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>

3 files changed, 117 insertions, 26 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)
diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index e105612ed577..fd2fffd20ba1 100644
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -486,6 +486,7 @@ struct asic_fixed_properties {
  * struct hl_fence - software synchronization primitive
  * @completion: fence is implemented using completion
  * @refcount: refcount for this fence
+ * @cs_sequence: sequence of the corresponding command submission
  * @error: mark this fence with error
  * @timestamp: timestamp upon completion
  *
@@ -493,6 +494,7 @@ struct asic_fixed_properties {
 struct hl_fence {
 	struct completion	completion;
 	struct kref		refcount;
+	u64			cs_sequence;
 	int			error;
 	ktime_t			timestamp;
 };
@@ -1176,7 +1178,11 @@ struct hl_userptr {
  * @tdr_active: true if TDR was activated for this CS (to prevent
  *		double TDR activation).
  * @aborted: true if CS was aborted due to some device error.
- * @timestamp: true if a timestmap must be captured upon completion
+ * @timestamp: true if a timestmap must be captured upon completion.
+ * @staged_last: true if this is the last staged CS and needs completion.
+ * @staged_first: true if this is the first staged CS and we need to receive
+ *                timeout for this CS.
+ * @staged_cs: true if this CS is part of a staged submission.
  */
 struct hl_cs {
 	u16			*jobs_in_queue_cnt;
@@ -1198,6 +1204,9 @@ struct hl_cs {
 	u8			tdr_active;
 	u8			aborted;
 	u8			timestamp;
+	u8			staged_last;
+	u8			staged_first;
+	u8			staged_cs;
 };
 
 /**
@@ -2118,7 +2127,7 @@ int hl_hw_queue_send_cb_no_cmpl(struct hl_device *hdev, u32 hw_queue_id,
 int hl_hw_queue_schedule_cs(struct hl_cs *cs);
 u32 hl_hw_queue_add_ptr(u32 ptr, u16 val);
 void hl_hw_queue_inc_ci_kernel(struct hl_device *hdev, u32 hw_queue_id);
-void hl_int_hw_queue_update_ci(struct hl_cs *cs);
+void hl_hw_queue_update_ci(struct hl_cs *cs);
 void hl_hw_queue_reset(struct hl_device *hdev, bool hard_reset);
 
 #define hl_queue_inc_ptr(p)		hl_hw_queue_add_ptr(p, 1)
@@ -2196,6 +2205,8 @@ int hl_gen_sob_mask(u16 sob_base, u8 sob_mask, u8 *mask);
 void hl_fence_put(struct hl_fence *fence);
 void hl_fence_get(struct hl_fence *fence);
 void cs_get(struct hl_cs *cs);
+bool cs_needs_completion(struct hl_cs *cs);
+bool cs_needs_timeout(struct hl_cs *cs);
 
 void goya_set_asic_funcs(struct hl_device *hdev);
 void gaudi_set_asic_funcs(struct hl_device *hdev);
diff --git a/drivers/misc/habanalabs/common/hw_queue.c b/drivers/misc/habanalabs/common/hw_queue.c
index 76217258780a..ad440ae785a3 100644
--- a/drivers/misc/habanalabs/common/hw_queue.c
+++ b/drivers/misc/habanalabs/common/hw_queue.c
@@ -38,7 +38,7 @@ static inline int queue_free_slots(struct hl_hw_queue *q, u32 queue_len)
 		return (abs(delta) - queue_len);
 }
 
-void hl_int_hw_queue_update_ci(struct hl_cs *cs)
+void hl_hw_queue_update_ci(struct hl_cs *cs)
 {
 	struct hl_device *hdev = cs->ctx->hdev;
 	struct hl_hw_queue *q;
@@ -53,8 +53,13 @@ void hl_int_hw_queue_update_ci(struct hl_cs *cs)
 	if (!hdev->asic_prop.max_queues || q->queue_type == QUEUE_TYPE_HW)
 		return;
 
+	/* We must increment CI for every queue that will never get a
+	 * completion, there are 2 scenarios this can happen:
+	 * 1. All queues of a non completion CS will never get a completion.
+	 * 2. Internal queues never gets completion.
+	 */
 	for (i = 0 ; i < hdev->asic_prop.max_queues ; i++, q++) {
-		if (q->queue_type == QUEUE_TYPE_INT)
+		if (!cs_needs_completion(cs) || q->queue_type == QUEUE_TYPE_INT)
 			atomic_add(cs->jobs_in_queue_cnt[i], &q->ci);
 	}
 }
@@ -292,6 +297,10 @@ static void ext_queue_schedule_job(struct hl_cs_job *job)
 	len = job->job_cb_size;
 	ptr = cb->bus_address;
 
+	/* Skip completion flow in case this is a non completion CS */
+	if (!cs_needs_completion(job->cs))
+		goto submit_bd;
+
 	cq_pkt.data = cpu_to_le32(
 			((q->pi << CQ_ENTRY_SHADOW_INDEX_SHIFT)
 				& CQ_ENTRY_SHADOW_INDEX_MASK) |
@@ -318,6 +327,7 @@ static void ext_queue_schedule_job(struct hl_cs_job *job)
 
 	cq->pi = hl_cq_inc_ptr(cq->pi);
 
+submit_bd:
 	ext_and_hw_queue_submit_bd(hdev, q, ctl, len, ptr);
 }
 
@@ -525,6 +535,7 @@ int hl_hw_queue_schedule_cs(struct hl_cs *cs)
 	struct hl_cs_job *job, *tmp;
 	struct hl_hw_queue *q;
 	int rc = 0, i, cq_cnt;
+	bool first_entry;
 	u32 max_queues;
 
 	cntr = &hdev->aggregated_cs_counters;
@@ -548,7 +559,9 @@ int hl_hw_queue_schedule_cs(struct hl_cs *cs)
 			switch (q->queue_type) {
 			case QUEUE_TYPE_EXT:
 				rc = ext_queue_sanity_checks(hdev, q,
-						cs->jobs_in_queue_cnt[i], true);
+						cs->jobs_in_queue_cnt[i],
+						cs_needs_completion(cs) ?
+								true : false);
 				break;
 			case QUEUE_TYPE_INT:
 				rc = int_queue_sanity_checks(hdev, q,
@@ -586,9 +599,10 @@ int hl_hw_queue_schedule_cs(struct hl_cs *cs)
 	list_add_tail(&cs->mirror_node, &hdev->cs_mirror_list);
 
 	/* Queue TDR if the CS is the first entry and if timeout is wanted */
+	first_entry = list_first_entry(&hdev->cs_mirror_list,
+					struct hl_cs, mirror_node) == cs;
 	if ((hdev->timeout_jiffies != MAX_SCHEDULE_TIMEOUT) &&
-			(list_first_entry(&hdev->cs_mirror_list,
-					struct hl_cs, mirror_node) == cs)) {
+				first_entry && cs_needs_timeout(cs)) {
 		cs->tdr_active = true;
 		schedule_delayed_work(&cs->work_tdr, hdev->timeout_jiffies);