1 /*
2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3  *  Copyright (C) 2007 The Regents of the University of California.
4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
6  *  UCRL-CODE-235197
7  *
8  *  This file is part of the SPL, Solaris Porting Layer.
9  *
10  *  The SPL is free software; you can redistribute it and/or modify it
11  *  under the terms of the GNU General Public License as published by the
12  *  Free Software Foundation; either version 2 of the License, or (at your
13  *  option) any later version.
14  *
15  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18  *  for more details.
19  *
20  *  You should have received a copy of the GNU General Public License along
21  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
22  */
23 
24 #ifndef _SPL_KMEM_CACHE_H
25 #define	_SPL_KMEM_CACHE_H
26 
27 #include <sys/taskq.h>
28 
29 /*
30  * Slab allocation interfaces.  The SPL slab differs from the standard
31  * Linux SLAB or SLUB primarily in that each cache may be backed by slabs
32  * allocated from the physical or virtual memory address space.  The virtual
33  * slabs allow for good behavior when allocation large objects of identical
34  * size.  This slab implementation also supports both constructors and
35  * destructors which the Linux slab does not.
36  */
37 typedef enum kmc_bit {
38 	KMC_BIT_NODEBUG		= 1,	/* Default behavior */
39 	KMC_BIT_KVMEM		= 7,	/* Use kvmalloc linux allocator  */
40 	KMC_BIT_SLAB		= 8,	/* Use Linux slab cache */
41 	KMC_BIT_DEADLOCKED	= 14,	/* Deadlock detected */
42 	KMC_BIT_GROWING		= 15,	/* Growing in progress */
43 	KMC_BIT_REAPING		= 16,	/* Reaping in progress */
44 	KMC_BIT_DESTROY		= 17,	/* Destroy in progress */
45 	KMC_BIT_TOTAL		= 18,	/* Proc handler helper bit */
46 	KMC_BIT_ALLOC		= 19,	/* Proc handler helper bit */
47 	KMC_BIT_MAX		= 20,	/* Proc handler helper bit */
48 } kmc_bit_t;
49 
50 /* kmem move callback return values */
51 typedef enum kmem_cbrc {
52 	KMEM_CBRC_YES		= 0,	/* Object moved */
53 	KMEM_CBRC_NO		= 1,	/* Object not moved */
54 	KMEM_CBRC_LATER		= 2,	/* Object not moved, try again later */
55 	KMEM_CBRC_DONT_NEED	= 3,	/* Neither object is needed */
56 	KMEM_CBRC_DONT_KNOW	= 4,	/* Object unknown */
57 } kmem_cbrc_t;
58 
59 #define	KMC_NODEBUG		(1 << KMC_BIT_NODEBUG)
60 #define	KMC_KVMEM		(1 << KMC_BIT_KVMEM)
61 #define	KMC_SLAB		(1 << KMC_BIT_SLAB)
62 #define	KMC_DEADLOCKED		(1 << KMC_BIT_DEADLOCKED)
63 #define	KMC_GROWING		(1 << KMC_BIT_GROWING)
64 #define	KMC_REAPING		(1 << KMC_BIT_REAPING)
65 #define	KMC_DESTROY		(1 << KMC_BIT_DESTROY)
66 #define	KMC_TOTAL		(1 << KMC_BIT_TOTAL)
67 #define	KMC_ALLOC		(1 << KMC_BIT_ALLOC)
68 #define	KMC_MAX			(1 << KMC_BIT_MAX)
69 
70 #define	KMC_REAP_CHUNK		INT_MAX
71 #define	KMC_DEFAULT_SEEKS	1
72 
73 #define	KMC_RECLAIM_ONCE	0x1	/* Force a single shrinker pass */
74 
75 extern struct list_head spl_kmem_cache_list;
76 extern struct rw_semaphore spl_kmem_cache_sem;
77 
78 #define	SKM_MAGIC			0x2e2e2e2e
79 #define	SKO_MAGIC			0x20202020
80 #define	SKS_MAGIC			0x22222222
81 #define	SKC_MAGIC			0x2c2c2c2c
