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SubjectRe: [PATCH 4/4] [SCSI] ufshcd: SCSI error handling
From
Hi,

In function:
+static int ufshcd_abort(struct scsi_cmnd *cmd)
+{...
- int err;
+ int err = -1;
...
+ spin_lock_irqsave(host->host_lock, flags);
+ pos = (1 << tag);
+
+ /* check if command is still pending */
+ if (!(hba->outstanding_reqs & pos)) {
- err = -1;
- spin_unlock_irqrestore(host->host_lock, flags);
+ goto out;
+ }
...
...
+out:
+ spin_unlock_irqrestore(host->host_lock, flags);
+ return err;
+}
this will also take of matching out
spin_lock_irqsave()->spin_unlock_irqrestore() before exiting the
function.
In function:
+static int
+ufshcd_issue_tm_cmd(struct ufs_hba *hba,
+ struct ufshcd_lrb *lrbp,
+ u8 tm_function)
...
+ spin_lock_irqsave(host->host_lock, flags);
+
+ /* If task management queue is full */
+ if (!ufshcd_is_tmq_full(hba->outstanding_tasks)) {
+ dev_err(&hba->pdev->dev, "Task management queue full\n");
I think this will map to a Buffered printf - which can potentially
result in BUG: Schedule while atomic()...
+ spin_unlock_irqrestore(host->host_lock, flags);
+ return err;
+ }
So, it could be like this:
+ spin_lock_irqsave(host->host_lock, flags);
+
+ /* If task management queue is full */
+ if (!ufshcd_is_tmq_full(hba->outstanding_tasks)) {
+ spin_unlock_irqrestore(host->host_lock, flags);
+ dev_err(&hba->pdev->dev, "Task management queue full\n");
+ return err;
+ }
Thanks & Regards,
Amit Sahrawat


On Thu, Feb 2, 2012 at 10:27 AM, Vinayak Holikatti
<vinholikatti@gmail.com> wrote:
> From: Santosh Yaraganavi <santoshsy@gmail.com>
>
> UFSHCD SCSI error handling includes following implementations,
>  - Abort task
>  - Device reset
>  - Host reset
>
> Signed-off-by: Santosh Yaraganavi <santoshsy@gmail.com>
> Signed-off-by: Vinayak Holikatti <vinholikatti@gmail.com>
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
> Reviewed-by: Saugata Das <saugata.das@linaro.org>
> Reviewed-by: Vishak G <vishak.g@samsung.com>
> Reviewed-by: Girish K S <girish.shivananjappa@linaro.org>
> ---
>  drivers/scsi/ufs/ufshcd.c |  312 +++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 312 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 1bfae84..7589dd1 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -76,6 +76,8 @@
>  #define NULL 0
>  #endif  /* NULL */
>
> +#define UFSHCD_MAX_TM_SLOTS    0xFF
> +
>  #define BYTES_TO_DWORDS(p)     (p >> 2)
>  #define UFSHCD_MMIO_BASE       (hba->mmio_base)
>
> @@ -83,6 +85,7 @@ enum {
>        UFSHCD_MAX_CHANNEL      = 1,
>        UFSHCD_MAX_ID           = 1,
>        UFSHCD_MAX_LUNS         = 8,
> +       UFSHCD_MAX_TM_CMDS      = 8,
>        UFSHCD_CMD_PER_LUN      = 16,
>        UFSHCD_CAN_QUEUE        = 32,
>        BYTES_128               = 128,
> @@ -149,6 +152,7 @@ struct uic_command {
>  * @host: Scsi_Host instance of the driver
>  * @pdev: PCI device handle
>  * @lrb: local reference block
> + * @outstanding_tasks: Bits representing outstanding task requests
>  * @outstanding_reqs: Bits representing outstanding transfer requests
>  * @capabilities: UFS Controller Capabilities
>  * @nutrs: Transfer Request Queue depth supported by controller
> @@ -192,6 +196,7 @@ struct ufs_hba {
>
>        struct ufshcd_lrb *lrb;
>
> +       u32 outstanding_tasks;
>        u32 outstanding_reqs;
>
>        u32 capabilities;
> @@ -200,6 +205,8 @@ struct ufs_hba {
>        u32 ufs_version;
>
>        struct uic_command active_uic_cmd;
> +       wait_queue_head_t ufshcd_tm_wait_queue;
> +       u8 tm_condition[UFSHCD_MAX_TM_CMDS];
>
>        u32 ufshcd_state;
>        u32 int_enable_mask;
> @@ -278,6 +285,30 @@ static inline int ufshcd_get_tr_ocs(struct ufshcd_lrb *lrbp)
>  }
>
>  /**
> + * ufshcd_get_tmr_ocs - Get the UTMRD Overall Command Status
> + * @task_req_descp: pointer to utp_task_req_desc structure
> + *
> + * This function is used to get the OCS field from UTMRD
> + * Returns the OCS field in the UTMRD
> + */
> +static inline int
> +ufshcd_get_tmr_ocs(struct utp_task_req_desc *task_req_descp)
