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 */ 176 177 /* Definitions for align */ 178 #define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */ 179 #define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */ 180 #define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */ 181 #define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */ 182 #define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */ 183 #define UMA_ALIGN_CACHE (16 - 1) /* Cache line size align */ 184 185 /* 186 * Destroys an empty uma zone. If the zone is not empty uma complains loudly. 187 * 188 * Arguments: 189 * zone The zone we want to destroy. 190 * 191 */ 192 193 void uma_zdestroy(uma_zone_t zone); 194 195 /* 196 * Allocates an item out of a zone 197 * 198 * Arguments: 199 * zone The zone we are allocating from 200 * arg This data is passed to the ctor function 201 * flags See sys/malloc.h for available flags. 202 * 203 * Returns: 204 * A non null pointer to an initialized element from the zone is 205 * garanteed if the wait flag is M_WAITOK, otherwise a null pointer may be 206 * returned if the zone is empty or the ctor failed. 207 */ 208 209 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags); 210 211 /* 212 * Allocates an item out of a zone without supplying an argument 213 * 214 * This is just a wrapper for uma_zalloc_arg for convenience. 215 * 216 */ 217 static __inline void *uma_zalloc(uma_zone_t zone, int flags); 218 219 static __inline void * 220 uma_zalloc(uma_zone_t zone, int flags) 221 { 222 return uma_zalloc_arg(zone, NULL, flags); 223 } 224 225 /* 226 * Frees an item back into the specified zone. 227 * 228 * Arguments: 229 * zone The zone the item was originally allocated out of. 230 * item The memory to be freed. 231 * arg Argument passed to the destructor 232 * 233 * Returns: 234 * Nothing. 235 */ 236 237 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg); 238 239 /* 240 * Frees an item back to a zone without supplying an argument 241 * 242 * This is just a wrapper for uma_zfree_arg for convenience. 243 * 244 */ 245 static __inline void uma_zfree(uma_zone_t zone, void *item); 246 247 static __inline void 248 uma_zfree(uma_zone_t zone, void *item) 249 { 250 return uma_zfree_arg(zone, item, NULL); 251 } 252 253 /* 254 * XXX The rest of the prototypes in this header are h0h0 magic for the VM. 255 * If you think you need to use it for a normal zone you're probably incorrect. 256 */ 257 258 /* 259 * Backend page supplier routines 260 * 261 * Arguments: 262 * zone The zone that is requesting pages 263 * size The number of bytes being requested 264 * pflag Flags for these memory pages, see below. 265 * wait Indicates our willingness to block. 266 * 267 * Returns: 268 * A pointer to the alloced memory or NULL on failure. 269 */ 270 271 typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait); 272 273 /* 274 * Backend page free routines 275 * 276 * Arguments: 277 * item A pointer to the previously allocated pages 278 * size The original size of the allocation 279 * pflag The flags for the slab. See UMA_SLAB_* below 280 * 281 * Returns: 282 * None 283 */ 284 typedef void (*uma_free)(void *item, int size, u_int8_t pflag); 285 286 287 288 /* 289 * Sets up the uma allocator. (Called by vm_mem_init) 290 * 291 * Arguments: 292 * bootmem A pointer to memory used to bootstrap the system. 293 * 294 * Returns: 295 * Nothing 296 * 297 * Discussion: 298 * This memory is used for zones which allocate things before the 299 * backend page supplier can give us pages. It should be 300 * UMA_SLAB_SIZE * UMA_BOOT_PAGES bytes. (see uma_int.h) 301 * 302 */ 303 304 void uma_startup(void *bootmem); 305 306 /* 307 * Finishes starting up the allocator. This should 308 * be called when kva is ready for normal allocs. 309 * 310 * Arguments: 311 * hash An area of memory that will become the malloc hash 312 * elems The number of elements in this array 313 * 314 * Returns: 315 * Nothing 316 * 317 * Discussion: 318 * uma_startup2 is called by kmeminit() to prepare the malloc 319 * hash bucket, and enable use of uma for malloc ops. 320 */ 321 322 void uma_startup2(void *hash, u_long elems); 323 324 /* 325 * Reclaims unused memory for all zones 326 * 327 * Arguments: 328 * None 329 * Returns: 330 * None 331 * 332 * This should only be called by the page out daemon. 333 */ 334 335 void uma_reclaim(void); 336 337 /* 338 * Switches the backing object of a zone 339 * 340 * Arguments: 341 * zone The zone to update 342 * obj The obj to use for future allocations 343 * size The size of the object to allocate 344 * 345 * Returns: 346 * 0 if kva space can not be allocated 347 * 1 if successful 348 * 349 * Discussion: 350 * A NULL object can be used and uma will allocate one for you. Setting 351 * the size will limit the amount of memory allocated to this zone. 352 * 353 */ 354 struct vm_object; 355 int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size); 356 357 /* 358 * Sets a high limit on the number of items allowed in a zone 359 * 360 * Arguments: 361 * zone The zone to limit 362 * 363 * Returns: 364 * Nothing 365 */ 366 void uma_zone_set_max(uma_zone_t zone, int nitems); 367 368 /* 369 * Replaces the standard page_alloc or obj_alloc functions for this zone 370 * 371 * Arguments: 372 * zone The zone whos back end allocator is being changed. 373 * allocf A pointer to the allocation function 374 * 375 * Returns: 376 * Nothing 377 * 378 * Discussion: 379 * This could be used to implement pageable allocation, or perhaps 380 * even DMA allocators if used in conjunction with the OFFPAGE 381 * zone flag. 382 */ 383 384 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf); 385 386 /* 387 * Used for freeing memory provided by the allocf above 388 * 389 * Arguments: 390 * zone The zone that intends to use this free routine. 391 * freef The page freeing routine. 392 * 393 * Returns: 394 * Nothing 395 */ 396 397 void uma_zone_set_freef(uma_zone_t zone, uma_free freef); 398 399 /* 400 * These flags are setable in the allocf and visable in the freef. 401 */ 402 #define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */ 403 #define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */ 404 #define UMA_SLAB_KMAP 0x04 /* Slab alloced from kernel_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