[PATCH 16/20] qla2xxx: Move atioq to a different lock to reduce lock contention

Himanshu Madhani
2015-12-08T01:29:32Z

From: Quinn Tran <quinn.tran@qlogic.com>

99% of the time the ATIOQ has SCSI command. The other 1% of time
is something else. Most of the time this interrupt does not need
to hold the hardware_lock. We're moving the ATIO interrupt thread
to a different lock to reduce lock contention.

Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
---
drivers/scsi/qla2xxx/qla_def.h | 1 +
drivers/scsi/qla2xxx/qla_gbl.h | 1 +
drivers/scsi/qla2xxx/qla_init.c | 6 ++-
drivers/scsi/qla2xxx/qla_isr.c | 44 +++++++++++++----
drivers/scsi/qla2xxx/qla_os.c | 2 +
drivers/scsi/qla2xxx/qla_target.c | 97 +++++++++++++++++++++++++++++++------
drivers/scsi/qla2xxx/qla_target.h | 4 +-
7 files changed, 127 insertions(+), 28 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 9165732..0ddb2de 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2936,6 +2936,7 @@ struct qlt_hw_data {
uint32_t leak_exchg_thresh_hold;
spinlock_t sess_lock;
int rspq_vector_cpuid;
+ spinlock_t atio_lock ____cacheline_aligned;
};

#define MAX_QFULL_CMDS_ALLOC 8192
diff --git a/drivers/scsi/qla2xxx/qla_gbl.h b/drivers/scsi/qla2xxx/qla_gbl.h
index 2e91966..5496e0a 100644
--- a/drivers/scsi/qla2xxx/qla_gbl.h
+++ b/drivers/scsi/qla2xxx/qla_gbl.h
@@ -779,5 +779,6 @@ extern int qla_set_exlogin_mem_cfg(scsi_qla_host_t *vha, dma_addr_t phys_addr);
extern int qla_get_exchoffld_status(scsi_qla_host_t *, uint16_t *, uint16_t *);
extern int qla_set_exchoffld_mem_cfg(scsi_qla_host_t *vha,
dma_addr_t phys_addr);
+extern void qlt_handle_abts_recv(struct scsi_qla_host *, response_t *);

#endif /* _QLA_GBL_H */
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index 35d1ea8..993dd25 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -4919,7 +4919,7 @@ qla2x00_restart_isp(scsi_qla_host_t *vha)
struct qla_hw_data *ha = vha->hw;
struct req_que *req = ha->req_q_map[0];
struct rsp_que *rsp = ha->rsp_q_map[0];
- unsigned long flags;
+ unsigned long flags, flags2;

/* If firmware needs to be loaded */
if (qla2x00_isp_firmware(vha)) {
@@ -4948,8 +4948,10 @@ qla2x00_restart_isp(scsi_qla_host_t *vha)
* while we weren't online.
*/
spin_lock_irqsave(&ha->hardware_lock, flags);
+ spin_lock_irqsave(&ha->tgt.atio_lock, flags2);
if (qla_tgt_mode_enabled(vha))
- qlt_24xx_process_atio_queue(vha);
+ qlt_24xx_process_atio_queue(vha, 1);
+ spin_unlock_irqrestore(&ha->tgt.atio_lock, flags2);
spin_unlock_irqrestore(&ha->hardware_lock, flags);

