scsi: mpi3mr: Resource Based Metering

Update driver to track cumulative pending large data size at the controller
level and at the throttle group level.  When one of the values meet or
exceed the controller's firmware-determined high threshold value, then the
driver will divert future selective I/O to the firmware. Once both
controller level and at the throttle group level cumulative pending large
data size reach controller's firmware determined low threshold value, then
the driver will stop diverting I/Os to the firmware.

Link: https://lore.kernel.org/r/20220708195020.8323-2-sreekanth.reddy@broadcom.com
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 160 insertions, 7 deletions

diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index da85eda84484..e1ccb5fcd68a 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -373,6 +373,9 @@ void mpi3mr_invalidate_devhandles(struct mpi3mr_ioc *mrioc)
 		if (tgtdev->starget && tgtdev->starget->hostdata) {
 			tgt_priv = tgtdev->starget->hostdata;
 			tgt_priv->dev_handle = MPI3MR_INVALID_DEV_HANDLE;
+			tgt_priv->io_throttle_enabled = 0;
+			tgt_priv->io_divert = 0;
+			tgt_priv->throttle_group = NULL;
 		}
 	}
 }
@@ -718,6 +721,35 @@ static struct mpi3mr_tgt_dev  *__mpi3mr_get_tgtdev_from_tgtpriv(
 }
 
 /**
+ * mpi3mr_set_io_divert_for_all_vd_in_tg -set divert for TG VDs
+ * @mrioc: Adapter instance reference
+ * @tg: Throttle group information pointer
+ * @divert_value: 1 or 0
+ *
+ * Accessor to set io_divert flag for each device associated
+ * with the given throttle group with the given value.
+ *
+ * Return: None.
+ */
+static void mpi3mr_set_io_divert_for_all_vd_in_tg(struct mpi3mr_ioc *mrioc,
+	struct mpi3mr_throttle_group_info *tg, u8 divert_value)
+{
+	unsigned long flags;
+	struct mpi3mr_tgt_dev *tgtdev;
+	struct mpi3mr_stgt_priv_data *tgt_priv;
+
+	spin_lock_irqsave(&mrioc->tgtdev_lock, flags);
+	list_for_each_entry(tgtdev, &mrioc->tgtdev_list, list) {
+		if (tgtdev->starget && tgtdev->starget->hostdata) {
+			tgt_priv = tgtdev->starget->hostdata;
+			if (tgt_priv->throttle_group == tg)
+				tgt_priv->io_divert = divert_value;
+		}
+	}
+	spin_unlock_irqrestore(&mrioc->tgtdev_lock, flags);
+}
+
+/**
  * mpi3mr_print_device_event_notice - print notice related to post processing of
  *					device event after controller reset.
  *
@@ -934,6 +966,7 @@ void mpi3mr_rfresh_tgtdevs(struct mpi3mr_ioc *mrioc)
  * @mrioc: Adapter instance reference
  * @tgtdev: Target device internal structure
  * @dev_pg0: New device page0
+ * @is_added: Flag to indicate the device is just added
  *
  * Update the information from the device page0 into the driver
  * cached target device structure.
@@ -941,10 +974,11 @@ void mpi3mr_rfresh_tgtdevs(struct mpi3mr_ioc *mrioc)
  * Return: Nothing.
  */
 static void mpi3mr_update_tgtdev(struct mpi3mr_ioc *mrioc,
-	struct mpi3mr_tgt_dev *tgtdev, struct mpi3_device_page0 *dev_pg0)
+	struct mpi3mr_tgt_dev *tgtdev, struct mpi3_device_page0 *dev_pg0,
+	bool is_added)
 {
 	u16 flags = 0;
-	struct mpi3mr_stgt_priv_data *scsi_tgt_priv_data;
+	struct mpi3mr_stgt_priv_data *scsi_tgt_priv_data = NULL;
 	u8 prot_mask = 0;
 
 	tgtdev->perst_id = le16_to_cpu(dev_pg0->persistent_id);
@@ -959,12 +993,19 @@ static void mpi3mr_update_tgtdev(struct mpi3mr_ioc *mrioc,
 	flags = le16_to_cpu(dev_pg0->flags);
 	tgtdev->is_hidden = (flags & MPI3_DEVICE0_FLAGS_HIDDEN);
 
