| 1 | /* $NetBSD: uvm_km.c,v 1.141 2016/07/27 16:45:00 maxv Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1997 Charles D. Cranor and Washington University. |
| 5 | * Copyright (c) 1991, 1993, The Regents of the University of California. |
| 6 | * |
| 7 | * All rights reserved. |
| 8 | * |
| 9 | * This code is derived from software contributed to Berkeley by |
| 10 | * The Mach Operating System project at Carnegie-Mellon University. |
| 11 | * |
| 12 | * Redistribution and use in source and binary forms, with or without |
| 13 | * modification, are permitted provided that the following conditions |
| 14 | * are met: |
| 15 | * 1. Redistributions of source code must retain the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer. |
| 17 | * 2. Redistributions in binary form must reproduce the above copyright |
| 18 | * notice, this list of conditions and the following disclaimer in the |
| 19 | * documentation and/or other materials provided with the distribution. |
| 20 | * 3. Neither the name of the University nor the names of its contributors |
| 21 | * may be used to endorse or promote products derived from this software |
| 22 | * without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | * |
| 36 | * @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 |
| 37 | * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp |
| 38 | * |
| 39 | * |
| 40 | * Copyright (c) 1987, 1990 Carnegie-Mellon University. |
| 41 | * All rights reserved. |
| 42 | * |
| 43 | * Permission to use, copy, modify and distribute this software and |
| 44 | * its documentation is hereby granted, provided that both the copyright |
| 45 | * notice and this permission notice appear in all copies of the |
| 46 | * software, derivative works or modified versions, and any portions |
| 47 | * thereof, and that both notices appear in supporting documentation. |
| 48 | * |
| 49 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" |
| 50 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND |
| 51 | * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. |
| 52 | * |
| 53 | * Carnegie Mellon requests users of this software to return to |
| 54 | * |
| 55 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU |
| 56 | * School of Computer Science |
| 57 | * Carnegie Mellon University |
| 58 | * Pittsburgh PA 15213-3890 |
| 59 | * |
| 60 | * any improvements or extensions that they make and grant Carnegie the |
| 61 | * rights to redistribute these changes. |
| 62 | */ |
| 63 | |
| 64 | /* |
| 65 | * uvm_km.c: handle kernel memory allocation and management |
| 66 | */ |
| 67 | |
| 68 | /* |
| 69 | * overview of kernel memory management: |
| 70 | * |
| 71 | * the kernel virtual address space is mapped by "kernel_map." kernel_map |
| 72 | * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS. |
| 73 | * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map). |
| 74 | * |
| 75 | * the kernel_map has several "submaps." submaps can only appear in |
| 76 | * the kernel_map (user processes can't use them). submaps "take over" |
| 77 | * the management of a sub-range of the kernel's address space. submaps |
| 78 | * are typically allocated at boot time and are never released. kernel |
| 79 | * virtual address space that is mapped by a submap is locked by the |
| 80 | * submap's lock -- not the kernel_map's lock. |
| 81 | * |
| 82 | * thus, the useful feature of submaps is that they allow us to break |
| 83 | * up the locking and protection of the kernel address space into smaller |
| 84 | * chunks. |
| 85 | * |
| 86 | * the vm system has several standard kernel submaps/arenas, including: |
| 87 | * kmem_arena => used for kmem/pool (memoryallocators(9)) |
| 88 | * pager_map => used to map "buf" structures into kernel space |
| 89 | * exec_map => used during exec to handle exec args |
| 90 | * etc... |
| 91 | * |
| 92 | * The kmem_arena is a "special submap", as it lives in a fixed map entry |
| 93 | * within the kernel_map and is controlled by vmem(9). |
| 94 | * |
| 95 | * the kernel allocates its private memory out of special uvm_objects whose |