> +{
> +       return task_req_descp->header.dword_2 & MASK_OCS;
> +}
> +
> +/**
> + * ufshcd_is_tmq_full - checks if the task management slots are full
> + * @outstanding_tasks: contains the task management doorbell value
> + *
> + * Returns 1 if a free slot available, 0 if task slots are full
> + */
> +static inline int ufshcd_is_tmq_full(u32 outstanding_tasks)
> +{
> +       return (UFSHCD_MAX_TM_SLOTS == outstanding_tasks) ? 0 : 1;
> +}
> +
> +/**
>  * ufshcd_get_lists_status - Check UCRDY, UTRLRDY and UTMRLRDY
>  * @reg: Register value of host controller status
>  *
> @@ -1098,6 +1129,45 @@ 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
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index)
> +{
> +       struct utp_upiu_task_rsp *task_rsp_upiup;
> +       struct utp_task_req_desc *task_req_descp;
> +       unsigned long flags;
> +       int ocs_value;
> +       int task_response = -1;
> +
> +       spin_lock_irqsave(hba->host->host_lock, flags);
> +
> +       /* clear completed tasks from outstanding_tasks */
> +       hba->outstanding_tasks ^= index;
> +
> +       task_req_descp =
> +               (struct utp_task_req_desc *)hba->utmrdl_virt_addr_aligned;
> +       ocs_value = ufshcd_get_tmr_ocs(&task_req_descp[index]);
> +
> +       if (OCS_SUCCESS == ocs_value) {
> +
> +               task_rsp_upiup = (struct utp_upiu_task_rsp *)
> +                                task_req_descp[index].task_rsp_upiu;
> +               task_response = be32_to_cpu(task_rsp_upiup->header.dword_1);
> +               task_response = ((task_response & MASK_TASK_RESPONSE) >> 8);
> +
> +               /* clear task response */
> +               memset(task_rsp_upiup, 0, sizeof(struct utp_upiu_task_rsp));
> +       }
> +       spin_unlock_irqrestore(hba->host->host_lock, flags);
> +
> +       return task_response;
> +}
> +
> +/**
>  * ufshcd_scsi_cmd_status - Update SCSI command result based on scsi status
>  * @lrb: pointer to local reference block of completed command
>  * @scsi_status: SCSI command status
> @@ -1314,6 +1384,31 @@ fatal_eh:
>  }
>
>  /**
> + * ufshcd_tmc_handler - handle task management function completion
> + * @hba: per adapter instance
> + */
> +static void ufshcd_tmc_handler(struct ufs_hba *hba)
> +{
> +       u32 completed_reqs;
> +       u32 tm_doorbell;
> +       int i;
> +
> +       tm_doorbell = readl(hba->mmio_base + REG_UTP_TASK_REQ_DOOR_BELL);
> +       completed_reqs = tm_doorbell ^ hba->outstanding_tasks;
> +       for (i = 0; i < hba->nutmrs; i++) {
> +               if (completed_reqs & (1 << i)) {
> +
> +                       /*
> +                        * Change the default value 0xFF to 0 to indicate
> +                        * completion of respective task management command
> +                        */
> +                       hba->tm_condition[i] = 0;
> +                       wake_up_interruptible(&hba->ufshcd_tm_wait_queue);
> +               }
> +       }
> +}
> +
> +/**
>  * ufshcd_sl_intr - Interrupt service routine
>  * @hba: per adapter instance
>  * @intr_status: contains interrupts generated by the controller
> @@ -1327,6 +1422,9 @@ static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
>        if (intr_status & UIC_COMMAND_COMPL)
>                schedule_work(&hba->uic_workq);
>
> +       if (intr_status & UTP_TASK_REQ_COMPL)
> +               ufshcd_tmc_handler(hba);
> +
>        if (intr_status & UTP_TRANSFER_REQ_COMPL)
>                ufshcd_transfer_req_compl(hba);
>  }
> @@ -1362,6 +1460,209 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
>        return retval;
>  }
>
> +/**
> + * ufshcd_issue_tm_cmd - issues task management commands to controller
> + * @hba: per adapter instance
> + * @lrbp: pointer to local reference block
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int
> +ufshcd_issue_tm_cmd(struct ufs_hba *hba,
> +                   struct ufshcd_lrb *lrbp,
> +                   u8 tm_function)
> +{
> +       struct utp_task_req_desc *task_req_descp;
