[PATCH v6 13/30] drm/xe/vf: Don't allow GT reset to be queued during VF post migration recovery

[Matthew Brost <matthew.brost@intel.com>]

With well-behaved software, a GT reset should never occur, nor should it
happen during VF post-migration recovery. If it does, trigger a warning
but suppress the GT reset, as VF post-migration recovery is expected to
bring the VF back to a working state.

v3:
 - Better commit message (Tomasz)
v5:
 - Use xe_gt_WARN_ON (Michal)

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Tomasz Lis <tomasz.lis@intel.com>
---
 drivers/gpu/drm/xe/xe_gt.c          |  9 -------
 drivers/gpu/drm/xe/xe_gt_sriov_vf.c |  7 -----
 drivers/gpu/drm/xe/xe_guc_submit.c  | 42 ++++-------------------------
 drivers/gpu/drm/xe/xe_guc_submit.h  |  3 ---
 4 files changed, 5 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index 2d032eb3bd6d..cf484a2da35e 100644
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -805,11 +805,6 @@ static int do_gt_restart(struct xe_gt *gt)
 	return 0;
 }
 
-static int gt_wait_reset_unblock(struct xe_gt *gt)
-{
-	return xe_guc_wait_reset_unblock(&gt->uc.guc);
-}
-
 static int gt_reset(struct xe_gt *gt)
 {
 	unsigned int fw_ref;
@@ -824,10 +819,6 @@ static int gt_reset(struct xe_gt *gt)
 
 	xe_gt_info(gt, "reset started\n");
 
-	err = gt_wait_reset_unblock(gt);
-	if (!err)
-		xe_gt_warn(gt, "reset block failed to get lifted");
-
 	xe_pm_runtime_get(gt_to_xe(gt));
 
 	if (xe_fault_inject_gt_reset()) {
diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
index 8a36f479df1b..7057260175f3 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
@@ -1103,17 +1103,11 @@ void xe_gt_sriov_vf_print_version(struct xe_gt *gt, struct drm_printer *p)
 
 static void vf_post_migration_shutdown(struct xe_gt *gt)
 {
-	int ret = 0;
-
 	spin_lock_irq(&gt->sriov.vf.migration.lock);
 	gt->sriov.vf.migration.recovery_queued = false;
 	spin_unlock_irq(&gt->sriov.vf.migration.lock);
 
 	xe_guc_submit_pause(&gt->uc.guc);
-	ret |= xe_guc_submit_reset_block(&gt->uc.guc);
-
-	if (ret)
-		xe_gt_sriov_info(gt, "migration recovery encountered ongoing reset\n");
 }
 
 static size_t post_migration_scratch_size(struct xe_device *xe)
@@ -1147,7 +1141,6 @@ static void vf_post_migration_kickstart(struct xe_gt *gt)
 	 */
 	xe_irq_resume(gt_to_xe(gt));
 
-	xe_guc_submit_reset_unblock(&gt->uc.guc);
 	xe_guc_submit_unpause(&gt->uc.guc);
 }
 
diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index d123bdb63369..59371b7cc8a4 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -27,6 +27,7 @@
 #include "xe_gt.h"
 #include "xe_gt_clock.h"
 #include "xe_gt_printk.h"
+#include "xe_gt_sriov_vf.h"
 #include "xe_guc.h"
 #include "xe_guc_capture.h"
 #include "xe_guc_ct.h"
@@ -1900,47 +1901,14 @@ static void guc_exec_queue_stop(struct xe_guc *guc, struct xe_exec_queue *q)
 	}
 }
 
-/**
- * xe_guc_submit_reset_block - Disallow reset calls on given GuC.
- * @guc: the &xe_guc struct instance
- */
-int xe_guc_submit_reset_block(struct xe_guc *guc)
-{
-	return atomic_fetch_or(1, &guc->submission_state.reset_blocked);
-}
-
-/**
- * xe_guc_submit_reset_unblock - Allow back reset calls on given GuC.
- * @guc: the &xe_guc struct instance
- */
-void xe_guc_submit_reset_unblock(struct xe_guc *guc)
-{
-	atomic_set_release(&guc->submission_state.reset_blocked, 0);
-	wake_up_all(&guc->ct.wq);
-}
-
-static int guc_submit_reset_is_blocked(struct xe_guc *guc)
-{
-	return atomic_read_acquire(&guc->submission_state.reset_blocked);
-}
-
-/* Maximum time of blocking reset */
-#define RESET_BLOCK_PERIOD_MAX (HZ * 5)
-
-/**
- * xe_guc_wait_reset_unblock - Wait until reset blocking flag is lifted, or timeout.
- * @guc: the &xe_guc struct instance
- */
-int xe_guc_wait_reset_unblock(struct xe_guc *guc)
-{
-	return wait_event_timeout(guc->ct.wq,
-				  !guc_submit_reset_is_blocked(guc), RESET_BLOCK_PERIOD_MAX);
-}
-
 int xe_guc_submit_reset_prepare(struct xe_guc *guc)
 {
 	int ret;
 
+	if (xe_gt_WARN_ON(guc_to_gt(guc),
+			  xe_gt_sriov_vf_recovery_pending(guc_to_gt(guc))))
+		return 0;
+
 	if (!guc->submission_state.initialized)
 		return 0;
 
diff --git a/drivers/gpu/drm/xe/xe_guc_submit.h b/drivers/gpu/drm/xe/xe_guc_submit.h
index 5b4a0a6fd818..f535fe3895e5 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.h
+++ b/drivers/gpu/drm/xe/xe_guc_submit.h
@@ -22,9 +22,6 @@ void xe_guc_submit_stop(struct xe_guc *guc);
 int xe_guc_submit_start(struct xe_guc *guc);
 void xe_guc_submit_pause(struct xe_guc *guc);
 void xe_guc_submit_unpause(struct xe_guc *guc);
-int xe_guc_submit_reset_block(struct xe_guc *guc);
-void xe_guc_submit_reset_unblock(struct xe_guc *guc);
-int xe_guc_wait_reset_unblock(struct xe_guc *guc);
 void xe_guc_submit_wedge(struct xe_guc *guc);
 
 int xe_guc_read_stopped(struct xe_guc *guc);
-- 
2.34.1