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Subject[PATCH 4/4] [SCSI] ufshcd: SCSI error handling
Date
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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