> +       struct utp_upiu_task_req *task_req_upiup;
> +       struct Scsi_Host *host;
> +       unsigned long flags;
> +       int i;
> +       int free_slot = 0;
> +       int err = -1;
> +
> +       host = hba->host;
> +
> +       spin_lock_irqsave(host->host_lock, flags);
> +
> +       /* If task management queue is full */
> +       if (!ufshcd_is_tmq_full(hba->outstanding_tasks)) {
> +               dev_err(&hba->pdev->dev, "Task management queue full\n");
> +               spin_unlock_irqrestore(host->host_lock, flags);
> +               return err;
> +       }
> +
> +       for (i = 0; i < hba->nutmrs; i++) {
> +               if (!(hba->outstanding_tasks & (1 << i))) {
> +                       free_slot = i;
> +                       break;
> +               }
> +       }
> +
> +       /* Configure task request descriptor */
> +       task_req_descp =
> +               (struct utp_task_req_desc *) hba->utmrdl_virt_addr_aligned;
> +       task_req_descp += free_slot;
> +
> +       memset(task_req_descp, 0, sizeof(struct utp_task_req_desc));
> +       task_req_descp->header.dword_0 = cpu_to_le32(UTP_REQ_DESC_INT_CMD);
> +       task_req_descp->header.dword_2 =
> +                       cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
> +
> +       /* Configure task request UPIU */
> +       task_req_upiup =
> +               (struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
> +       task_req_upiup->header.dword_0 =
> +               cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
> +                                             lrbp->lun, lrbp->task_tag));
> +       task_req_upiup->header.dword_1 =
> +       cpu_to_be32(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);
> +
> +       /* send command to the controller */
> +       hba->outstanding_tasks |= (1 << free_slot);
> +       writel((1 << free_slot),
> +              (UFSHCD_MMIO_BASE + REG_UTP_TASK_REQ_DOOR_BELL));
> +
> +       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,
> +                                        (hba->tm_condition[free_slot] != 0),
> +                                        60 * HZ);
> +       hba->tm_condition[free_slot] = 0xFF;
> +       if (!err) {
> +               dev_err(&hba->pdev->dev,
> +                       "Task management command timed-out\n");
> +               return err;
> +       }
> +       return ufshcd_task_req_compl(hba, free_slot);
> +}
> +
> +/**
> + * ufshcd_device_reset - reset device and abort all the pending commands
> + * @cmd: SCSI command pointer
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int ufshcd_device_reset(struct scsi_cmnd *cmd)
> +{
> +       struct Scsi_Host *host;
> +       struct ufs_hba *hba;
> +       unsigned long flags;
> +       int reset_lun;
> +       unsigned int tag;
> +       u32 i;
> +       u32 pos; /* pos: represents a bit in a register */
> +       int err = -1;
> +
> +       host = cmd->device->host;
> +       hba = (struct ufs_hba *)host->hostdata;
> +       tag = cmd->request->tag;
> +
> +       if ((hba->lrb[tag].cmd == cmd))
> +               reset_lun = hba->lrb[tag].lun;
> +       else
> +               goto out;
> +
> +       err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_LOGICAL_RESET);
> +       if (!err) {
> +               spin_lock_irqsave(host->host_lock, flags);
> +               for (i = 0; i < hba->nutrs; i++) {
> +                       pos = (1 << i);
> +                       if ((pos & hba->outstanding_reqs) &&
> +                           (reset_lun == hba->lrb[i].lun)) {
> +
> +                               /* clear the respective UTRLCLR bit */
> +                               writel(~pos, (UFSHCD_MMIO_BASE +
> +                               REG_UTP_TRANSFER_REQ_LIST_CLEAR));
> +
> +                               hba->outstanding_reqs ^= pos;
> +
> +                               if (hba->lrb[i].cmd) {
> +                                       scsi_dma_unmap(hba->lrb[i].cmd);
> +                                       hba->lrb[i].cmd->result =
