include/net/libeth/cache.h

   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 */