Commit e8e7f271 authored by Sujit Reddy Thumma's avatar Sujit Reddy Thumma Committed by Christoph Hellwig

scsi: ufs: Improve UFS fatal error handling

Error handling in UFS driver is broken and resets the host controller
for fatal errors without re-initialization. Correct the fatal error
handling sequence according to UFS Host Controller Interface (HCI)
v1.1 specification.

o Processed requests which are completed w/wo error are reported to
  SCSI layer and any pending commands that are not started are aborted
  in the controller and re-queued into scsi mid-layer queue.

o Upon determining fatal error condition the host controller may hang
  forever until a reset is applied. Block SCSI layer for sending new
  requests and apply reset in a separate error handling work.

o SCSI is informed about the expected Unit-Attention exception from the
  device for the immediate command after a reset so that the SCSI layer
  take necessary steps to establish communication with the device.
Signed-off-by: default avatarSujit Reddy Thumma <sthumma@codeaurora.org>
Reviewed-by: default avatarYaniv Gardi <ygardi@codeaurora.org>
Tested-by: default avatarDolev Raviv <draviv@codeaurora.org>
Acked-by: default avatarVinayak Holikatti <vinholikatti@gmail.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 3441da7d
......@@ -84,6 +84,14 @@ enum {
UFSHCD_EH_IN_PROGRESS = (1 << 0),
};
/* UFSHCD UIC layer error flags */
enum {
UFSHCD_UIC_DL_PA_INIT_ERROR = (1 << 0), /* Data link layer error */
UFSHCD_UIC_NL_ERROR = (1 << 1), /* Network layer error */
UFSHCD_UIC_TL_ERROR = (1 << 2), /* Transport Layer error */
UFSHCD_UIC_DME_ERROR = (1 << 3), /* DME error */
};
/* Interrupt configuration options */
enum {
UFSHCD_INT_DISABLE,
......@@ -100,6 +108,8 @@ enum {
static void ufshcd_tmc_handler(struct ufs_hba *hba);
static void ufshcd_async_scan(void *data, async_cookie_t cookie);
static int ufshcd_reset_and_restore(struct ufs_hba *hba);
static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
/*
* ufshcd_wait_for_register - wait for register value to change
......@@ -1735,9 +1745,6 @@ static int ufshcd_make_hba_operational(struct ufs_hba *hba)
goto out;
}
if (hba->ufshcd_state == UFSHCD_STATE_RESET)
scsi_unblock_requests(hba->host);
out:
return err;
}
......@@ -1862,66 +1869,6 @@ static int ufshcd_verify_dev_init(struct ufs_hba *hba)
return err;
}
/**
* ufshcd_do_reset - reset the host controller
* @hba: per adapter instance
*
* Returns SUCCESS/FAILED
*/
static int ufshcd_do_reset(struct ufs_hba *hba)
{
struct ufshcd_lrb *lrbp;
unsigned long flags;
int tag;
/* block commands from midlayer */
scsi_block_requests(hba->host);
spin_lock_irqsave(hba->host->host_lock, flags);
hba->ufshcd_state = UFSHCD_STATE_RESET;
/* send controller to reset state */
ufshcd_hba_stop(hba);
spin_unlock_irqrestore(hba->host->host_lock, flags);
/* abort outstanding commands */
for (tag = 0; tag < hba->nutrs; tag++) {
if (test_bit(tag, &hba->outstanding_reqs)) {
lrbp = &hba->lrb[tag];
if (lrbp->cmd) {
scsi_dma_unmap(lrbp->cmd);
lrbp->cmd->result = DID_RESET << 16;
lrbp->cmd->scsi_done(lrbp->cmd);
lrbp->cmd = NULL;
clear_bit_unlock(tag, &hba->lrb_in_use);
}
}
}
/* complete device management command */
if (hba->dev_cmd.complete)
complete(hba->dev_cmd.complete);
/* clear outstanding request/task bit maps */
hba->outstanding_reqs = 0;
hba->outstanding_tasks = 0;
/* Host controller enable */
if (ufshcd_hba_enable(hba)) {
dev_err(hba->dev,
"Reset: Controller initialization failed\n");
return FAILED;
}
if (ufshcd_link_startup(hba)) {
dev_err(hba->dev,
"Reset: Link start-up failed\n");
return FAILED;
}
return SUCCESS;
}
/**
* ufshcd_slave_alloc - handle initial SCSI device configurations
