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, int 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! */ 175 176 /* Definitions for align */ 177 #define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */ 178 #define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */ 179 #define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */ 180 #define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */ 181 #define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */ 182 #define UMA_ALIGN_CACHE (16 - 1) /* Cache line size align */ 183 184 /* 185 * Destroys a uma zone 186 * 187 * Arguments: 188 * zone The zone we want to destroy. 189 * wait This flag indicates whether or not we should wait for all 190 * allocations to free, or return an errno on outstanding memory. 191 * 192 * Returns: 193 * 0 on successful completion, or EWOULDBLOCK if there are outstanding 194 * allocations and the wait flag is M_NOWAIT 195 */ 196 197 int uma_zdestroy(uma_zone_t zone, int wait); 198 199 /* 200 * Allocates an item out of a zone 201 * 202 * Arguments: 203 * zone The zone we are allocating from 204 * arg This data is passed to the ctor function 205 * wait This flag indicates whether or not we are allowed to block while 206 * allocating memory for this zone should we run out. 207 * 208 * Returns: 209 * A non null pointer to an initialized element from the zone is 210 * garanteed if the wait flag is M_WAITOK, otherwise a null pointer may be 211 * returned if the zone is empty or the ctor failed. 212 */ 213 214 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int wait); 215 216 /* 217 * Allocates an item out of a zone without supplying an argument 218 * 219 * This is just a wrapper for uma_zalloc_arg for convenience. 220 * 221 */ 222 static __inline void *uma_zalloc(uma_zone_t zone, int wait); 223 224 static __inline void * 225 uma_zalloc(uma_zone_t zone, int wait) 226 { 227 return uma_zalloc_arg(zone, NULL, wait); 228 } 229 230 /* 231 * Frees an item back into the specified zone. 232 * 233 * Arguments: 234 * zone The zone the item was originally allocated out of. 235 * item The memory to be freed. 236 * arg Argument passed to the destructor 237 * 238 * Returns: 239 * Nothing. 240 */ 241 242 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg); 243 244 /* 245 * Frees an item back to a zone without supplying an argument 246 * 247 * This is just a wrapper for uma_zfree_arg for convenience. 248 * 249 */ 250 static __inline void uma_zfree(uma_zone_t zone, void *item); 251 252 static __inline void 253 uma_zfree(uma_zone_t zone, void *item) 254 { 255 return uma_zfree_arg(zone, item, NULL); 256 } 257 258 /* 259 * XXX The rest of the prototypes in this header are h0h0 magic for the VM. 260 * If you think you need to use it for a normal zone you're probably incorrect. 261 */ 262 263 /* 264 * Backend page supplier routines 265 * 266 * Arguments: 267 * zone The zone that is requesting pages 268 * size The number of bytes being requested 269 * pflag Flags for these memory pages, see below. 270 * wait Indicates our willingness to block. 271 * 272 * Returns: 273 * A pointer to the alloced memory or NULL on failure. 274 */ 275 276 typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait); 277 278 /* 279 * Backend page free routines 280 * 281 * Arguments: 282 * item A pointer to the previously allocated pages 283 * size The original size of the allocation 284 * pflag The flags for the slab. See UMA_SLAB_* below 285 * 286 * Returns: 287 * None 288 */ 289 typedef void (*uma_free)(void *item, int size, u_int8_t pflag); 290 291 292 293 /* 294 * Sets up the uma allocator. (Called by vm_mem_init) 295 * 296 * Arguments: 297 * bootmem A pointer to memory used to bootstrap the system. 298 * 299 * Returns: 300 * Nothing 301 * 302 * Discussion: 303 * This memory is used for zones which allocate things before the 304 * backend page supplier can give us pages. It should be 305 * UMA_SLAB_SIZE * UMA_BOOT_PAGES bytes. (see uma_int.h) 306 * 307 */ 308 309 void uma_startup(void *bootmem); 310 311 /* 312 * Finishes starting up the allocator. This should 313 * be called when kva is ready for normal allocs. 314 * 315 * Arguments: 316 * hash An area of memory that will become the malloc hash 317 * elems The number of elements in this array 318 * 319 * Returns: 320 * Nothing 321 * 322 * Discussion: 323 * uma_startup2 is called by kmeminit() to prepare the malloc 324 * hash bucket, and enable use of uma for malloc ops. 325 */ 326 327 void uma_startup2(void *hash, u_long elems); 328 329 /* 330 * Reclaims unused memory for all zones 331 * 332 * Arguments: 333 * None 334 * Returns: 335 * None 336 * 337 * This should only be called by the page out daemon. 338 */ 339 340 void uma_reclaim(void); 341 342 /* 343 * Switches the backing object of a zone 344 * 345 * Arguments: 346 * zone The zone to update 347 * obj The obj to use for future allocations 348 * size The size of the object to allocate 349 * 350 * Returns: 351 * 0 if kva space can not be allocated 352 * 1 if successful 353 * 354 * Discussion: 355 * A NULL object can be used and uma will allocate one for you. Setting 356 * the size will limit the amount of memory allocated to this zone. 357 * 358 */ 359 struct vm_object; 360 int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size); 361 362 /* 363 * Sets a high limit on the number of items allowed in a zone 364 * 365 * Arguments: 366 * zone The zone to limit 367 * 368 * Returns: 369 * Nothing 370 */ 371 void uma_zone_set_max(uma_zone_t zone, int nitems); 372 373 /* 374 * Replaces the standard page_alloc or obj_alloc functions for this zone 375 * 376 * Arguments: 377 * zone The zone whos back end allocator is being changed. 378 * allocf A pointer to the allocation function 379 * 380 * Returns: 381 * Nothing 382 * 383 * Discussion: 384 * This could be used to implement pageable allocation, or perhaps 385 * even DMA allocators if used in conjunction with the OFFPAGE 386 * zone flag. 387 */ 388 389 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf); 390 391 /* 392 * Used for freeing memory provided by the allocf above 393 * 394 * Arguments: 395 * zone The zone that intends to use this free routine. 396 * freef The page freeing routine. 397 * 398 * Returns: 399 * Nothing 400 */ 401 402 void uma_zone_set_freef(uma_zone_t zone, uma_free freef); 403 404 /* 405 * These flags are setable in the allocf and visable in the freef. 406 */ 407 #define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */ 408 #define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */ 409 #define UMA_SLAB_KMAP 0x04 /* Slab alloced from kernel_map */ 410 #define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */ 411 #define UMA_SLAB_OFFP 0x10 /* Slab is managed seperately */ 412 #define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */ 413 /* 0x40 and 0x80 are available */ 414 415 /* 416 * Used to pre-fill a zone with some number of items 417 * 418 * Arguments: 419 * zone The zone to fill 420 * itemcnt The number of items to reserve 421 * 422 * Returns: 423 * Nothing 424 * 425 * NOTE: This is blocking and should only be done at startup 426 */ 427 void uma_prealloc(uma_zone_t zone, int itemcnt); 428 429 430 #endif 431