bpf: Remove location field in tcx_link

Use attach_type in bpf_link to replace the location filed, and
remove location field in tcx_link.

Signed-off-by: Tao Chen <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Acked-by: John Fastabend <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: Tao Chen

include/net/tcx.h

@@ -20,7 +20,6 @@ struct tcx_entry {
 struct tcx_link {
 	struct bpf_link link;
 	struct net_device *dev;
-	u32 location;
 };
 
 static inline void tcx_set_ingress(struct sk_buff *skb, bool ingress)

kernel/bpf/tcx.c

@@ -142,7 +142,7 @@ static int tcx_link_prog_attach(struct bpf_link *link, u32 flags, u32 id_or_fd,
 				u64 revision)
 {
 	struct tcx_link *tcx = tcx_link(link);
-	bool created, ingress = tcx->location == BPF_TCX_INGRESS;
+	bool created, ingress = link->attach_type == BPF_TCX_INGRESS;
 	struct bpf_mprog_entry *entry, *entry_new;
 	struct net_device *dev = tcx->dev;
 	int ret;
@@ -169,7 +169,7 @@ static int tcx_link_prog_attach(struct bpf_link *link, u32 flags, u32 id_or_fd,
 static void tcx_link_release(struct bpf_link *link)
 {
 	struct tcx_link *tcx = tcx_link(link);
-	bool ingress = tcx->location == BPF_TCX_INGRESS;
+	bool ingress = link->attach_type == BPF_TCX_INGRESS;
 	struct bpf_mprog_entry *entry, *entry_new;
 	struct net_device *dev;
 	int ret = 0;
@@ -204,7 +204,7 @@ static int tcx_link_update(struct bpf_link *link, struct bpf_prog *nprog,
 			   struct bpf_prog *oprog)
 {
 	struct tcx_link *tcx = tcx_link(link);
-	bool ingress = tcx->location == BPF_TCX_INGRESS;
+	bool ingress = link->attach_type == BPF_TCX_INGRESS;
 	struct bpf_mprog_entry *entry, *entry_new;
 	struct net_device *dev;
 	int ret = 0;
@@ -260,8 +260,8 @@ static void tcx_link_fdinfo(const struct bpf_link *link, struct seq_file *seq)
 
 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
 	seq_printf(seq, "attach_type:\t%u (%s)\n",
-		   tcx->location,
-		   tcx->location == BPF_TCX_INGRESS ? "ingress" : "egress");
+		   link->attach_type,
+		   link->attach_type == BPF_TCX_INGRESS ? "ingress" : "egress");
 }
 
 static int tcx_link_fill_info(const struct bpf_link *link,
@@ -276,7 +276,7 @@ static int tcx_link_fill_info(const struct bpf_link *link,
 	rtnl_unlock();
 
 	info->tcx.ifindex = ifindex;
-	info->tcx.attach_type = tcx->location;
+	info->tcx.attach_type = link->attach_type;
 	return 0;
 }
 
@@ -303,7 +303,6 @@ static int tcx_link_init(struct tcx_link *tcx,
 {
 	bpf_link_init(&tcx->link, BPF_LINK_TYPE_TCX, &tcx_link_lops, prog,
 		      attr->link_create.attach_type);
-	tcx->location = attr->link_create.attach_type;
 	tcx->dev = dev;
 	return bpf_link_prime(&tcx->link, link_primer);
 }