Merge branch 'device-ops-as-cb'

Quentin Monnet says:

====================
For passing device functions for offloaded eBPF programs, there used to
be no place where to store the pointer without making the non-offloaded
programs pay a memory price.

As a consequence, three functions were called with ndo_bpf() through
specific commands. Now that we have struct bpf_offload_dev, and since none
of those operations rely on RTNL, we can turn these three commands into
hooks inside the struct bpf_prog_offload_ops, and pass them as part of
bpf_offload_dev_create().

This patch set changes the offload architecture to do so, and brings the
relevant changes to the nfp and netdevsim drivers.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

5 files changed, 50 insertions, 54 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.c b/drivers/net/ethernet/netronome/nfp/bpf/main.c
index 6243af0ab025..dccae0319204 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.c
@@ -465,7 +465,7 @@ static int nfp_bpf_init(struct nfp_app *app)
 		app->ctrl_mtu = nfp_bpf_ctrl_cmsg_mtu(bpf);
 	}
 
-	bpf->bpf_dev = bpf_offload_dev_create();
+	bpf->bpf_dev = bpf_offload_dev_create(&nfp_bpf_dev_ops);
 	err = PTR_ERR_OR_ZERO(bpf->bpf_dev);
 	if (err)
 		goto err_free_neutral_maps;
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h
index 7f591d71ab28..941277936475 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h
@@ -509,7 +509,11 @@ void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt);
 int nfp_bpf_jit(struct nfp_prog *prog);
 bool nfp_bpf_supported_opcode(u8 code);
 
-extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
+int nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx,
+		    int prev_insn_idx);
+int nfp_bpf_finalize(struct bpf_verifier_env *env);
+
+extern const struct bpf_prog_offload_ops nfp_bpf_dev_ops;
 
 struct netdev_bpf;
 struct nfp_app;
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
index 07bdc1f61996..f0283854fade 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
@@ -33,9 +33,6 @@ nfp_map_ptr_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog,
 	struct nfp_bpf_neutral_map *record;
 	int err;
 
-	/* Map record paths are entered via ndo, update side is protected. */
-	ASSERT_RTNL();
-
 	/* Reuse path - other offloaded program is already tracking this map. */
 	record = rhashtable_lookup_fast(&bpf->maps_neutral, &map->id,
 					nfp_bpf_maps_neutral_params);
@@ -84,8 +81,6 @@ nfp_map_ptrs_forget(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog)
 	bool freed = false;
 	int i;
 
-	ASSERT_RTNL();
-
 	for (i = 0; i < nfp_prog->map_records_cnt; i++) {
 		if (--nfp_prog->map_records[i]->count) {
 			nfp_prog->map_records[i] = NULL;
@@ -187,11 +182,10 @@ static void nfp_prog_free(struct nfp_prog *nfp_prog)
 	kfree(nfp_prog);
 }
 
-static int
-nfp_bpf_verifier_prep(struct nfp_app *app, struct nfp_net *nn,
-		      struct netdev_bpf *bpf)
+static int nfp_bpf_verifier_prep(struct bpf_prog *prog)
 {
-	struct bpf_prog *prog = bpf->verifier.prog;
+	struct nfp_net *nn = netdev_priv(prog->aux->offload->netdev);
+	struct nfp_app *app = nn->app;
 	struct nfp_prog *nfp_prog;
 	int ret;
 
@@ -209,7 +203,6 @@ nfp_bpf_verifier_prep(struct nfp_app *app, struct nfp_net *nn,
 		goto err_free;
 
 	nfp_prog->verifier_meta = nfp_prog_first_meta(nfp_prog);
-	bpf->verifier.ops = &nfp_bpf_analyzer_ops;
 
 	return 0;
 
@@ -219,8 +212,9 @@ err_free:
 	return ret;
 }
 
-static int nfp_bpf_translate(struct nfp_net *nn, 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;
 	unsigned int max_instr;
 	int err;
@@ -242,15 +236,13 @@ static int nfp_bpf_translate(struct nfp_net *nn, struct bpf_prog *prog)
 	return nfp_map_ptrs_record(nfp_prog->bpf, nfp_prog, prog);
 }
 
-static int nfp_bpf_destroy(struct nfp_net *nn, struct bpf_prog *prog)
+static void nfp_bpf_destroy(struct bpf_prog *prog)
 {
 	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
 
 	kvfree(nfp_prog->prog);
 	nfp_map_ptrs_forget(nfp_prog->bpf, nfp_prog);
 	nfp_prog_free(nfp_prog);
-
-	return 0;
 }
 
