1 /* 2 * Copyright (c) 2002, Jeffrey Roberson <jroberson@chesapeake.net> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 * 28 */ 29 30 /* 31 * uma.h - External definitions for the Universal Memory Allocator 32 * 33 * Jeff Roberson <jroberson@chesapeake.net> 34 */ 35 36 #ifndef VM_UMA_H 37 #define VM_UMA_H 38 39 #include <sys/param.h> /* For NULL */ 40 #include <sys/malloc.h> /* For M_* */ 41 42 /* User visable parameters */ 43 #define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */ 44 45 /* Types and type defs */ 46 47 struct uma_zone; 48 /* Opaque type used as a handle to the zone */ 49 typedef struct uma_zone * uma_zone_t; 50 51 /* 52 * Item constructor 53 * 54 * Arguments: 55 * item A pointer to the memory which has been allocated. 56 * arg The arg field passed to uma_zalloc_arg 57 * size The size of the allocated item 58 * 59 * Returns: 60 * Nothing 61 * 62 * Discussion: 63 * The constructor is called just before the memory is returned 64 * to the user. It may block if neccisary. 65 */ 66 typedef void (*uma_ctor)(void *mem, int size, void *arg); 67 68 /* 69 * Item destructor 70 * 71 * Arguments: 72 * item A pointer to the memory which has been allocated. 73 * size The size of the item being destructed. 74 * arg Argument passed through uma_zfree_arg 75 * 76 * Returns: 77 * Nothing 78 * 79 * Discussion: 80 * The destructor may perform operations that differ from those performed 81 * by the initializer, but it must leave the object in the same state. 82 * This IS type stable storage. This is called after EVERY zfree call. 83 */ 84 typedef void (*uma_dtor)(void *mem, int size, void *arg); 85 86 /* 87 * Item initializer 88 * 89 * Arguments: 90 * item A pointer to the memory which has been allocated. 91 * size The size of the item being initialized. 92 * 93 * Returns: 94 * Nothing 95 * 96 * Discussion: 97 * The initializer is called when the memory is cached in the uma zone. 98 * this should be the same state that the destructor leaves the object in. 99 */ 100 typedef void (*uma_init)(void *mem, int size); 101 102 /* 103 * Item discard function 104 * 105 * Arguments: 106 * item A pointer to memory which has been 'freed' but has not left the 107 * zone's cache. 108 * size The size of the item being discarded. 109 * 110 * Returns: 111 * Nothing 112 * 113 * Discussion: 114 * This routine is called when memory leaves a zone and is returned to the 115 * system for other uses. It is the counter part to the init function. 116 */ 117 typedef void (*uma_fini)(void *mem, int size); 118 119 /* 120 * What's the difference between initializing and constructing? 121 * 122 * The item is initialized when it is cached, and this is the state that the 123 * object should be in when returned to the allocator. The purpose of this is 124 * to remove some code which would otherwise be called on each allocation by 125 * utilizing a known, stable state. This differs from the constructor which 126 * will be called on EVERY allocation. 127 * 128 * For example, in the initializer you may want to initialize embeded locks, 129 * NULL list pointers, set up initial states, magic numbers, etc. This way if 130 * the object is held in the allocator and re-used it won't be neccisary to 131 * re-initialize it. 132 * 133 * The constructor may be used to lock a data structure, link it on to lists, 134 * bump reference counts or total counts of outstanding structures, etc. 135 * 136 */ 137 138 139 /* Function proto types */ 140 141 /* 142 * Create a new uma zone 143 * 144 * Arguments: 145 * name The text name of the zone for debugging and stats, this memory 146 * should not be freed until the zone has been deallocated. 147 * size The size of the object that is being created. 148 * ctor The constructor that is called when the object is allocated 149 * dtor The destructor that is called when the object is freed. 150 * init An initializer that sets up the initial state of the memory. 