[PATCH AUTOSEL 5.5 34/58] net: ena: rss: do not allocate key when not supported

Sasha Levin
2020-02-23T02:22:23Z

From: Sameeh Jubran <sameehj@amazon.com>

[ Upstream commit 6a4f7dc82d1e3abd3feb0c60b5041056fcd9880c ]

Currently we allocate the key whether the device supports setting the
key or not. This commit adds a check to the allocation function and
handles the error accordingly.

Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/amazon/ena/ena_com.c | 24 ++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c
index d6b894b06fa30..6f758ece86f60 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -1057,6 +1057,20 @@ static void ena_com_hash_key_fill_default_key(struct ena_com_dev *ena_dev)
static int ena_com_hash_key_allocate(struct ena_com_dev *ena_dev)
{
struct ena_rss *rss = &ena_dev->rss;
+ struct ena_admin_feature_rss_flow_hash_control *hash_key;
+ struct ena_admin_get_feat_resp get_resp;
+ int rc;
+
+ hash_key = (ena_dev->rss).hash_key;
+
+ rc = ena_com_get_feature_ex(ena_dev, &get_resp,
+ ENA_ADMIN_RSS_HASH_FUNCTION,
+ ena_dev->rss.hash_key_dma_addr,
+ sizeof(ena_dev->rss.hash_key), 0);
+ if (unlikely(rc)) {
+ hash_key = NULL;
+ return -EOPNOTSUPP;
+ }

rss->hash_key =
dma_alloc_coherent(ena_dev->dmadev, sizeof(*rss->hash_key),
@@ -2640,11 +2654,15 @@ int ena_com_rss_init(struct ena_com_dev *ena_dev, u16 indr_tbl_log_size)
if (unlikely(rc))
goto err_indr_tbl;

+ /* The following function might return unsupported in case the
+ * device doesn't support setting the key / hash function. We can safely
+ * ignore this error and have indirection table support only.
+ */
rc = ena_com_hash_key_allocate(ena_dev);
- if (unlikely(rc))
+ if (unlikely(rc) && rc != -EOPNOTSUPP)
goto err_hash_key;
-
- ena_com_hash_key_fill_default_key(ena_dev);
+ else if (rc != -EOPNOTSUPP)
+ ena_com_hash_key_fill_default_key(ena_dev);

rc = ena_com_hash_ctrl_init(ena_dev);
if (unlikely(rc))
--
2.20.1