[PATCH 5.15 079/230] scsi: qla2xxx: Move heartbeat handling from DPC thread to workqueue

From: Greg Kroah-Hartman
Date: Mon Jul 11 2022 - 05:47:21 EST


From: Manish Rangankar <mrangankar@xxxxxxxxxxx>

[ Upstream commit 3a4e1f3b3a3c733de3b82b9b522e54803e1165ae ]

DPC thread gets restricted due to a no-op mailbox, which is a blocking call
and has a high execution frequency. To free up the DPC thread we move no-op
handling to the workqueue. Also, modified qla_do_heartbeat() to send no-op
MBC if we don’t have any active interrupts, but there are still I/Os
outstanding with firmware.

Link: https://lore.kernel.org/r/20210908164622.19240-9-njavali@xxxxxxxxxxx
Fixes: d94d8158e184 ("scsi: qla2xxx: Add heartbeat check")
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Signed-off-by: Manish Rangankar <mrangankar@xxxxxxxxxxx>
Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/qla2xxx/qla_def.h | 4 +-
drivers/scsi/qla2xxx/qla_init.c | 2 +
drivers/scsi/qla2xxx/qla_os.c | 78 +++++++++++++++------------------
3 files changed, 40 insertions(+), 44 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 2ea35e47ea44..0589ab8e6467 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -3759,6 +3759,7 @@ struct qla_qpair {
struct qla_fw_resources fwres ____cacheline_aligned;
u32 cmd_cnt;
u32 cmd_completion_cnt;
+ u32 prev_completion_cnt;
};

/* Place holder for FW buffer parameters */
@@ -4618,6 +4619,7 @@ struct qla_hw_data {
struct qla_chip_state_84xx *cs84xx;
struct isp_operations *isp_ops;
struct workqueue_struct *wq;
+ struct work_struct heartbeat_work;
struct qlfc_fw fw_buf;

/* FCP_CMND priority support */
@@ -4719,7 +4721,6 @@ struct qla_hw_data {

struct qla_hw_data_stat stat;
pci_error_state_t pci_error_state;
- u64 prev_cmd_cnt;
struct dma_pool *purex_dma_pool;
struct btree_head32 host_map;

@@ -4865,7 +4866,6 @@ typedef struct scsi_qla_host {
#define SET_ZIO_THRESHOLD_NEEDED 32
#define ISP_ABORT_TO_ROM 33
#define VPORT_DELETE 34
-#define HEARTBEAT_CHK 38

#define PROCESS_PUREX_IOCB 63

diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index af8df5a800c6..c3ba2995209b 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -7096,12 +7096,14 @@ qla2x00_abort_isp_cleanup(scsi_qla_host_t *vha)
ha->chip_reset++;
ha->base_qpair->chip_reset = ha->chip_reset;
ha->base_qpair->cmd_cnt = ha->base_qpair->cmd_completion_cnt = 0;
+ ha->base_qpair->prev_completion_cnt = 0;
for (i = 0; i < ha->max_qpairs; i++) {
if (ha->queue_pair_map[i]) {
ha->queue_pair_map[i]->chip_reset =
ha->base_qpair->chip_reset;
ha->queue_pair_map[i]->cmd_cnt =
ha->queue_pair_map[i]->cmd_completion_cnt = 0;
+ ha->base_qpair->prev_completion_cnt = 0;
}
}

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 77c0bf06f162..b224326bacee 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -2779,6 +2779,16 @@ qla2xxx_scan_finished(struct Scsi_Host *shost, unsigned long time)
return atomic_read(&vha->loop_state) == LOOP_READY;
}

+static void qla_heartbeat_work_fn(struct work_struct *work)
+{
+ struct qla_hw_data *ha = container_of(work,
+ struct qla_hw_data, heartbeat_work);
+ struct scsi_qla_host *base_vha = pci_get_drvdata(ha->pdev);
+
+ if (!ha->flags.mbox_busy && base_vha->flags.init_done)
+ qla_no_op_mb(base_vha);
+}
+
static void qla2x00_iocb_work_fn(struct work_struct *work)
{
struct scsi_qla_host *vha = container_of(work,
@@ -3217,6 +3227,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
host->transportt, sht->vendor_id);