> +                                                       DID_ABORT << 16;
> +                                       hba->lrb[i].cmd->scsi_done(cmd);
> +                                       hba->lrb[i].cmd = NULL;
> +                               }
> +                       }
> +               } /* end of for */
> +               spin_unlock_irqrestore(host->host_lock, flags);
> +       } /*end of if */
> +out:
> +       return err;
> +}
> +
> +/**
> + * ufshcd_host_reset - Main reset function registered with scsi layer
> + * @cmd: SCSI command pointer
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int ufshcd_host_reset(struct scsi_cmnd *cmd)
> +{
> +       struct ufs_hba *hba = NULL;
> +
> +       hba = (struct ufs_hba *) &cmd->device->host->hostdata[0];
> +
> +       if (UFSHCD_STATE_RESET == hba->ufshcd_state)
> +               return 0;
> +
> +       return ufshcd_do_reset(hba) ? -1 : 0;
> +}
> +
> +/**
> + * ufshcd_abort - abort a specific command
> + * @cmd: SCSI command pointer
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int ufshcd_abort(struct scsi_cmnd *cmd)
> +{
> +       struct Scsi_Host *host;
> +       struct ufs_hba *hba;
> +       unsigned long flags;
> +       unsigned int tag;
> +       unsigned int pos;
> +       int err;
> +
> +       host = cmd->device->host;
> +       hba = (struct ufs_hba *) host->hostdata;
> +       tag = cmd->request->tag;
> +
> +       spin_lock_irqsave(host->host_lock, flags);
> +       pos = (1 << tag);
> +
> +       /* check if command is still pending */
> +       if (!(hba->outstanding_reqs & pos)) {
> +               err = -1;
> +               spin_unlock_irqrestore(host->host_lock, flags);
> +               goto out;
> +       }
> +
> +       err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_ABORT_TASK);
> +       if (!err) {
> +               spin_lock_irqsave(host->host_lock, flags);
> +               scsi_dma_unmap(cmd);
> +
> +               /* clear the respective UTRLCLR bit */
> +               writel(~pos,
> +                       (UFSHCD_MMIO_BASE +
> +                        REG_UTP_TRANSFER_REQ_LIST_CLEAR));
> +               hba->outstanding_reqs &= ~pos;
> +               hba->lrb[tag].cmd = NULL;
> +               spin_unlock_irqrestore(host->host_lock, flags);
> +       }
> +out:
> +       return err;
> +}
> +
>  static struct scsi_host_template ufshcd_driver_template = {
>        .module                 = THIS_MODULE,
>        .name                   = UFSHCD,
> @@ -1369,6 +1670,9 @@ static struct scsi_host_template ufshcd_driver_template = {
>        .queuecommand           = ufshcd_queuecommand,
>        .slave_alloc            = ufshcd_slave_alloc,
>        .slave_destroy          = ufshcd_slave_destroy,
> +       .eh_abort_handler       = ufshcd_abort,
> +       .eh_device_reset_handler = ufshcd_device_reset,
> +       .eh_host_reset_handler  = ufshcd_host_reset,
>        .this_id                = -1,
>        .sg_tablesize           = SG_ALL,
>        .cmd_per_lun            = UFSHCD_CMD_PER_LUN,
> @@ -1483,6 +1787,7 @@ ufshcd_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>        struct Scsi_Host *host;
>        struct ufs_hba *hba;
>        int ufs_hba_len;
> +       int index;
>        int err;
>
>        ufs_hba_len = sizeof(struct ufs_hba);
> @@ -1547,6 +1852,13 @@ ufshcd_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>        host->unique_id = host->host_no;
>        host->max_cmd_len = MAX_CDB_SIZE;
>
> +       /* Initailze wait queue for task management */
> +       init_waitqueue_head(&hba->ufshcd_tm_wait_queue);
> +
> +       /* Initially assign invalid value to tm_condition */
> +       for (index = 0; index < hba->nutmrs; index++)
> +               hba->tm_condition[index] = 0xFF;
> +
>        /* Initialize work queues */
>        INIT_WORK(&hba->uic_workq, ufshcd_uic_cc_handler);
>        INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);
> --
> 1.7.5.4
>
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