+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs
+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+ u32 val, unsigned long interval_us, unsigned long timeout_ms)
I feel like this function's role is to wait for clearing register (specially, doorbells).
If you really don't intend to apply other all register, I think it would better to change the
function name.
ex> ufshcd_wait_for_clear_doorbell or ufshcd_wait_for_clear_reg?
Although, this API is introduced in this patch and used only for
clearing the doorbell, I have intentionally made it generic to avoid
duplication of wait condition code in future (not just clearing but
also for setting a bit). For example, when we write to HCE.ENABLE we
wait for it turn to 1.
And if you like it, it could be more simple like below
static bool ufshcd_wait_for_clear_reg(struct ufs_hba *hba, u32 reg, u32 mask,
unsigned long interval_us,
unsigned int timeout_ms)
{
unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
Jiffies on 100Hz systems have minimum granularity of 10ms. So we really
wait for more 10ms even though the timeout_ms < 10ms.
Yes. Real timeout depends on system.
But normally actual wait will be maintained until 'ufshcd_readl' is done.
Timeout is valid for failure case. If we don't need to apply a strict timeout value, it's not bad.
Hmm.. make sense. Will take care in the next patchset.
/* wakeup within 50us of expiry */
const unsigned int expiry = 50;
while (ufshcd_readl(hba, reg) & mask) {
usleep_range(interval_us, interval_us + expiry);
if (time_after(jiffies, timeout)) {
if (ufshcd_readl(hba, reg) & mask)
return false;
I really want the caller to decide on what to do after the timeout.
This helps in error handling cases where we try to clear off the entire
door-bell register but only a few of the bits are cleared after timeout.
I don't know what we can do with the report of the partial success on clearing bit.
It's just failure case. Isn't enough with false/true?
The point is, if a bit can't be cleared it can be regarded as a
permanent failure (only for that request), otherwise, it can be
retried with the same tag value.
else
return true;
}
}
return true;
}
+{
+ u32 tmp;
+ ktime_t start;
+ unsigned long diff;
+
+ tmp = ufshcd_readl(hba, reg);
+
+ if ((val & mask) != val) {
+ dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+ __func__, val);
+ goto out;
+ }
+
+ start = ktime_get();
+ while ((tmp & mask) != val) {
+ /* wakeup within 50us of expiry */
+ usleep_range(interval_us, interval_us + 50);
+ tmp = ufshcd_readl(hba, reg);
+ diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+ if (diff > timeout_ms) {
+ tmp = ufshcd_readl(hba, reg);
+ break;
+ }
+ }
+out:
+ return tmp;
+}
+
..
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+ int err = 0;
+ unsigned long flags;
+ u32 reg;
+ u32 mask = 1 << tag;
+
+ /* clear outstanding transaction before retry */
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ ufshcd_utrl_clear(hba, tag);
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+ /*
+ * wait for for h/w to clear corresponding bit in door-bell.
+ * max. wait is 1 sec.
+ */
+ reg = ufshcd_wait_for_register(hba,
+ REG_UTP_TRANSFER_REQ_DOOR_BELL,
+ mask, 0, 1000, 1000);
4th argument should be (~mask) instead of '0', right?
True, but not really for this implementation. It breaks the check in
in wait_for_register -
if ((val & mask) != val)
dev_err(...);
Hmm, it seems complicated to use.
Ok. Is right the following about val as 4th argument?
- clear: val should be '0' regardless corresponding bit.
- set: val should be same with mask.
If the related comment is added, it will be helpful.
Thinking again it looks like it is complicated. How about changing
the check to -
val = val & mask; /* ignore the bits we don't intend to wait on */
while (ufshcd_readl() & mask != val) {
sleep
}
Usage will be ~mask for clearing the bits, mask for setting the bits
in the fourth argument.
Actually, mask value involves the corresponding bit to be cleared.
So, 4th argument may be unnecessary.
As I described above, the wait_for_register can also be used to
check if the value is set or not. In which case, we need 4th argument.
+ if ((reg & mask) == mask)
+ err = -ETIMEDOUT;
Also, checking the result can be involved in ufshcd_wait_for_register.
Any comment?
Sorry I missed this. But the point was the same. To make
wait_for_register() just to wait a definite time and not return any
error condition when the bits don't turn as expected.
