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@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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;
 

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;
 

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);
 };
 

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;