[PATCH v1] ufs: core: fix ufshcd_abort_all racing issue

[peter.wang at mediatek.com]

From: Peter Wang <peter.wang at mediatek.com>

When ufshcd_abort_all racing with complete ISR,
the completed tag of request will be release by ISR.
And ufshca_abort_all call ufshcd_mcq_req_to_hwq will
get NULL pointer KE.
Also change the return value success when request is
completed by ISR beacuse sq dosen't need cleanup.

Below is KE back trace.
  ufshcd_try_to_abort_task: cmd at tag 41 not pending in the device.
  ufshcd_try_to_abort_task: cmd at tag=41 is cleared.
  Aborting tag 41 / CDB 0x28 succeeded
  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194
  pc : [0xffffffddd7a79bf8] blk_mq_unique_tag+0x8/0x14
  lr : [0xffffffddd6155b84] ufshcd_mcq_req_to_hwq+0x1c/0x40 [ufs_mediatek_mod_ise]
   do_mem_abort+0x58/0x118
   el1_abort+0x3c/0x5c
   el1h_64_sync_handler+0x54/0x90
   el1h_64_sync+0x68/0x6c
   blk_mq_unique_tag+0x8/0x14
   ufshcd_err_handler+0xae4/0xfa8 [ufs_mediatek_mod_ise]
   process_one_work+0x208/0x4fc
   worker_thread+0x228/0x438
   kthread+0x104/0x1d4
   ret_from_fork+0x10/0x20

Signed-off-by: Peter Wang <peter.wang at mediatek.com>
---
 drivers/ufs/core/ufs-mcq.c | 5 +++--
 drivers/ufs/core/ufshcd.c  | 9 +++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 8944548c30fa..3b2e5bcb08a7 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -512,8 +512,9 @@ int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
 		return -ETIMEDOUT;
 
 	if (task_tag != hba->nutrs - UFSHCD_NUM_RESERVED) {
-		if (!cmd)
-			return -EINVAL;
+		/* Should return 0 if cmd is already complete by irq */
+		if (!cmd || !ufshcd_cmd_inflight(cmd))
+			return 0;
 		hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd));
 	} else {
 		hwq = hba->dev_cmd_queue;
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index e5e9da61f15d..e8bca62ceed8 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -6455,11 +6455,12 @@ static bool ufshcd_abort_one(struct request *rq, void *priv)
 
 	/* Release cmd in MCQ mode if abort succeeds */
 	if (is_mcq_enabled(hba) && (*ret == 0)) {
-		hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(lrbp->cmd));
-		spin_lock_irqsave(&hwq->cq_lock, flags);
-		if (ufshcd_cmd_inflight(lrbp->cmd))
+		if (ufshcd_cmd_inflight(lrbp->cmd)) {
+			hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(lrbp->cmd));
+			spin_lock_irqsave(&hwq->cq_lock, flags);
 			ufshcd_release_scsi_cmd(hba, lrbp);
-		spin_unlock_irqrestore(&hwq->cq_lock, flags);
+			spin_unlock_irqrestore(&hwq->cq_lock, flags);
+		}
 	}
 
 	return *ret == 0;
-- 
2.18.0