drm/xe: Initialize GuC earlier during probe

SR-IOV VF has limited access to MMIO registers. Fortunately, it is able
to access a curated subset that is needed to initialize the driver by
communicating with SR-IOV PF using GuC CT.
Initialize GuC earlier in order to keep the unified probe ordering
between VF and PF modes.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240219130530.1406044-4-michal.winiarski@intel.com

drivers/gpu/drm/xe/xe_device.c

@@ -463,6 +463,12 @@ int xe_device_probe(struct xe_device *xe)
 		}
 	}
 
+	for_each_gt(gt, xe, id) {
+		err = xe_gt_init_hwconfig(gt);
+		if (err)
+			return err;
+	}
+
 	err = drmm_add_action_or_reset(&xe->drm, xe_driver_flr_fini, xe);
 	if (err)
 		return err;

drivers/gpu/drm/xe/xe_gt.c

@@ -315,7 +315,6 @@ int xe_gt_init_early(struct xe_gt *gt)
 		return err;
 
 	xe_gt_topology_init(gt);
-	xe_gt_mcr_init(gt);
 
 	err = xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
 	if (err)
@@ -354,8 +353,6 @@ static int gt_fw_domain_init(struct xe_gt *gt)
 	if (err)
 		goto err_hw_fence_irq;
 
-	xe_pat_init(gt);
-
 	if (!xe_gt_is_media_type(gt)) {
 		err = xe_ggtt_init(gt_to_tile(gt)->mem.ggtt);
 		if (err)
@@ -364,19 +361,8 @@ static int gt_fw_domain_init(struct xe_gt *gt)
 			xe_lmtt_init(&gt_to_tile(gt)->sriov.pf.lmtt);
 	}
 
-	err = xe_uc_init(&gt->uc);
-	if (err)
-		goto err_force_wake;
-
-	err = xe_uc_init_hwconfig(&gt->uc);
-	if (err)
-		goto err_force_wake;
-
 	xe_gt_idle_sysfs_init(&gt->gtidle);
 
-	/* XXX: Fake that we pull the engine mask from hwconfig blob */
-	gt->info.engine_mask = gt->info.__engine_mask;
-
 	/* Enable per hw engine IRQs */
 	xe_irq_enable_hwe(gt);
 
@@ -444,10 +430,6 @@ static int all_fw_domain_init(struct xe_gt *gt)
 	if (err)
 		goto err_force_wake;
 
-	err = xe_uc_init_post_hwconfig(&gt->uc);
-	if (err)
-		goto err_force_wake;
-
 	if (!xe_gt_is_media_type(gt)) {
 		/*
 		 * USM has its only SA pool to non-block behind user operations
@@ -474,6 +456,10 @@ static int all_fw_domain_init(struct xe_gt *gt)
 		}
 	}
 
+	err = xe_uc_init_post_hwconfig(&gt->uc);
+	if (err)
+		goto err_force_wake;
+
 	err = xe_uc_init_hw(&gt->uc);
 	if (err)
 		goto err_force_wake;
@@ -503,6 +489,41 @@ static int all_fw_domain_init(struct xe_gt *gt)
 	return err;
 }
 
+/*
+ * Initialize enough GT to be able to load GuC in order to obtain hwconfig and
+ * enable CTB communication.
+ */
+int xe_gt_init_hwconfig(struct xe_gt *gt)
+{
+	int err;
+
+	xe_device_mem_access_get(gt_to_xe(gt));
+	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
+	if (err)
+		goto out;
+
+	xe_gt_mcr_init(gt);
+	xe_pat_init(gt);
+
+	err = xe_uc_init(&gt->uc);
+	if (err)
+		goto out_fw;
+
+	err = xe_uc_init_hwconfig(&gt->uc);
+	if (err)
+		goto out_fw;
+
+	/* XXX: Fake that we pull the engine mask from hwconfig blob */
+	gt->info.engine_mask = gt->info.__engine_mask;
+
+out_fw:
+	xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
+out:
+	xe_device_mem_access_put(gt_to_xe(gt));
+
+	return err;
+}
+
 int xe_gt_init(struct xe_gt *gt)
 {
 	int err;

drivers/gpu/drm/xe/xe_gt.h

@@ -33,6 +33,7 @@ static inline bool xe_fault_inject_gt_reset(void)
 #endif
 
 struct xe_gt *xe_gt_alloc(struct xe_tile *tile);
+int xe_gt_init_hwconfig(struct xe_gt *gt);
 int xe_gt_init_early(struct xe_gt *gt);
 int xe_gt_init(struct xe_gt *gt);
 int xe_gt_record_default_lrcs(struct xe_gt *gt);

drivers/gpu/drm/xe/xe_uc.c

@@ -32,13 +32,15 @@ uc_to_xe(struct xe_uc *uc)
 /* Should be called once at driver load only */
 int xe_uc_init(struct xe_uc *uc)
 {
+	struct xe_device *xe = uc_to_xe(uc);
 	int ret;
 
+	xe_device_mem_access_get(xe);
+
 	/*
 	 * We call the GuC/HuC/GSC init functions even if GuC submission is off
 	 * to correctly move our tracking of the FW state to "disabled".
 	 */
-
 	ret = xe_guc_init(&uc->guc);
 	if (ret)
 		goto err;
@@ -52,7 +54,7 @@ int xe_uc_init(struct xe_uc *uc)
 		goto err;
 
 	if (!xe_device_uc_enabled(uc_to_xe(uc)))
-		return 0;
+		goto err;
 
 	ret = xe_wopcm_init(&uc->wopcm);
 	if (ret)
@@ -66,9 +68,13 @@ int xe_uc_init(struct xe_uc *uc)
 	if (ret)
 		goto err;
 
+	xe_device_mem_access_put(xe);
+
 	return 0;
 
 err:
+	xe_device_mem_access_put(xe);
+
 	return ret;
 }