[PATCH 1/2] crypto: iaa - Fix nr_cpus < nr_iaa case

[Tom Zanussi]

If nr_cpus < nr_iaa, the calculated cpus_per_iaa will be 0, which
causes a divide-by-0 in rebalance_wq_table().

Make sure cpus_per_iaa is 1 in that case, and also in the nr_iaa == 0
case, even though cpus_per_iaa is never used if nr_iaa == 0, for
paranoia.

Reported-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
---
 drivers/crypto/intel/iaa/iaa_crypto_main.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/intel/iaa/iaa_crypto_main.c
index 1cd304de5388..b2191ade9011 100644
--- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
+++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
@@ -806,6 +806,8 @@ static int save_iaa_wq(struct idxd_wq *wq)
 		return -EINVAL;
 
 	cpus_per_iaa = (nr_nodes * nr_cpus_per_node) / nr_iaa;
+	if (!cpus_per_iaa)
+		cpus_per_iaa = 1;
 out:
 	return 0;
 }
@@ -821,10 +823,12 @@ static void remove_iaa_wq(struct idxd_wq *wq)
 		}
 	}
 
-	if (nr_iaa)
+	if (nr_iaa) {
 		cpus_per_iaa = (nr_nodes * nr_cpus_per_node) / nr_iaa;
-	else
-		cpus_per_iaa = 0;
+		if (!cpus_per_iaa)
+			cpus_per_iaa = 1;
+	} else
+		cpus_per_iaa = 1;
 }
 
 static int wq_table_add_wqs(int iaa, int cpu)
-- 
2.34.1