[PATCH] drm/xe: Split MCR initialization

[Michal Wajdeczko]

We can't follow the same initialization order of GT topology, MCR,
PAT and GuC HWconfig, as done today on native/PF driver, on the VF
driver, since fuse registers used in GT topology discovery will be
obtained by the VF driver from the GuC.

While we need to program the HW PAT table prior to loading the GuC,
this requires only basic functionality of the MCR code, which could
be done separately from the full MCR initialization that may need
the GT topology.

Split MCR initialization into two steps to avoid introducing VF
specific code paths. This also fixes duplicated spin_lock inits.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: Michał Winiarski <michal.winiarski at intel.com>
Cc: Zhanjun Dong <zhanjun.dong at intel.com>
---
This is alternate solution than proposed in [1] that VF needs.

[1] https://patchwork.freedesktop.org/series/134157/
---
 drivers/gpu/drm/xe/xe_gt.c     |  6 ++++--
 drivers/gpu/drm/xe/xe_gt_mcr.c | 29 +++++++++++++++++++++++------
 drivers/gpu/drm/xe/xe_gt_mcr.h |  1 +
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index 34c1896807e9..7c87edc06ffc 100644
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -502,8 +502,7 @@ int xe_gt_init_hwconfig(struct xe_gt *gt)
 	if (err)
 		goto out;
 
-	xe_gt_topology_init(gt);
-	xe_gt_mcr_init(gt);
+	xe_gt_mcr_init_early(gt);
 	xe_pat_init(gt);
 
 	err = xe_uc_init(&gt->uc);
@@ -514,6 +513,9 @@ int xe_gt_init_hwconfig(struct xe_gt *gt)
 	if (err)
 		goto out_fw;
 
+	xe_gt_topology_init(gt);
+	xe_gt_mcr_init(gt);
+
 out_fw:
 	xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
 out:
diff --git a/drivers/gpu/drm/xe/xe_gt_mcr.c b/drivers/gpu/drm/xe/xe_gt_mcr.c
index 577bd7043740..386ac3269909 100644
--- a/drivers/gpu/drm/xe/xe_gt_mcr.c
+++ b/drivers/gpu/drm/xe/xe_gt_mcr.c
@@ -375,17 +375,34 @@ static const struct {
 	[IMPLICIT_STEERING] = { "IMPLICIT", NULL },
 };
 
-void xe_gt_mcr_init(struct xe_gt *gt)
+/**
+ * xe_gt_mcr_init_early - Early initialization of the MCR support
+ * @gt: GT structure
+ *
+ * Perform early software only initialization of the MCR lock to allow
+ * the synchronization on accessing the STEER_SEMAPHORE register and
+ * use the xe_gt_mcr_multicast_write() function.
+ */
+void xe_gt_mcr_init_early(struct xe_gt *gt)
 {
-	struct xe_device *xe = gt_to_xe(gt);
-
 	BUILD_BUG_ON(IMPLICIT_STEERING + 1 != NUM_STEERING_TYPES);
 	BUILD_BUG_ON(ARRAY_SIZE(xe_steering_types) != NUM_STEERING_TYPES);
 
-	if (IS_SRIOV_VF(xe))
-		return;
-
 	spin_lock_init(&gt->mcr_lock);
+}
+
+/**
+ * xe_gt_mcr_init - Normal initialization of the MCR support
+ * @gt: GT structure
+ *
+ * Perform normal initialization of the MCR for all usages.
+ */
+void xe_gt_mcr_init(struct xe_gt *gt)
+{
+	struct xe_device *xe = gt_to_xe(gt);
+
+	if (IS_SRIOV_VF(xe))
+		return;
 
 	if (gt->info.type == XE_GT_TYPE_MEDIA) {
 		drm_WARN_ON(&xe->drm, MEDIA_VER(xe) < 13);
diff --git a/drivers/gpu/drm/xe/xe_gt_mcr.h b/drivers/gpu/drm/xe/xe_gt_mcr.h
index e7d03e001a49..8d119a0d5493 100644
--- a/drivers/gpu/drm/xe/xe_gt_mcr.h
+++ b/drivers/gpu/drm/xe/xe_gt_mcr.h
@@ -12,6 +12,7 @@
 struct drm_printer;
 struct xe_gt;
 
+void xe_gt_mcr_init_early(struct xe_gt *gt);
 void xe_gt_mcr_init(struct xe_gt *gt);
 
 void xe_gt_mcr_set_implicit_defaults(struct xe_gt *gt);
-- 
2.43.0