Currently, sending Task Management (TM) command to the card might
be broken in some scenarios as listed below:
- 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.
- 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.
- 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.
- While preparing the TM command descriptor the tag used should be the
free slot of TM command and not the task tag of the command which
the TM command is trying to manage.
Fix: Use free slot tag instead of task tag of SCSI command
- 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 <sthumma@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 174 +++++++++++++++++++++++++++++----------------
drivers/scsi/ufs/ufshcd.h | 6 +-
2 files changed, 117 insertions(+), 63 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index aa1f11e..7d043f4 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 */
+
#define SCSI_CMD_QUEUE_SIZE (hba->nutrs - 1)
/* Reserved tag for internal commands */
#define INTERNAL_CMD_TAG (hba->nutrs - 1)
@@ -188,13 +191,32 @@ 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;
+
+ do {
+ tag = find_first_zero_bit(
+ &hba->outstanding_tasks, hba->nutmrs);
+ if (tag >= hba->nutmrs)
+ return false;
+ } while (test_and_set_bit_lock(tag, &hba->outstanding_tasks));
+
+ if (free_slot)
+ *free_slot = tag;
+
+ return true;
+}
+
+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->outstanding_tasks);
}
/**
@@ -1745,10 +1767,11 @@ 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;
@@ -1758,9 +1781,6 @@ static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index)
spin_lock_irqsave(hba->host->host_lock, flags);
- /* Clear completed tasks from outstanding_tasks */
- __clear_bit(index, &hba->outstanding_tasks);
-
task_req_descp = hba->utmrdl_base_addr;
ocs_value = ufshcd_get_tmr_ocs(&task_req_descp[index]);
@@ -1769,19 +1789,15 @@ 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;
}
/**
@@ -2258,7 +2274,7 @@ 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);
}
/**
@@ -2308,17 +2324,42 @@ 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;
@@ -2329,17 +2370,10 @@ ufshcd_issue_tm_cmd(struct ufs_hba *hba,
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 */
+ 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;
@@ -2353,38 +2387,39 @@ ufshcd_issue_tm_cmd(struct ufs_hba *hba,
(struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
task_req_upiup->header.dword_0 =
UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
- lrbp->lun, lrbp->task_tag);
+ lun_id, free_slot);
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);
+ /*
+ * outstanding_tasks variable is already updated with corresponding
+ * bit while acquiring free slot. Ring doorbell here.
+ */
ufshcd_writel(hba, 1 << free_slot, 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,
- (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;
}
@@ -2401,14 +2436,22 @@ 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,
+ UFS_LOGICAL_RESET, &resp);
+ if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
+ err = FAILED;
goto out;
+ } else {
+ err = SUCCESS;
+ }
for (pos = 0; pos < SCSI_CMD_QUEUE_SIZE; pos++) {
if (test_bit(pos, &hba->outstanding_reqs) &&
@@ -2468,6 +2511,8 @@ 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);
@@ -2483,9 +2528,15 @@ 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);
@@ -2714,7 +2765,8 @@ 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 682c285..8ca08fe 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -172,7 +172,8 @@ struct ufs_internal_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
* @ufshcd_state: UFSHCD states
* @intr_mask: Interrupt Mask Bits
@@ -213,7 +214,8 @@ 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;
u32 ufshcd_state;
--
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