FREQUENCY_MULTIPLIER;
-	}
+
+	struct xe_gt *gt = pc_to_gt(pc);
+	u32 reg;
+
+	reg = xe_mmio_read32(&gt->mmio, PVC_RP_STATE_CAP);
+	return REG_FIELD_GET(RP0_MASK, reg) * GT_FREQUENCY_MULTIPLIER;
+}
+
+static u32 tgl_get_rpa_freq(struct xe_guc_pc *pc)
+{
+	struct xe_gt *gt = pc_to_gt(pc);
+	u32 reg;
+
+	reg = xe_mmio_read32(&gt->mmio, FREQ_INFO_REC);
+	return REG_FIELD_GET(RPA_MASK, reg) * GT_FREQUENCY_MULTIPLIER;
 }
 
 static u32 pvc_get_rpe_freq(struct xe_guc_pc *pc)
@@ -427,17 +431,6 @@ static u32 tgl_get_rpe_freq(struct xe_guc_pc *pc)
 	return REG_FIELD_GET(RPE_MASK, reg) * GT_FREQUENCY_MULTIPLIER;
 }
 
-static void pc_update_rp_values(struct xe_guc_pc *pc)
-{
-	struct xe_gt *gt = pc_to_gt(pc);
-	struct xe_device *xe = gt_to_xe(gt);
-
-	if (GRAPHICS_VERx100(xe) >= 1270)
-		mtl_update_rpa_value(pc);
-	else
-		tgl_update_rpa_value(pc);
-}
-
 /**
  * xe_guc_pc_get_act_freq - Get Actual running frequency
  * @pc: The GuC PC
@@ -536,9 +529,15 @@ u32 xe_guc_pc_get_rp0_freq(struct xe_guc_pc *pc)
  */
 u32 xe_guc_pc_get_rpa_freq(struct xe_guc_pc *pc)
 {
-	pc_update_rp_values(pc);
+	struct xe_gt *gt = pc_to_gt(pc);
+	struct xe_device *xe = gt_to_xe(gt);
 
-	return pc->rpa_freq;
+	if (GRAPHICS_VERx100(xe) == 1260)
+		return pvc_get_rpa_freq(pc);
+	else if (GRAPHICS_VERx100(xe) >= 1270)
+		return mtl_get_rpa_freq(pc);
+	else
+		return tgl_get_rpa_freq(pc);
 }
 
 /**
@@ -1135,8 +1134,6 @@ static int pc_init_freqs(struct xe_guc_pc *pc)
 	if (ret)
 		goto out;
 
-	pc_update_rp_values(pc);
-
 	pc_init_pcode_freq(pc);
 
 	/*
diff --git a/drivers/gpu/drm/xe/xe_guc_pc_types.h b/drivers/gpu/drm/xe/xe_guc_pc_types.h
index f27c05d81706..711bbcdcb0d3 100644
--- a/drivers/gpu/drm/xe/xe_guc_pc_types.h
+++ b/drivers/gpu/drm/xe/xe_guc_pc_types.h
@@ -19,8 +19,6 @@ struct xe_guc_pc {
 	atomic_t flush_freq_limit;
 	/** @rp0_freq: HW RP0 frequency - The Maximum one */
 	u32 rp0_freq;
-	/** @rpa_freq: HW RPa frequency - The Achievable one */
-	u32 rpa_freq;
 	/** @rpn_freq: HW RPN frequency - The Minimum one */
 	u32 rpn_freq;
 	/** @user_requested_min: Stash the minimum requested freq by user */
-- 
2.43.0