scsi: ufs: qcom-ice: block further requests until ICE config is complete

Requests that need to go through the ICE must be setup with a key
before and have a key index ready. In cases where the key is not
ready as it is not in the key cache, the ICE 'config_start' callback
returns -EAGAIN and we need to block further requests and call
'config_start' again from a non-atomic context until key setup
is ready and then resume requests handling.

Change-Id: I51ff1e99240386ce533b5ab3f5f024043532b0ad
Signed-off-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Andrey Markovytch <andreym@codeaurora.org>

3 files changed, 74 insertions, 12 deletions

diff --git a/drivers/scsi/ufs/ufs-qcom-ice.c b/drivers/scsi/ufs/ufs-qcom-ice.c
index 195f6b39989d..6d2a8f8cf3c1 100644
--- a/drivers/scsi/ufs/ufs-qcom-ice.c
+++ b/drivers/scsi/ufs/ufs-qcom-ice.c
@@ -164,7 +164,35 @@ int ufs_qcom_ice_get_dev(struct ufs_qcom_host *qcom_host)
 
 out:
 	return err;
+}
+
+static void ufs_qcom_ice_cfg_work(struct work_struct *work)
+{
+	struct ice_data_setting ice_set;
+	struct ufs_qcom_host *qcom_host =
+		container_of(work, struct ufs_qcom_host, ice_cfg_work);
+
+	if (!qcom_host->ice.vops->config_start || !qcom_host->req_pending)
+		return;
+
+	memset(&ice_set, 0, sizeof(ice_set));
+
+	/*
+	 * config_start is called again as previous attempt returned -EAGAIN,
+	 * this call shall now take care of the necessary key setup.
+	 * 'ice_set' will not actually be used, instead the next call to
+	 * config_start() for this request, in the normal call flow, will
+	 * succeed as the key has now been setup.
+	 */
+	qcom_host->ice.vops->config_start(qcom_host->ice.pdev,
+		qcom_host->req_pending, &ice_set, false);
 
+	/*
+	 * Resume with requests processing. We assume config_start has been
+	 * successful, but even if it wasn't we still must resume in order to
+	 * allow for the request to be retried.
+	 */
+	ufshcd_scsi_unblock_requests(qcom_host->hba);
 }
 
 /**
@@ -193,6 +221,7 @@ int ufs_qcom_ice_init(struct ufs_qcom_host *qcom_host)
 	}
 
 	qcom_host->dbg_print_en |= UFS_QCOM_ICE_DEFAULT_DBG_PRINT_EN;
+	INIT_WORK(&qcom_host->ice_cfg_work, ufs_qcom_ice_cfg_work);
 
 out:
 	return err;
@@ -300,8 +329,22 @@ int ufs_qcom_ice_cfg_start(struct ufs_qcom_host *qcom_host,
 		err = qcom_host->ice.vops->config_start(qcom_host->ice.pdev,
 							req, &ice_set, true);
 		if (err) {
-			dev_err(dev, "%s: error in ice_vops->config %d\n",
-				__func__, err);
+			/*
+			 * config_start() returns -EAGAIN when a key slot is
+			 * available but still not configured. As configuration
+			 * requires a non-atomic context, this means we should
+			 * call the function again from the worker thread to do
+			 * the configuration. For this request the error will
+			 * propagate so it will be re-queued and until the
+			 * configuration is is completed we block further
+			 * request processing.
+			 */
+			if (err == -EAGAIN) {
+				qcom_host->req_pending = req;
+				if (schedule_work(&qcom_host->ice_cfg_work))
+					ufshcd_scsi_block_requests(
+							qcom_host->hba);
+			}
 			goto out;
 		}
 	}
diff --git a/drivers/scsi/ufs/ufs-qcom.h b/drivers/scsi/ufs/ufs-qcom.h
index 7dbae4764c5e..ec22c290c45d 100644
--- a/drivers/scsi/ufs/ufs-qcom.h
+++ b/drivers/scsi/ufs/ufs-qcom.h
@@ -337,6 +337,9 @@ struct ufs_qcom_host {
 	/* Bitmask for enabling debug prints */
 	u32 dbg_print_en;
 	struct ufs_qcom_testbus testbus;
+
+	struct work_struct ice_cfg_work;
+	struct request *req_pending;
 };
 
 static inline u32
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 66d66f9799df..6863cc1013f8 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1954,14 +1954,6 @@ int ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
 {
 	int ret = 0;
 
