habanalabs: refactor fence handling in hl_cs_poll_fences

To avoid checking if fence exists multipled times, changed fence
handling to depend only on the fence status field:

Busy, which means CS still did not completed :
	Add its QID so multi CS wait on its completion.
Finished, which means CS completed and fence exists:
	Raise its completion bit if it finished mcs handling and
	update if necessary the earliest timestamp.
Gone, which means CS already completed and fence deleted:
	Update multi CS data to ignore timestamp and raise its
	completion bit.

Signed-off-by: Dani Liberman <dliberman@habana.ai>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c
index f94ac2350a9b94f030a07518125818c8f8bc7e2e..4c8000fd246cddfce14fb3c8cee153a9b076a11d 100644 (file)
--- a/drivers/misc/habanalabs/common/command_submission.c
+++ b/drivers/misc/habanalabs/common/command_submission.c
@@ -2382,47 +2382,48 @@ static int hl_cs_poll_fences(struct multi_cs_data *mcs_data)
                        break;
                }
 
-               /*
-                * It is possible to get an old sequence numbers from user
-                * which related to already completed CSs and their fences
-                * already gone. In this case, no need to consider its QID for
-                * mcs completion.
-                */
-               if (fence)
+               switch (status) {
+               case CS_WAIT_STATUS_BUSY:
+                       /* CS did not finished, keep waiting on its QID*/
                        mcs_data->stream_master_qid_map |=
                                        fence->stream_master_qid_map;
+                       break;
+               case CS_WAIT_STATUS_COMPLETED:
+                       /*
+                        * Using mcs_handling_done to avoid possibility of mcs_data
+                        * returns to user indicating CS completed before it finished
+                        * all of its mcs handling, to avoid race the next time the
+                        * user waits for mcs.
+                        */
+                       if (!fence->mcs_handling_done)
+                               break;
 
-               /*
-                * Using mcs_handling_done to avoid possibility of mcs_data
-                * returns to user indicating CS completed before it finished
-                * all of its mcs handling, to avoid race the next time the
-                * user waits for mcs.
-                */
-               if (status == CS_WAIT_STATUS_BUSY ||
-                               (fence && !fence->mcs_handling_done))
-                       continue;
-
-               mcs_data->completion_bitmap |= BIT(i);
-
-               /*
-                * best effort to extract timestamp. few notes:
-                * - if even single fence is gone we cannot extract timestamp
-                *   (as fence not exist anymore)
-                * - for all completed CSs we take the earliest timestamp.
-                *   for this we have to validate that:
-                *       1. given timestamp was indeed set
-                *       2. the timestamp is earliest of all timestamps so far
-                */
-
-               if (status == CS_WAIT_STATUS_GONE) {
+                       mcs_data->completion_bitmap |= BIT(i);
+                       /*
+                        * For all completed CSs we take the earliest timestamp.
+                        * For this we have to validate that the timestamp is
+                        * earliest of all timestamps so far.
+                        */
+                       if (mcs_data->update_ts &&
+                                       (ktime_compare(fence->timestamp, first_cs_time) < 0))
+                               first_cs_time = fence->timestamp;
+                       break;
+               case CS_WAIT_STATUS_GONE:
                        mcs_data->update_ts = false;
                        mcs_data->gone_cs = true;
-               } else if (mcs_data->update_ts &&
-                       (ktime_compare(fence->timestamp,
-                                               ktime_set(0, 0)) > 0) &&
-                       (ktime_compare(fence->timestamp, first_cs_time) < 0)) {
-                       first_cs_time = fence->timestamp;
+                       /*
+                        * It is possible to get an old sequence numbers from user
+                        * which related to already completed CSs and their fences
+                        * already gone. In this case, CS set as completed but
+                        * no need to consider its QID for mcs completion.
+                        */
+                       mcs_data->completion_bitmap |= BIT(i);
+                       break;
+               default:
+                       dev_err(hdev->dev, "Invalid fence status\n");
+                       return -EINVAL;
                }
+
        }
 
        hl_fences_put(mcs_data->fence_arr, arr_len);