[PATCH] net/ice: fix sizing of filter hash table

[Bruce Richardson <bruce.richardson@intel.com>]

The hash table used for managing the filter rules in the ice driver was
dimensioned to a hard-coded 16k, which is insufficient for holding all
the filters supported by E830 HW.

Rather than using a hard-coded value which may need updates for new
hardware support, we can query the NIC max filter support from hardware
and scale the hash table size based on that value.

Fixes: 1a2fc1799f09 ("net/ice: reject duplicated flow for flow director")

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

---

NOTE: Omission of "Cc: stable..." is deliberate. Although this
is a fix for an issue originally introduced in an old commit, the issue
only manifests with newly-supported HW, so the fix does not need
backporting.
---
 drivers/net/ice/ice_ethdev.h      | 2 --
 drivers/net/ice/ice_fdir_filter.c | 9 +++++++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ice/ice_ethdev.h b/drivers/net/ice/ice_ethdev.h
index d73faaed49..3ea9f37dc8 100644
--- a/drivers/net/ice/ice_ethdev.h
+++ b/drivers/net/ice/ice_ethdev.h
@@ -351,8 +351,6 @@ struct ice_fdir_filter_conf {
 	u8 pkt_len;
 };
 
-#define ICE_MAX_FDIR_FILTER_NUM		(1024 * 16)
-
 struct ice_fdir_fltr_pattern {
 	enum ice_fltr_ptype flow_type;
 
diff --git a/drivers/net/ice/ice_fdir_filter.c b/drivers/net/ice/ice_fdir_filter.c
index 0b7920ad44..edd8cc8f1a 100644
--- a/drivers/net/ice/ice_fdir_filter.c
+++ b/drivers/net/ice/ice_fdir_filter.c
@@ -375,12 +375,17 @@ ice_fdir_init_filter_list(struct ice_pf *pf)
 {
 	struct rte_eth_dev *dev = &rte_eth_devices[pf->dev_data->port_id];
 	struct ice_fdir_info *fdir_info = &pf->fdir;
+	struct ice_hw *hw = &pf->adapter->hw;
 	char fdir_hash_name[RTE_HASH_NAMESIZE];
+	const uint32_t max_fd_filter_entries =
+			hw->func_caps.fd_fltr_guar + hw->func_caps.fd_fltr_best_effort;
+	/* dimension hash table as max filters + 12.5% to ensure a little headroom */
+	const uint32_t hash_table_entries = max_fd_filter_entries + (max_fd_filter_entries >> 3);
 	int ret;
 
 	struct rte_hash_parameters fdir_hash_params = {
 		.name = fdir_hash_name,
-		.entries = ICE_MAX_FDIR_FILTER_NUM,
+		.entries = hash_table_entries,
 		.key_len = sizeof(struct ice_fdir_fltr_pattern),
 		.hash_func = rte_hash_crc,
 		.hash_func_init_val = 0,
@@ -398,7 +403,7 @@ ice_fdir_init_filter_list(struct ice_pf *pf)
 	}
 	fdir_info->hash_map = rte_zmalloc("ice_fdir_hash_map",
 					  sizeof(*fdir_info->hash_map) *
-					  ICE_MAX_FDIR_FILTER_NUM,
+					  hash_table_entries,
 					  0);
 	if (!fdir_info->hash_map) {
 		PMD_INIT_LOG(ERR,
-- 
2.43.0