* @sdev: pointer to SCSI device
......@@ -1939,6 +1886,9 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
sdev->use_10_for_ms = 1;
scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
/* allow SCSI layer to restart the device in case of errors */
sdev->allow_restart = 1;
/*
* Inform SCSI Midlayer that the LUN queue depth is same as the
* controller queue depth. If a LUN queue depth is less than the
......@@ -2134,6 +2084,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
case OCS_ABORTED:
result |= DID_ABORT << 16;
break;
case OCS_INVALID_COMMAND_STATUS:
result |= DID_REQUEUE << 16;
break;
case OCS_INVALID_CMD_TABLE_ATTR:
case OCS_INVALID_PRDT_ATTR:
case OCS_MISMATCH_DATA_BUF_SIZE:
......@@ -2451,45 +2404,145 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
}
/**
* ufshcd_fatal_err_handler - handle fatal errors
* @hba: per adapter instance
* ufshcd_err_handler - handle UFS errors that require s/w attention
* @work: pointer to work structure
*/
static void ufshcd_fatal_err_handler(struct work_struct *work)
static void ufshcd_err_handler(struct work_struct *work)
{
struct ufs_hba *hba;
hba = container_of(work, struct ufs_hba, feh_workq);
unsigned long flags;
u32 err_xfer = 0;
u32 err_tm = 0;
int err = 0;
int tag;
hba = container_of(work, struct ufs_hba, eh_work);
pm_runtime_get_sync(hba->dev);
/* check if reset is already in progress */
if (hba->ufshcd_state != UFSHCD_STATE_RESET)
ufshcd_do_reset(hba);
spin_lock_irqsave(hba->host->host_lock, flags);
if (hba->ufshcd_state == UFSHCD_STATE_RESET) {
spin_unlock_irqrestore(hba->host->host_lock, flags);
goto out;
}
hba->ufshcd_state = UFSHCD_STATE_RESET;
ufshcd_set_eh_in_progress(hba);
/* Complete requests that have door-bell cleared by h/w */
ufshcd_transfer_req_compl(hba);
ufshcd_tmc_handler(hba);
spin_unlock_irqrestore(hba->host->host_lock, flags);
/* Clear pending transfer requests */
for_each_set_bit(tag, &hba->outstanding_reqs, hba->nutrs)
if (ufshcd_clear_cmd(hba, tag))
err_xfer |= 1 << tag;
/* Clear pending task management requests */
for_each_set_bit(tag, &hba->outstanding_tasks, hba->nutmrs)
if (ufshcd_clear_tm_cmd(hba, tag))
err_tm |= 1 << tag;
/* Complete the requests that are cleared by s/w */
spin_lock_irqsave(hba->host->host_lock, flags);
ufshcd_transfer_req_compl(hba);
ufshcd_tmc_handler(hba);
spin_unlock_irqrestore(hba->host->host_lock, flags);
/* Fatal errors need reset */
if (err_xfer || err_tm || (hba->saved_err & INT_FATAL_ERRORS) ||
((hba->saved_err & UIC_ERROR) &&
(hba->saved_uic_err & UFSHCD_UIC_DL_PA_INIT_ERROR))) {
err = ufshcd_reset_and_restore(hba);
if (err) {
dev_err(hba->dev, "%s: reset and restore failed\n",
__func__);
hba->ufshcd_state = UFSHCD_STATE_ERROR;
}
/*
* Inform scsi mid-layer that we did reset and allow to handle
* Unit Attention properly.
*/
scsi_report_bus_reset(hba->host, 0);
hba->saved_err = 0;
hba->saved_uic_err = 0;
}
ufshcd_clear_eh_in_progress(hba);
out:
scsi_unblock_requests(hba->host);
pm_runtime_put_sync(hba->dev);
}
/**
* ufshcd_err_handler - Check for fatal errors
* @work: pointer to a work queue structure
* ufshcd_update_uic_error - check and set fatal UIC error flags.
* @hba: per-adapter instance
*/
static void ufshcd_err_handler(struct ufs_hba *hba)
static void ufshcd_update_uic_error(struct ufs_hba *hba)
{
u32 reg;
/* PA_INIT_ERROR is fatal and needs UIC reset */
reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
hba->uic_error |= UFSHCD_UIC_DL_PA_INIT_ERROR;
/* UIC NL/TL/DME errors needs software retry */
reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_NETWORK_LAYER);
if (reg)
hba->uic_error |= UFSHCD_UIC_NL_ERROR;
reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_TRANSPORT_LAYER);
