Re: [RFC PATCH v1 4/4] ufs: mcq: Added ufshcd_mcq_abort()

["Bao D. Nguyen" <quic_nguyenb@quicinc.com>]

On 3/8/2023 10:21 PM, Stanley Chu wrote:
> Hi Bao,
>
> On Thu, Mar 9, 2023 at 1:31 PM Bao D. Nguyen <quic_nguyenb@quicinc.com> wrote:
>> On 3/8/2023 7:10 PM, Stanley Chu wrote:
>>> Hi Bao,
>>>
>>> On Wed, Mar 8, 2023 at 12:10 PM Bao D. Nguyen <quic_nguyenb@quicinc.com> wrote:
>>>> Add ufshcd_mcq_abort() to support ufs abort in mcq mode.
>>>>
>>>> Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
>>>> ---
>>>>    drivers/ufs/core/ufs-mcq.c     | 76 ++++++++++++++++++++++++++++++++++++++++++
>>>>    drivers/ufs/core/ufshcd-priv.h |  5 ++-
>>>>    drivers/ufs/core/ufshcd.c      | 11 ++++--
>>>>    3 files changed, 88 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
>>>> index e27d8eb..6c65cd5 100644
>>>> --- a/drivers/ufs/core/ufs-mcq.c
>>>> +++ b/drivers/ufs/core/ufs-mcq.c
>>>> @@ -646,3 +646,79 @@ static bool ufshcd_mcq_cqe_search(struct ufs_hba *hba,
>>>>           spin_unlock(&hwq->cq_lock);
>>>>           return ret;
>>>>    }
>>>> +
>>>> +/**
>>>> + * ufshcd_mcq_abort - Abort the command in MCQ.
>>>> + * @cmd - The command to be aborted.
>>>> + *
>>>> + * Returns SUCCESS or FAILED error codes
>>>> + */
>>>> +int ufshcd_mcq_abort(struct scsi_cmnd *cmd)
>>>> +{
>>>> +       struct Scsi_Host *host = cmd->device->host;
>>>> +       struct ufs_hba *hba = shost_priv(host);
>>>> +       int tag = scsi_cmd_to_rq(cmd)->tag;
>>>> +       struct ufshcd_lrb *lrbp = &hba->lrb[tag];
>>>> +       struct ufs_hw_queue *hwq;
>>>> +       int err = FAILED;
>>>> +
>>>> +       if (!lrbp->cmd) {
>>>> +               dev_err(hba->dev,
>>>> +                       "%s: skip abort. cmd at tag %d already completed.\n",
>>>> +                       __func__, tag);
>>>> +               goto out;
>>>> +       }
>>>> +
>>>> +       /* Skip task abort in case previous aborts failed and report failure */
>>>> +       if (lrbp->req_abort_skip) {
>>>> +               dev_err(hba->dev, "%s: skip abort. tag %d failed earlier\n",
>>>> +                       __func__, tag);
>>>> +               goto out;
>>>> +       }
>>>> +
>>>> +       hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd));
>>>> +
>>>> +       if (ufshcd_mcq_sqe_search(hba, hwq, tag)) {
>>>> +               /*
>>>> +                * Failure. The command should not be "stuck" in SQ for
>>>> +                * a long time which resulted in command being aborted.
>>>> +                */
>>>> +               dev_err(hba->dev, "%s: cmd found in sq. hwq=%d, tag=%d\n",
>>>> +                               __func__, hwq->id, tag);
>>>> +               /* Set the Command Type to 0xF per the spec */
>>>> +               ufshcd_mcq_nullify_cmd(hba, hwq);
>>>> +               goto out;
>>>> +       }
>>>> +
>>>> +       if (ufshcd_mcq_cqe_search(hba, hwq, tag)) {
>>>> +               dev_err(hba->dev, "%s: cmd found in cq. hwq=%d, tag=%d\n",
>>>> +                               __func__, hwq->id, tag);
>>>> +               /*
>>>> +                * The command should not be 'stuck' in the CQ for such a long time.
>>>> +                * Is interrupt missing? Process the CQEs here. If the interrupt is
>>>> +                * invoked at a later time, the CQ will be empty because the CQEs
>>>> +                * are already processed here.
>>>> +                */
>>>> +               ufshcd_mcq_poll_cqe_lock(hba, hwq);
>>>> +               err = SUCCESS;
>>>> +               goto out;
>>>> +       }
>>>> +
>>>> +       /*
>>>> +        * The command is not in the Submission Queue, and it is not
>>>> +        * in the Completion Queue either. Query the device to see if
>>>> +        * the command is being processed in the device.
>>>> +        */
>>>> +       if (ufshcd_try_to_abort_task(hba, tag)) {
>>>> +               dev_err(hba->dev, "%s: device abort failed %d\n", __func__, err);
>>>> +               lrbp->req_abort_skip = true;
>>>> +               goto out;
