[Intel-xe] [RFC PATCH v2 1/3] drm/xe: Introduce function pointers in xe_gt.c with local structure

[Francois Dugast]

A local structure of function pointers is used as a minimal
hardware abstraction layer to split between common and platform
specific code. This structure is initialized once with the
functions matching the platform, then it is used in the common
code with no need for switch or if/else to detect the platform.
For now only the function setup_private_ppat() is refactored.

Signed-off-by: Francois Dugast <francois.dugast at intel.com>
---
 drivers/gpu/drm/xe/xe_device_types.h |  1 +
 drivers/gpu/drm/xe/xe_gt.c           | 46 +++++++++++++++++++---------
 2 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 034e0956f4ea..411e7a62d28a 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -311,6 +311,7 @@ struct xe_device {
 		u32 lvds_channel_mode;
 	} params;
 #endif
+	struct xe_gt_platform_funcs *gt_funcs;
 };
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index daa433d0f2f5..3b092f951378 100644
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -42,6 +42,10 @@
 #include "xe_wa.h"
 #include "xe_wopcm.h"
 
+struct xe_gt_platform_funcs {
+	void (*setup_private_ppat)(struct xe_gt *gt);
+};
+
 struct xe_gt *xe_find_full_gt(struct xe_gt *gt)
 {
 	struct xe_gt *search;
@@ -157,18 +161,6 @@ static void mtl_setup_private_ppat(struct xe_gt *gt)
 			MTL_PPAT_0_WB | MTL_3_COH_2W);
 }
 
-static void setup_private_ppat(struct xe_gt *gt)
-{
-	struct xe_device *xe = gt_to_xe(gt);
-
-	if (xe->info.platform == XE_METEORLAKE)
-		mtl_setup_private_ppat(gt);
-	else if (xe->info.platform == XE_PVC)
-		pvc_setup_private_ppat(gt);
-	else
-		tgl_setup_private_ppat(gt);
-}
-
 static int gt_ttm_mgr_init(struct xe_gt *gt)
 {
 	struct xe_device *xe = gt_to_xe(gt);
@@ -380,6 +372,28 @@ int xe_gt_record_default_lrcs(struct xe_gt *gt)
 int xe_gt_init_early(struct xe_gt *gt)
 {
 	int err;
+	struct xe_device *xe = gt_to_xe(gt);
+
+	xe->gt_funcs = kzalloc(sizeof(*xe->gt_funcs), GFP_KERNEL);
+	switch (xe->info.platform) {
+	case XE_METEORLAKE:
+		xe->gt_funcs->setup_private_ppat = mtl_setup_private_ppat;
+		break;
+	case XE_PVC:
+		xe->gt_funcs->setup_private_ppat = pvc_setup_private_ppat;
+		break;
+	case XE_ROCKETLAKE:
+	case XE_DG1:
+	case XE_DG2:
+	case XE_ALDERLAKE_S:
+	case XE_ALDERLAKE_P:
+	case XE_TIGERLAKE:
+		xe->gt_funcs->setup_private_ppat = tgl_setup_private_ppat;
+		break;
+	default:
+		DRM_ERROR("Unsupported platform\n");
+		break;
+	}
 
 	xe_force_wake_init_gt(gt, gt_to_fw(gt));
 
@@ -441,13 +455,15 @@ int xe_gt_init_noalloc(struct xe_gt *gt)
 static int gt_fw_domain_init(struct xe_gt *gt)
 {
 	int err, i;
+	struct xe_device *xe = gt_to_xe(gt);
 
 	xe_device_mem_access_get(gt_to_xe(gt));
 	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
 	if (err)
 		goto err_hw_fence_irq;
 
-	setup_private_ppat(gt);
+	if (xe->gt_funcs->setup_private_ppat)
+		xe->gt_funcs->setup_private_ppat(gt);
 
 	if (!xe_gt_is_media_type(gt)) {
 		err = xe_ggtt_init(gt, gt->mem.ggtt);
@@ -630,8 +646,10 @@ static int do_gt_restart(struct xe_gt *gt)
 	struct xe_hw_engine *hwe;
 	enum xe_hw_engine_id id;
 	int err;
+	struct xe_device *xe = gt_to_xe(gt);
 
-	setup_private_ppat(gt);
+	if (xe->gt_funcs->setup_private_ppat)
+		xe->gt_funcs->setup_private_ppat(gt);
 
 	xe_gt_mcr_set_implicit_defaults(gt);
 	xe_reg_sr_apply_mmio(&gt->reg_sr, gt);
-- 
2.25.1