habanalabs: add CS completion and timeout properties

In order to support staged submission feature, we need to
distinguish on which command submission we want to receive
timeout and for which we want to receive completion.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

1 files changed, 85 insertions, 19 deletions

diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c
index a5e9bb0a4855..57daff0e59ae 100644
--- a/drivers/misc/habanalabs/common/command_submission.c
+++ b/drivers/misc/habanalabs/common/command_submission.c
@@ -149,9 +149,10 @@ void hl_fence_get(struct hl_fence *fence)
 		kref_get(&fence->refcount);
 }
 
-static void hl_fence_init(struct hl_fence *fence)
+static void hl_fence_init(struct hl_fence *fence, u64 sequence)
 {
 	kref_init(&fence->refcount);
+	fence->cs_sequence = sequence;
 	fence->error = 0;
 	fence->timestamp = ktime_set(0, 0);
 	init_completion(&fence->completion);
@@ -184,6 +185,28 @@ static void cs_job_put(struct hl_cs_job *job)
 	kref_put(&job->refcount, cs_job_do_release);
 }
 
+bool cs_needs_completion(struct hl_cs *cs)
+{
+	/* In case this is a staged CS, only the last CS in sequence should
+	 * get a completion, any non staged CS will always get a completion
+	 */
+	if (cs->staged_cs && !cs->staged_last)
+		return false;
+
+	return true;
+}
+
+bool cs_needs_timeout(struct hl_cs *cs)
+{
+	/* In case this is a staged CS, only the first CS in sequence should
+	 * get a timeout, any non staged CS will always get a timeout
+	 */
+	if (cs->staged_cs && !cs->staged_first)
+		return false;
+
+	return true;
+}
+
 static bool is_cb_patched(struct hl_device *hdev, struct hl_cs_job *job)
 {
 	/*
@@ -225,7 +248,7 @@ static int cs_parser(struct hl_fpriv *hpriv, struct hl_cs_job *job)
 	parser.queue_type = job->queue_type;
 	parser.is_kernel_allocated_cb = job->is_kernel_allocated_cb;
 	job->patched_cb = NULL;
-	parser.completion = true;
+	parser.completion = cs_needs_completion(job->cs);
 
 	rc = hdev->asic_funcs->cs_parser(hdev, &parser);
 
@@ -291,8 +314,21 @@ static void complete_job(struct hl_device *hdev, struct hl_cs_job *job)
 
 	hl_debugfs_remove_job(hdev, job);
 
-	if (job->queue_type == QUEUE_TYPE_EXT ||
-			job->queue_type == QUEUE_TYPE_HW)
+	/* We decrement reference only for a CS that gets completion
+	 * because the reference was incremented only for this kind of CS
+	 * right before it was scheduled.
+	 *
+	 * In staged submission, only the last CS marked as 'staged_last'
+	 * gets completion, hence its release function will be called from here.
+	 * As for all the rest CS's in the staged submission which do not get
+	 * completion, their CS reference will be decremented by the
+	 * 'staged_last' CS during the CS release flow.
+	 * All relevant PQ CI counters will be incremented during the CS release
+	 * flow by calling 'hl_hw_queue_update_ci'.
+	 */
+	if (cs_needs_completion(cs) &&
+		(job->queue_type == QUEUE_TYPE_EXT ||
+			job->queue_type == QUEUE_TYPE_HW))
 		cs_put(cs);
 
 	cs_job_put(job);
@@ -347,8 +383,8 @@ static void cs_do_release(struct kref *ref)
 
 	hdev->asic_funcs->hw_queues_unlock(hdev);
 
-	/* Need to update CI for internal queues */
-	hl_int_hw_queue_update_ci(cs);
+	/* Need to update CI for all queue jobs that does not get completion */
+	hl_hw_queue_update_ci(cs);
 
 	/* remove CS from CS mirror list */
 	spin_lock(&hdev->cs_mirror_lock);
@@ -359,6 +395,7 @@ static void cs_do_release(struct kref *ref)
 	 * running from the TDR context
 	 */
 	if (!cs->timedout && hdev->timeout_jiffies != MAX_SCHEDULE_TIMEOUT) {
+		bool next_entry_found = false;
 		struct hl_cs *next;
 
 		if (cs->tdr_active)
@@ -367,10 +404,13 @@ static void cs_do_release(struct kref *ref)
 		spin_lock(&hdev->cs_mirror_lock);
 
 		/* queue TDR for next CS */
-		next = list_first_entry_or_null(&hdev->cs_mirror_list,
-						struct hl_cs, mirror_node);
+		list_for_each_entry(next, &hdev->cs_mirror_list, mirror_node)
+			if (cs_needs_timeout(next)) {
+				next_entry_found = true;
+				break;
+			}
 
-		if (next && !next->tdr_active) {
+		if (next_entry_found && !next->tdr_active) {
 			next->tdr_active = true;
 			schedule_delayed_work(&next->work_tdr,
 						hdev->timeout_jiffies);
@@ -462,7 +502,8 @@ static void cs_timedout(struct work_struct *work)
 }
 
 static int allocate_cs(struct hl_device *hdev, struct hl_ctx *ctx,
-			enum hl_cs_type cs_type, struct hl_cs **cs_new)
+			enum hl_cs_type cs_type, u64 user_sequence,
+			struct hl_cs **cs_new)
 {
 	struct hl_cs_counters_atomic *cntr;
 	struct hl_fence *other = NULL;
@@ -511,6 +552,18 @@ static int allocate_cs(struct hl_device *hdev, struct hl_ctx *ctx,
 				(hdev->asic_prop.max_pending_cs - 1)];
 
