On Tue, July 09, 2013 Sujit Reddy Thumma wrote:
> Currently, sending Task Management (TM) command to the card might
> be broken in some scenarios as listed below:
>
> Problem: If there are more than 8 TM commands the implementation
> returns error to the caller.
> Fix: Wait for one of the slots to be emptied and send the command.
>
> Problem: Sometimes it is necessary for the caller to know the TM service
> response code to determine the task status.
> Fix: Propogate the service response to the caller.
>
> Problem: If the TM command times out no proper error recovery is
> implemented.
> Fix: Clear the command in the controller door-bell register, so that
> further commands for the same slot don't fail.
>
> Problem: While preparing the TM command descriptor, the task tag used
> should be unique across SCSI/NOP/QUERY/TM commands and not the
> task tag of the command which the TM command is trying to manage.
> Fix: Use a unique task tag instead of task tag of SCSI command.
>
> Problem: Since the TM command involves H/W communication, abruptly ending
> the request on kill interrupt signal might cause h/w malfunction.
> Fix: Wait for hardware completion interrupt with TASK_UNINTERRUPTIBLE
> set.
>
> Signed-off-by: Sujit Reddy Thumma <sthu...@codeaurora.org>
> ---
> drivers/scsi/ufs/ufshcd.c | 177
> ++++++++++++++++++++++++++++++---------------
> drivers/scsi/ufs/ufshcd.h | 8 ++-
> 2 files changed, 126 insertions(+), 59 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index af7d01d..a176421 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -53,6 +53,9 @@
> /* Query request timeout */
> #define QUERY_REQ_TIMEOUT 30 /* msec */
>
> +/* Task management command timeout */
> +#define TM_CMD_TIMEOUT 100 /* msecs */
> +
> /* Expose the flag value from utp_upiu_query.value */
> #define MASK_QUERY_UPIU_FLAG_LOC 0xFF
>
> @@ -190,13 +193,35 @@ ufshcd_get_tmr_ocs(struct utp_task_req_desc
> *task_req_descp)
> /**
> * ufshcd_get_tm_free_slot - get a free slot for task management request
> * @hba: per adapter instance
> + * @free_slot: pointer to variable with available slot value
> *
> - * Returns maximum number of task management request slots in case of
> - * task management queue full or returns the free slot number
> + * Get a free tag and lock it until ufshcd_put_tm_slot() is called.
> + * Returns 0 if free slot is not available, else return 1 with tag value
> + * in @free_slot.
> */
> -static inline int ufshcd_get_tm_free_slot(struct ufs_hba *hba)
> +static bool ufshcd_get_tm_free_slot(struct ufs_hba *hba, int *free_slot)
> +{
> + int tag;
> + bool ret = false;
> +
> + if (!free_slot)
> + goto out;
> +
> + do {
> + tag = find_first_zero_bit(&hba->tm_slots_in_use, hba->nutmrs);
> + if (tag >= hba->nutmrs)
> + goto out;
> + } while (test_and_set_bit_lock(tag, &hba->tm_slots_in_use));
> +
> + *free_slot = tag;
> + ret = true;
> +out:
> + return ret;
> +}
> +
> +static inline void ufshcd_put_tm_slot(struct ufs_hba *hba, int slot)
> {
> - return find_first_zero_bit(&hba->outstanding_tasks, hba->nutmrs);
> + clear_bit_unlock(slot, &hba->tm_slots_in_use);
> }
>
> /**
> @@ -1778,10 +1803,11 @@ static void ufshcd_slave_destroy(struct scsi_device
> *sdev)
> * ufshcd_task_req_compl - handle task management request completion
> * @hba: per adapter instance
> * @index: index of the completed request
> + * @resp: task management service response
> *
> - * Returns SUCCESS/FAILED
> + * Returns non-zero value on error, zero on success
> */
> -static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index)
> +static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index, u8 *resp)
> {
> struct utp_task_req_desc *task_req_descp;
> struct utp_upiu_task_rsp *task_rsp_upiup;
> @@ -1802,19 +1828,15 @@ static int ufshcd_task_req_compl(struct ufs_hba *hba,
