From: Arthur Kiyanovski akiyano@amazon.com
[ Upstream commit 4844470d472d660c26149ad764da2406adb13423 ]
The device receives, stores and retrieves the hash function value as bits and not as their enum value.
The bug: * In ena_com_set_hash_function() we set cmd.u.flow_hash_func.selected_func to the bit value of rss->hash_func. (1 << rss->hash_func) * In ena_com_get_hash_function() we retrieve the hash function and store it's bit value in rss->hash_func. (Now the bit value of rss->hash_func is stored in rss->hash_func instead of it's enum value)
The fix: This commit fixes the issue by converting the retrieved hash function values from the device to the matching enum value of the set bit using ffs(). ffs() finds the first set bit's index in a word. Since the function returns 1 for the LSB's index, we need to subtract 1 from the returned value (note that BIT(0) is 1).
Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)") Signed-off-by: Sameeh Jubran sameehj@amazon.com Signed-off-by: Arthur Kiyanovski akiyano@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 | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c index be8a2d48c98f2..e1f694322e41a 100644 --- a/drivers/net/ethernet/amazon/ena/ena_com.c +++ b/drivers/net/ethernet/amazon/ena/ena_com.c @@ -2093,7 +2093,11 @@ int ena_com_get_hash_function(struct ena_com_dev *ena_dev, if (unlikely(rc)) return rc;
- rss->hash_func = get_resp.u.flow_hash_func.selected_func; + /* ffs() returns 1 in case the lsb is set */ + rss->hash_func = ffs(get_resp.u.flow_hash_func.selected_func); + if (rss->hash_func) + rss->hash_func--; + if (func) *func = rss->hash_func;