| 96 | * reference count is set to UVM_OBJ_KERN (thus indicating that the objects |
| 97 | * are "special" and never die). all kernel objects should be thought of |
| 98 | * as large, fixed-sized, sparsely populated uvm_objects. each kernel |
| 99 | * object is equal to the size of kernel virtual address space (i.e. the |
| 100 | * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). |
| 101 | * |
| 102 | * note that just because a kernel object spans the entire kernel virtual |
| 103 | * address space doesn't mean that it has to be mapped into the entire space. |
| 104 | * large chunks of a kernel object's space go unused either because |
| 105 | * that area of kernel VM is unmapped, or there is some other type of |
| 106 | * object mapped into that range (e.g. a vnode). for submap's kernel |
| 107 | * objects, the only part of the object that can ever be populated is the |
| 108 | * offsets that are managed by the submap. |
| 109 | * |
| 110 | * note that the "offset" in a kernel object is always the kernel virtual |
| 111 | * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). |
| 112 | * example: |
| 113 | * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a |
| 114 | * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the |
| 115 | * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, |
| 116 | * then that means that the page at offset 0x235000 in kernel_object is |
| 117 | * mapped at 0xf8235000. |
| 118 | * |
| 119 | * kernel object have one other special property: when the kernel virtual |
| 120 | * memory mapping them is unmapped, the backing memory in the object is |
| 121 | * freed right away. this is done with the uvm_km_pgremove() function. |
| 122 | * this has to be done because there is no backing store for kernel pages |
| 123 | * and no need to save them after they are no longer referenced. |
| 124 | * |
| 125 | * Generic arenas: |
| 126 | * |
| 127 | * kmem_arena: |
| 128 | * Main arena controlling the kernel KVA used by other arenas. |
| 129 | * |
| 130 | * kmem_va_arena: |
| 131 | * Implements quantum caching in order to speedup allocations and |
| 132 | * reduce fragmentation. The pool(9), unless created with a custom |
| 133 | * meta-data allocator, and kmem(9) subsystems use this arena. |
| 134 | * |
| 135 | * Arenas for meta-data allocations are used by vmem(9) and pool(9). |
| 136 | * These arenas cannot use quantum cache. However, kmem_va_meta_arena |
| 137 | * compensates this by importing larger chunks from kmem_arena. |
| 138 | * |
| 139 | * kmem_va_meta_arena: |
| 140 | * Space for meta-data. |
| 141 | * |
| 142 | * kmem_meta_arena: |
| 143 | * Imports from kmem_va_meta_arena. Allocations from this arena are |
| 144 | * backed with the pages. |
| 145 | * |
| 146 | * Arena stacking: |
| 147 | * |
| 148 | * kmem_arena |
| 149 | * kmem_va_arena |
| 150 | * kmem_va_meta_arena |
| 151 | * kmem_meta_arena |
| 152 | */ |
| 153 | |
| 154 | #include <sys/cdefs.h> |
| 155 | __KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.141 2016/07/27 16:45:00 maxv Exp $" ); |
| 156 | |
| 157 | #include "opt_uvmhist.h" |
| 158 | |
| 159 | #include "opt_kmempages.h" |
| 160 | |
| 161 | #ifndef NKMEMPAGES |
| 162 | #define NKMEMPAGES 0 |
| 163 | #endif |
| 164 | |
| 165 | /* |
| 166 | * Defaults for lower and upper-bounds for the kmem_arena page count. |
| 167 | * Can be overridden by kernel config options. |
| 168 | */ |
| 169 | #ifndef NKMEMPAGES_MIN |
| 170 | #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT |
| 171 | #endif |
| 172 | |
| 173 | #ifndef NKMEMPAGES_MAX |
| 174 | #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT |
| 175 | #endif |
| 176 | |
| 177 | |
| 178 | #include <sys/param.h> |
| 179 | #include <sys/systm.h> |
| 180 | #include <sys/proc.h> |
| 181 | #include <sys/pool.h> |
| 182 | #include <sys/vmem.h> |
| 183 | #include <sys/vmem_impl.h> |
| 184 | #include <sys/kmem.h> |
| 185 | |
| 186 | #include <uvm/uvm.h> |
| 187 | |
| 188 | /* |
| 189 | * global data structures |
| 190 | */ |
| 191 | |
| 192 | struct vm_map *kernel_map = NULL; |
