[PATCH v7 3/8] 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/reinit() helpers.

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Tested-by: Lukasz Laguna <lukasz.laguna@intel.com>
---
v2: Add kernel doc (Matthew Brost)
v4: Teardown exec queues instead of mangling scheduler pending list (Matthew Brost)
v6: Add IS_DGFX() assert (Daniele)
    s/flr_done/reinit (Daniele)
---
 drivers/gpu/drm/xe/xe_gsc.c      | 14 +++++++
 drivers/gpu/drm/xe/xe_gsc.h      |  1 +
 drivers/gpu/drm/xe/xe_gt.c       | 23 ++++++++++
 drivers/gpu/drm/xe/xe_gt.h       |  2 +
 drivers/gpu/drm/xe/xe_guc.c      | 29 +++++++++++++
 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       | 72 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_uc.h       |  2 +
 drivers/gpu/drm/xe/xe_uc_types.h | 14 +++++++
 11 files changed, 174 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gsc.c b/drivers/gpu/drm/xe/xe_gsc.c
index aab59dc647fb..7d5700624e46 100644
--- a/drivers/gpu/drm/xe/xe_gsc.c
+++ b/drivers/gpu/drm/xe/xe_gsc.c
@@ -549,6 +549,20 @@ void xe_gsc_wait_for_worker_completion(struct xe_gsc *gsc)
 		flush_work(&gsc->work);
 }
 
+/**
+ * xe_gsc_reinit() - Re-initialize GSC after FLR
+ * @gsc: The GSC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_gsc_reinit(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..ce390bffb163 100644
--- a/drivers/gpu/drm/xe/xe_gsc.h
+++ b/drivers/gpu/drm/xe/xe_gsc.h
@@ -15,6 +15,7 @@ struct xe_hw_engine;
 
 int xe_gsc_init(struct xe_gsc *gsc);
 int xe_gsc_init_post_hwconfig(struct xe_gsc *gsc);
+int xe_gsc_reinit(struct xe_gsc *gsc);
 void xe_gsc_wait_for_worker_completion(struct xe_gsc *gsc);
 void xe_gsc_stop_prepare(struct xe_gsc *gsc);
 void xe_gsc_load_start(struct xe_gsc *gsc);
diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index 783eb6d631b5..acc28389b0d8 100644
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -908,6 +908,29 @@ static int do_gt_restart(struct xe_gt *gt)
 	return 0;
 }
 
+/**
+ * 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)
+{
+	xe_gt_sanitize(gt);
+	xe_uc_flr_prepare(&gt->uc);
+}
+
+/**
+ * xe_gt_reinit() - Re-initialize GT after FLR
+ * @gt: the GT object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_gt_reinit(struct xe_gt *gt)
+{
+	return xe_uc_reinit(&gt->uc);
+}
+
 static void gt_reset_worker(struct work_struct *w)
 {
 	struct xe_gt *gt = container_of(w, typeof(*gt), reset.worker);
diff --git a/drivers/gpu/drm/xe/xe_gt.h b/drivers/gpu/drm/xe/xe_gt.h
index 4150aa594f05..488009b9b938 100644
--- a/drivers/gpu/drm/xe/xe_gt.h
+++ b/drivers/gpu/drm/xe/xe_gt.h
@@ -45,8 +45,10 @@ static inline bool xe_fault_inject_gt_reset(void)
 }
 
 struct xe_gt *xe_gt_alloc(struct xe_tile *tile);
+void xe_gt_flr_prepare(struct xe_gt *gt);
 int xe_gt_init_early(struct xe_gt *gt);
 int xe_gt_init(struct xe_gt *gt);
+int xe_gt_reinit(struct xe_gt *gt);
 void xe_gt_mmio_init(struct xe_gt *gt);
 void xe_gt_declare_wedged(struct xe_gt *gt);
 int xe_gt_record_default_lrcs(struct xe_gt *gt);
diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
index e468b638271b..ec291588c482 100644
--- a/drivers/gpu/drm/xe/xe_guc.c
+++ b/drivers/gpu/drm/xe/xe_guc.c
@@ -1689,6 +1689,35 @@ 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_reinit() - Re-initialize GuC after FLR
+ * @guc: The GuC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_guc_reinit(struct xe_guc *guc)
+{
+	if (!xe_uc_fw_is_loadable(&guc->fw))
+		return 0;
+
+	return xe_uc_fw_reinit(&guc->fw);
+}
+
 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..0eea9277439a 100644
--- a/drivers/gpu/drm/xe/xe_guc.h
+++ b/drivers/gpu/drm/xe/xe_guc.h
@@ -32,10 +32,12 @@
 struct drm_printer;
 