-	ret = ufshcd_vops_crypto_engine_cfg_start(hba, task_tag);
-	if (ret) {
-		dev_err(hba->dev,
-			"%s: failed to configure crypto engine %d\n",
-			__func__, ret);
-		return ret;
-	}
-
 	hba->lrb[task_tag].issue_time_stamp = ktime_get();
 	hba->lrb[task_tag].complete_time_stamp = ktime_set(0, 0);
 	ufshcd_clk_scaling_start_busy(hba);
@@ -2627,6 +2619,22 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 		goto out;
 	}
 
+	err = ufshcd_vops_crypto_engine_cfg_start(hba, tag);
+	if (err) {
+		if (err != -EAGAIN)
+			dev_err(hba->dev,
+				"%s: failed to configure crypto engine %d\n",
+				__func__, err);
+
+		scsi_dma_unmap(lrbp->cmd);
+		lrbp->cmd = NULL;
+		clear_bit_unlock(tag, &hba->lrb_in_use);
+		ufshcd_release_all(hba);
+		ufshcd_vops_pm_qos_req_end(hba, cmd->request, true);
+
+		goto out;
+	}
+
 	/* Make sure descriptors are ready before ringing the doorbell */
 	wmb();
 	/* issue command to the controller */
@@ -2640,6 +2648,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 		clear_bit_unlock(tag, &hba->lrb_in_use);
 		ufshcd_release_all(hba);
 		ufshcd_vops_pm_qos_req_end(hba, cmd->request, true);
+		ufshcd_vops_crypto_engine_cfg_end(hba, lrbp, cmd->request);
 		dev_err(hba->dev, "%s: failed sending command, %d\n",
 							__func__, err);
 		err = DID_ERROR;
@@ -4938,7 +4947,7 @@ void ufshcd_abort_outstanding_transfer_requests(struct ufs_hba *hba, int result)
 			/* Mark completed command as NULL in LRB */
 			lrbp->cmd = NULL;
 			ufshcd_release_all(hba);
-			if (cmd->request)
+			if (cmd->request) {
 				/*
 				 * As we are accessing the "request" structure,
 				 * this must be called before calling
@@ -4946,6 +4955,9 @@ void ufshcd_abort_outstanding_transfer_requests(struct ufs_hba *hba, int result)
 				 */
 				ufshcd_vops_pm_qos_req_end(hba, cmd->request,
 					true);
+				ufshcd_vops_crypto_engine_cfg_end(hba,
+						lrbp, cmd->request);
+			}
 			/* Do not touch lrbp after scsi done */
 			cmd->scsi_done(cmd);
 		} else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
@@ -4990,7 +5002,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
 			lrbp->cmd = NULL;
 			__ufshcd_release(hba, false);
 			__ufshcd_hibern8_release(hba, false);
-			if (cmd->request)
+			if (cmd->request) {
 				/*
 				 * As we are accessing the "request" structure,
 				 * this must be called before calling
@@ -4998,6 +5010,10 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
 				 */
 				ufshcd_vops_pm_qos_req_end(hba, cmd->request,
 					false);
+				ufshcd_vops_crypto_engine_cfg_end(hba,
+					lrbp, cmd->request);
+			}
+
 			/* Do not touch lrbp after scsi done */
 			cmd->scsi_done(cmd);
 		} else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {