diff mbox series

[net-next,05/13] bnxt_en: Add function to calculate Toeplitz hash

Message ID 20231221220218.197386-6-michael.chan@broadcom.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series bnxt_en: Add basic ntuple filter support | expand

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Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1113 this patch: 1113
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 1140 this patch: 1140
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1144 this patch: 1144
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 152 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Michael Chan Dec. 21, 2023, 10:02 p.m. UTC
From: Pavan Chebbi <pavan.chebbi@broadcom.com>

For ntuple filters added by aRFS, the Toeplitz hash calculated by our
NIC is available and is used to store the ntuple filter for quick
retrieval.  In the next patches, user defined ntuple filter support
will be added and we need to calculate the same hash for these
filters.  The same hash function needs to be used so we can detect
duplicates.

Add the function bnxt_toeplitz() to calculate the Toeplitz hash for
user defined ntuple filters.  bnxt_toeplitz() uses the same Toeplitz
key and the same key length as the NIC.

bnxt_get_ntp_filter_idx() is added to return the hash index.  For
aRFS, the hash comes from the NIC.  For user defined ntuple, we call
bnxt_toeplitz() to calculate the hash index.

Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 100 +++++++++++++++++++++-
 drivers/net/ethernet/broadcom/bnxt/bnxt.h |  11 +++
 2 files changed, 108 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 31289803ff92..66ec7d4d1398 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -4199,13 +4199,22 @@  static void bnxt_init_vnics(struct bnxt *bp)
 		vnic->fw_l2_ctx_id = INVALID_HW_RING_ID;
 
 		if (bp->vnic_info[i].rss_hash_key) {
-			if (i == 0)
+			if (!i) {
+				u8 *key = (void *)vnic->rss_hash_key;
+				int k;
+
+				bp->toeplitz_prefix = 0;
 				get_random_bytes(vnic->rss_hash_key,
 					      HW_HASH_KEY_SIZE);
-			else
+				for (k = 0; k < 8; k++) {
+					bp->toeplitz_prefix <<= 8;
+					bp->toeplitz_prefix |= key[k];
+				}
+			} else {
 				memcpy(vnic->rss_hash_key,
 				       bp->vnic_info[0].rss_hash_key,
 				       HW_HASH_KEY_SIZE);
+			}
 		}
 	}
 }
@@ -5374,6 +5383,79 @@  static struct bnxt_l2_filter *bnxt_lookup_l2_filter(struct bnxt *bp,
 	return fltr;
 }
 
+#define BNXT_IPV4_4TUPLE(bp, fkeys)					\
+	(((fkeys)->basic.ip_proto == IPPROTO_TCP &&			\
+	  (bp)->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_TCP_IPV4) ||	\
+	 ((fkeys)->basic.ip_proto == IPPROTO_UDP &&			\
+	  (bp)->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_UDP_IPV4))
+
+#define BNXT_IPV6_4TUPLE(bp, fkeys)					\
+	(((fkeys)->basic.ip_proto == IPPROTO_TCP &&			\
+	  (bp)->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_TCP_IPV6) ||	\
+	 ((fkeys)->basic.ip_proto == IPPROTO_UDP &&			\
+	  (bp)->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_UDP_IPV6))
+
+static u32 bnxt_get_rss_flow_tuple_len(struct bnxt *bp, struct flow_keys *fkeys)
+{
+	if (fkeys->basic.n_proto == htons(ETH_P_IP)) {
+		if (BNXT_IPV4_4TUPLE(bp, fkeys))
+			return sizeof(fkeys->addrs.v4addrs) +
+			       sizeof(fkeys->ports);
+
+		if (bp->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_IPV4)
+			return sizeof(fkeys->addrs.v4addrs);
+	}
+
+	if (fkeys->basic.n_proto == htons(ETH_P_IPV6)) {
+		if (BNXT_IPV6_4TUPLE(bp, fkeys))
+			return sizeof(fkeys->addrs.v6addrs) +
+			       sizeof(fkeys->ports);
+
+		if (bp->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6)
+			return sizeof(fkeys->addrs.v6addrs);
+	}
+
+	return 0;
+}
+
+static u32 bnxt_toeplitz(struct bnxt *bp, struct flow_keys *fkeys,
+			 const unsigned char *key)
+{
+	u64 prefix = bp->toeplitz_prefix, hash = 0;
+	struct bnxt_ipv4_tuple tuple4;
+	struct bnxt_ipv6_tuple tuple6;
+	int i, j, len = 0;
+	u8 *four_tuple;
+
+	len = bnxt_get_rss_flow_tuple_len(bp, fkeys);
+	if (!len)
+		return 0;
+
+	if (fkeys->basic.n_proto == htons(ETH_P_IP)) {
+		tuple4.v4addrs = fkeys->addrs.v4addrs;
+		tuple4.ports = fkeys->ports;
+		four_tuple = (unsigned char *)&tuple4;
+	} else {
+		tuple6.v6addrs = fkeys->addrs.v6addrs;
+		tuple6.ports = fkeys->ports;
+		four_tuple = (unsigned char *)&tuple6;
+	}
+
+	for (i = 0, j = 8; i < len; i++, j++) {
+		u8 byte = four_tuple[i];
+		int bit;
+
+		for (bit = 0; bit < 8; bit++, prefix <<= 1, byte <<= 1) {
+			if (byte & 0x80)
+				hash ^= prefix;
+		}
+		prefix |= (j < HW_HASH_KEY_SIZE) ? key[j] : 0;
+	}
+
+	/* The valid part of the hash is in the upper 32 bits. */
+	return (hash >> 32) & BNXT_NTP_FLTR_HASH_MASK;
+}
+
 #ifdef CONFIG_RFS_ACCEL
 static struct bnxt_l2_filter *
 bnxt_lookup_l2_filter_from_key(struct bnxt *bp, struct bnxt_l2_key *key)
@@ -13770,6 +13852,18 @@  static int bnxt_setup_tc(struct net_device *dev, enum tc_setup_type type,
 	}
 }
 
+static u32 bnxt_get_ntp_filter_idx(struct bnxt *bp, struct flow_keys *fkeys,
+				   const struct sk_buff *skb)
+{
+	struct bnxt_vnic_info *vnic;
+
+	if (skb)
+		return skb_get_hash_raw(skb) & BNXT_NTP_FLTR_HASH_MASK;
+
+	vnic = &bp->vnic_info[0];
+	return bnxt_toeplitz(bp, fkeys, (void *)vnic->rss_hash_key);
+}
+
 #ifdef CONFIG_RFS_ACCEL
 static bool bnxt_fltr_match(struct bnxt_ntuple_filter *f1,
 			    struct bnxt_ntuple_filter *f2)
@@ -13862,7 +13956,7 @@  static int bnxt_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
 
 	new_fltr->l2_fltr = l2_fltr;
 
-	idx = skb_get_hash_raw(skb) & BNXT_NTP_FLTR_HASH_MASK;
+	idx = bnxt_get_ntp_filter_idx(bp, fkeys, skb);
 	head = &bp->ntp_fltr_hash_tbl[idx];
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(fltr, head, base.hash) {
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 5d67b8299328..3f4e4708f7d8 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1370,6 +1370,16 @@  struct bnxt_l2_key {
 	};
 };
 
+struct bnxt_ipv4_tuple {
+	struct flow_dissector_key_ipv4_addrs v4addrs;
+	struct flow_dissector_key_ports ports;
+};
+
+struct bnxt_ipv6_tuple {
+	struct flow_dissector_key_ipv6_addrs v6addrs;
+	struct flow_dissector_key_ports ports;
+};
+
 #define BNXT_L2_KEY_SIZE	(sizeof(struct bnxt_l2_key) / 4)
 
 struct bnxt_l2_filter {
@@ -2413,6 +2423,7 @@  struct bnxt {
 	struct hlist_head	l2_fltr_hash_tbl[BNXT_L2_FLTR_HASH_SIZE];
 
 	u32			hash_seed;
+	u64			toeplitz_prefix;
 
 	/* To protect link related settings during link changes and
 	 * ethtool settings changes.