[PATCH 7/9] scsi: hisi_sas: Tidy hisi_sas_task_prep()

From: John Garry
Date: Wed Jul 18 2018 - 10:16:20 EST


From: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>

To decrease the usage of spinlock during delivery IO, relocate some code
in hisi_sas_task_prep().

Also an invalid comment is removed.

Signed-off-by: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
drivers/scsi/hisi_sas/hisi_sas_main.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index b0bcd14..432a38a 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -296,8 +296,8 @@ static int hisi_sas_task_prep(struct sas_task *task,
struct device *dev = hisi_hba->dev;
int dlvry_queue_slot, dlvry_queue, rc, slot_idx;
int n_elem = 0, n_elem_req = 0, n_elem_resp = 0;
- unsigned long flags, flags_dq;
struct hisi_sas_dq *dq;
+ unsigned long flags;
int wr_q_index;

if (!sas_port) {
@@ -393,16 +393,17 @@ static int hisi_sas_task_prep(struct sas_task *task,

slot = &hisi_hba->slot_info[slot_idx];

- spin_lock_irqsave(&dq->lock, flags_dq);
+ spin_lock_irqsave(&dq->lock, flags);
wr_q_index = hisi_hba->hw->get_free_slot(hisi_hba, dq);
if (wr_q_index < 0) {
- spin_unlock_irqrestore(&dq->lock, flags_dq);
+ spin_unlock_irqrestore(&dq->lock, flags);
rc = -EAGAIN;
goto err_out_tag;
}

list_add_tail(&slot->delivery, &dq->list);
- spin_unlock_irqrestore(&dq->lock, flags_dq);
+ list_add_tail(&slot->entry, &sas_dev->list);
+ spin_unlock_irqrestore(&dq->lock, flags);

dlvry_queue = dq->id;
dlvry_queue_slot = wr_q_index;
@@ -440,9 +441,6 @@ static int hisi_sas_task_prep(struct sas_task *task,
break;
}

- spin_lock_irqsave(&dq->lock, flags);
- list_add_tail(&slot->entry, &sas_dev->list);
- spin_unlock_irqrestore(&dq->lock, flags);
spin_lock_irqsave(&task->task_state_lock, flags);
task->task_state_flags |= SAS_TASK_AT_INITIATOR;
spin_unlock_irqrestore(&task->task_state_lock, flags);
@@ -818,7 +816,6 @@ static void hisi_sas_do_release_task(struct hisi_hba *hisi_hba, struct sas_task
hisi_sas_slot_task_free(hisi_hba, task, slot);
}

-/* hisi_hba.lock should be locked */
static void hisi_sas_release_task(struct hisi_hba *hisi_hba,
struct domain_device *device)
{
--
1.9.1