+
+ return err;
+}
+
+/**
+ * ufshcd_dev_cmd_completion() - handles device management command responses
+ * @hba: per adapter instance
+ * @lrbp: pointer to local reference block
+ */
+static int
+ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+ int resp;
+ int err = 0;
+
+ resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+ switch (resp) {
+ case UPIU_TRANSACTION_NOP_IN:
+ if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
+ err = -EINVAL;
+ dev_err(hba->dev, "%s: unexpected response %x\n",
+ __func__, resp);
+ }
+ break;
+ case UPIU_TRANSACTION_REJECT_UPIU:
+ /* TODO: handle Reject UPIU Response */
+ err = -EPERM;
+ dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
+ __func__);
+ break;
+ default:
+ err = -EINVAL;
+ dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
+ __func__, resp);
+ break;
+ }
+
+ return err;
+}
+
+/**
+ * ufshcd_get_dev_cmd_tag - Get device management command tag
+ * @hba: per-adapter instance
+ * @tag: pointer to variable with available slot value
+ *
+ * Get a free slot and lock it until device management command
+ * completes.
+ *
+ * Returns false if free slot is unavailable for locking, else
+ * return true with tag value in @tag.
+ */
+static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
+{
+ int tag;
+ bool ret = false;
+ unsigned long tmp;
+
+ if (!tag_out)
+ goto out;
+
+ do {
+ tmp = ~hba->lrb_in_use;
+ tag = find_last_bit(&tmp, hba->nutrs);
+ if (tag >= hba->nutrs)
+ goto out;
+ } while (test_and_set_bit_lock(tag, &hba->lrb_in_use));
+
+ *tag_out = tag;
+ ret = true;
+out:
+ return ret;
+}
+
+static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
+{
+ clear_bit_unlock(tag, &hba->lrb_in_use);
+}
+
+/**
+ * ufshcd_exec_dev_cmd - API for sending device management requests
+ * @hba - UFS hba
+ * @cmd_type - specifies the type (NOP, Query...)
+ * @timeout - time in seconds
+ *
+ * NOTE: There is only one available tag for device management commands. Thus
+ * synchronisation is the responsibilty of the user.
+ */
+static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
+ enum dev_cmd_type cmd_type, int timeout)
+{
+ struct ufshcd_lrb *lrbp;
+ int err;
+ int tag;
+ struct completion wait;
+ unsigned long flags;
+
+ /*
+ * Get free slot, sleep if slots are unavailable.
+ * Even though we use wait_event() which sleeps indefinitely,
+ * the maximum wait time is bounded by SCSI request timeout.
+ */
+ wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+ init_completion(&wait);
+ lrbp = &hba->lrb[tag];
+ WARN_ON(lrbp->cmd);
+ err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
+ if (unlikely(err))
+ goto out_put_tag;
+
+ hba->dev_cmd.complete = &wait;
+
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ ufshcd_send_command(hba, tag);
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+ err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
+
<snip>
+ if (err == -ETIMEDOUT) {
+ if (!ufshcd_clear_cmd(hba, tag))
+ err = -EAGAIN;
+ } else if (!err) {
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ err = ufshcd_dev_cmd_completion(hba, lrbp);
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+ }
</snip>
I think sniped part can be involved in ufshcd_wait_for_dev_cmd.
How do you think about that?
Yes, it can be moved.
+
+out_put_tag:
+ ufshcd_put_dev_cmd_tag(hba, tag);
+ wake_up(&hba->dev_cmd.tag_wq);
+ return err;
+}
+
/**
* ufshcd_memory_alloc - allocate memory for host memory space data structures
* @hba: per adapter instance
@@ -774,8 +1075,8 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
- hba->lrb[i].ucd_cmd_ptr =
- (struct utp_upiu_cmd *)(cmd_descp + i);
+ hba->lrb[i].ucd_req_ptr =
+ (struct utp_upiu_req *)(cmd_descp + i);
hba->lrb[i].ucd_rsp_ptr =
(struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
hba->lrb[i].ucd_prdt_ptr =
@@ -961,6 +1262,38 @@ out:
}
/**
+ * ufshcd_validate_dev_connection() - Check device connection status
+ * @hba: per-adapter instance
+ *
+ * Send NOP OUT UPIU and wait for NOP IN response to check whether the
+ * device Transport Protocol (UTP) layer is ready after a reset.
+ * If the UTP layer at the device side is not initialized, it may
+ * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
+ * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
+ */
+static int ufshcd_validate_dev_connection(struct ufs_hba *hba)
I think ufshcd_verify_dev_init is close to standard description.
Okay.
+{
+ int err = 0;
+ int retries;
+
+ mutex_lock(&hba->dev_cmd.lock);
+ for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
+ err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
+ NOP_OUT_TIMEOUT);
+
+ if (!err || err == -ETIMEDOUT)
+ break;
+
+ dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+ }
+ mutex_unlock(&hba->dev_cmd.lock);
+
+ if (err)
+ dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
+ return err;
+}
+
+/**
* ufshcd_do_reset - reset the host controller
* @hba: per adapter instance
*
@@ -986,13 +1319,20 @@ static int ufshcd_do_reset(struct ufs_hba *hba)
for (tag = 0; tag < hba->nutrs; tag++) {
if (test_bit(tag, &hba->outstanding_reqs)) {
lrbp = &hba->lrb[tag];
- scsi_dma_unmap(lrbp->cmd);
- lrbp->cmd->result = DID_RESET << 16;
- lrbp->cmd->scsi_done(lrbp->cmd);
- lrbp->cmd = NULL;
+ 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);
+ }
I know above.