INIT_WORK(&base_vha->iocb_work, qla2x00_iocb_work_fn);
+ INIT_WORK(&ha->heartbeat_work, qla_heartbeat_work_fn);

/* Set up the irqs */
ret = qla2x00_request_irqs(ha, rsp);
@@ -7103,17 +7114,6 @@ qla2x00_do_dpc(void *data)
qla2x00_lip_reset(base_vha);
}

- if (test_bit(HEARTBEAT_CHK, &base_vha->dpc_flags)) {
- /*
- * if there is a mb in progress then that's
- * enough of a check to see if fw is still ticking.
- */
- if (!ha->flags.mbox_busy && base_vha->flags.init_done)
- qla_no_op_mb(base_vha);
-
- clear_bit(HEARTBEAT_CHK, &base_vha->dpc_flags);
- }
-
ha->dpc_active = 0;
end_loop:
set_current_state(TASK_INTERRUPTIBLE);
@@ -7172,57 +7172,51 @@ qla2x00_rst_aen(scsi_qla_host_t *vha)

static bool qla_do_heartbeat(struct scsi_qla_host *vha)
{
- u64 cmd_cnt, prev_cmd_cnt;
- bool do_hb = false;
struct qla_hw_data *ha = vha->hw;
- int i;
+ u32 cmpl_cnt;
+ u16 i;
+ bool do_heartbeat = false;

- /* if cmds are still pending down in fw, then do hb */
- if (ha->base_qpair->cmd_cnt != ha->base_qpair->cmd_completion_cnt) {
- do_hb = true;
+ /*
+ * Allow do_heartbeat only if we don’t have any active interrupts,
+ * but there are still IOs outstanding with firmware.
+ */
+ cmpl_cnt = ha->base_qpair->cmd_completion_cnt;
+ if (cmpl_cnt == ha->base_qpair->prev_completion_cnt &&
+ cmpl_cnt != ha->base_qpair->cmd_cnt) {
+ do_heartbeat = true;
goto skip;
}
+ ha->base_qpair->prev_completion_cnt = cmpl_cnt;

for (i = 0; i < ha->max_qpairs; i++) {
- if (ha->queue_pair_map[i] &&
- ha->queue_pair_map[i]->cmd_cnt !=
- ha->queue_pair_map[i]->cmd_completion_cnt) {
- do_hb = true;
- break;
+ if (ha->queue_pair_map[i]) {
+ cmpl_cnt = ha->queue_pair_map[i]->cmd_completion_cnt;
+ if (cmpl_cnt == ha->queue_pair_map[i]->prev_completion_cnt &&
+ cmpl_cnt != ha->queue_pair_map[i]->cmd_cnt) {
+ do_heartbeat = true;
+ break;
+ }
+ ha->queue_pair_map[i]->prev_completion_cnt = cmpl_cnt;
}
}

skip:
- prev_cmd_cnt = ha->prev_cmd_cnt;
- cmd_cnt = ha->base_qpair->cmd_cnt;
- for (i = 0; i < ha->max_qpairs; i++) {
- if (ha->queue_pair_map[i])
- cmd_cnt += ha->queue_pair_map[i]->cmd_cnt;
- }
- ha->prev_cmd_cnt = cmd_cnt;
-
- if (!do_hb && ((cmd_cnt - prev_cmd_cnt) > 50))
- /*
- * IOs are completing before periodic hb check.
- * IOs seems to be running, do hb for sanity check.
- */
- do_hb = true;
-
- return do_hb;
+ return do_heartbeat;
}

static void qla_heart_beat(struct scsi_qla_host *vha)
{
+ struct qla_hw_data *ha = vha->hw;
+
if (vha->vp_idx)
return;

if (vha->hw->flags.eeh_busy || qla2x00_chip_is_down(vha))
return;

- if (qla_do_heartbeat(vha)) {
- set_bit(HEARTBEAT_CHK, &vha->dpc_flags);
- qla2xxx_wake_dpc(vha);
- }
+ if (qla_do_heartbeat(vha))
+ queue_work(ha->wq, &ha->heartbeat_work);
}

/**************************************************************************
--
2.35.1