| 193 | |
| 194 | /* |
| 195 | * local data structues |
| 196 | */ |
| 197 | |
| 198 | static struct vm_map kernel_map_store; |
| 199 | static struct vm_map_entry kernel_image_mapent_store; |
| 200 | static struct vm_map_entry kernel_kmem_mapent_store; |
| 201 | |
| 202 | int nkmempages = 0; |
| 203 | vaddr_t kmembase; |
| 204 | vsize_t kmemsize; |
| 205 | |
| 206 | static struct vmem kmem_arena_store; |
| 207 | vmem_t *kmem_arena = NULL; |
| 208 | static struct vmem kmem_va_arena_store; |
| 209 | vmem_t *kmem_va_arena; |
| 210 | |
| 211 | /* |
| 212 | * kmeminit_nkmempages: calculate the size of kmem_arena. |
| 213 | */ |
| 214 | void |
| 215 | kmeminit_nkmempages(void) |
| 216 | { |
| 217 | int npages; |
| 218 | |
| 219 | if (nkmempages != 0) { |
| 220 | /* |
| 221 | * It's already been set (by us being here before) |
| 222 | * bail out now; |
| 223 | */ |
| 224 | return; |
| 225 | } |
| 226 | |
| 227 | #if defined(PMAP_MAP_POOLPAGE) |
| 228 | npages = (physmem / 4); |
| 229 | #else |
| 230 | npages = (physmem / 3) * 2; |
| 231 | #endif /* defined(PMAP_MAP_POOLPAGE) */ |
| 232 | |
| 233 | #ifndef NKMEMPAGES_MAX_UNLIMITED |
| 234 | if (npages > NKMEMPAGES_MAX) |
| 235 | npages = NKMEMPAGES_MAX; |
| 236 | #endif |
| 237 | |
| 238 | if (npages < NKMEMPAGES_MIN) |
| 239 | npages = NKMEMPAGES_MIN; |
| 240 | |
| 241 | nkmempages = npages; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e. |
| 246 | * KVM already allocated for text, data, bss, and static data structures). |
| 247 | * |
| 248 | * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. |
| 249 | * we assume that [vmin -> start] has already been allocated and that |
| 250 | * "end" is the end. |
| 251 | */ |
| 252 | |
| 253 | void |
| 254 | uvm_km_bootstrap(vaddr_t start, vaddr_t end) |
| 255 | { |
| 256 | bool kmem_arena_small; |
| 257 | vaddr_t base = VM_MIN_KERNEL_ADDRESS; |
| 258 | struct uvm_map_args args; |
| 259 | int error; |
| 260 | |
| 261 | UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); |
| 262 | UVMHIST_LOG(maphist, "start=%" PRIxVADDR" end=%#" PRIxVADDR, |
| 263 | start, end, 0,0); |
| 264 | |
| 265 | kmeminit_nkmempages(); |
| 266 | kmemsize = (vsize_t)nkmempages * PAGE_SIZE; |
| 267 | kmem_arena_small = kmemsize < 64 * 1024 * 1024; |
| 268 | |
| 269 | UVMHIST_LOG(maphist, "kmemsize=%#" PRIxVSIZE, kmemsize, 0,0,0); |
| 270 | |
| 271 | /* |
| 272 | * next, init kernel memory objects. |
| 273 | */ |
| 274 | |
| 275 | /* kernel_object: for pageable anonymous kernel memory */ |
| 276 | uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - |
| 277 | VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); |
| 278 | |
| 279 | /* |
| 280 | * init the map and reserve any space that might already |
| 281 | * have been allocated kernel space before installing. |
| 282 | */ |
| 283 | |
| 284 | uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); |
| 285 | kernel_map_store.pmap = pmap_kernel(); |
| 286 | if (start != base) { |
| 287 | error = uvm_map_prepare(&kernel_map_store, |
| 288 | base, start - base, |
| 289 | NULL, UVM_UNKNOWN_OFFSET, 0, |
| 290 | UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, |
| 291 | UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); |
| 292 | if (!error) { |
| 293 | kernel_image_mapent_store.flags = |
| 294 | UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; |
| 295 | error = uvm_map_enter(&kernel_map_store, &args, |
| 296 | &kernel_image_mapent_store); |
| 297 | } |
| 298 | |
| 299 | if (error) |
| 300 | panic( |
| 301 | "uvm_km_bootstrap: could not reserve space for kernel" ); |
| 302 | |
| 303 | kmembase = args.uma_start + args.uma_size; |
| 304 | } else { |
| 305 | kmembase = base; |
| 306 | } |
| 307 | |
| 308 | error = uvm_map_prepare(&kernel_map_store, |
| 309 | kmembase, kmemsize, |
| 310 | NULL, UVM_UNKNOWN_OFFSET, 0, |
| 311 | UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, |
| 312 | UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); |
| 313 | if (!error) { |
| 314 | kernel_kmem_mapent_store.flags = |
