[SCSI] qla2xxx: Ramp down queue depth for attached SCSI devices when driver resources are low.

Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

6 files changed, 135 insertions, 7 deletions

diff --git a/drivers/scsi/qla2xxx/qla_dbg.c b/drivers/scsi/qla2xxx/qla_dbg.c
index 2f3e7655db0d..f7cdd259ef0b 100644
--- a/drivers/scsi/qla2xxx/qla_dbg.c
+++ b/drivers/scsi/qla2xxx/qla_dbg.c
@@ -17,7 +17,7 @@
  * |                              |                    | 0x113a         |
  * | Device Discovery             |       0x2087       | 0x2020-0x2022, |
  * |                              |                    | 0x2016         |
- * | Queue Command and IO tracing |       0x3030       | 0x3006-0x300b  |
+ * | Queue Command and IO tracing |       0x3031       | 0x3006-0x300b  |
  * |                              |                    | 0x3027-0x3028  |
  * |                              |                    | 0x302d-0x302e  |
  * | DPC Thread                   |       0x401d       | 0x4002,0x4013  |
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index a84bb8d6ff74..06c6271d5911 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2536,6 +2536,7 @@ struct req_que {
         srb_t **outstanding_cmds;
         uint32_t current_outstanding_cmd;
         uint16_t num_outstanding_cmds;
+#define MAX_Q_DEPTH             32
         int max_q_depth;
 };
 
@@ -3058,6 +3059,12 @@ struct qla_hw_data {
         struct work_struct idc_state_handler;
         struct work_struct nic_core_unrecoverable;
 
+#define HOST_QUEUE_RAMPDOWN_INTERVAL           (60 * HZ)
+#define HOST_QUEUE_RAMPUP_INTERVAL             (30 * HZ)
+        unsigned long   host_last_rampdown_time;
+        unsigned long   host_last_rampup_time;
+        int             cfg_lun_q_depth;
+
         struct qlt_hw_data tgt;
 };
 
@@ -3117,6 +3124,8 @@ typedef struct scsi_qla_host {
 #define MPI_RESET_NEEDED        19      /* Initiate MPI FW reset */
 #define ISP_QUIESCE_NEEDED      20      /* Driver need some quiescence */
 #define SCR_PENDING             21      /* SCR in target mode */
+#define HOST_RAMP_DOWN_QUEUE_DEPTH     22
+#define HOST_RAMP_UP_QUEUE_DEPTH       23
 
         uint32_t        device_flags;
 #define SWITCH_FOUND            BIT_0
diff --git a/drivers/scsi/qla2xxx/qla_gbl.h b/drivers/scsi/qla2xxx/qla_gbl.h
index fba0651f678e..1732713e80cc 100644
--- a/drivers/scsi/qla2xxx/qla_gbl.h
+++ b/drivers/scsi/qla2xxx/qla_gbl.h
@@ -97,6 +97,7 @@ extern int qlport_down_retry;
 extern int ql2xplogiabsentdevice;
 extern int ql2xloginretrycount;
 extern int ql2xfdmienable;
+extern int ql2xmaxqdepth;
 extern int ql2xallocfwdump;
 extern int ql2xextended_error_logging;
 extern int ql2xiidmaenable;
diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h
index c0462c04c885..deb8618d1b81 100644
--- a/drivers/scsi/qla2xxx/qla_inline.h
+++ b/drivers/scsi/qla2xxx/qla_inline.h
@@ -213,3 +213,22 @@ qla2x00_gid_list_size(struct qla_hw_data *ha)
 {
         return sizeof(struct gid_list_info) * ha->max_fibre_devices;
 }
+
+static inline void
+qla2x00_do_host_ramp_up(scsi_qla_host_t *vha)
+{
+        if (vha->hw->cfg_lun_q_depth >= ql2xmaxqdepth)
+                return;
+
+        /* Wait at least HOST_QUEUE_RAMPDOWN_INTERVAL before ramping up */
+        if (time_before(jiffies, (vha->hw->host_last_rampdown_time +
+            HOST_QUEUE_RAMPDOWN_INTERVAL)))
+                return;
+
+        /* Wait at least HOST_QUEUE_RAMPUP_INTERVAL between each ramp up */
+        if (time_before(jiffies, (vha->hw->host_last_rampup_time +
+            HOST_QUEUE_RAMPUP_INTERVAL)))
+                return;
+
+        set_bit(HOST_RAMP_UP_QUEUE_DEPTH, &vha->dpc_flags);
+}
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 45130738c2bf..1b192c8bb133 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -1934,6 +1934,7 @@ qla2x00_status_entry(scsi_qla_host_t *vha, struct rsp_que *rsp, void *pkt)
 