+	if (is_added == true)
+		tgtdev->io_throttle_enabled =
+		    (flags & MPI3_DEVICE0_FLAGS_IO_THROTTLING_REQUIRED) ? 1 : 0;
+
+
 	if (tgtdev->starget && tgtdev->starget->hostdata) {
 		scsi_tgt_priv_data = (struct mpi3mr_stgt_priv_data *)
 		    tgtdev->starget->hostdata;
 		scsi_tgt_priv_data->perst_id = tgtdev->perst_id;
 		scsi_tgt_priv_data->dev_handle = tgtdev->dev_handle;
 		scsi_tgt_priv_data->dev_type = tgtdev->dev_type;
+		scsi_tgt_priv_data->io_throttle_enabled =
+		    tgtdev->io_throttle_enabled;
 	}
 
 	switch (dev_pg0->access_status) {
@@ -1042,10 +1083,27 @@ static void mpi3mr_update_tgtdev(struct mpi3mr_ioc *mrioc,
 	{
 		struct mpi3_device0_vd_format *vdinf =
 		    &dev_pg0->device_specific.vd_format;
+		struct mpi3mr_throttle_group_info *tg = NULL;
+		u16 vdinf_io_throttle_group =
+		    le16_to_cpu(vdinf->io_throttle_group);
 
-		tgtdev->dev_spec.vol_inf.state = vdinf->vd_state;
+		tgtdev->dev_spec.vd_inf.state = vdinf->vd_state;
 		if (vdinf->vd_state == MPI3_DEVICE0_VD_STATE_OFFLINE)
 			tgtdev->is_hidden = 1;
+		tgtdev->dev_spec.vd_inf.tg_id = vdinf_io_throttle_group;
+		tgtdev->dev_spec.vd_inf.tg_high =
+		    le16_to_cpu(vdinf->io_throttle_group_high) * 2048;
+		tgtdev->dev_spec.vd_inf.tg_low =
+		    le16_to_cpu(vdinf->io_throttle_group_low) * 2048;
+		if (vdinf_io_throttle_group < mrioc->num_io_throttle_group) {
+			tg = mrioc->throttle_groups + vdinf_io_throttle_group;
+			tg->id = vdinf_io_throttle_group;
+			tg->high = tgtdev->dev_spec.vd_inf.tg_high;
+			tg->low = tgtdev->dev_spec.vd_inf.tg_low;
+		}
+		tgtdev->dev_spec.vd_inf.tg = tg;
+		if (scsi_tgt_priv_data)
+			scsi_tgt_priv_data->throttle_group = tg;
 		break;
 	}
 	default:
@@ -1142,7 +1200,7 @@ static void mpi3mr_devinfochg_evt_bh(struct mpi3mr_ioc *mrioc,
 	tgtdev = mpi3mr_get_tgtdev_by_handle(mrioc, dev_handle);
 	if (!tgtdev)
 		goto out;
-	mpi3mr_update_tgtdev(mrioc, tgtdev, dev_pg0);
+	mpi3mr_update_tgtdev(mrioc, tgtdev, dev_pg0, false);
 	if (!tgtdev->is_hidden && !tgtdev->host_exposed)
 		mpi3mr_report_tgtdev_to_host(mrioc, perst_id);
 	if (tgtdev->is_hidden && tgtdev->host_exposed)
@@ -1548,13 +1606,13 @@ static int mpi3mr_create_tgtdev(struct mpi3mr_ioc *mrioc,
 	perst_id = le16_to_cpu(dev_pg0->persistent_id);
 	tgtdev = mpi3mr_get_tgtdev_by_perst_id(mrioc, perst_id);
 	if (tgtdev) {
-		mpi3mr_update_tgtdev(mrioc, tgtdev, dev_pg0);
+		mpi3mr_update_tgtdev(mrioc, tgtdev, dev_pg0, true);
 		mpi3mr_tgtdev_put(tgtdev);
 	} else {
 		tgtdev = mpi3mr_alloc_tgtdev();
 		if (!tgtdev)
 			return -ENOMEM;
-		mpi3mr_update_tgtdev(mrioc, tgtdev, dev_pg0);
+		mpi3mr_update_tgtdev(mrioc, tgtdev, dev_pg0, true);
 		mpi3mr_tgtdev_add_to_list(mrioc, tgtdev);
 	}
 
