xref: /openbmc/linux/mm/mm_slot.h (revision cf21eb6a)
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 */
56