         /* Fast path completion. */
         if (comp_status == CS_COMPLETE && scsi_status == 0) {
+                qla2x00_do_host_ramp_up(vha);
                 qla2x00_process_completed_request(vha, req, handle);
 
                 return;
@@ -2193,6 +2194,9 @@ out:
                     cp->cmnd[8], cp->cmnd[9], scsi_bufflen(cp), rsp_info_len,
                     resid_len, fw_resid_len);
 
+        if (!res)
+                qla2x00_do_host_ramp_up(vha);
+
         if (rsp->status_srb == NULL)
                 sp->done(ha, sp, res);
 }
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 53efffce13a2..da86d3828c1d 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -111,8 +111,7 @@ MODULE_PARM_DESC(ql2xfdmienable,
                 "Enables FDMI registrations. "
                 "0 - no FDMI. Default is 1 - perform FDMI.");
 
-#define MAX_Q_DEPTH    32
-static int ql2xmaxqdepth = MAX_Q_DEPTH;
+int ql2xmaxqdepth = MAX_Q_DEPTH;
 module_param(ql2xmaxqdepth, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(ql2xmaxqdepth,
                 "Maximum queue depth to set for each LUN. "
@@ -720,8 +719,10 @@ qla2xxx_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
         }
 
         sp = qla2x00_get_sp(base_vha, fcport, GFP_ATOMIC);
-        if (!sp)
+        if (!sp) {
+                set_bit(HOST_RAMP_DOWN_QUEUE_DEPTH, &vha->dpc_flags);
                 goto qc24_host_busy;
+        }
 
         sp->u.scmd.cmd = cmd;
         sp->type = SRB_SCSI_CMD;
@@ -734,6 +735,7 @@ qla2xxx_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
         if (rval != QLA_SUCCESS) {
                 ql_dbg(ql_dbg_io + ql_dbg_verbose, vha, 0x3013,
                     "Start scsi failed rval=%d for cmd=%p.\n", rval, cmd);
+                set_bit(HOST_RAMP_DOWN_QUEUE_DEPTH, &vha->dpc_flags);
                 goto qc24_host_busy_free_sp;
         }
 
@@ -1458,6 +1460,81 @@ qla2x00_change_queue_type(struct scsi_device *sdev, int tag_type)
         return tag_type;
 }
 
+static void
+qla2x00_host_ramp_down_queuedepth(scsi_qla_host_t *vha)
+{
+        scsi_qla_host_t *vp;
+        struct Scsi_Host *shost;
+        struct scsi_device *sdev;
+        struct qla_hw_data *ha = vha->hw;
+        unsigned long flags;
+
+        ha->host_last_rampdown_time = jiffies;
+
+        if (ha->cfg_lun_q_depth <= vha->host->cmd_per_lun)
+                return;
+
+        if ((ha->cfg_lun_q_depth / 2) < vha->host->cmd_per_lun)
+                ha->cfg_lun_q_depth = vha->host->cmd_per_lun;
+        else
+                ha->cfg_lun_q_depth = ha->cfg_lun_q_depth / 2;
+
+        /*
+         * Geometrically ramp down the queue depth for all devices on this
+         * adapter
+         */
+        spin_lock_irqsave(&ha->vport_slock, flags);
+        list_for_each_entry(vp, &ha->vp_list, list) {
+                shost = vp->host;
+                shost_for_each_device(sdev, shost) {
+                        if (sdev->queue_depth > shost->cmd_per_lun) {
+                                if (sdev->queue_depth < ha->cfg_lun_q_depth)
+                                        continue;
+                                ql_log(ql_log_warn, vp, 0x3031,
+                                    "%ld:%d:%d: Ramping down queue depth to %d",
+                                    vp->host_no, sdev->id, sdev->lun,
+                                    ha->cfg_lun_q_depth);
+                                qla2x00_change_queue_depth(sdev,
+                                    ha->cfg_lun_q_depth, SCSI_QDEPTH_DEFAULT);
+                        }
+                }
+        }
+        spin_unlock_irqrestore(&ha->vport_slock, flags);
+
+        return;
+}
+
+static void
+qla2x00_host_ramp_up_queuedepth(scsi_qla_host_t *vha)
+{
+        scsi_qla_host_t *vp;
+        struct Scsi_Host *shost;
+        struct scsi_device *sdev;
+        struct qla_hw_data *ha = vha->hw;
+        unsigned long flags;
+
+        ha->host_last_rampup_time = jiffies;
+        ha->cfg_lun_q_depth++;
+
+        /*
+         * Linearly ramp up the queue depth for all devices on this
+         * adapter
+         */
+        spin_lock_irqsave(&ha->vport_slock, flags);
+        list_for_each_entry(vp, &ha->vp_list, list) {
+                shost = vp->host;
+                shost_for_each_device(sdev, shost) {
+                        if (sdev->queue_depth > ha->cfg_lun_q_depth)
+                                continue;
+                        qla2x00_change_queue_depth(sdev, ha->cfg_lun_q_depth,
+                            SCSI_QDEPTH_RAMP_UP);
+                }
+        }
+        spin_unlock_irqrestore(&ha->vport_slock, flags);
+
+        return;
+}
+
 /**
  * qla2x00_config_dma_addressing() - Configure OS DMA addressing method.
  * @ha: HA context
@@ -2235,6 +2312,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
         ha->init_cb_size = sizeof(init_cb_t);
         ha->link_data_rate = PORT_SPEED_UNKNOWN;
         ha->optrom_size = OPTROM_SIZE_2300;
+        ha->cfg_lun_q_depth = ql2xmaxqdepth;
 
