habanalabs: save ctx inside encaps signal

Compute context pointer in hdev shouldn't be used for fetching the
context's pointer.

If an object needs the context's pointer, it should get it while
incrementing its kref, and when the object is released, put it.
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

drivers/misc/habanalabs/common/command_submission.c

 // SPDX-License-Identifier: GPL-2.0
 
 /*
- * Copyright 2016-2019 HabanaLabs, Ltd.
+ * Copyright 2016-2021 HabanaLabs, Ltd.
  * All Rights Reserved.
  */
 
@@ -1829,6 +1829,9 @@ static int cs_ioctl_reserve_signals(struct hl_fpriv *hpriv,
 	}
 
 	handle->count = count;
+
+	hl_ctx_get(hdev, hpriv->ctx);
+	handle->ctx = hpriv->ctx;
 	mgr = &hpriv->ctx->sig_mgr;
 
 	spin_lock(&mgr->lock);
@@ -1838,7 +1841,7 @@ static int cs_ioctl_reserve_signals(struct hl_fpriv *hpriv,
 	if (hdl_id < 0) {
 		dev_err(hdev->dev, "Failed to allocate IDR for a new signal reservation\n");
 		rc = -EINVAL;
-		goto free_handle;
+		goto put_ctx;
 	}
 
 	handle->id = hdl_id;
@@ -1891,7 +1894,8 @@ static int cs_ioctl_reserve_signals(struct hl_fpriv *hpriv,
 	idr_remove(&mgr->handles, hdl_id);
 	spin_unlock(&mgr->lock);
 
-free_handle:
+put_ctx:
+	hl_ctx_put(handle->ctx);
 	kfree(handle);
 
 out:
@@ -1953,6 +1957,7 @@ static int cs_ioctl_unreserve_signals(struct hl_fpriv *hpriv, u32 handle_id)
 
 		/* Release the id and free allocated memory of the handle */
 		idr_remove(&mgr->handles, handle_id);
+		hl_ctx_put(encaps_sig_hdl->ctx);
 		kfree(encaps_sig_hdl);
 	} else {
 		rc = -EINVAL;

drivers/misc/habanalabs/common/context.c

 // SPDX-License-Identifier: GPL-2.0
 
 /*
- * Copyright 2016-2019 HabanaLabs, Ltd.
+ * Copyright 2016-2021 HabanaLabs, Ltd.
  * All Rights Reserved.
  */
 
@@ -13,13 +13,13 @@ void hl_encaps_handle_do_release(struct kref *ref)
 {
 	struct hl_cs_encaps_sig_handle *handle =
 		container_of(ref, struct hl_cs_encaps_sig_handle, refcount);
-	struct hl_ctx *ctx = handle->hdev->compute_ctx;
-	struct hl_encaps_signals_mgr *mgr = &ctx->sig_mgr;
+	struct hl_encaps_signals_mgr *mgr = &handle->ctx->sig_mgr;
 
 	spin_lock(&mgr->lock);
 	idr_remove(&mgr->handles, handle->id);
 	spin_unlock(&mgr->lock);
 
+	hl_ctx_put(handle->ctx);
 	kfree(handle);
 }
 
@@ -27,8 +27,7 @@ static void hl_encaps_handle_do_release_sob(struct kref *ref)
 {
 	struct hl_cs_encaps_sig_handle *handle =
 		container_of(ref, struct hl_cs_encaps_sig_handle, refcount);
-	struct hl_ctx *ctx = handle->hdev->compute_ctx;
-	struct hl_encaps_signals_mgr *mgr = &ctx->sig_mgr;
+	struct hl_encaps_signals_mgr *mgr = &handle->ctx->sig_mgr;
 
 	/* if we're here, then there was a signals reservation but cs with
 	 * encaps signals wasn't submitted, so need to put refcount
@@ -40,6 +39,7 @@ static void hl_encaps_handle_do_release_sob(struct kref *ref)
 	idr_remove(&mgr->handles, handle->id);
 	spin_unlock(&mgr->lock);
 
+	hl_ctx_put(handle->ctx);
 	kfree(handle);
 }
 

drivers/misc/habanalabs/common/habanalabs.h

@@ -2757,6 +2757,7 @@ struct hl_device {
  *            wait cs are used to wait of the reserved encaps signals.
  * @hdev: pointer to habanalabs device structure.
  * @hw_sob: pointer to  H/W SOB used in the reservation.
+ * @ctx: pointer to the user's context data structure
  * @cs_seq: staged cs sequence which contains encapsulated signals
  * @id: idr handler id to be used to fetch the handler info
  * @q_idx: stream queue index
@@ -2767,6 +2768,7 @@ struct hl_cs_encaps_sig_handle {
 	struct kref refcount;
 	struct hl_device *hdev;
 	struct hl_hw_sob *hw_sob;
+	struct hl_ctx *ctx;
 	u64  cs_seq;
 	u32  id;
 	u32  q_idx;

drivers/misc/habanalabs/common/hw_queue.c

@@ -574,7 +574,7 @@ static int encaps_sig_first_staged_cs_handler
 	struct hl_encaps_signals_mgr *mgr;
 	int rc = 0;
 
-	mgr = &hdev->compute_ctx->sig_mgr;
+	mgr = &cs->ctx->sig_mgr;
 
 	spin_lock(&mgr->lock);
 	encaps_sig_hdl = idr_find(&mgr->handles, cs->encaps_sig_hdl_id);