 	if (other && !completion_done(&other->completion)) {
+		/* If the following statement is true, it means we have reached
+		 * a point in which only part of the staged submission was
+		 * submitted and we don't have enough room in the 'cs_pending'
+		 * array for the rest of the submission.
+		 * This causes a deadlock because this CS will never be
+		 * completed as it depends on future CS's for completion.
+		 */
+		if (other->cs_sequence == user_sequence)
+			dev_crit_ratelimited(hdev->dev,
+				"Staged CS %llu deadlock due to lack of resources",
+				user_sequence);
+
 		dev_dbg_ratelimited(hdev->dev,
 			"Rejecting CS because of too many in-flights CS\n");
 		atomic64_inc(&ctx->cs_counters.max_cs_in_flight_drop_cnt);
@@ -529,7 +582,7 @@ static int allocate_cs(struct hl_device *hdev, struct hl_ctx *ctx,
 	}
 
 	/* init hl_fence */
-	hl_fence_init(&cs_cmpl->base_fence);
+	hl_fence_init(&cs_cmpl->base_fence, cs_cmpl->cs_seq);
 
 	cs->sequence = cs_cmpl->cs_seq;
 
@@ -825,7 +878,7 @@ static int hl_cs_copy_chunk_array(struct hl_device *hdev,
 static int cs_ioctl_default(struct hl_fpriv *hpriv, void __user *chunks,
 				u32 num_chunks, u64 *cs_seq, u32 flags)
 {
-	bool int_queues_only = true;
+	bool staged_mid, int_queues_only = true;
 	struct hl_device *hdev = hpriv->hdev;
 	struct hl_cs_chunk *cs_chunk_array;
 	struct hl_cs_counters_atomic *cntr;
@@ -833,9 +886,11 @@ static int cs_ioctl_default(struct hl_fpriv *hpriv, void __user *chunks,
 	struct hl_cs_job *job;
 	struct hl_cs *cs;
 	struct hl_cb *cb;
+	u64 user_sequence;
 	int rc, i;
 
 	cntr = &hdev->aggregated_cs_counters;
+	user_sequence = *cs_seq;
 	*cs_seq = ULLONG_MAX;
 
 	rc = hl_cs_copy_chunk_array(hdev, &cs_chunk_array, chunks, num_chunks,
@@ -843,7 +898,14 @@ static int cs_ioctl_default(struct hl_fpriv *hpriv, void __user *chunks,
 	if (rc)
 		goto out;
 
-	rc = allocate_cs(hdev, hpriv->ctx, CS_TYPE_DEFAULT, &cs);
+	if ((flags & HL_CS_FLAGS_STAGED_SUBMISSION) &&
+			!(flags & HL_CS_FLAGS_STAGED_SUBMISSION_FIRST))
+		staged_mid = true;
+	else
+		staged_mid = false;
+
+	rc = allocate_cs(hdev, hpriv->ctx, CS_TYPE_DEFAULT,
+			staged_mid ? user_sequence : ULLONG_MAX, &cs);
 	if (rc)
 		goto free_cs_chunk_array;
 
@@ -911,8 +973,9 @@ static int cs_ioctl_default(struct hl_fpriv *hpriv, void __user *chunks,
 		 * Only increment for JOB on external or H/W queues, because
 		 * only for those JOBs we get completion
 		 */
-		if (job->queue_type == QUEUE_TYPE_EXT ||
-				job->queue_type == QUEUE_TYPE_HW)
+		if (cs_needs_completion(cs) &&
+			(job->queue_type == QUEUE_TYPE_EXT ||
+				job->queue_type == QUEUE_TYPE_HW))
 			cs_get(cs);
 
 		hl_debugfs_add_job(hdev, job);
@@ -928,11 +991,14 @@ static int cs_ioctl_default(struct hl_fpriv *hpriv, void __user *chunks,
 		}
 	}
 
-	if (int_queues_only) {
+	/* We allow a CS with any queue type combination as long as it does
+	 * not get a completion
+	 */
+	if (int_queues_only && cs_needs_completion(cs)) {
 		atomic64_inc(&ctx->cs_counters.validation_drop_cnt);
 		atomic64_inc(&cntr->validation_drop_cnt);
 		dev_err(hdev->dev,
-			"Reject CS %d.%llu because only internal queues jobs are present\n",
+			"Reject CS %d.%llu since it contains only internal queues jobs and needs completion\n",
 			cs->ctx->asid, cs->sequence);
 		rc = -EINVAL;
 		goto free_cs_object;
@@ -1037,7 +1103,7 @@ static int hl_submit_pending_cb(struct hl_fpriv *hpriv)
 		list_move_tail(&pending_cb->cb_node, &local_cb_list);
 	spin_unlock(&ctx->pending_cb_lock);
 
-	rc = allocate_cs(hdev, ctx, CS_TYPE_DEFAULT, &cs);
+	rc = allocate_cs(hdev, ctx, CS_TYPE_DEFAULT, ULLONG_MAX, &cs);
 	if (rc)
 		goto add_list_elements;
 
@@ -1410,7 +1476,7 @@ static int cs_ioctl_signal_wait(struct hl_fpriv *hpriv, enum hl_cs_type cs_type,
 		}
 	}
 
-	rc = allocate_cs(hdev, ctx, cs_type, &cs);
+	rc = allocate_cs(hdev, ctx, cs_type, ULLONG_MAX, &cs);
 	if (rc) {
 		if (cs_type == CS_TYPE_WAIT ||
 			cs_type == CS_TYPE_COLLECTIVE_WAIT)