>>>> +       }
>>>> +
>>>> +       err = SUCCESS;
>>>> +       if (lrbp->cmd)
>>>> +               ufshcd_release_scsi_cmd(hba, lrbp);
>>>> +
>>>> +out:
>>>> +       return err;
>>>> +}
>>>> diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
>>>> index 0527926..d883c03 100644
>>>> --- a/drivers/ufs/core/ufshcd-priv.h
>>>> +++ b/drivers/ufs/core/ufshcd-priv.h
>>>> @@ -77,7 +77,10 @@ unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
>>>>                                          struct ufs_hw_queue *hwq);
>>>>
>>>>    int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag, int *result);
>>>> -
>>>> +int ufshcd_mcq_abort(struct scsi_cmnd *cmd);
>>>> +int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag);
>>>> +void ufshcd_release_scsi_cmd(struct ufs_hba *hba,
>>>> +                               struct ufshcd_lrb *lrbp);
>>>>    #define UFSHCD_MCQ_IO_QUEUE_OFFSET     1
>>>>    #define SD_ASCII_STD true
>>>>    #define SD_RAW false
>>>> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
>>>> index 408c16c..e06399e 100644
>>>> --- a/drivers/ufs/core/ufshcd.c
>>>> +++ b/drivers/ufs/core/ufshcd.c
>>>> @@ -302,7 +302,6 @@ static int ufshcd_setup_hba_vreg(struct ufs_hba *hba, bool on);
>>>>    static int ufshcd_setup_vreg(struct ufs_hba *hba, bool on);
>>>>    static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba,
>>>>                                            struct ufs_vreg *vreg);
>>>> -static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag);
>>>>    static void ufshcd_wb_toggle_buf_flush_during_h8(struct ufs_hba *hba,
>>>>                                                    bool enable);
>>>>    static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba);
>>>> @@ -5414,7 +5413,7 @@ static irqreturn_t ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
>>>>    }
>>>>
>>>>    /* Release the resources allocated for processing a SCSI command. */
>>>> -static void ufshcd_release_scsi_cmd(struct ufs_hba *hba,
>>>> +void ufshcd_release_scsi_cmd(struct ufs_hba *hba,
>>>>                                       struct ufshcd_lrb *lrbp)
>>>>    {
>>>>           struct scsi_cmnd *cmd = lrbp->cmd;
>>>> @@ -7340,7 +7339,7 @@ static void ufshcd_set_req_abort_skip(struct ufs_hba *hba, unsigned long bitmap)
>>>>     *
>>>>     * Returns zero on success, non-zero on failure
>>>>     */
>>>> -static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag)
>>>> +int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag)
>>>>    {
>>>>           struct ufshcd_lrb *lrbp = &hba->lrb[tag];
>>>>           int err = 0;
>>>> @@ -7500,6 +7499,12 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>>>>                   goto release;
>>>>           }
>>>>
>>>> +       if (is_mcq_enabled(hba)) {
>>>> +               /* MCQ mode. Branch off to handle abort for mcq mode */
>>>> +               err = ufshcd_mcq_abort(cmd);
>>>> +               goto release;
>>>> +       }
>>>> +
>>>>           /* Skip task abort in case previous aborts failed and report failure */
>>>>           if (lrbp->req_abort_skip) {
>>>>                   dev_err(hba->dev, "%s: skipping abort\n", __func__);
>>>> --
>>>> 2.7.4
>>>>
>>> It seems that ufshcd_abort_all() also needs an error handling flow for MCQ.
>> Hi Stanley, thank you for the reviews.
>>
>> I am not able to find the function ufshcd_abort_all() in the drivers/ufs
>> directory. Can you please clarify where this function is located? Thanks.
> The function ufshcd_abort_all() was introduced in the following link:
> https://android.googlesource.com/kernel/common/+/b817e6ffbad7a1a0a5ca5bb7d4020823c3f4d9d0

Ah ok. Thank you for this info. The ufshcd_abort_all() is in 
ufshcd_err_handler(), it is unrelated to the ufshcd_abort().

Adding MCQ support to ufshcd_err_handler() will be in a separate patch.

> Can you confirm if these patches are based on the latest kernel
> 6.3-rc1 or the latest linux-next tree?
>
> Thanks,
> Stanley
>
>>> Thanks,
>>> Stanley
>>