82 
83 #define	SPL_KMEM_CACHE_OBJ_PER_SLAB	8	/* Target objects per slab */
84 #define	SPL_KMEM_CACHE_ALIGN		8	/* Default object alignment */
85 #ifdef _LP64
86 #define	SPL_KMEM_CACHE_MAX_SIZE		32	/* Max slab size in MB */
87 #else
88 #define	SPL_KMEM_CACHE_MAX_SIZE		4	/* Max slab size in MB */
89 #endif
90 
91 #define	SPL_MAX_ORDER			(MAX_ORDER - 3)
92 #define	SPL_MAX_ORDER_NR_PAGES		(1 << (SPL_MAX_ORDER - 1))
93 
94 #ifdef CONFIG_SLUB
95 #define	SPL_MAX_KMEM_CACHE_ORDER	PAGE_ALLOC_COSTLY_ORDER
96 #define	SPL_MAX_KMEM_ORDER_NR_PAGES	(1 << (SPL_MAX_KMEM_CACHE_ORDER - 1))
97 #else
98 #define	SPL_MAX_KMEM_ORDER_NR_PAGES	(KMALLOC_MAX_SIZE >> PAGE_SHIFT)
99 #endif
100 
101 #define	POINTER_IS_VALID(p)		0	/* Unimplemented */
102 #define	POINTER_INVALIDATE(pp)			/* Unimplemented */
103 
104 typedef int (*spl_kmem_ctor_t)(void *, void *, int);
105 typedef void (*spl_kmem_dtor_t)(void *, void *);
106 
107 typedef struct spl_kmem_magazine {
108 	uint32_t		skm_magic;	/* Sanity magic */
109 	uint32_t		skm_avail;	/* Available objects */
110 	uint32_t		skm_size;	/* Magazine size */
111 	uint32_t		skm_refill;	/* Batch refill size */
112 	struct spl_kmem_cache	*skm_cache;	/* Owned by cache */
113 	unsigned int		skm_cpu;	/* Owned by cpu */
114 	void			*skm_objs[0];	/* Object pointers */
115 } spl_kmem_magazine_t;
116 
117 typedef struct spl_kmem_obj {
118 	uint32_t		sko_magic;	/* Sanity magic */
119 	void			*sko_addr;	/* Buffer address */
120 	struct spl_kmem_slab	*sko_slab;	/* Owned by slab */
121 	struct list_head	sko_list;	/* Free object list linkage */
122 } spl_kmem_obj_t;
123 
124 typedef struct spl_kmem_slab {
125 	uint32_t		sks_magic;	/* Sanity magic */
126 	uint32_t		sks_objs;	/* Objects per slab */
127 	struct spl_kmem_cache	*sks_cache;	/* Owned by cache */
128 	struct list_head	sks_list;	/* Slab list linkage */
129 	struct list_head	sks_free_list;	/* Free object list */
130 	unsigned long		sks_age;	/* Last modify jiffie */
131 	uint32_t		sks_ref;	/* Ref count used objects */
132 } spl_kmem_slab_t;
133 
134 typedef struct spl_kmem_alloc {
135 	struct spl_kmem_cache	*ska_cache;	/* Owned by cache */
136 	int			ska_flags;	/* Allocation flags */
137 	taskq_ent_t		ska_tqe;	/* Task queue entry */
138 } spl_kmem_alloc_t;
139 
140 typedef struct spl_kmem_emergency {
141 	struct rb_node		ske_node;	/* Emergency tree linkage */
142 	unsigned long		ske_obj;	/* Buffer address */
143 } spl_kmem_emergency_t;
144 
145 typedef struct spl_kmem_cache {
146 	uint32_t		skc_magic;	/* Sanity magic */
147 	uint32_t		skc_name_size;	/* Name length */
148 	char			*skc_name;	/* Name string */
149 	spl_kmem_magazine_t	**skc_mag;	/* Per-CPU warm cache */
150 	uint32_t		skc_mag_size;	/* Magazine size */
151 	uint32_t		skc_mag_refill;	/* Magazine refill count */
152 	spl_kmem_ctor_t		skc_ctor;	/* Constructor */
153 	spl_kmem_dtor_t		skc_dtor;	/* Destructor */
154 	void			*skc_private;	/* Private data */
155 	void			*skc_vmp;	/* Unused */
156 	struct kmem_cache	*skc_linux_cache; /* Linux slab cache if used */
157 	unsigned long		skc_flags;	/* Flags */
