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From:   Larysa Zaremba <larysa.zaremba@intel.com>
To:     bpf@vger.kernel.org
Cc:     Larysa Zaremba <larysa.zaremba@intel.com>,
        Stanislav Fomichev <sdf@google.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        Anatoly Burakov <anatoly.burakov@intel.com>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Alexander Lobakin <alexandr.lobakin@intel.com>,
        Magnus Karlsson <magnus.karlsson@gmail.com>,
        Maryam Tahhan <mtahhan@redhat.com>, xdp-hints@xdp-project.net,
        netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH RESEND bpf-next 01/15] ice: make RX hash reading code more reusable
Date:   Fri, 12 May 2023 17:25:53 +0200
Message-Id: <20230512152607.992209-2-larysa.zaremba@intel.com>
In-Reply-To: <20230512152607.992209-1-larysa.zaremba@intel.com>
References: <20230512152607.992209-1-larysa.zaremba@intel.com>
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Precedence: bulk

Previously, we only needed RX hash in skb path,
hence all related code was written with skb in mind.
But with the addition of XDP hints via kfuncs to the ice driver,
the same logic will be needed in .xmo_() callbacks.

Separate generic process of reading RX hash from a descriptor
into a separate function.

Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 38 +++++++++++++------
 1 file changed, 27 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
index c8322fb6f2b3..fc67bbf600af 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
@@ -63,28 +63,44 @@ static enum pkt_hash_types ice_ptype_to_htype(u16 ptype)
 }
 
 /**
- * ice_rx_hash - set the hash value in the skb
+ * ice_copy_rx_hash_from_desc - copy hash value from descriptor to address
+ * @rx_desc: specific descriptor
+ * @dst: address to copy hash value to
+ *
+ * Returns true, if valid hash has been copied into the destination address.
+ */
+static bool
+ice_copy_rx_hash_from_desc(union ice_32b_rx_flex_desc *rx_desc, u32 *dst)
+{
+	struct ice_32b_rx_flex_desc_nic *nic_mdid;
+
+	if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
+		return false;
+
+	nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
+	*dst = le32_to_cpu(nic_mdid->rss_hash);
+	return true;
+}
+
+/**
+ * ice_rx_hash_to_skb - set the hash value in the skb
  * @rx_ring: descriptor ring
  * @rx_desc: specific descriptor
  * @skb: pointer to current skb
  * @rx_ptype: the ptype value from the descriptor
  */
 static void
-ice_rx_hash(struct ice_rx_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
-	    struct sk_buff *skb, u16 rx_ptype)
+ice_rx_hash_to_skb(struct ice_rx_ring *rx_ring,
+		   union ice_32b_rx_flex_desc *rx_desc,
+		   struct sk_buff *skb, u16 rx_ptype)
 {
-	struct ice_32b_rx_flex_desc_nic *nic_mdid;
 	u32 hash;
 
 	if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
 		return;
 
-	if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
-		return;
-
-	nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
-	hash = le32_to_cpu(nic_mdid->rss_hash);
-	skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
+	if (ice_copy_rx_hash_from_desc(rx_desc, &hash))
+		skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
 }
 
 /**
@@ -186,7 +202,7 @@ ice_process_skb_fields(struct ice_rx_ring *rx_ring,
 		       union ice_32b_rx_flex_desc *rx_desc,
 		       struct sk_buff *skb, u16 ptype)
 {
-	ice_rx_hash(rx_ring, rx_desc, skb, ptype);
+	ice_rx_hash_to_skb(rx_ring, rx_desc, skb, ptype);
 
 	/* modifies the skb - consumes the enet header */
 	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
-- 
2.35.3