Commit b2faac38 authored by Dani Liberman's avatar Dani Liberman Committed by Oded Gabbay
Browse files

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: default avatarDani Liberman <dliberman@habana.ai>
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: default avatarOded Gabbay <ogabbay@kernel.org>
Signed-off-by: default avatarOded Gabbay <ogabbay@kernel.org>
parent fae13263

drivers/misc/habanalabs/common/command_submission.c

+36 −35
Original line number Diff line number Diff line
@@ -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 (status == CS_WAIT_STATUS_BUSY ||

				(fence && !fence->mcs_handling_done))

			continue;

			if (!fence->mcs_handling_done)

				break;



			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

			 * 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 (status == CS_WAIT_STATUS_GONE) {

			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);