set_bit(LOOP_RESYNC_NEEDED, &vha->dpc_flags);
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 26fa4d8..72d1cdc 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -2605,8 +2605,14 @@ process_err:
qla24xx_els_ct_entry(vha, rsp->req, pkt, ELS_IOCB_TYPE);
break;
case ABTS_RECV_24XX:
- /* ensure that the ATIO queue is empty */
- qlt_24xx_process_atio_queue(vha);
+ if (IS_QLA83XX(ha) || IS_QLA27XX(ha)) {
+ /* ensure that the ATIO queue is empty */
+ qlt_handle_abts_recv(vha, (response_t *)pkt);
+ break;
+ } else {
+ /* drop through */
+ qlt_24xx_process_atio_queue(vha, 1);
+ }
case ABTS_RESP_24XX:
case CTIO_TYPE7:
case NOTIFY_ACK_TYPE:
@@ -2773,13 +2779,22 @@ qla24xx_intr_handler(int irq, void *dev_id)
case INTR_RSP_QUE_UPDATE_83XX:
qla24xx_process_response_queue(vha, rsp);
break;
- case INTR_ATIO_QUE_UPDATE:
- qlt_24xx_process_atio_queue(vha);
+ case INTR_ATIO_QUE_UPDATE:{
+ unsigned long flags2;
+ spin_lock_irqsave(&ha->tgt.atio_lock, flags2);
+ qlt_24xx_process_atio_queue(vha, 1);
+ spin_unlock_irqrestore(&ha->tgt.atio_lock, flags2);
break;
- case INTR_ATIO_RSP_QUE_UPDATE:
- qlt_24xx_process_atio_queue(vha);
+ }
+ case INTR_ATIO_RSP_QUE_UPDATE: {
+ unsigned long flags2;
+ spin_lock_irqsave(&ha->tgt.atio_lock, flags2);
+ qlt_24xx_process_atio_queue(vha, 1);
+ spin_unlock_irqrestore(&ha->tgt.atio_lock, flags2);
+
qla24xx_process_response_queue(vha, rsp);
break;
+ }
default:
ql_dbg(ql_dbg_async, vha, 0x504f,
"Unrecognized interrupt type (%d).\n", stat * 0xff);
@@ -2938,13 +2953,22 @@ qla24xx_msix_default(int irq, void *dev_id)
case INTR_RSP_QUE_UPDATE_83XX:
qla24xx_process_response_queue(vha, rsp);
break;
- case INTR_ATIO_QUE_UPDATE:
- qlt_24xx_process_atio_queue(vha);
+ case INTR_ATIO_QUE_UPDATE:{
+ unsigned long flags2;
+ spin_lock_irqsave(&ha->tgt.atio_lock, flags2);
+ qlt_24xx_process_atio_queue(vha, 1);
+ spin_unlock_irqrestore(&ha->tgt.atio_lock, flags2);
break;
- case INTR_ATIO_RSP_QUE_UPDATE:
- qlt_24xx_process_atio_queue(vha);
+ }
+ case INTR_ATIO_RSP_QUE_UPDATE: {
+ unsigned long flags2;
+ spin_lock_irqsave(&ha->tgt.atio_lock, flags2);
+ qlt_24xx_process_atio_queue(vha, 1);
+ spin_unlock_irqrestore(&ha->tgt.atio_lock, flags2);
+
qla24xx_process_response_queue(vha, rsp);
break;
+ }
default:
ql_dbg(ql_dbg_async, vha, 0x5051,
"Unrecognized interrupt type (%d).\n", stat & 0xff);
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 8b45642..b350905 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -2337,6 +2337,8 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
INIT_LIST_HEAD(&ha->tgt.q_full_list);
spin_lock_init(&ha->tgt.q_full_lock);
spin_lock_init(&ha->tgt.sess_lock);
+ spin_lock_init(&ha->tgt.atio_lock);
+

/* Clear our data area */
ha->bars = bars;
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index b33c018..69f88d3 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -100,7 +100,7 @@ enum fcp_resp_rsp_codes {
*/
/* Predefs for callbacks handed to qla2xxx LLD */
static void qlt_24xx_atio_pkt(struct scsi_qla_host *ha,
- struct atio_from_isp *pkt);
+ struct atio_from_isp *pkt, uint8_t);
static void qlt_response_pkt(struct scsi_qla_host *ha, response_t *pkt);
static int qlt_issue_task_mgmt(struct qla_tgt_sess *sess, uint32_t lun,
int fn, void *iocb, int flags);
@@ -230,7 +230,7 @@ static inline void qlt_decr_num_pend_cmds(struct scsi_qla_host *vha)
}

static void qlt_24xx_atio_pkt_all_vps(struct scsi_qla_host *vha,
- struct atio_from_isp *atio)
+ struct atio_from_isp *atio, uint8_t ha_locked)
{
ql_dbg(ql_dbg_tgt, vha, 0xe072,
"%s: qla_target(%d): type %x ox_id %04x\n",
@@ -251,7 +251,7 @@ static void qlt_24xx_atio_pkt_all_vps(struct scsi_qla_host *vha,
atio->u.isp24.fcp_hdr.d_id[2]);
break;
}
- qlt_24xx_atio_pkt(host, atio);
+ qlt_24xx_atio_pkt(host, atio, ha_locked);
break;
}

@@ -274,7 +274,7 @@ static void qlt_24xx_atio_pkt_all_vps(struct scsi_qla_host *vha,
break;
}
}
- qlt_24xx_atio_pkt(host, atio);
+ qlt_24xx_atio_pkt(host, atio, ha_locked);
break;
}