But there is no relation to this patch.
Can be it moved to scsi: ufs: Fix device and host reset methods?
Yes, but it is basically to avoid NULL pointer derefernce in case
someone picks this patch but not the other one.
}
}
+ /* 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;
@@ -1199,27 +1539,37 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
switch (ocs) {
case OCS_SUCCESS:
-
/* check if the returned transfer response is valid */
As replaced with new function, comment isn't valid.
Remove or "get the TR response transaction type" seems proper.
Okay.
- result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
- if (result) {
+ result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+ switch (result) {
+ case UPIU_TRANSACTION_RESPONSE:
+ /*
+ * get the response UPIU result to extract
+ * the SCSI command status
+ */
+ result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+ /*
+ * get the result based on SCSI status response
+ * to notify the SCSI midlayer of the command status
+ */
+ scsi_status = result & MASK_SCSI_STATUS;
+ result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+ break;
+ case UPIU_TRANSACTION_REJECT_UPIU:
+ /* TODO: handle Reject UPIU Response */
+ result = DID_ERROR << 16;
+ dev_err(hba->dev,
+ "Reject UPIU not fully implemented\n");
+ break;
+ default:
+ result = DID_ERROR << 16;
dev_err(hba->dev,
- "Invalid response = %x\n", result);
+ "Unexpected request response code = %x\n",
+ result);
break;
}
-
- /*
- * get the response UPIU result to extract
- * the SCSI command status
- */
- result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
-
- /*
- * get the result based on SCSI status response
- * to notify the SCSI midlayer of the command status
- */
- scsi_status = result & MASK_SCSI_STATUS;
- result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
break;
case OCS_ABORTED:
result |= DID_ABORT << 16;
@@ -1259,28 +1609,37 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
*/
static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
{
- struct ufshcd_lrb *lrb;
+ struct ufshcd_lrb *lrbp;
+ struct scsi_cmnd *cmd;
unsigned long completed_reqs;
u32 tr_doorbell;
int result;
int index;
+ bool int_aggr_reset = false;
- lrb = hba->lrb;
tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
for (index = 0; index < hba->nutrs; index++) {
if (test_bit(index, &completed_reqs)) {
-
- result = ufshcd_transfer_rsp_status(hba, &lrb[index]);
-
- if (lrb[index].cmd) {
- scsi_dma_unmap(lrb[index].cmd);
- lrb[index].cmd->result = result;
- lrb[index].cmd->scsi_done(lrb[index].cmd);
-
+ lrbp = &hba->lrb[index];
+ cmd = lrbp->cmd;
+ /* Don't reset counters for interrupt cmd */
+ int_aggr_reset |= !lrbp->intr_cmd;
+
+ if (cmd) {
+ result = ufshcd_transfer_rsp_status(hba, lrbp);
+ scsi_dma_unmap(cmd);
+ cmd->result = result;
/* Mark completed command as NULL in LRB */
- lrb[index].cmd = NULL;
+ lrbp->cmd = NULL;
+ clear_bit_unlock(index, &hba->lrb_in_use);
+ /* Do not touch lrbp after scsi done */
+ cmd->scsi_done(cmd);
+ } else if (lrbp->command_type ==
+ UTP_CMD_TYPE_DEV_MANAGE) {
+ if (hba->dev_cmd.complete)
+ complete(hba->dev_cmd.complete);
}
} /* end of if */
} /* end of for */
@@ -1288,8 +1647,12 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
/* clear corresponding bits of completed commands */
hba->outstanding_reqs ^= completed_reqs;
+ /* we might have free'd some tags above */
+ wake_up(&hba->dev_cmd.tag_wq);
+
/* Reset interrupt aggregation counters */
- ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
+ if (int_aggr_reset)
+ ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
Do you assume that interrupt command(device management command) is completed alone?
Of course, interrupt command is not counted in aggregation unlike regular command.
We need to consider that interrupt command comes along with regular command?
If right, ufshcd_config_int_aggr should not be skipped.
True. We are not skipping it. int_aggr_reset will be false only when
there is single interrupt command completed.
Check the above part which reads -
for_all_completed_commands() {
int_aggr_reset |= !lrbp->intr_cmd;
}
Even if one of the command in the iteration is not interrupt command
(lrbp->intr_cmd is false) then int_aggr_reset is always true.
Clear!
But I confused it with your comment line. (/* Don't reset counters for interrupt cmd */)
How about changing like below?
'Don't skip to reset counters if a regular command is present'
Makes sense.
--
Regards,
Sujit
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