> u32 index)
> task_req_descp[index].task_rsp_upiu;
> task_result = be32_to_cpu(task_rsp_upiup->header.dword_1);
> task_result = ((task_result & MASK_TASK_RESPONSE) >> 8);
> -
> - if (task_result != UPIU_TASK_MANAGEMENT_FUNC_COMPL &&
> - task_result != UPIU_TASK_MANAGEMENT_FUNC_SUCCEEDED)
> - task_result = FAILED;
> - else
> - task_result = SUCCESS;
> + if (resp)
> + *resp = (u8)task_result;
> } else {
> - task_result = FAILED;
> - dev_err(hba->dev,
> - "trc: Invalid ocs = %x\n", ocs_value);
> + dev_err(hba->dev, "%s: failed, ocs = 0x%x\n",
> + __func__, ocs_value);
> }
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> - return task_result;
> +
> + return ocs_value;
> }
>
> /**
> @@ -2298,7 +2320,7 @@ static void ufshcd_tmc_handler(struct ufs_hba *hba)
>
> tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
> hba->tm_condition = tm_doorbell ^ hba->outstanding_tasks;
> - wake_up_interruptible(&hba->ufshcd_tm_wait_queue);
> + wake_up(&hba->tm_wq);
> }
>
> /**
> @@ -2348,38 +2370,61 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
> return retval;
> }
>
> +static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag)
> +{
> + int err = 0;
> + u32 reg;
> + u32 mask = 1 << tag;
> + unsigned long flags;
> +
> + if (!test_bit(tag, &hba->outstanding_reqs))
> + goto out;
> +
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + ufshcd_writel(hba, ~(1 << tag), REG_UTP_TASK_REQ_LIST_CLEAR);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> +
> + /* poll for max. 1 sec to clear door bell register by h/w */
> + reg = ufshcd_wait_for_register(hba,
> + REG_UTP_TASK_REQ_DOOR_BELL,
> + mask, 0, 1000, 1000);
> + if ((reg & mask) == mask)
> + err = -ETIMEDOUT;
> +out:
> + return err;
> +}
> +
> /**
> * ufshcd_issue_tm_cmd - issues task management commands to controller
> * @hba: per adapter instance
> - * @lrbp: pointer to local reference block
> + * @lun_id: LUN ID to which TM command is sent
> + * @task_id: task ID to which the TM command is applicable
> + * @tm_function: task management function opcode
> + * @tm_response: task management service response return value
> *
> - * Returns SUCCESS/FAILED
> + * Returns non-zero value on error, zero on success.
> */
> -static int
> -ufshcd_issue_tm_cmd(struct ufs_hba *hba,
> - struct ufshcd_lrb *lrbp,
> - u8 tm_function)
> +static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
> + u8 tm_function, u8 *tm_response)
> {
> struct utp_task_req_desc *task_req_descp;
> struct utp_upiu_task_req *task_req_upiup;
> struct Scsi_Host *host;
> unsigned long flags;
> - int free_slot = 0;
> + int free_slot;
> int err;
> + int task_tag;
>
> host = hba->host;
>
> - spin_lock_irqsave(host->host_lock, flags);
> -
> - /* If task management queue is full */
> - free_slot = ufshcd_get_tm_free_slot(hba);
> - if (free_slot >= hba->nutmrs) {
> - spin_unlock_irqrestore(host->host_lock, flags);
> - dev_err(hba->dev, "Task management queue full\n");
> - err = FAILED;
> - goto out;
> - }
> + /*
> + * Get free slot, sleep if slots are unavailable.
> + * Even though we use wait_event() which sleeps indefinitely,
> + * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
> + */
> + wait_event(hba->tm_tag_wq, ufshcd_get_tm_free_slot(hba, &free_slot));
>
> + spin_lock_irqsave(host->host_lock, flags);
> task_req_descp = hba->utmrdl_base_addr;
> task_req_descp += free_slot;
>
> @@ -2391,18 +2436,15 @@ ufshcd_issue_tm_cmd(struct ufs_hba *hba,
> /* Configure task request UPIU */
> task_req_upiup =
> (struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
> + task_tag = hba->nutrs + free_slot;
Possible, did you intend 'hba->nutmrs', not 'hba->nutrs'?
I think it's safer with hba->nutmrs if we can't sure that NUTRS is larger than
NUTMRS.
