netdev - [PATCH bpf-next 9/9] bpf: do not pass netdev to translate() and prepare() offload callbacks

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Date:   Fri,  9 Nov 2018 13:03:32 +0000
From:   Quentin Monnet <quentin.monnet@...ronome.com>
To:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>
Cc:     netdev@...r.kernel.org, oss-drivers@...ronome.com,
        Quentin Monnet <quentin.monnet@...ronome.com>
Subject: [PATCH bpf-next 9/9] bpf: do not pass netdev to translate() and prepare() offload callbacks

The kernel functions to prepare verifier and translate for offloaded
program retrieve "offload" from "prog", and "netdev" from "offload".
Then both "prog" and "netdev" are passed to the callbacks.

Simplify this by letting the drivers retrieve the net device themselves
from the offload object attached to prog - if they need it at all. There
is currently no need to pass the netdev as an argument to those
functions.

Signed-off-by: Quentin Monnet <quentin.monnet@...ronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@...ronome.com>
---
 drivers/net/ethernet/netronome/nfp/bpf/offload.c | 9 ++++-----
 drivers/net/netdevsim/bpf.c                      | 7 +++----
 include/linux/bpf.h                              | 4 ++--
 kernel/bpf/offload.c                             | 4 ++--
 4 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
index e6b26d2f651d..f0283854fade 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
@@ -182,10 +182,9 @@ static void nfp_prog_free(struct nfp_prog *nfp_prog)
 	kfree(nfp_prog);
 }
 
-static int
-nfp_bpf_verifier_prep(struct net_device *netdev, struct bpf_prog *prog)
+static int nfp_bpf_verifier_prep(struct bpf_prog *prog)
 {
-	struct nfp_net *nn = netdev_priv(netdev);
+	struct nfp_net *nn = netdev_priv(prog->aux->offload->netdev);
 	struct nfp_app *app = nn->app;
 	struct nfp_prog *nfp_prog;
 	int ret;
@@ -213,10 +212,10 @@ nfp_bpf_verifier_prep(struct net_device *netdev, struct bpf_prog *prog)
 	return ret;
 }
 
-static int nfp_bpf_translate(struct net_device *netdev, struct bpf_prog *prog)
+static int nfp_bpf_translate(struct bpf_prog *prog)
 {
+	struct nfp_net *nn = netdev_priv(prog->aux->offload->netdev);
 	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
-	struct nfp_net *nn = netdev_priv(netdev);
 	unsigned int max_instr;
 	int err;
 
diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c
index 560bdaf1c98b..6a5b7bd9a1f9 100644
--- a/drivers/net/netdevsim/bpf.c
+++ b/drivers/net/netdevsim/bpf.c
@@ -258,10 +258,9 @@ static int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog)
 	return 0;
 }
 
-static int
-nsim_bpf_verifier_prep(struct net_device *dev, struct bpf_prog *prog)
+static int nsim_bpf_verifier_prep(struct bpf_prog *prog)
 {
-	struct netdevsim *ns = netdev_priv(dev);
+	struct netdevsim *ns = netdev_priv(prog->aux->offload->netdev);
 
 	if (!ns->bpf_bind_accept)
 		return -EOPNOTSUPP;
@@ -269,7 +268,7 @@ nsim_bpf_verifier_prep(struct net_device *dev, struct bpf_prog *prog)
 	return nsim_bpf_create_prog(ns, prog);
 }
 
-static int nsim_bpf_translate(struct net_device *dev, struct bpf_prog *prog)
+static int nsim_bpf_translate(struct bpf_prog *prog)
 {
 	struct nsim_bpf_bound_prog *state = prog->aux->offload->dev_priv;
 
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 888111350d0e..987815152629 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -268,8 +268,8 @@ struct bpf_prog_offload_ops {
 	int (*insn_hook)(struct bpf_verifier_env *env,
 			 int insn_idx, int prev_insn_idx);
 	int (*finalize)(struct bpf_verifier_env *env);
-	int (*prepare)(struct net_device *netdev, struct bpf_prog *prog);
-	int (*translate)(struct net_device *netdev, struct bpf_prog *prog);
+	int (*prepare)(struct bpf_prog *prog);
+	int (*translate)(struct bpf_prog *prog);
 	void (*destroy)(struct bpf_prog *prog);
 };
 
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 397d206e184b..52c5617e3716 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -131,7 +131,7 @@ int bpf_prog_offload_verifier_prep(struct bpf_prog *prog)
 	down_read(&bpf_devs_lock);
 	offload = prog->aux->offload;
 	if (offload)
-		ret = offload->offdev->ops->prepare(offload->netdev, prog);
+		ret = offload->offdev->ops->prepare(prog);
 	offload->dev_state = !ret;
 	up_read(&bpf_devs_lock);
 
@@ -203,7 +203,7 @@ static int bpf_prog_offload_translate(struct bpf_prog *prog)
 	down_read(&bpf_devs_lock);
 	offload = prog->aux->offload;
 	if (offload)
-		ret = offload->offdev->ops->translate(offload->netdev, prog);
+		ret = offload->offdev->ops->translate(prog);
 	up_read(&bpf_devs_lock);
 
 	return ret;
-- 
2.17.1