[PATCH v4 3/9] drm/xe/gt: Introduce FLR helpers

[Raag Jadav <raag.jadav@intel.com>]

In preparation of usecases which require preparing/re-initializing GT and
all its uCs before/after PCIe FLR, introduce flr_prepare/done() helpers.

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
---
v2: Add kernel doc (Matthew Brost)
v4: Teardown exec queues instead of mangling scheduler pending list (Matthew Brost)
---
 drivers/gpu/drm/xe/xe_gsc.c      | 14 ++++++++++++
 drivers/gpu/drm/xe/xe_gsc.h      |  1 +
 drivers/gpu/drm/xe/xe_gt.c       | 37 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_gt.h       |  2 ++
 drivers/gpu/drm/xe/xe_gt_types.h |  9 ++++++++
 drivers/gpu/drm/xe/xe_guc.c      | 36 +++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_guc.h      |  2 ++
 drivers/gpu/drm/xe/xe_huc.c      | 14 ++++++++++++
 drivers/gpu/drm/xe/xe_huc.h      |  1 +
 drivers/gpu/drm/xe/xe_uc.c       | 37 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_uc.h       |  2 ++
 11 files changed, 155 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gsc.c b/drivers/gpu/drm/xe/xe_gsc.c
index e5c234f3d795..7bf6a90ea1a2 100644
--- a/drivers/gpu/drm/xe/xe_gsc.c
+++ b/drivers/gpu/drm/xe/xe_gsc.c
@@ -552,6 +552,20 @@ void xe_gsc_wait_for_worker_completion(struct xe_gsc *gsc)
 		flush_work(&gsc->work);
 }
 
+/**
+ * xe_gsc_flr_done() - Re-initialize GSC after FLR
+ * @gsc: The GSC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_gsc_flr_done(struct xe_gsc *gsc)
+{
+	if (!xe_uc_fw_is_loadable(&gsc->fw))
+		return 0;
+
+	return xe_uc_fw_reinit(&gsc->fw);
+}
+
 void xe_gsc_stop_prepare(struct xe_gsc *gsc)
 {
 	struct xe_gt *gt = gsc_to_gt(gsc);
diff --git a/drivers/gpu/drm/xe/xe_gsc.h b/drivers/gpu/drm/xe/xe_gsc.h
index b8b8e0810ad9..8b7fd98f0be6 100644
--- a/drivers/gpu/drm/xe/xe_gsc.h
+++ b/drivers/gpu/drm/xe/xe_gsc.h
@@ -13,6 +13,7 @@ struct xe_gsc;
 struct xe_gt;
 struct xe_hw_engine;
 
+int xe_gsc_flr_done(struct xe_gsc *gsc);
 int xe_gsc_init(struct xe_gsc *gsc);
 int xe_gsc_init_post_hwconfig(struct xe_gsc *gsc);
 void xe_gsc_wait_for_worker_completion(struct xe_gsc *gsc);
diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index 8a31c963c372..c395d8cc3b5a 100644
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -991,6 +991,43 @@ void xe_gt_reset_async(struct xe_gt *gt)
 		xe_pm_runtime_put(gt_to_xe(gt));
 }
 
+static void xe_gt_flr_prepare_work(struct work_struct *w)
+{
+	struct xe_gt *gt = container_of(w, typeof(*gt), flr.worker);
+
+	xe_uc_flr_prepare(&gt->uc);
+}
+
+/**
+ * xe_gt_flr_prepare() - Prepare GT for FLR
+ * @gt: the GT object
+ *
+ * Prepare all GT uCs for FLR.
+ */
+void xe_gt_flr_prepare(struct xe_gt *gt)
+{
+	/*
+	 * We'll be tearing down exec queues which signals all fences and frees the
+	 * jobs but all of that happens asynchronously, so make sure we don't disrupt
+	 * the scheduler while jobs are still in-flight.
+	 */
+	INIT_WORK_ONSTACK(&gt->flr.worker, xe_gt_flr_prepare_work);
+	queue_work(gt->ordered_wq, &gt->flr.worker);
+	flush_work(&gt->flr.worker);
+	destroy_work_on_stack(&gt->flr.worker);
+}
+
+/**
+ * xe_gt_flr_done() - Re-initialize GT after FLR
+ * @gt: the GT object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_gt_flr_done(struct xe_gt *gt)
+{
+	return xe_uc_flr_done(&gt->uc);
+}
+
 void xe_gt_suspend_prepare(struct xe_gt *gt)
 {
 	CLASS(xe_force_wake, fw_ref)(gt_to_fw(gt), XE_FORCEWAKE_ALL);
diff --git a/drivers/gpu/drm/xe/xe_gt.h b/drivers/gpu/drm/xe/xe_gt.h
index de7e47763411..5e6e4eb09efe 100644
--- a/drivers/gpu/drm/xe/xe_gt.h
+++ b/drivers/gpu/drm/xe/xe_gt.h
@@ -63,6 +63,8 @@ int xe_gt_record_default_lrcs(struct xe_gt *gt);
  */
 void xe_gt_record_user_engines(struct xe_gt *gt);
 
