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 <sthumma@xxxxxxxxxxxxxx>
---
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;
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,
+ 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;
--
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