@@ -1209,7 +1209,7 @@ void qlt_stop_phase2(struct qla_tgt *tgt)

mutex_lock(&vha->vha_tgt.tgt_mutex);
spin_lock_irqsave(&ha->hardware_lock, flags);
- while (tgt->irq_cmd_count != 0) {
+ while ((tgt->irq_cmd_count != 0) || (tgt->atio_irq_cmd_count != 0)) {
spin_unlock_irqrestore(&ha->hardware_lock, flags);
udelay(2);
spin_lock_irqsave(&ha->hardware_lock, flags);
@@ -5372,11 +5372,12 @@ qlt_chk_qfull_thresh_hold(struct scsi_qla_host *vha,
/* ha->hardware_lock supposed to be held on entry */
/* called via callback from qla2xxx */
static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
- struct atio_from_isp *atio)
+ struct atio_from_isp *atio, uint8_t ha_locked)
{
struct qla_hw_data *ha = vha->hw;
struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
int rc;
+ unsigned long flags;

if (unlikely(tgt == NULL)) {
ql_dbg(ql_dbg_io, vha, 0x3064,
@@ -5388,7 +5389,7 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
* Otherwise, some commands can stuck.
*/

- tgt->irq_cmd_count++;
+ tgt->atio_irq_cmd_count++;

switch (atio->u.raw.entry_type) {
case ATIO_TYPE7:
@@ -5398,7 +5399,11 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
"qla_target(%d): ATIO_TYPE7 "
"received with UNKNOWN exchange address, "
"sending QUEUE_FULL\n", vha->vp_idx);
+ if (!ha_locked)
+ spin_lock_irqsave(&ha->hardware_lock, flags);
qlt_send_busy(vha, atio, SAM_STAT_TASK_SET_FULL);
+ if (!ha_locked)
+ spin_unlock_irqrestore(&ha->hardware_lock, flags);
break;
}

@@ -5407,7 +5412,7 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
if (likely(atio->u.isp24.fcp_cmnd.task_mgmt_flags == 0)) {
rc = qlt_chk_qfull_thresh_hold(vha, atio);
if (rc != 0) {
- tgt->irq_cmd_count--;
+ tgt->atio_irq_cmd_count--;
return;
}
rc = qlt_handle_cmd_for_atio(vha, atio);
@@ -5416,11 +5421,18 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
}
if (unlikely(rc != 0)) {
if (rc == -ESRCH) {
+ if (!ha_locked)
+ spin_lock_irqsave(&ha->hardware_lock, flags);
+
#if 1 /* With TERM EXCHANGE some FC cards refuse to boot */
qlt_send_busy(vha, atio, SAM_STAT_BUSY);
#else
qlt_send_term_exchange(vha, NULL, atio, 1, 0);
#endif
+
+ if (!ha_locked)
+ spin_unlock_irqrestore(&ha->hardware_lock, flags);
+
} else {
if (tgt->tgt_stop) {
ql_dbg(ql_dbg_tgt, vha, 0xe059,
@@ -5432,7 +5444,13 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
"qla_target(%d): Unable to send "
"command to target, sending BUSY "
"status.\n", vha->vp_idx);
+ if (!ha_locked)
+ spin_lock_irqsave(
+ &ha->hardware_lock, flags);
qlt_send_busy(vha, atio, SAM_STAT_BUSY);
+ if (!ha_locked)
+ spin_unlock_irqrestore(
+ &ha->hardware_lock, flags);
}
}
}
@@ -5449,7 +5467,12 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
break;
}
ql_dbg(ql_dbg_tgt, vha, 0xe02e, "%s", "IMMED_NOTIFY ATIO");
+
+ if (!ha_locked)
+ spin_lock_irqsave(&ha->hardware_lock, flags);
qlt_handle_imm_notify(vha, (struct imm_ntfy_from_isp *)atio);
+ if (!ha_locked)
+ spin_unlock_irqrestore(&ha->hardware_lock, flags);
break;
}

@@ -5460,7 +5483,7 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
break;
}

- tgt->irq_cmd_count--;
+ tgt->atio_irq_cmd_count--;
}

/* ha->hardware_lock supposed to be held on entry */
@@ -6405,7 +6428,7 @@ qlt_init_atio_q_entries(struct scsi_qla_host *vha)
* @ha: SCSI driver HA context
*/
void
-qlt_24xx_process_atio_queue(struct scsi_qla_host *vha)
+qlt_24xx_process_atio_queue(struct scsi_qla_host *vha, uint8_t ha_locked)
{
struct qla_hw_data *ha = vha->hw;
struct atio_from_isp *pkt;
@@ -6418,7 +6441,8 @@ qlt_24xx_process_atio_queue(struct scsi_qla_host *vha)
pkt = (struct atio_from_isp *)ha->tgt.atio_ring_ptr;
cnt = pkt->u.raw.entry_count;