+int xe_gt_flr_done(struct xe_gt *gt);
+void xe_gt_flr_prepare(struct xe_gt *gt);
 void xe_gt_suspend_prepare(struct xe_gt *gt);
 int xe_gt_suspend(struct xe_gt *gt);
 void xe_gt_shutdown(struct xe_gt *gt);
diff --git a/drivers/gpu/drm/xe/xe_gt_types.h b/drivers/gpu/drm/xe/xe_gt_types.h
index 8b55cf25a75f..f6694cc90582 100644
--- a/drivers/gpu/drm/xe/xe_gt_types.h
+++ b/drivers/gpu/drm/xe/xe_gt_types.h
@@ -201,6 +201,15 @@ struct xe_gt {
 		struct work_struct worker;
 	} reset;
 
+	/** @flr: state for FLR */
+	struct {
+		/**
+		 * @flr.worker: worker for FLR to be done async allowing to safely
+		 * flush all code paths
+		 */
+		struct work_struct worker;
+	} flr;
+
 	/** @tlb_inval: TLB invalidation state */
 	struct xe_tlb_inval tlb_inval;
 
diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
index ccebb437e37f..7db1fb8fea2b 100644
--- a/drivers/gpu/drm/xe/xe_guc.c
+++ b/drivers/gpu/drm/xe/xe_guc.c
@@ -1681,6 +1681,42 @@ void xe_guc_sanitize(struct xe_guc *guc)
 	xe_guc_submit_disable(guc);
 }
 
+/**
+ * xe_guc_flr_prepare() - Prepare GuC for FLR
+ * @guc: The GuC object
+ *
+ * Stop GuC submission and tear down exec queues.
+ */
+void xe_guc_flr_prepare(struct xe_guc *guc)
+{
+	if (!xe_uc_fw_is_loadable(&guc->fw))
+		return;
+
+	xe_guc_submit_stop(guc);
+	xe_guc_submit_pause_abort(guc);
+}
+
+/**
+ * xe_guc_flr_done() - Re-initialize GuC after FLR
+ * @guc: The GuC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_guc_flr_done(struct xe_guc *guc)
+{
+	int err;
+
+	if (!xe_uc_fw_is_loadable(&guc->fw))
+		return 0;
+
+	err = xe_uc_fw_reinit(&guc->fw);
+	if (err)
+		return err;
+
+	xe_guc_submit_reinit(guc);
+	return 0;
+}
+
 int xe_guc_reset_prepare(struct xe_guc *guc)
 {
 	return xe_guc_submit_reset_prepare(guc);
diff --git a/drivers/gpu/drm/xe/xe_guc.h b/drivers/gpu/drm/xe/xe_guc.h
index 02514914f404..1fcc623cf24e 100644
--- a/drivers/gpu/drm/xe/xe_guc.h
+++ b/drivers/gpu/drm/xe/xe_guc.h
@@ -32,6 +32,8 @@
 struct drm_printer;
 
 void xe_guc_comm_init_early(struct xe_guc *guc);
+int xe_guc_flr_done(struct xe_guc *guc);
+void xe_guc_flr_prepare(struct xe_guc *guc);
 int xe_guc_init_noalloc(struct xe_guc *guc);
 int xe_guc_init(struct xe_guc *guc);
 int xe_guc_init_post_hwconfig(struct xe_guc *guc);
diff --git a/drivers/gpu/drm/xe/xe_huc.c b/drivers/gpu/drm/xe/xe_huc.c
index 57afe21444b1..96c1bbb6f52c 100644
--- a/drivers/gpu/drm/xe/xe_huc.c
+++ b/drivers/gpu/drm/xe/xe_huc.c
@@ -296,6 +296,20 @@ void xe_huc_sanitize(struct xe_huc *huc)
 	xe_uc_fw_sanitize(&huc->fw);
 }
 