> task_req_upiup->header.dword_0 =
> UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
> - lrbp->lun, lrbp->task_tag);
> + lun_id, task_tag);
> task_req_upiup->header.dword_1 =
> UPIU_HEADER_DWORD(0, tm_function, 0, 0);
>
> - task_req_upiup->input_param1 = lrbp->lun;
> - task_req_upiup->input_param1 =
> - cpu_to_be32(task_req_upiup->input_param1);
> - task_req_upiup->input_param2 = lrbp->task_tag;
> - task_req_upiup->input_param2 =
> - cpu_to_be32(task_req_upiup->input_param2);
> + task_req_upiup->input_param1 = cpu_to_be32(lun_id);
> + task_req_upiup->input_param2 = cpu_to_be32(task_id);
>
> /* send command to the controller */
> __set_bit(free_slot, &hba->outstanding_tasks);
> @@ -2411,20 +2453,24 @@ ufshcd_issue_tm_cmd(struct ufs_hba *hba,
> spin_unlock_irqrestore(host->host_lock, flags);
>
> /* wait until the task management command is completed */
> - err =
> - wait_event_interruptible_timeout(hba->ufshcd_tm_wait_queue,
> - (test_bit(free_slot,
> - &hba->tm_condition) != 0),
> - 60 * HZ);
> + err = wait_event_timeout(hba->tm_wq,
> + test_bit(free_slot, &hba->tm_condition),
> + msecs_to_jiffies(TM_CMD_TIMEOUT));
> if (!err) {
> - dev_err(hba->dev,
> - "Task management command timed-out\n");
> - err = FAILED;
> - goto out;
> + dev_err(hba->dev, "%s: task management cmd 0x%.2x timed-out\n",
> + __func__, tm_function);
> + if (ufshcd_clear_tm_cmd(hba, free_slot))
> + dev_WARN(hba->dev, "%s: unable clear tm cmd (slot %d)
> after timeout\n",
> + __func__, free_slot);
> + err = -ETIMEDOUT;
> + } else {
> + err = ufshcd_task_req_compl(hba, free_slot, tm_response);
> }
> +
> clear_bit(free_slot, &hba->tm_condition);
> - err = ufshcd_task_req_compl(hba, free_slot);
> -out:
> + ufshcd_put_tm_slot(hba, free_slot);
> + wake_up(&hba->tm_tag_wq);
> +
> return err;
> }
>
> @@ -2441,14 +2487,22 @@ static int ufshcd_device_reset(struct scsi_cmnd *cmd)
> unsigned int tag;
> u32 pos;
> int err;
> + u8 resp;
> + struct ufshcd_lrb *lrbp;
>
> host = cmd->device->host;
> hba = shost_priv(host);
> tag = cmd->request->tag;
>
> - err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_LOGICAL_RESET);
> - if (err == FAILED)
> + lrbp = &hba->lrb[tag];
> + err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
Argument 2nd, 3rd can be replaced by lrbp.
Then, we can reduce the number of argument.
Thanks,
Seungwon Jeon
> + UFS_LOGICAL_RESET, &resp);
> + if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
> + err = FAILED;
> goto out;
> + } else {
> + err = SUCCESS;
> + }
>
> for (pos = 0; pos < hba->nutrs; pos++) {
> if (test_bit(pos, &hba->outstanding_reqs) &&
> @@ -2505,6 +2559,8 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
> unsigned long flags;
> unsigned int tag;
> int err;
> + u8 resp;
> + struct ufshcd_lrb *lrbp;
>
> host = cmd->device->host;
> hba = shost_priv(host);
> @@ -2520,9 +2576,15 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
> }
> spin_unlock_irqrestore(host->host_lock, flags);
>
> - err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_ABORT_TASK);
> - if (err == FAILED)
> + lrbp = &hba->lrb[tag];
> + err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
> + UFS_ABORT_TASK, &resp);
> + if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
> + err = FAILED;
> goto out;
> + } else {
> + err = SUCCESS;
> + }
>
> scsi_dma_unmap(cmd);
>
> @@ -2744,7 +2806,8 @@ int ufshcd_init(struct device *dev, struct ufs_hba
> **hba_handle,
> host->max_cmd_len = MAX_CDB_SIZE;
>
> /* Initailize wait queue for task management */
> - init_waitqueue_head(&hba->ufshcd_tm_wait_queue);
> + init_waitqueue_head(&hba->tm_wq);
> + init_waitqueue_head(&hba->tm_tag_wq);
>
> /* Initialize work queues */
> INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 6c9bd35..5d4542c 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -174,8 +174,10 @@ struct ufs_dev_cmd {
> * @irq: Irq number of the controller
> * @active_uic_cmd: handle of active UIC command
> * @uic_cmd_mutex: mutex for uic command
> - * @ufshcd_tm_wait_queue: wait queue for task management
> + * @tm_wq: wait queue for task management
> + * @tm_tag_wq: wait queue for free task management slots
> * @tm_condition: condition variable for task management
> + * @tm_slots_in_use: bit map of task management request slots in use
> * @ufshcd_state: UFSHCD states
> * @intr_mask: Interrupt Mask Bits
> * @ee_ctrl_mask: Exception event control mask
> @@ -216,8 +218,10 @@ struct ufs_hba {
> struct uic_command *active_uic_cmd;
> struct mutex uic_cmd_mutex;
>
> - wait_queue_head_t ufshcd_tm_wait_queue;
> + wait_queue_head_t tm_wq;
> + wait_queue_head_t tm_tag_wq;
> unsigned long tm_condition;
> + unsigned long tm_slots_in_use;
>
> u32 ufshcd_state;
> u32 intr_mask;
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation.
>
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