151 * fini A discard function that undoes initialization done by init. 152 * ctor/dtor/init/fini may all be null, see notes above. 153 * align A bitmask that corisponds to the requested alignment 154 * eg 4 would be 0x3 155 * flags A set of parameters that control the behavior of the zone 156 * 157 * Returns: 158 * A pointer to a structure which is intended to be opaque to users of 159 * the interface. The value may be null if the wait flag is not set. 160 */ 161 162 uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor, 163 uma_init uminit, uma_fini fini, int align, 164 u_int16_t flags); 165 166 /* Definitions for uma_zcreate flags */ 167 #define UMA_ZONE_PAGEABLE 0x0001 /* Return items not fully backed by 168 physical memory XXX Not yet */ 169 #define UMA_ZONE_ZINIT 0x0002 /* Initialize with zeros */ 170 #define UMA_ZONE_STATIC 0x0004 /* Staticly sized zone */ 171 #define UMA_ZONE_OFFPAGE 0x0008 /* Force the slab structure allocation 172 off of the real memory */ 173 #define UMA_ZONE_MALLOC 0x0010 /* For use by malloc(9) only! */ 174 #define UMA_ZONE_NOFREE 0x0020 /* Do not free slabs of this type! */ 175 #define UMA_ZONE_MTXCLASS 0x0040 /* Create a new lock class */ 176 #define UMA_ZONE_VM 0x0080 /* Used for internal vm datastructures */ 177 178 /* Definitions for align */ 179 #define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */ 180 #define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */ 181 #define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */ 182 #define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */ 183 #define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */ 184 #define UMA_ALIGN_CACHE (16 - 1) /* Cache line size align */ 185 186 /* 187 * Destroys an empty uma zone. If the zone is not empty uma complains loudly. 188 * 189 * Arguments: 190 * zone The zone we want to destroy. 191 * 192 */ 193 194 void uma_zdestroy(uma_zone_t zone); 195 196 /* 197 * Allocates an item out of a zone 198 * 199 * Arguments: 200 * zone The zone we are allocating from 201 * arg This data is passed to the ctor function 202 * flags See sys/malloc.h for available flags. 203 * 204 * Returns: 205 * A non null pointer to an initialized element from the zone is 206 * garanteed if the wait flag is M_WAITOK, otherwise a null pointer may be 207 * returned if the zone is empty or the ctor failed. 208 */ 209 210 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags); 211 212 /* 213 * Allocates an item out of a zone without supplying an argument 214 * 215 * This is just a wrapper for uma_zalloc_arg for convenience. 216 * 217 */ 218 static __inline void *uma_zalloc(uma_zone_t zone, int flags); 219 220 static __inline void * 221 uma_zalloc(uma_zone_t zone, int flags) 222 { 223 return uma_zalloc_arg(zone, NULL, flags); 224 } 225 226 /* 227 * Frees an item back into the specified zone. 228 * 229 * Arguments: 230 * zone The zone the item was originally allocated out of. 231 * item The memory to be freed. 232 * arg Argument passed to the destructor 233 * 234 * Returns: 235 * Nothing. 236 */ 237 238 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg); 239 240 /* 241 * Frees an item back to a zone without supplying an argument 242 * 243 * This is just a wrapper for uma_zfree_arg for convenience. 244 * 245 */ 246 static __inline void uma_zfree(uma_zone_t zone, void *item); 247 248 static __inline void 249 uma_zfree(uma_zone_t zone, void *item) 250 { 251 uma_zfree_arg(zone, item, NULL); 252 } 253 254 /* 255 * XXX The rest of the prototypes in this header are h0h0 magic for the VM. 256 * If you think you need to use it for a normal zone you're probably incorrect. 257 */ 258 259 /* 260 * Backend page supplier routines 261 * 262 * Arguments: 263 * zone The zone that is requesting pages 264 * size The number of bytes being requested 265 * pflag Flags for these memory pages, see below. 266 * wait Indicates our willingness to block. 267 * 268 * Returns: 269 * A pointer to the alloced memory or NULL on failure. 