From: Xiaofei Tan <tanxiaofei@huawei.com>
Date: Sat, 24 Mar 2018 00:05:13 +0800
Subject: scsi: hisi_sas: check IPTT is valid before using it for v3 hw
Git-commit: 327f242fa806c199a183c2197592e94d336c8266
Patch-mainline: v4.18-rc1
References: FATE#326253
There is a bug of v3 hw development version. When AXI error happen, hw
may return an abnormal CQ that IPTT value is 0xffff. This will cause
IPTT out-of-bounds reference.
This patch adds a check of IPTT in cq_tasklet_v3_hw() and discards
invalid slot. This workaround scheme is just to enhance fault-tolerance
of the driver. So, we will apply this scheme for all version of v3 hw,
although release version has fixed this SoC bug.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index efe64bcfa4f2..aa52d5e424f7 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -1731,15 +1731,19 @@ static void cq_tasklet_v3_hw(unsigned long val)
while (rd_point != wr_point) {
struct hisi_sas_complete_v3_hdr *complete_hdr;
+ struct device *dev = hisi_hba->dev;
int iptt;
complete_hdr = &complete_queue[rd_point];
iptt = (complete_hdr->dw1) & CMPLT_HDR_IPTT_MSK;
- slot = &hisi_hba->slot_info[iptt];
- slot->cmplt_queue_slot = rd_point;
- slot->cmplt_queue = queue;
- slot_complete_v3_hw(hisi_hba, slot);
+ if (likely(iptt < HISI_SAS_COMMAND_ENTRIES_V3_HW)) {
+ slot = &hisi_hba->slot_info[iptt];
+ slot->cmplt_queue_slot = rd_point;
+ slot->cmplt_queue = queue;
+ slot_complete_v3_hw(hisi_hba, slot);
+ } else
+ dev_err(dev, "IPTT %d is invalid, discard it.\n", iptt);
if (++rd_point >= HISI_SAS_QUEUE_SLOTS)
rd_point = 0;