habanalabs: get multiple fences under same cs_lock

To add proper support for wait-for-multi-CS, locking the CS lock
for each CS fence in the list is not efficient.

Instead, this patch add support to lock the CS lock once to get all
required fences.

Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

1 files changed, 66 insertions, 42 deletions

diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c
index a0846880400c..b373a52a47a7 100644
--- a/drivers/misc/habanalabs/common/command_submission.c
+++ b/drivers/misc/habanalabs/common/command_submission.c
@@ -152,8 +152,17 @@ free:
 
 void hl_fence_put(struct hl_fence *fence)
 {
-	if (fence)
-		kref_put(&fence->refcount, hl_fence_release);
+	if (IS_ERR_OR_NULL(fence))
+		return;
+	kref_put(&fence->refcount, hl_fence_release);
+}
+
+void hl_fences_put(struct hl_fence **fence, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++, fence++)
+		hl_fence_put(*fence);
 }
 
 void hl_fence_get(struct hl_fence *fence)
@@ -1896,61 +1905,76 @@ out:
 	return rc;
 }
 
-static int _hl_cs_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx,
-				u64 timeout_us, u64 seq,
-				enum hl_cs_wait_status *status, s64 *timestamp)
+static int hl_wait_for_fence(struct hl_ctx *ctx, u64 seq, struct hl_fence *fence,
+				enum hl_cs_wait_status *status, u64 timeout_us,
+				s64 *timestamp)
 {
-	struct hl_fence *fence;
-	unsigned long timeout;
-	int rc = 0;
+	struct hl_device *hdev = ctx->hdev;
 	long completion_rc;
+	int rc = 0;
 
-	if (timestamp)
-		*timestamp = 0;
-
-	if (timeout_us == MAX_SCHEDULE_TIMEOUT)
-		timeout = timeout_us;
-	else
-		timeout = usecs_to_jiffies(timeout_us);
-
-	hl_ctx_get(hdev, ctx);
-
-	fence = hl_ctx_get_fence(ctx, seq);
 	if (IS_ERR(fence)) {
 		rc = PTR_ERR(fence);
 		if (rc == -EINVAL)
 			dev_notice_ratelimited(hdev->dev,
 				"Can't wait on CS %llu because current CS is at seq %llu\n",
 				seq, ctx->cs_sequence);
-	} else if (fence) {
-		if (!timeout_us)
-			completion_rc = completion_done(&fence->completion);
-		else
-			completion_rc =
-				wait_for_completion_interruptible_timeout(
-					&fence->completion, timeout);
-
-		if (completion_rc > 0) {
-			*status = CS_WAIT_STATUS_COMPLETED;
-			if (timestamp)
-				*timestamp = ktime_to_ns(fence->timestamp);
-		} else {
-			*status = CS_WAIT_STATUS_BUSY;
-		}
-
-		if (fence->error == -ETIMEDOUT)
-			rc = -ETIMEDOUT;
-		else if (fence->error == -EIO)
-			rc = -EIO;
+		return rc;
+	}
 
-		hl_fence_put(fence);
-	} else {
+	if (!fence) {
 		dev_dbg(hdev->dev,
 			"Can't wait on seq %llu because current CS is at seq %llu (Fence is gone)\n",
-			seq, ctx->cs_sequence);
+				seq, ctx->cs_sequence);
+
 		*status = CS_WAIT_STATUS_GONE;
+		return 0;
+	}
+
+	if (!timeout_us) {
+		completion_rc = completion_done(&fence->completion);
+	} else {
+		unsigned long timeout;
+
+		timeout = (timeout_us == MAX_SCHEDULE_TIMEOUT) ?
+				timeout_us : usecs_to_jiffies(timeout_us);
+		completion_rc =
+			wait_for_completion_interruptible_timeout(
+				&fence->completion, timeout);
 	}
 
+	if (completion_rc > 0) {
+		*status = CS_WAIT_STATUS_COMPLETED;
+		if (timestamp)
+			*timestamp = ktime_to_ns(fence->timestamp);
+	} else {
+		*status = CS_WAIT_STATUS_BUSY;
+	}
+
+	if (fence->error == -ETIMEDOUT)
+		rc = -ETIMEDOUT;
+	else if (fence->error == -EIO)
+		rc = -EIO;
+
+	return rc;
+}
+
+static int _hl_cs_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx,
+				u64 timeout_us, u64 seq,
+				enum hl_cs_wait_status *status, s64 *timestamp)
+{
+	struct hl_fence *fence;
+	int rc = 0;
+
+	if (timestamp)
+		*timestamp = 0;
+
+	hl_ctx_get(hdev, ctx);
+
+	fence = hl_ctx_get_fence(ctx, seq);
+
+	rc = hl_wait_for_fence(ctx, seq, fence, status, timeout_us, timestamp);
+	hl_fence_put(fence);
 	hl_ctx_put(ctx);
 
 	return rc;