[PATCH bpf-next v1 09/14] resolve_btfids: Emit a decl tag for kfuncs with KF_FASTCALL

[Ihor Solodrai <ihor.solodrai@linux.dev>]

Following bpf_kfunc, also emit the bpf_fastcall decl tag for kfuncs
marked with KF_FASTCALL, so resolve_btfids becomes the source of truth
for this annotation too.

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
---
 tools/bpf/resolve_btfids/main.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index 30a07ec4ebb6..f276200b1a68 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -161,6 +161,7 @@ struct object {
 	int max_addr_syms;
 };
 
+#define KF_FASTCALL (1 << 12)
 #define KF_IMPLICIT_ARGS (1 << 16)
 #define KF_IMPL_SUFFIX "_impl"
 
@@ -1309,6 +1310,12 @@ static int btf2btf(struct object *obj)
 		if (err)
 			goto out;
 
+		if (kfunc->flags & KF_FASTCALL) {
+			err = ensure_decl_tag(&ctx, "bpf_fastcall", kfunc->btf_id, -1);
+			if (err)
+				goto out;
+		}
+
 		if (kfunc->flags & KF_IMPLICIT_ARGS) {
 			err = process_kfunc_with_implicit_args(&ctx, kfunc);
 			if (err)
-- 
2.54.0