mm/mm_slot.h

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #ifndef _LINUX_MM_SLOT_H
   4 #define _LINUX_MM_SLOT_H
   5
   6 #include <linux/hashtable.h>
   7 #include <linux/slab.h>
   8
   9 /*
  10  * struct mm_slot - hash lookup from mm to mm_slot
  11  * @hash: link to the mm_slots hash list
  12  * @mm_node: link into the mm_slots list
  13  * @mm: the mm that this information is valid for
  14  */
  15 struct mm_slot {
  16         struct hlist_node hash;
  17         struct list_head mm_node;
  18         struct mm_struct *mm;
  19 };
  20
  21 #define mm_slot_entry(ptr, type, member) \
  22         container_of(ptr, type, member)
  23
  24 static inline void *mm_slot_alloc(struct kmem_cache *cache)
  25 {
  26         if (!cache)     /* initialization failed */
  27                 return NULL;
  28         return kmem_cache_zalloc(cache, GFP_KERNEL);
  29 }
  30
  31 static inline void mm_slot_free(struct kmem_cache *cache, void *objp)
  32 {
  33         kmem_cache_free(cache, objp);
  34 }
  35
  36 #define mm_slot_lookup(_hashtable, _mm)                                        \
  37 ({                                                                             \
  38         struct mm_slot *tmp_slot, *mm_slot = NULL;                             \
  39                                                                                \
  40         hash_for_each_possible(_hashtable, tmp_slot, hash, (unsigned long)_mm) \
  41                 if (_mm == tmp_slot->mm) {                                     \
  42                         mm_slot = tmp_slot;                                    \
  43                         break;                                                 \
  44                 }                                                              \
  45                                                                                \
  46         mm_slot;                                                               \
  47 })
  48
  49 #define mm_slot_insert(_hashtable, _mm, _mm_slot)                              \
  50 ({                                                                             \
  51         _mm_slot->mm = _mm;                                                    \
  52         hash_add(_hashtable, &_mm_slot->hash, (unsigned long)_mm);             \
  53 })
  54
  55 #endif /* _LINUX_MM_SLOT_H */