 /* Atomic engine requires values to be in big endian, we need to byte swap
@@ -422,12 +414,6 @@ nfp_bpf_map_free(struct nfp_app_bpf *bpf, struct bpf_offloaded_map *offmap)
 int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn, struct netdev_bpf *bpf)
 {
 	switch (bpf->command) {
-	case BPF_OFFLOAD_VERIFIER_PREP:
-		return nfp_bpf_verifier_prep(app, nn, bpf);
-	case BPF_OFFLOAD_TRANSLATE:
-		return nfp_bpf_translate(nn, bpf->offload.prog);
-	case BPF_OFFLOAD_DESTROY:
-		return nfp_bpf_destroy(nn, bpf->offload.prog);
 	case BPF_OFFLOAD_MAP_ALLOC:
 		return nfp_bpf_map_alloc(app->priv, bpf->offmap);
 	case BPF_OFFLOAD_MAP_FREE:
@@ -601,3 +587,11 @@ int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
 
 	return 0;
 }
+
+const struct bpf_prog_offload_ops nfp_bpf_dev_ops = {
+	.insn_hook	= nfp_verify_insn,
+	.finalize	= nfp_bpf_finalize,
+	.prepare	= nfp_bpf_verifier_prep,
+	.translate	= nfp_bpf_translate,
+	.destroy	= nfp_bpf_destroy,
+};
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
index 99f977bfd8cc..337bb862ec1d 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -623,8 +623,8 @@ nfp_bpf_check_alu(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
 	return 0;
 }
 
-static int
-nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx)
+int nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx,
+		    int prev_insn_idx)
 {
 	struct nfp_prog *nfp_prog = env->prog->aux->offload->dev_priv;
 	struct nfp_insn_meta *meta = nfp_prog->verifier_meta;
@@ -745,7 +745,7 @@ continue_subprog:
 	goto continue_subprog;
 }
 
-static int nfp_bpf_finalize(struct bpf_verifier_env *env)
+int nfp_bpf_finalize(struct bpf_verifier_env *env)
 {
 	struct bpf_subprog_info *info;
 	struct nfp_prog *nfp_prog;
@@ -788,8 +788,3 @@ static int nfp_bpf_finalize(struct bpf_verifier_env *env)
 
 	return 0;
 }
-
-const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops = {
-	.insn_hook	= nfp_verify_insn,
-	.finalize	= nfp_bpf_finalize,
-};
diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c
index cb3518474f0e..6a5b7bd9a1f9 100644
--- a/drivers/net/netdevsim/bpf.c
+++ b/drivers/net/netdevsim/bpf.c
@@ -91,11 +91,6 @@ static int nsim_bpf_finalize(struct bpf_verifier_env *env)
 	return 0;
 }
 
-static const struct bpf_prog_offload_ops nsim_bpf_analyzer_ops = {
-	.insn_hook	= nsim_bpf_verify_insn,
-	.finalize	= nsim_bpf_finalize,
-};
-
 static bool nsim_xdp_offload_active(struct netdevsim *ns)
 {
 	return ns->xdp_hw.prog;
@@ -263,6 +258,24 @@ static int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog)
 	return 0;
 }
 
+static int nsim_bpf_verifier_prep(struct bpf_prog *prog)
+{
+	struct netdevsim *ns = netdev_priv(prog->aux->offload->netdev);
+
+	if (!ns->bpf_bind_accept)
+		return -EOPNOTSUPP;
+
+	return nsim_bpf_create_prog(ns, prog);
+}
+
+static int nsim_bpf_translate(struct bpf_prog *prog)
+{
+	struct nsim_bpf_bound_prog *state = prog->aux->offload->dev_priv;
+
+	state->state = "xlated";
+	return 0;
+}
+
 static void nsim_bpf_destroy_prog(struct bpf_prog *prog)
 {
 	struct nsim_bpf_bound_prog *state;
@@ -275,6 +288,14 @@ static void nsim_bpf_destroy_prog(struct bpf_prog *prog)
 	kfree(state);
 }
 
+static const struct bpf_prog_offload_ops nsim_bpf_dev_ops = {
+	.insn_hook	= nsim_bpf_verify_insn,
+	.finalize	= nsim_bpf_finalize,
+	.prepare	= nsim_bpf_verifier_prep,
+	.translate	= nsim_bpf_translate,
+	.destroy	= nsim_bpf_destroy_prog,
+};
+
 static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
 {
 	if (bpf->prog && bpf->prog->aux->offload) {
@@ -539,24 +560,6 @@ int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
 	ASSERT_RTNL();
 
 	switch (bpf->command) {
-	case BPF_OFFLOAD_VERIFIER_PREP:
-		if (!ns->bpf_bind_accept)
-			return -EOPNOTSUPP;
-
-		err = nsim_bpf_create_prog(ns, bpf->verifier.prog);
-		if (err)
-			return err;
-
-		bpf->verifier.ops = &nsim_bpf_analyzer_ops;
-		return 0;
-	case BPF_OFFLOAD_TRANSLATE:
-		state = bpf->offload.prog->aux->offload->dev_priv;
-
-		state->state = "xlated";
-		return 0;
-	case BPF_OFFLOAD_DESTROY:
-		nsim_bpf_destroy_prog(bpf->offload.prog);
-		return 0;
 	case XDP_QUERY_PROG:
 		return xdp_attachment_query(&ns->xdp, bpf);
 	case XDP_QUERY_PROG_HW:
@@ -599,7 +602,7 @@ int nsim_bpf_init(struct netdevsim *ns)
 		if (IS_ERR_OR_NULL(ns->sdev->ddir_bpf_bound_progs))
 			return -ENOMEM;
 
-		ns->sdev->bpf_dev = bpf_offload_dev_create();
+		ns->sdev->bpf_dev = bpf_offload_dev_create(&nsim_bpf_dev_ops);
 		err = PTR_ERR_OR_ZERO(ns->sdev->bpf_dev);
 		if (err)
 			return err;