@@ -2566,6 +2624,11 @@ void mpi3mr_process_op_reply_desc(struct mpi3mr_ioc *mrioc,
 	u32 xfer_count = 0, sense_count = 0, resp_data = 0;
 	u16 dev_handle = 0xFFFF;
 	struct scsi_sense_hdr sshdr;
+	struct mpi3mr_stgt_priv_data *stgt_priv_data = NULL;
+	struct mpi3mr_sdev_priv_data *sdev_priv_data = NULL;
+	u32 ioc_pend_data_len = 0, tg_pend_data_len = 0, data_len_blks = 0;
+	struct mpi3mr_throttle_group_info *tg = NULL;
+	u8 throttle_enabled_dev = 0;
 
 	*reply_dma = 0;
 	reply_desc_type = le16_to_cpu(reply_desc->reply_flags) &
@@ -2622,6 +2685,51 @@ void mpi3mr_process_op_reply_desc(struct mpi3mr_ioc *mrioc,
 		goto out;
 	}
 	priv = scsi_cmd_priv(scmd);
+
+	data_len_blks = scsi_bufflen(scmd) >> 9;
+	sdev_priv_data = scmd->device->hostdata;
+	if (sdev_priv_data) {
+		stgt_priv_data = sdev_priv_data->tgt_priv_data;
+		if (stgt_priv_data) {
+			tg = stgt_priv_data->throttle_group;
+			throttle_enabled_dev =
+			    stgt_priv_data->io_throttle_enabled;
+		}
+	}
+	if (unlikely((data_len_blks >= mrioc->io_throttle_data_length) &&
+	    throttle_enabled_dev)) {
+		ioc_pend_data_len = atomic_sub_return(data_len_blks,
+		    &mrioc->pend_large_data_sz);
+		if (tg) {
+			tg_pend_data_len = atomic_sub_return(data_len_blks,
+			    &tg->pend_large_data_sz);
+			if (tg->io_divert  && ((ioc_pend_data_len <=
+			    mrioc->io_throttle_low) &&
+			    (tg_pend_data_len <= tg->low))) {
+				tg->io_divert = 0;
+				mpi3mr_set_io_divert_for_all_vd_in_tg(
+				    mrioc, tg, 0);
+			}
+		} else {
+			if (ioc_pend_data_len <= mrioc->io_throttle_low)
+				stgt_priv_data->io_divert = 0;
+		}
+	} else if (unlikely((stgt_priv_data && stgt_priv_data->io_divert))) {
+		ioc_pend_data_len = atomic_read(&mrioc->pend_large_data_sz);
+		if (!tg) {
+			if (ioc_pend_data_len <= mrioc->io_throttle_low)
+				stgt_priv_data->io_divert = 0;
+
+		} else if (ioc_pend_data_len <= mrioc->io_throttle_low) {
+			tg_pend_data_len = atomic_read(&tg->pend_large_data_sz);
+			if (tg->io_divert  && (tg_pend_data_len <= tg->low)) {
+				tg->io_divert = 0;
+				mpi3mr_set_io_divert_for_all_vd_in_tg(
+				    mrioc, tg, 0);
+			}
+		}
+	}
+
 	if (success_desc) {
 		scmd->result = DID_OK << 16;
 		goto out_success;
@@ -3842,6 +3950,11 @@ static int mpi3mr_target_alloc(struct scsi_target *starget)
 		tgt_dev->starget = starget;
 		atomic_set(&scsi_tgt_priv_data->block_io, 0);
 		retval = 0;
+		scsi_tgt_priv_data->io_throttle_enabled =
+		    tgt_dev->io_throttle_enabled;
+		if (tgt_dev->dev_type == MPI3_DEVICE_DEVFORM_VD)
+			scsi_tgt_priv_data->throttle_group =
+			    tgt_dev->dev_spec.vd_inf.tg;
 	} else
 		retval = -ENXIO;
 	spin_unlock_irqrestore(&mrioc->tgtdev_lock, flags);
@@ -3997,10 +4110,13 @@ static int mpi3mr_qcmd(struct Scsi_Host *shost,
 	int retval = 0;
 	u16 dev_handle;
 	u16 host_tag;
-	u32 scsiio_flags = 0;
+	u32 scsiio_flags = 0, data_len_blks = 0;
 	struct request *rq = scsi_cmd_to_rq(scmd);
 	int iprio_class;
 	u8 is_pcie_dev = 0;
+	u32 tracked_io_sz = 0;
+	u32 ioc_pend_data_len = 0, tg_pend_data_len = 0;
+	struct mpi3mr_throttle_group_info *tg = NULL;
 
