1/* SPDX-License-Identifier: GPL-2.0-only */
 2/* Copyright (C) 2024 Intel Corporation */
 3
 4#ifndef __LIBETH_CACHE_H
 5#define __LIBETH_CACHE_H
 6
 7#include <linux/cache.h>
 8
 9/**
10 * libeth_cacheline_group_assert - make sure cacheline group size is expected
11 * @type: type of the structure containing the group
12 * @grp: group name inside the struct
13 * @sz: expected group size
14 */
15#if defined(CONFIG_64BIT) && SMP_CACHE_BYTES == 64
16#define libeth_cacheline_group_assert(type, grp, sz)			      \
17	static_assert(offsetof(type, __cacheline_group_end__##grp) -	      \
18		      offsetofend(type, __cacheline_group_begin__##grp) ==    \
19		      (sz))
20#define __libeth_cacheline_struct_assert(type, sz)			      \
21	static_assert(sizeof(type) == (sz))
22#else /* !CONFIG_64BIT || SMP_CACHE_BYTES != 64 */
23#define libeth_cacheline_group_assert(type, grp, sz)			      \
24	static_assert(offsetof(type, __cacheline_group_end__##grp) -	      \
25		      offsetofend(type, __cacheline_group_begin__##grp) <=    \
26		      (sz))
27#define __libeth_cacheline_struct_assert(type, sz)			      \
28	static_assert(sizeof(type) <= (sz))
29#endif /* !CONFIG_64BIT || SMP_CACHE_BYTES != 64 */
30
31#define __libeth_cls1(sz1)	SMP_CACHE_ALIGN(sz1)
32#define __libeth_cls2(sz1, sz2)	(SMP_CACHE_ALIGN(sz1) + SMP_CACHE_ALIGN(sz2))
33#define __libeth_cls3(sz1, sz2, sz3)					      \
34	(SMP_CACHE_ALIGN(sz1) + SMP_CACHE_ALIGN(sz2) + SMP_CACHE_ALIGN(sz3))
35#define __libeth_cls(...)						      \
36	CONCATENATE(__libeth_cls, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__)
37
38/**
39 * libeth_cacheline_struct_assert - make sure CL-based struct size is expected
40 * @type: type of the struct
41 * @...: from 1 to 3 CL group sizes (read-mostly, read-write, cold)
42 *
43 * When a struct contains several CL groups, it's difficult to predict its size
44 * on different architectures. The macro instead takes sizes of all of the
45 * groups the structure contains and generates the final struct size.
46 */
47#define libeth_cacheline_struct_assert(type, ...)			      \
48	__libeth_cacheline_struct_assert(type, __libeth_cls(__VA_ARGS__));    \
49	static_assert(__alignof(type) >= SMP_CACHE_BYTES)
50
51/**
52 * libeth_cacheline_set_assert - make sure CL-based struct layout is expected
53 * @type: type of the struct
54 * @ro: expected size of the read-mostly group
55 * @rw: expected size of the read-write group
56 * @c: expected size of the cold group
57 *
58 * Check that each group size is expected and then do final struct size check.
59 */
60#define libeth_cacheline_set_assert(type, ro, rw, c)			      \
61	libeth_cacheline_group_assert(type, read_mostly, ro);		      \
62	libeth_cacheline_group_assert(type, read_write, rw);		      \
63	libeth_cacheline_group_assert(type, cold, c);			      \
64	libeth_cacheline_struct_assert(type, ro, rw, c)
65
66#endif /* __LIBETH_CACHE_H */