xref: /linux/include/net/libeth/cache.h (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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 */
67