270 */ 271 272 typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait); 273 274 /* 275 * Backend page free routines 276 * 277 * Arguments: 278 * item A pointer to the previously allocated pages 279 * size The original size of the allocation 280 * pflag The flags for the slab. See UMA_SLAB_* below 281 * 282 * Returns: 283 * None 284 */ 285 typedef void (*uma_free)(void *item, int size, u_int8_t pflag); 286 287 288 289 /* 290 * Sets up the uma allocator. (Called by vm_mem_init) 291 * 292 * Arguments: 293 * bootmem A pointer to memory used to bootstrap the system. 294 * 295 * Returns: 296 * Nothing 297 * 298 * Discussion: 299 * This memory is used for zones which allocate things before the 300 * backend page supplier can give us pages. It should be 301 * UMA_SLAB_SIZE * UMA_BOOT_PAGES bytes. (see uma_int.h) 302 * 303 */ 304 305 void uma_startup(void *bootmem); 306 307 /* 308 * Finishes starting up the allocator. This should 309 * be called when kva is ready for normal allocs. 310 * 311 * Arguments: 312 * hash An area of memory that will become the malloc hash 313 * elems The number of elements in this array 314 * 315 * Returns: 316 * Nothing 317 * 318 * Discussion: 319 * uma_startup2 is called by kmeminit() to prepare the malloc 320 * hash bucket, and enable use of uma for malloc ops. 321 */ 322 323 void uma_startup2(void *hash, u_long elems); 324 325 /* 326 * Reclaims unused memory for all zones 327 * 328 * Arguments: 329 * None 330 * Returns: 331 * None 332 * 333 * This should only be called by the page out daemon. 334 */ 335 336 void uma_reclaim(void); 337 338 /* 339 * Switches the backing object of a zone 340 * 341 * Arguments: 342 * zone The zone to update 343 * obj The obj to use for future allocations 344 * size The size of the object to allocate 345 * 346 * Returns: 347 * 0 if kva space can not be allocated 348 * 1 if successful 349 * 350 * Discussion: 351 * A NULL object can be used and uma will allocate one for you. Setting 352 * the size will limit the amount of memory allocated to this zone. 353 * 354 */ 355 struct vm_object; 356 int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size); 357 358 /* 359 * Sets a high limit on the number of items allowed in a zone 360 * 361 * Arguments: 362 * zone The zone to limit 363 * 364 * Returns: 365 * Nothing 366 */ 367 void uma_zone_set_max(uma_zone_t zone, int nitems); 368 369 /* 370 * Replaces the standard page_alloc or obj_alloc functions for this zone 371 * 372 * Arguments: 373 * zone The zone whos back end allocator is being changed. 374 * allocf A pointer to the allocation function 375 * 376 * Returns: 377 * Nothing 378 * 379 * Discussion: 380 * This could be used to implement pageable allocation, or perhaps 381 * even DMA allocators if used in conjunction with the OFFPAGE 382 * zone flag. 383 */ 384 385 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf); 386 387 /* 388 * Used for freeing memory provided by the allocf above 389 * 390 * Arguments: 391 * zone The zone that intends to use this free routine. 392 * freef The page freeing routine. 393 * 394 * Returns: 395 * Nothing 396 */ 397 398 void uma_zone_set_freef(uma_zone_t zone, uma_free freef); 399 400 /* 401 * These flags are setable in the allocf and visable in the freef. 402 */ 403 #define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */ 404 #define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */ 405 #define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */ 406 #define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */ 407 #define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */ 408 /* 0x40 and 0x80 are available */ 409 410 /* 411 * Used to pre-fill a zone with some number of items 412 * 413 * Arguments: 414 * zone The zone to fill 415 * itemcnt The number of items to reserve 416 * 417 * Returns: 418 * Nothing 419 * 420 * NOTE: This is blocking and should only be done at startup 421 */ 422 void uma_prealloc(uma_zone_t zone, int itemcnt); 423 424 425 #endif 426