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 */
15struct 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
24static 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
31static 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 */