 	if (mrioc->unrecoverable) {
 		scmd->result = DID_ERROR << 16;
@@ -4104,11 +4220,48 @@ static int mpi3mr_qcmd(struct Scsi_Host *shost,
 		goto out;
 	}
 	op_req_q = &mrioc->req_qinfo[scmd_priv_data->req_q_idx];
+		data_len_blks = scsi_bufflen(scmd) >> 9;
+	if ((data_len_blks >= mrioc->io_throttle_data_length) &&
+	    stgt_priv_data->io_throttle_enabled) {
+		tracked_io_sz = data_len_blks;
+		tg = stgt_priv_data->throttle_group;
+		if (tg) {
+			ioc_pend_data_len = atomic_add_return(data_len_blks,
+			    &mrioc->pend_large_data_sz);
+			tg_pend_data_len = atomic_add_return(data_len_blks,
+			    &tg->pend_large_data_sz);
+			if (!tg->io_divert  && ((ioc_pend_data_len >=
+			    mrioc->io_throttle_high) ||
+			    (tg_pend_data_len >= tg->high))) {
+				tg->io_divert = 1;
+				mpi3mr_set_io_divert_for_all_vd_in_tg(mrioc,
+				    tg, 1);
+			}
+		} else {
+			ioc_pend_data_len = atomic_add_return(data_len_blks,
+			    &mrioc->pend_large_data_sz);
+			if (ioc_pend_data_len >= mrioc->io_throttle_high)
+				stgt_priv_data->io_divert = 1;
+		}
+	}
+
+	if (stgt_priv_data->io_divert) {
+		scsiio_req->msg_flags |=
+		    MPI3_SCSIIO_MSGFLAGS_DIVERT_TO_FIRMWARE;
+		scsiio_flags |= MPI3_SCSIIO_FLAGS_DIVERT_REASON_IO_THROTTLING;
+	}
+	scsiio_req->flags = cpu_to_le32(scsiio_flags);
 
 	if (mpi3mr_op_request_post(mrioc, op_req_q,
 	    scmd_priv_data->mpi3mr_scsiio_req)) {
 		mpi3mr_clear_scmd_priv(mrioc, scmd);
 		retval = SCSI_MLQUEUE_HOST_BUSY;
+		if (tracked_io_sz) {
+			atomic_sub(tracked_io_sz, &mrioc->pend_large_data_sz);
+			if (tg)
+				atomic_sub(tracked_io_sz,
+				    &tg->pend_large_data_sz);
+		}
 		goto out;
 	}