From e293313262d3c780632f7888878c982fa0a9bf7e Mon Sep 17 00:00:00 2001 From: Sujit Reddy Thumma Date: Mon, 26 May 2014 10:59:12 +0530 Subject: [PATCH] scsi: ufs: Fix broken task management command implementation 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 Reviewed-by: Yaniv Gardi Tested-by: Dolev Raviv Acked-by: Vinayak Holikatti Signed-off-by: Christoph Hellwig --- drivers/scsi/ufs/ufshcd.c | 169 ++++++++++++++++++++++++++------------ drivers/scsi/ufs/ufshcd.h | 8 +- 2 files changed, 122 insertions(+), 55 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index d476cc34453c..c3acadc2cf0a 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -55,6 +55,9 @@ /* 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 @@ -182,13 +185,35 @@ 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) { - return find_first_zero_bit(&hba->outstanding_tasks, hba->nutmrs); + 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) +{ + clear_bit_unlock(slot, &hba->tm_slots_in_use); } /** @@ -1912,10 +1937,11 @@ 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; @@ -1936,19 +1962,15 @@ 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; } /** @@ -2447,7 +2469,7 @@ 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); } /** @@ -2497,38 +2519,58 @@ 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 mask = 1 << tag; + unsigned long flags; + + if (!test_bit(tag, &hba->outstanding_tasks)) + 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 */ + err = ufshcd_wait_for_register(hba, + REG_UTP_TASK_REQ_DOOR_BELL, + mask, 0, 1000, 1000); +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; @@ -2540,14 +2582,15 @@ 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; 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 = cpu_to_be32(lrbp->lun); - task_req_upiup->input_param2 = cpu_to_be32(lrbp->task_tag); + 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); @@ -2556,20 +2599,24 @@ 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; } @@ -2586,14 +2633,21 @@ static int ufshcd_device_reset(struct scsi_cmnd *cmd) unsigned int tag; u32 pos; int err; + u8 resp = 0xF; + 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, 0, 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) && @@ -2650,6 +2704,8 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) unsigned long flags; unsigned int tag; int err; + u8 resp = 0xF; + struct ufshcd_lrb *lrbp; host = cmd->device->host; hba = shost_priv(host); @@ -2665,9 +2721,15 @@ 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); @@ -2890,7 +2952,8 @@ 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 767ee9ebfaf1..84d09d1ae881 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -174,7 +174,9 @@ 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_slots_in_use: bit map of task management request slots in use * @pwr_done: completion for power mode change * @tm_condition: condition variable for task management * @ufshcd_state: UFSHCD states @@ -217,8 +219,10 @@ 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; struct completion *pwr_done; -- 2.39.5