+/**
+ * xe_huc_flr_done() - Re-initialize HuC after FLR
+ * @huc: The HuC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_huc_flr_done(struct xe_huc *huc)
+{
+	if (!xe_uc_fw_is_loadable(&huc->fw))
+		return 0;
+
+	return xe_uc_fw_reinit(&huc->fw);
+}
+
 void xe_huc_print_info(struct xe_huc *huc, struct drm_printer *p)
 {
 	struct xe_gt *gt = huc_to_gt(huc);
diff --git a/drivers/gpu/drm/xe/xe_huc.h b/drivers/gpu/drm/xe/xe_huc.h
index fa1c45e70443..7600ea196908 100644
--- a/drivers/gpu/drm/xe/xe_huc.h
+++ b/drivers/gpu/drm/xe/xe_huc.h
@@ -17,6 +17,7 @@ enum xe_huc_auth_types {
 	XE_HUC_AUTH_TYPES_COUNT
 };
 
+int xe_huc_flr_done(struct xe_huc *huc);
 int xe_huc_init(struct xe_huc *huc);
 int xe_huc_init_post_hwconfig(struct xe_huc *huc);
 int xe_huc_upload(struct xe_huc *huc);
diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
index 75091bde0d50..e41aa95a4322 100644
--- a/drivers/gpu/drm/xe/xe_uc.c
+++ b/drivers/gpu/drm/xe/xe_uc.c
@@ -15,6 +15,7 @@
 #include "xe_guc_pc.h"
 #include "xe_guc_rc.h"
 #include "xe_guc_engine_activity.h"
+#include "xe_guc_submit.h"
 #include "xe_huc.h"
 #include "xe_sriov.h"
 #include "xe_wopcm.h"
@@ -275,6 +276,42 @@ static void uc_reset_wait(struct xe_uc *uc)
 		goto again;
 }
 
+/**
+ * xe_uc_flr_prepare() - Prepare uCs for FLR
+ * @uc: The uC object
+ *
+ * Tear down pending work and stop all uCs.
+ */
+void xe_uc_flr_prepare(struct xe_uc *uc)
+{
+	xe_gsc_wait_for_worker_completion(&uc->gsc);
+	xe_uc_reset_prepare(uc);
+	xe_guc_flr_prepare(&uc->guc);
+	xe_uc_stop(uc);
+	xe_uc_sanitize(uc);
+}
+
+/**
+ * xe_uc_flr_done() - Re-initialize uCs after FLR
+ * @uc: The uC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_uc_flr_done(struct xe_uc *uc)
+{
+	int ret;
+
+	ret = xe_guc_flr_done(&uc->guc);
+	if (ret)
+		return ret;
+
+	ret = xe_huc_flr_done(&uc->huc);
+	if (ret)
+		return ret;
+
+	return xe_gsc_flr_done(&uc->gsc);
+}
+
 void xe_uc_suspend_prepare(struct xe_uc *uc)
 {
 	xe_gsc_wait_for_worker_completion(&uc->gsc);
diff --git a/drivers/gpu/drm/xe/xe_uc.h b/drivers/gpu/drm/xe/xe_uc.h
index 255a54a8f876..1756821edea1 100644
--- a/drivers/gpu/drm/xe/xe_uc.h
+++ b/drivers/gpu/drm/xe/xe_uc.h
@@ -8,6 +8,8 @@
 
 struct xe_uc;
 
+int xe_uc_flr_done(struct xe_uc *uc);
+void xe_uc_flr_prepare(struct xe_uc *uc);
 int xe_uc_init_noalloc(struct xe_uc *uc);
 int xe_uc_init(struct xe_uc *uc);
 int xe_uc_init_post_hwconfig(struct xe_uc *uc);
-- 
2.43.0