staging: ccree: remove BUG macro usage

Replace BUG() macro usage that crash the kernel with alternatives
that signal error and/or try to recover.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ccree/ssi_buffer_mgr.c

@@ -81,11 +81,6 @@ static unsigned int ssi_buffer_mgr_get_sgl_nents(
 	unsigned int nents = 0;
 
 	while (nbytes != 0) {
-		if (sg_is_chain(sg_list)) {
-			SSI_LOG_ERR("Unexpected chained entry "
-				   "in sg (entry =0x%X)\n", nents);
-			BUG();
-		}
 		if (sg_list->length != 0) {
 			nents++;
 			/* get the number of bytes in the last entry */
@@ -854,7 +849,7 @@ static inline int ssi_buffer_mgr_aead_chain_assoc(
 			//if have reached the end of the sgl, then this is unexpected
 			if (!current_sg) {
 				SSI_LOG_ERR("reached end of sg list. unexpected\n");
-				BUG();
+				return -EINVAL;
 			}
 			sg_index += current_sg->length;
 			mapped_nents++;
@@ -1134,10 +1129,9 @@ static inline int ssi_buffer_mgr_aead_chain_data(
 
 	offset = size_to_skip;
 
-	if (!sg_data) {
-		rc = -EINVAL;
-		goto chain_data_exit;
-	}
+	if (!sg_data)
+		return -EINVAL;
+
 	areq_ctx->src_sgl = req->src;
 	areq_ctx->dst_sgl = req->dst;
 
@@ -1154,7 +1148,7 @@ static inline int ssi_buffer_mgr_aead_chain_data(
 		//if have reached the end of the sgl, then this is unexpected
 		if (!areq_ctx->src_sgl) {
 			SSI_LOG_ERR("reached end of sg list. unexpected\n");
-			BUG();
+			return -EINVAL;
 		}
 		sg_index += areq_ctx->src_sgl->length;
 		src_mapped_nents--;
@@ -1198,7 +1192,7 @@ static inline int ssi_buffer_mgr_aead_chain_data(
 		//if have reached the end of the sgl, then this is unexpected
 		if (!areq_ctx->dst_sgl) {
 			SSI_LOG_ERR("reached end of sg list. unexpected\n");
-			BUG();
+			return -EINVAL;
 		}
 		sg_index += areq_ctx->dst_sgl->length;
 		dst_mapped_nents--;

drivers/staging/ccree/ssi_cipher.c

@@ -541,7 +541,6 @@ ssi_blkcipher_create_setup_desc(
 		break;
 	default:
 		SSI_LOG_ERR("Unsupported cipher mode (%d)\n", cipher_mode);
-		BUG();
 	}
 }
 

drivers/staging/ccree/ssi_pm.c

@@ -109,7 +109,8 @@ int ssi_power_mgr_runtime_put_suspend(struct device *dev)
 		rc = pm_runtime_put_autosuspend(dev);
 	} else {
 		/* Something wrong happens*/
-		BUG();
+		SSI_LOG_ERR("request to suspend already suspended queue");
+		rc = -EBUSY;
 	}
 	return rc;
 }

drivers/staging/ccree/ssi_request_mgr.c

@@ -369,11 +369,16 @@ int send_request(
 	enqueue_seq(cc_base, &req_mgr_h->compl_desc, (is_dout ? 0 : 1));
 
 	if (unlikely(req_mgr_h->q_free_slots < total_seq_len)) {
-		/*This means that there was a problem with the resume*/
-		BUG();
+		/* This situation should never occur. Maybe indicating problem
+		 * with resuming power. Set the free slot count to 0 and hope
+		 * for the best.
+		 */
+		SSI_LOG_ERR("HW free slot count mismatch.");
+		req_mgr_h->q_free_slots = 0;
+	} else {
+		/* Update the free slots in HW queue */
+		req_mgr_h->q_free_slots -= total_seq_len;
 	}
-	/* Update the free slots in HW queue */
-	req_mgr_h->q_free_slots -= total_seq_len;
 
 	spin_unlock_bh(&req_mgr_h->hw_lock);
 
@@ -460,8 +465,13 @@ static void proc_completions(struct ssi_drvdata *drvdata)
 
 		/* Dequeue request */
 		if (unlikely(request_mgr_handle->req_queue_head == request_mgr_handle->req_queue_tail)) {
-			SSI_LOG_ERR("Request queue is empty req_queue_head==req_queue_tail==%u\n", request_mgr_handle->req_queue_head);
-			BUG();
+			/* We are supposed to handle a completion but our
+			 * queue is empty. This is not normal. Return and
+			 * hope for the best.
+			 */
+			SSI_LOG_ERR("Request queue is empty head == tail %u\n",
+				    request_mgr_handle->req_queue_head);
+			break;
 		}
 
 		ssi_req = &request_mgr_handle->req_queue[request_mgr_handle->req_queue_tail];