158 	uint32_t		skc_obj_size;	/* Object size */
159 	uint32_t		skc_obj_align;	/* Object alignment */
160 	uint32_t		skc_slab_objs;	/* Objects per slab */
161 	uint32_t		skc_slab_size;	/* Slab size */
162 	atomic_t		skc_ref;	/* Ref count callers */
163 	taskqid_t		skc_taskqid;	/* Slab reclaim task */
164 	struct list_head	skc_list;	/* List of caches linkage */
165 	struct list_head	skc_complete_list; /* Completely alloc'ed */
166 	struct list_head	skc_partial_list;  /* Partially alloc'ed */
167 	struct rb_root		skc_emergency_tree; /* Min sized objects */
168 	spinlock_t		skc_lock;	/* Cache lock */
169 	spl_wait_queue_head_t	skc_waitq;	/* Allocation waiters */
170 	uint64_t		skc_slab_fail;	/* Slab alloc failures */
171 	uint64_t		skc_slab_create;  /* Slab creates */
172 	uint64_t		skc_slab_destroy; /* Slab destroys */
173 	uint64_t		skc_slab_total;	/* Slab total current */
174 	uint64_t		skc_slab_alloc;	/* Slab alloc current */
175 	uint64_t		skc_slab_max;	/* Slab max historic  */
176 	uint64_t		skc_obj_total;	/* Obj total current */
177 	uint64_t		skc_obj_alloc;	/* Obj alloc current */
178 	struct percpu_counter	skc_linux_alloc;   /* Linux-backed Obj alloc  */
179 	uint64_t		skc_obj_max;	/* Obj max historic */
180 	uint64_t		skc_obj_deadlock;  /* Obj emergency deadlocks */
181 	uint64_t		skc_obj_emergency; /* Obj emergency current */
182 	uint64_t		skc_obj_emergency_max; /* Obj emergency max */
183 } spl_kmem_cache_t;
184 #define	kmem_cache_t		spl_kmem_cache_t
185 
186 extern spl_kmem_cache_t *spl_kmem_cache_create(char *name, size_t size,
187     size_t align, spl_kmem_ctor_t ctor, spl_kmem_dtor_t dtor,
188     void *reclaim, void *priv, void *vmp, int flags);
189 extern void spl_kmem_cache_set_move(spl_kmem_cache_t *,
190     kmem_cbrc_t (*)(void *, void *, size_t, void *));
191 extern void spl_kmem_cache_destroy(spl_kmem_cache_t *skc);
192 extern void *spl_kmem_cache_alloc(spl_kmem_cache_t *skc, int flags);
193 extern void spl_kmem_cache_free(spl_kmem_cache_t *skc, void *obj);
194 extern void spl_kmem_cache_set_allocflags(spl_kmem_cache_t *skc, gfp_t flags);
195 extern void spl_kmem_cache_reap_now(spl_kmem_cache_t *skc);
196 extern void spl_kmem_reap(void);
197 extern uint64_t spl_kmem_cache_inuse(kmem_cache_t *cache);
198 extern uint64_t spl_kmem_cache_entry_size(kmem_cache_t *cache);
199 
200 #define	kmem_cache_create(name, size, align, ctor, dtor, rclm, priv, vmp, fl) \
201     spl_kmem_cache_create(name, size, align, ctor, dtor, rclm, priv, vmp, fl)
202 #define	kmem_cache_set_move(skc, move)	spl_kmem_cache_set_move(skc, move)
203 #define	kmem_cache_destroy(skc)		spl_kmem_cache_destroy(skc)
204 #define	kmem_cache_alloc(skc, flags)	spl_kmem_cache_alloc(skc, flags)
205 #define	kmem_cache_free(skc, obj)	spl_kmem_cache_free(skc, obj)
206 #define	kmem_cache_reap_now(skc)	spl_kmem_cache_reap_now(skc)
207 #define	kmem_reap()			spl_kmem_reap()
208 
209 /*
210  * The following functions are only available for internal use.
211  */
212 extern int spl_kmem_cache_init(void);
213 extern void spl_kmem_cache_fini(void);
214 
215 #endif	/* _SPL_KMEM_CACHE_H */
216