From: Colin Ian King <colin.king@canonical.com>
Date: Fri, 31 May 2019 10:21:00 +0100
Subject: RDMA/hns: Fix comparison of unsigned long variable 'end' with less
 than zero
Patch-mainline: v5.4-rc1
Git-commit: a511f82218fb14b3d6fbbce3c35759aa4920a734
References: bsc#1104427 FATE#326416 bsc#1137236

Currently the comparison of end with less than zero is always false
because end is an unsigned long.  Also, replace checks of end with
non-zero with end > 0 as it is possible that the #defined decrement may be
changed in the future causing end to step over zero and go negative.

The initialization of end with 0 is also redundant as this value is never
read and is later set to HW_SYNC_TIMEOUT_MSECS, so fix this by
initializing it with this value to begin with.

Link: https://lore.kernel.org/r/20190531092101.28772-1-colin.king@canonical.com
Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 669cefb654cb ("RDMA/hns: Remove jiffies operation in disable interrupt context")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hns/hns_roce_hem.c   |    4 ++--
 drivers/infiniband/hw/hns/hns_roce_hw_v1.c |   12 ++++++------
 2 files changed, 8 insertions(+), 8 deletions(-)

--- a/drivers/infiniband/hw/hns/hns_roce_hem.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.c
@@ -326,7 +326,7 @@ static int hns_roce_set_hem(struct hns_r
 {
 	spinlock_t *lock = &hr_dev->bt_cmd_lock;
 	struct device *dev = hr_dev->dev;
-	unsigned long end = 0;
+	long end;
 	unsigned long flags;
 	struct hns_roce_hem_iter iter;
 	void __iomem *bt_cmd;
@@ -377,7 +377,7 @@ static int hns_roce_set_hem(struct hns_r
 		bt_cmd = hr_dev->reg_base + ROCEE_BT_CMD_H_REG;
 
 		end = HW_SYNC_TIMEOUT_MSECS;
-		while (end) {
+		while (end > 0) {
 			if (!(readl(bt_cmd) >> BT_CMD_SYNC_SHIFT))
 				break;
 
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
@@ -960,7 +960,7 @@ static int hns_roce_v1_recreate_lp_qp(st
 	struct hns_roce_free_mr *free_mr;
 	struct hns_roce_v1_priv *priv;
 	struct completion comp;
-	unsigned long end = HNS_ROCE_V1_RECREATE_LP_QP_TIMEOUT_MSECS;
+	long end = HNS_ROCE_V1_RECREATE_LP_QP_TIMEOUT_MSECS;
 
 	priv = (struct hns_roce_v1_priv *)hr_dev->priv;
 	free_mr = &priv->free_mr;
@@ -980,7 +980,7 @@ static int hns_roce_v1_recreate_lp_qp(st
 
 	queue_work(free_mr->free_mr_wq, &(lp_qp_work->work));
 
-	while (end) {
+	while (end > 0) {
 		if (try_wait_for_completion(&comp))
 			return 0;
 		msleep(HNS_ROCE_V1_RECREATE_LP_QP_WAIT_VALUE);
@@ -1098,7 +1098,7 @@ static int hns_roce_v1_dereg_mr(struct h
 	struct hns_roce_free_mr *free_mr;
 	struct hns_roce_v1_priv *priv;
 	struct completion comp;
-	unsigned long end = HNS_ROCE_V1_FREE_MR_TIMEOUT_MSECS;
+	long end = HNS_ROCE_V1_FREE_MR_TIMEOUT_MSECS;
 	unsigned long start = jiffies;
 	int npages;
 	int ret = 0;
@@ -1128,7 +1128,7 @@ static int hns_roce_v1_dereg_mr(struct h
 
 	queue_work(free_mr->free_mr_wq, &(mr_work->work));
 
-	while (end) {
+	while (end > 0) {
 		if (try_wait_for_completion(&comp))
 			goto free_mr;
 		msleep(HNS_ROCE_V1_FREE_MR_WAIT_VALUE);
@@ -2465,7 +2465,8 @@ static int hns_roce_v1_clear_hem(struct
 {
 	struct device *dev = &hr_dev->pdev->dev;
 	struct hns_roce_v1_priv *priv;
-	unsigned long end = 0, flags = 0;
+	unsigned long flags = 0;
+	long end = HW_SYNC_TIMEOUT_MSECS;
 	__le32 bt_cmd_val[2] = {0};
 	void __iomem *bt_cmd;
 	u64 bt_ba = 0;
@@ -2503,7 +2504,6 @@ static int hns_roce_v1_clear_hem(struct
 
 	bt_cmd = hr_dev->reg_base + ROCEE_BT_CMD_H_REG;
 
-	end = HW_SYNC_TIMEOUT_MSECS;
 	while (1) {
 		if (readl(bt_cmd) >> BT_CMD_SYNC_SHIFT) {
 			if (!end) {