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From:   Ong Boon Leong <boon.leong.ong@intel.com>
To:     Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Jose Abreu <joabreu@synopsys.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>
Cc:     alexandre.torgue@foss.st.com,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        KP Singh <kpsingh@kernel.org>, netdev@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        bpf@vger.kernel.org, Ong Boon Leong <boon.leong.ong@intel.com>
Subject: [PATCH net-next v2 5/7] net: stmmac: Refactor __stmmac_xdp_run_prog for XDP ZC
Date:   Tue, 13 Apr 2021 17:36:24 +0800
Message-Id: <20210413093626.3447-6-boon.leong.ong@intel.com>
In-Reply-To: <20210413093626.3447-1-boon.leong.ong@intel.com>
References: <20210413093626.3447-1-boon.leong.ong@intel.com>
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Precedence: bulk

Prepare stmmac_xdp_run_prog() for AF_XDP zero-copy support which will be
added by upcoming patches by splitting out the XDP verdict processing
into __stmmac_xdp_run_prog() and it callable for XDP ZC path which does
not need to verify bpf_prog is not NULL.

The stmmac_xdp_run_prog() is used for regular XDP Rx path which requires
bpf_prog to be verified.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 35 ++++++++++++-------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0804674e628e..329a3abbac76 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4408,20 +4408,13 @@ static int stmmac_xdp_xmit_back(struct stmmac_priv *priv,
 	return res;
 }
 
-static struct sk_buff *stmmac_xdp_run_prog(struct stmmac_priv *priv,
-					   struct xdp_buff *xdp)
+/* This function assumes rcu_read_lock() is held by the caller. */
+static int __stmmac_xdp_run_prog(struct stmmac_priv *priv,
+				 struct bpf_prog *prog,
+				 struct xdp_buff *xdp)
 {
-	struct bpf_prog *prog;
-	int res;
 	u32 act;
-
-	rcu_read_lock();
-
-	prog = READ_ONCE(priv->xdp_prog);
-	if (!prog) {
-		res = STMMAC_XDP_PASS;
-		goto unlock;
-	}
+	int res;
 
 	act = bpf_prog_run_xdp(prog, xdp);
 	switch (act) {
@@ -4448,6 +4441,24 @@ static struct sk_buff *stmmac_xdp_run_prog(struct stmmac_priv *priv,
 		break;
 	}
 
+	return res;
+}
+
+static struct sk_buff *stmmac_xdp_run_prog(struct stmmac_priv *priv,
+					   struct xdp_buff *xdp)
+{
+	struct bpf_prog *prog;
+	int res;
+
+	rcu_read_lock();
+
+	prog = READ_ONCE(priv->xdp_prog);
+	if (!prog) {
+		res = STMMAC_XDP_PASS;
+		goto unlock;
+	}
+
+	res = __stmmac_xdp_run_prog(priv, prog, xdp);
 unlock:
 	rcu_read_unlock();
 	return ERR_PTR(-res);
-- 
2.25.1