- qlt_24xx_atio_pkt_all_vps(vha, (struct atio_from_isp *)pkt);
+ qlt_24xx_atio_pkt_all_vps(vha, (struct atio_from_isp *)pkt,
+ ha_locked);

for (i = 0; i < cnt; i++) {
ha->tgt.atio_ring_index++;
@@ -6702,16 +6726,59 @@ qla83xx_msix_atio_q(int irq, void *dev_id)
ha = rsp->hw;
vha = pci_get_drvdata(ha->pdev);

- spin_lock_irqsave(&ha->hardware_lock, flags);
+ spin_lock_irqsave(&ha->tgt.atio_lock, flags);

- qlt_24xx_process_atio_queue(vha);
- qla24xx_process_response_queue(vha, rsp);
+ qlt_24xx_process_atio_queue(vha, 0);

- spin_unlock_irqrestore(&ha->hardware_lock, flags);
+ spin_unlock_irqrestore(&ha->tgt.atio_lock, flags);

return IRQ_HANDLED;
}

+static void
+qlt_handle_abts_recv_work(struct work_struct *work)
+{
+ struct qla_tgt_sess_op *op = container_of(work,
+ struct qla_tgt_sess_op, work);
+ scsi_qla_host_t *vha = op->vha;
+ struct qla_hw_data *ha = vha->hw;
+ unsigned long flags;
+
+ if (qla2x00_reset_active(vha) || (op->chip_reset != ha->chip_reset))
+ return;
+
+ spin_lock_irqsave(&ha->tgt.atio_lock, flags);
+ qlt_24xx_process_atio_queue(vha, 0);
+ spin_unlock_irqrestore(&ha->tgt.atio_lock, flags);
+
+ spin_lock_irqsave(&ha->hardware_lock, flags);
+ qlt_response_pkt_all_vps(vha, (response_t *)&op->atio);
+ spin_unlock_irqrestore(&ha->hardware_lock, flags);
+}
+
+void
+qlt_handle_abts_recv(struct scsi_qla_host *vha, response_t *pkt)
+{
+ struct qla_tgt_sess_op *op;
+
+ op = kzalloc(sizeof(*op), GFP_ATOMIC);
+
+ if (!op) {
+ /* do not reach for ATIO queue here. This is best effort err
+ * recovery at this point.
+ */
+ qlt_response_pkt_all_vps(vha, pkt);
+ return;
+ }
+
+ memcpy(&op->atio, pkt, sizeof(*pkt));
+ op->vha = vha;
+ op->chip_reset = vha->hw->chip_reset;
+ INIT_WORK(&op->work, qlt_handle_abts_recv_work);
+ queue_work(qla_tgt_wq, &op->work);
+ return;
+}
+
int
qlt_mem_alloc(struct qla_hw_data *ha)
{
diff --git a/drivers/scsi/qla2xxx/qla_target.h b/drivers/scsi/qla2xxx/qla_target.h
index a079c237..22a6a76 100644
--- a/drivers/scsi/qla2xxx/qla_target.h
+++ b/drivers/scsi/qla2xxx/qla_target.h
@@ -835,6 +835,7 @@ struct qla_tgt {
* HW lock.
*/
int irq_cmd_count;
+ int atio_irq_cmd_count;

int datasegs_per_cmd, datasegs_per_cont, sg_tablesize;

@@ -883,6 +884,7 @@ struct qla_tgt {

struct qla_tgt_sess_op {
struct scsi_qla_host *vha;
+ uint32_t chip_reset;
struct atio_from_isp atio;
struct work_struct work;
struct list_head cmd_list;
@@ -1164,7 +1166,7 @@ extern void qlt_enable_vha(struct scsi_qla_host *);
extern void qlt_vport_create(struct scsi_qla_host *, struct qla_hw_data *);
extern void qlt_rff_id(struct scsi_qla_host *, struct ct_sns_req *);
extern void qlt_init_atio_q_entries(struct scsi_qla_host *);
-extern void qlt_24xx_process_atio_queue(struct scsi_qla_host *);
+extern void qlt_24xx_process_atio_queue(struct scsi_qla_host *, uint8_t);
extern void qlt_24xx_config_rings(struct scsi_qla_host *);
extern void qlt_24xx_config_nvram_stage1(struct scsi_qla_host *,
struct nvram_24xx *);
--
1.7.7