if (reg)
hba->uic_error |= UFSHCD_UIC_TL_ERROR;
reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DME);
if (reg)
hba->uic_error |= UFSHCD_UIC_DME_ERROR;
dev_dbg(hba->dev, "%s: UIC error flags = 0x%08x\n",
__func__, hba->uic_error);
}
/**
* ufshcd_check_errors - Check for errors that need s/w attention
* @hba: per-adapter instance
*/
static void ufshcd_check_errors(struct ufs_hba *hba)
{
bool queue_eh_work = false;
if (hba->errors & INT_FATAL_ERRORS)
goto fatal_eh;
queue_eh_work = true;
if (hba->errors & UIC_ERROR) {
reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
goto fatal_eh;
hba->uic_error = 0;
ufshcd_update_uic_error(hba);
if (hba->uic_error)
queue_eh_work = true;
}
return;
fatal_eh:
/* handle fatal errors only when link is functional */
if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) {
/* block commands at driver layer until error is handled */
hba->ufshcd_state = UFSHCD_STATE_ERROR;
schedule_work(&hba->feh_workq);
if (queue_eh_work) {
/* handle fatal errors only when link is functional */
if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) {
/* block commands from scsi mid-layer */
scsi_block_requests(hba->host);
/* transfer error masks to sticky bits */
hba->saved_err |= hba->errors;
hba->saved_uic_err |= hba->uic_error;
hba->ufshcd_state = UFSHCD_STATE_ERROR;
schedule_work(&hba->eh_work);
}
}
/*
* if (!queue_eh_work) -
* Other errors are either non-fatal where host recovers
* itself without s/w intervention or errors that will be
* handled by the SCSI core layer.
*/
}
/**
......@@ -2514,7 +2567,7 @@ static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
{
hba->errors = UFSHCD_ERROR_MASK & intr_status;
if (hba->errors)
ufshcd_err_handler(hba);
ufshcd_check_errors(hba);
if (intr_status & UFSHCD_UIC_MASK)
ufshcd_uic_cmd_compl(hba, intr_status);
......@@ -2889,12 +2942,12 @@ static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd)
*/
do {
spin_lock_irqsave(hba->host->host_lock, flags);
if (!(work_pending(&hba->feh_workq) ||
if (!(work_pending(&hba->eh_work) ||
hba->ufshcd_state == UFSHCD_STATE_RESET))
break;
spin_unlock_irqrestore(hba->host->host_lock, flags);
dev_dbg(hba->dev, "%s: reset in progress\n", __func__);
flush_work(&hba->feh_workq);
flush_work(&hba->eh_work);
} while (1);
hba->ufshcd_state = UFSHCD_STATE_RESET;
......@@ -3130,7 +3183,7 @@ int ufshcd_init(struct device *dev, struct ufs_hba **hba_handle,
init_waitqueue_head(&hba->tm_tag_wq);
/* Initialize work queues */
INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);
INIT_WORK(&hba->eh_work, ufshcd_err_handler);
INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);
/* Initialize UIC command mutex */
......
......@@ -183,9 +183,12 @@ struct ufs_dev_cmd {
* @eh_flags: Error handling flags
* @intr_mask: Interrupt Mask Bits
* @ee_ctrl_mask: Exception event control mask
* @feh_workq: Work queue for fatal controller error handling
* @eh_work: Worker to handle UFS errors that require s/w attention
* @eeh_work: Worker to handle exception events
* @errors: HBA errors
* @uic_error: UFS interconnect layer error status
* @saved_err: sticky error mask
* @saved_uic_err: sticky UIC error mask
* @dev_cmd: ufs device management command information
* @auto_bkops_enabled: to track whether bkops is enabled in device
*/
......@@ -233,11 +236,14 @@ struct ufs_hba {
u16 ee_ctrl_mask;
/* Work Queues */
struct work_struct feh_workq;
struct work_struct eh_work;
struct work_struct eeh_work;
/* HBA Errors */
u32 errors;
u32 uic_error;
u32 saved_err;
u32 saved_uic_err;
/* Device management request data */
struct ufs_dev_cmd dev_cmd;
......
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