[PATCH 5/5][Bionic] scsi: hisi_sas: complete all tasklets prior to host reset

[dann frazier]

From: Xiaofei Tan <tanxiaofei at huawei.com>

BugLink: https://bugs.launchpad.net/bugs/1739807

The CQ event is handled in tasklet context, and it could be delayed if
the system loading is high.

It is possible to run into some problems when executing a host reset
when cq_tasklet_vx_hw() is being executed.

So, prior to host reset, execute tasklet_kill() to ensure that all CQ
tasklets are complete.

Besides, as the function hisi_sas_wait_tasklets_done() is added to do
tasklet_kill(), this patch refactors some code where tasklet_kill() is
used.

Signed-off-by: Xiaofei Tan <tanxiaofei at huawei.com>
Signed-off-by: John Garry <john.garry at huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(backported from commit 571295f8055c0b69c9911021ae6cf1a6973cf517)
[dannf: resolved trivial merge conflict in hisi_sas.h]
Signed-off-by: dann frazier <dann.frazier at canonical.com>
---
 drivers/scsi/hisi_sas/hisi_sas.h       |  1 +
 drivers/scsi/hisi_sas/hisi_sas_main.c  | 11 +++++++++++
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c |  8 ++------
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c |  3 ++-
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index 172e19fbf20f..f3a767e98cee 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -420,4 +420,5 @@ extern void hisi_sas_slot_task_free(struct hisi_hba *hisi_hba,
 				    struct sas_task *task,
 				    struct hisi_sas_slot *slot);
 extern void hisi_sas_init_mem(struct hisi_hba *hisi_hba);
+extern void hisi_sas_kill_tasklets(struct hisi_hba *hisi_hba);
 #endif
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index e2ed753e76dd..74b82612c3e1 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1546,6 +1546,17 @@ void hisi_sas_phy_down(struct hisi_hba *hisi_hba, int phy_no, int rdy)
 }
 EXPORT_SYMBOL_GPL(hisi_sas_phy_down);
 
+void hisi_sas_kill_tasklets(struct hisi_hba *hisi_hba)
+{
+	int i;
+
+	for (i = 0; i < hisi_hba->queue_count; i++) {
+		struct hisi_sas_cq *cq = &hisi_hba->cq[i];
+
+		tasklet_kill(&cq->tasklet);
+	}
+}
+EXPORT_SYMBOL_GPL(hisi_sas_kill_tasklets);
 
 struct scsi_transport_template *hisi_sas_stt;
 EXPORT_SYMBOL_GPL(hisi_sas_stt);
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index 7f71528ec59c..93b33766df3c 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -3410,6 +3410,7 @@ static int soft_reset_v2_hw(struct hisi_hba *hisi_hba)
 
 	interrupt_disable_v2_hw(hisi_hba);
 	hisi_sas_write32(hisi_hba, DLVRY_QUEUE_ENABLE, 0x0);
+	hisi_sas_kill_tasklets(hisi_hba);
 
 	hisi_sas_stop_phys(hisi_hba);
 
@@ -3493,16 +3494,11 @@ static int hisi_sas_v2_remove(struct platform_device *pdev)
 {
 	struct sas_ha_struct *sha = platform_get_drvdata(pdev);
 	struct hisi_hba *hisi_hba = sha->lldd_ha;
-	int i;
 
 	if (timer_pending(&hisi_hba->timer))
 		del_timer(&hisi_hba->timer);
 
-	for (i = 0; i < hisi_hba->queue_count; i++) {
-		struct hisi_sas_cq *cq = &hisi_hba->cq[i];
-
-		tasklet_kill(&cq->tasklet);
-	}
+	hisi_sas_kill_tasklets(hisi_hba);
 
 	return hisi_sas_remove(pdev);
 }
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 1b50c6eda226..fe32e0888588 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -1757,6 +1757,7 @@ static int soft_reset_v3_hw(struct hisi_hba *hisi_hba)
 
 	interrupt_disable_v3_hw(hisi_hba);
 	hisi_sas_write32(hisi_hba, DLVRY_QUEUE_ENABLE, 0x0);
+	hisi_sas_kill_tasklets(hisi_hba);
 
 	hisi_sas_stop_phys(hisi_hba);
 
@@ -1964,7 +1965,6 @@ hisi_sas_v3_destroy_irqs(struct pci_dev *pdev, struct hisi_hba *hisi_hba)
 		struct hisi_sas_cq *cq = &hisi_hba->cq[i];
 
 		free_irq(pci_irq_vector(pdev, i+16), cq);
-		tasklet_kill(&cq->tasklet);
 	}
 	pci_free_irq_vectors(pdev);
 }
@@ -1980,6 +1980,7 @@ static void hisi_sas_v3_remove(struct pci_dev *pdev)
 	sas_remove_host(sha->core.shost);
 
 	hisi_sas_v3_destroy_irqs(pdev, hisi_hba);
+	hisi_sas_kill_tasklets(hisi_hba);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
 	hisi_sas_free(hisi_hba);
-- 
2.15.1