         /* Assign ISP specific operations. */
         if (IS_QLA2100(ha)) {
@@ -4610,6 +4688,18 @@ qla2x00_do_dpc(void *data)
                         qla2xxx_flash_npiv_conf(base_vha);
                 }
 
+                if (test_and_clear_bit(HOST_RAMP_DOWN_QUEUE_DEPTH,
+                    &base_vha->dpc_flags)) {
+                        /* Prevents simultaneous ramp up and down */
+                        clear_bit(HOST_RAMP_UP_QUEUE_DEPTH,
+                            &base_vha->dpc_flags);
+                        qla2x00_host_ramp_down_queuedepth(base_vha);
+                }
+
+                if (test_and_clear_bit(HOST_RAMP_UP_QUEUE_DEPTH,
+                    &base_vha->dpc_flags))
+                        qla2x00_host_ramp_up_queuedepth(base_vha);
+
                 if (!ha->interrupts_on)
                         ha->isp_ops->enable_intrs(ha);
 
@@ -4807,7 +4897,9 @@ qla2x00_timer(scsi_qla_host_t *vha)
             test_bit(ISP_UNRECOVERABLE, &vha->dpc_flags) ||
             test_bit(FCOE_CTX_RESET_NEEDED, &vha->dpc_flags) ||
             test_bit(VP_DPC_NEEDED, &vha->dpc_flags) ||
-            test_bit(RELOGIN_NEEDED, &vha->dpc_flags))) {
+            test_bit(RELOGIN_NEEDED, &vha->dpc_flags) ||
+            test_bit(HOST_RAMP_DOWN_QUEUE_DEPTH, &vha->dpc_flags) ||
+            test_bit(HOST_RAMP_UP_QUEUE_DEPTH, &vha->dpc_flags))) {
                 ql_dbg(ql_dbg_timer, vha, 0x600b,
                     "isp_abort_needed=%d loop_resync_needed=%d "
                     "fcport_update_needed=%d start_dpc=%d "
@@ -4820,12 +4912,15 @@ qla2x00_timer(scsi_qla_host_t *vha)
                 ql_dbg(ql_dbg_timer, vha, 0x600c,
                     "beacon_blink_needed=%d isp_unrecoverable=%d "
                     "fcoe_ctx_reset_needed=%d vp_dpc_needed=%d "
-                    "relogin_needed=%d.\n",
+                    "relogin_needed=%d, host_ramp_down_needed=%d "
+                    "host_ramp_up_needed=%d.\n",
                     test_bit(BEACON_BLINK_NEEDED, &vha->dpc_flags),
                     test_bit(ISP_UNRECOVERABLE, &vha->dpc_flags),
                     test_bit(FCOE_CTX_RESET_NEEDED, &vha->dpc_flags),
                     test_bit(VP_DPC_NEEDED, &vha->dpc_flags),
-                    test_bit(RELOGIN_NEEDED, &vha->dpc_flags));
+                    test_bit(RELOGIN_NEEDED, &vha->dpc_flags),
+                    test_bit(HOST_RAMP_UP_QUEUE_DEPTH, &vha->dpc_flags),
+                    test_bit(HOST_RAMP_DOWN_QUEUE_DEPTH, &vha->dpc_flags));
                 qla2xxx_wake_dpc(vha);
         }