xref: /linux/tools/sched_ext/include/scx/compat.bpf.h (revision 5209c03c8ed215357a4827496a71fd32167d83ef)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
4  * Copyright (c) 2024 Tejun Heo <tj@kernel.org>
5  * Copyright (c) 2024 David Vernet <dvernet@meta.com>
6  */
7 #ifndef __SCX_COMPAT_BPF_H
8 #define __SCX_COMPAT_BPF_H
9 
10 #define __COMPAT_ENUM_OR_ZERO(__type, __ent)					\
11 ({										\
12 	__type __ret = 0;							\
13 	if (bpf_core_enum_value_exists(__type, __ent))				\
14 		__ret = __ent;							\
15 	__ret;									\
16 })
17 
18 /* v6.12: 819513666966 ("sched_ext: Add cgroup support") */
19 #define __COMPAT_scx_bpf_task_cgroup(p)						\
20 	(bpf_ksym_exists(scx_bpf_task_cgroup) ?					\
21 	 scx_bpf_task_cgroup((p)) : NULL)
22 
23 /* v6.12: 4c30f5ce4f7a ("sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()") */
24 #define __COMPAT_scx_bpf_dispatch_from_dsq_set_slice(it, slice)			\
25 	(bpf_ksym_exists(scx_bpf_dispatch_from_dsq_set_slice) ?			\
26 	 scx_bpf_dispatch_from_dsq_set_slice((it), (slice)) : (void)0)
27 #define __COMPAT_scx_bpf_dispatch_from_dsq_set_vtime(it, vtime)			\
28 	(bpf_ksym_exists(scx_bpf_dispatch_from_dsq_set_vtime) ?			\
29 	 scx_bpf_dispatch_from_dsq_set_vtime((it), (vtime)) : (void)0)
30 #define __COMPAT_scx_bpf_dispatch_from_dsq(it, p, dsq_id, enq_flags)		\
31 	(bpf_ksym_exists(scx_bpf_dispatch_from_dsq) ?				\
32 	 scx_bpf_dispatch_from_dsq((it), (p), (dsq_id), (enq_flags)) : false)
33 #define __COMPAT_scx_bpf_dispatch_vtime_from_dsq(it, p, dsq_id, enq_flags)	\
34 	(bpf_ksym_exists(scx_bpf_dispatch_vtime_from_dsq) ?			\
35 	 scx_bpf_dispatch_vtime_from_dsq((it), (p), (dsq_id), (enq_flags)) : false)
36 
37 /*
38  * v6.13: The verb `dispatch` was too overloaded and confusing. kfuncs are
39  * renamed to unload the verb.
40  *
41  * Build error is triggered if old names are used. New binaries work with both
42  * new and old names. The compat macros will be removed on v6.15 release.
43  */
44 void scx_bpf_dispatch___compat(struct task_struct *p, u64 dsq_id, u64 slice, u64 enq_flags) __ksym __weak;
45 void scx_bpf_dispatch_vtime___compat(struct task_struct *p, u64 dsq_id, u64 slice, u64 vtime, u64 enq_flags) __ksym __weak;
46 bool scx_bpf_consume___compat(u64 dsq_id) __ksym __weak;
47 
48 #define scx_bpf_dsq_insert(p, dsq_id, slice, enq_flags)				\
49 	(bpf_ksym_exists(scx_bpf_dsq_insert) ?					\
50 	 scx_bpf_dsq_insert((p), (dsq_id), (slice), (enq_flags)) :		\
51 	 scx_bpf_dispatch___compat((p), (dsq_id), (slice), (enq_flags)))
52 
53 #define scx_bpf_dsq_insert_vtime(p, dsq_id, slice, vtime, enq_flags)		\
54 	(bpf_ksym_exists(scx_bpf_dsq_insert_vtime) ?				\
55 	 scx_bpf_dsq_insert_vtime((p), (dsq_id), (slice), (vtime), (enq_flags)) : \
56 	 scx_bpf_dispatch_vtime___compat((p), (dsq_id), (slice), (vtime), (enq_flags)))
57 
58 #define scx_bpf_dsq_move_to_local(dsq_id)					\
59 	(bpf_ksym_exists(scx_bpf_dsq_move_to_local) ?				\
60 	 scx_bpf_dsq_move_to_local((dsq_id)) :					\
61 	 scx_bpf_consume___compat((dsq_id)))
62 
63 #define scx_bpf_dispatch(p, dsq_id, slice, enq_flags)				\
64 	_Static_assert(false, "scx_bpf_dispatch() renamed to scx_bpf_dsq_insert()")
65 
66 #define scx_bpf_dispatch_vtime(p, dsq_id, slice, vtime, enq_flags)		\
67 	_Static_assert(false, "scx_bpf_dispatch_vtime() renamed to scx_bpf_dsq_insert_vtime()")
68 
69 #define scx_bpf_consume(dsq_id) ({						\
70 	_Static_assert(false, "scx_bpf_consume() renamed to scx_bpf_dsq_move_to_local()"); \
71 	false;									\
72 })
73 
74 /*
75  * Define sched_ext_ops. This may be expanded to define multiple variants for
76  * backward compatibility. See compat.h::SCX_OPS_LOAD/ATTACH().
77  */
78 #define SCX_OPS_DEFINE(__name, ...)						\
79 	SEC(".struct_ops.link")							\
80 	struct sched_ext_ops __name = {						\
81 		__VA_ARGS__,							\
82 	};
83 
84 #endif	/* __SCX_COMPAT_BPF_H */
85