 void xe_guc_comm_init_early(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);
 int xe_guc_post_load_init(struct xe_guc *guc);
+int xe_guc_reinit(struct xe_guc *guc);
 int xe_guc_reset(struct xe_guc *guc);
 int xe_guc_upload(struct xe_guc *guc);
 int xe_guc_min_load_for_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..c73e1acbd091 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_reinit() - Re-initialize HuC after FLR
+ * @huc: The HuC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_huc_reinit(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..cb1a770b4a9c 100644
--- a/drivers/gpu/drm/xe/xe_huc.h
+++ b/drivers/gpu/drm/xe/xe_huc.h
@@ -19,6 +19,7 @@ enum xe_huc_auth_types {
 
 int xe_huc_init(struct xe_huc *huc);
 int xe_huc_init_post_hwconfig(struct xe_huc *huc);
+int xe_huc_reinit(struct xe_huc *huc);
 int xe_huc_upload(struct xe_huc *huc);
 int xe_huc_auth(struct xe_huc *huc, enum xe_huc_auth_types type);
 bool xe_huc_is_authenticated(struct xe_huc *huc, enum xe_huc_auth_types type);
diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
index 75091bde0d50..a9b2442494ec 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 +276,77 @@ static void uc_reset_wait(struct xe_uc *uc)
 		goto again;
 }
 
+static void uc_flr_prepare(struct work_struct *w)
+{
+	struct xe_uc_flr *flr = container_of(w, struct xe_uc_flr, work);
+	struct xe_uc *uc = flr->uc;
+
+	xe_assert(uc_to_xe(uc), xe_device_wedged(uc_to_xe(uc)));
+
+	xe_uc_reset_prepare(uc);
+	xe_guc_flr_prepare(&uc->guc);
+}
+
+static void uc_flr_sanitize(struct work_struct *w)
+{
+	struct xe_uc_flr *flr = container_of(w, struct xe_uc_flr, work);
+	struct xe_uc *uc = flr->uc;
+
+	/* TODO: Sanitize GSC firmware */
+	xe_assert(uc_to_xe(uc), IS_DGFX(uc_to_xe(uc)));
+
+	xe_uc_stop(uc);
+	xe_uc_sanitize(uc);
+}
+
+/**
+ * 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)
+{
+	struct xe_uc_flr flr = { .uc = uc };
+	struct xe_gt *gt = uc_to_gt(uc);
+
+	/*
+	 * 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(&flr.work, uc_flr_prepare);
+	queue_work(gt->ordered_wq, &flr.work);
+	flush_work(&flr.work);
+	destroy_work_on_stack(&flr.work);
+
+	INIT_WORK_ONSTACK(&flr.work, uc_flr_sanitize);
+	queue_work(gt->ordered_wq, &flr.work);
+	flush_work(&flr.work);
+	destroy_work_on_stack(&flr.work);
+}
+
+/**
+ * xe_uc_reinit() - Re-initialize uCs after FLR
+ * @uc: The uC object
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_uc_reinit(struct xe_uc *uc)
+{
+	int ret;
+
+	ret = xe_guc_reinit(&uc->guc);
+	if (ret)
+		return ret;
+
+	ret = xe_huc_reinit(&uc->huc);
+	if (ret)
+		return ret;
+
+	return xe_gsc_reinit(&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..e06f7937111f 100644
--- a/drivers/gpu/drm/xe/xe_uc.h
+++ b/drivers/gpu/drm/xe/xe_uc.h
@@ -8,10 +8,12 @@
 
 struct xe_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);
 int xe_uc_load_hw(struct xe_uc *uc);
+int xe_uc_reinit(struct xe_uc *uc);
 int xe_uc_reset_prepare(struct xe_uc *uc);
 void xe_uc_runtime_resume(struct xe_uc *uc);
 void xe_uc_runtime_suspend(struct xe_uc *uc);
diff --git a/drivers/gpu/drm/xe/xe_uc_types.h b/drivers/gpu/drm/xe/xe_uc_types.h
index 1708379dc834..2b47382f7b3b 100644
--- a/drivers/gpu/drm/xe/xe_uc_types.h
+++ b/drivers/gpu/drm/xe/xe_uc_types.h
@@ -25,4 +25,18 @@ struct xe_uc {
 	struct xe_wopcm wopcm;
 };
 
+/**
+ * struct xe_uc_flr - uC FLR teardown
+ */
+struct xe_uc_flr {
+	/** @uc: uC to schedule FLR worker on */
+	struct xe_uc *uc;
+
+	/**
+	 * @work: worker for FLR teardown to be done async allowing to safely
+	 * flush all code paths
+	 */
+	struct work_struct work;
+};
+
 #endif
-- 
2.43.0