| 315 | UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; |
| 316 | error = uvm_map_enter(&kernel_map_store, &args, |
| 317 | &kernel_kmem_mapent_store); |
| 318 | } |
| 319 | |
| 320 | if (error) |
| 321 | panic("uvm_km_bootstrap: could not reserve kernel kmem" ); |
| 322 | |
| 323 | /* |
| 324 | * install! |
| 325 | */ |
| 326 | |
| 327 | kernel_map = &kernel_map_store; |
| 328 | |
| 329 | pool_subsystem_init(); |
| 330 | |
| 331 | kmem_arena = vmem_init(&kmem_arena_store, "kmem" , |
| 332 | kmembase, kmemsize, PAGE_SIZE, NULL, NULL, NULL, |
| 333 | 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); |
| 334 | #ifdef PMAP_GROWKERNEL |
| 335 | /* |
| 336 | * kmem_arena VA allocations happen independently of uvm_map. |
| 337 | * grow kernel to accommodate the kmem_arena. |
| 338 | */ |
| 339 | if (uvm_maxkaddr < kmembase + kmemsize) { |
| 340 | uvm_maxkaddr = pmap_growkernel(kmembase + kmemsize); |
| 341 | KASSERTMSG(uvm_maxkaddr >= kmembase + kmemsize, |
| 342 | "%#" PRIxVADDR" %#" PRIxVADDR" %#" PRIxVSIZE, |
| 343 | uvm_maxkaddr, kmembase, kmemsize); |
| 344 | } |
| 345 | #endif |
| 346 | |
| 347 | vmem_subsystem_init(kmem_arena); |
| 348 | |
| 349 | UVMHIST_LOG(maphist, "kmem vmem created (base=%#" PRIxVADDR |
| 350 | ", size=%#" PRIxVSIZE, kmembase, kmemsize, 0,0); |
| 351 | |
| 352 | kmem_va_arena = vmem_init(&kmem_va_arena_store, "kva" , |
| 353 | 0, 0, PAGE_SIZE, vmem_alloc, vmem_free, kmem_arena, |
| 354 | (kmem_arena_small ? 4 : VMEM_QCACHE_IDX_MAX) * PAGE_SIZE, |
| 355 | VM_NOSLEEP, IPL_VM); |
| 356 | |
| 357 | UVMHIST_LOG(maphist, "<- done" , 0,0,0,0); |
| 358 | } |
| 359 | |
| 360 | /* |
| 361 | * uvm_km_init: init the kernel maps virtual memory caches |
| 362 | * and start the pool/kmem allocator. |
| 363 | */ |
| 364 | void |
| 365 | uvm_km_init(void) |
| 366 | { |
| 367 | kmem_init(); |
| 368 | } |
| 369 | |
| 370 | /* |
| 371 | * uvm_km_suballoc: allocate a submap in the kernel map. once a submap |
| 372 | * is allocated all references to that area of VM must go through it. this |
| 373 | * allows the locking of VAs in kernel_map to be broken up into regions. |
| 374 | * |
| 375 | * => if `fixed' is true, *vmin specifies where the region described |
| 376 | * pager_map => used to map "buf" structures into kernel space |
| 377 | * by the submap must start |
| 378 | * => if submap is non NULL we use that as the submap, otherwise we |
| 379 | * alloc a new map |
| 380 | */ |
| 381 | |
| 382 | struct vm_map * |
| 383 | uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */, |
| 384 | vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed, |
| 385 | struct vm_map *submap) |
| 386 | { |
| 387 | int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); |
| 388 | UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); |
| 389 | |
| 390 | KASSERT(vm_map_pmap(map) == pmap_kernel()); |
| 391 | |
| 392 | size = round_page(size); /* round up to pagesize */ |
| 393 | |
| 394 | /* |
| 395 | * first allocate a blank spot in the parent map |
| 396 | */ |
| 397 | |
| 398 | if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0, |
| 399 | UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, |
| 400 | UVM_ADV_RANDOM, mapflags)) != 0) { |
| 401 | panic("%s: unable to allocate space in parent map" , __func__); |
| 402 | } |
| 403 | |
| 404 | /* |
| 405 | * set VM bounds (vmin is filled in by uvm_map) |
| 406 | */ |
| 407 | |
| 408 | *vmax = *vmin + size; |
| 409 | |
| 410 | /* |
| 411 | * add references to pmap and create or init the submap |
| 412 | */ |
| 413 | |
| 414 | pmap_reference(vm_map_pmap(map)); |
| 415 | if (submap == NULL) { |
| 416 | submap = kmem_alloc(sizeof(*submap), KM_SLEEP); |
| 417 | if (submap == NULL) |
| 418 | panic("uvm_km_suballoc: unable to create submap" ); |
| 419 | } |
| 420 | uvm_map_setup(submap, *vmin, *vmax, flags); |
| 421 | submap->pmap = vm_map_pmap(map); |
| 422 | |
| 423 | /* |
| 424 | * now let uvm_map_submap plug in it... |
| 425 | */ |
| 426 | |
| 427 | if (uvm_map_submap(map, *vmin, *vmax, submap) != 0) |
| 428 | panic("uvm_km_suballoc: submap allocation failed" ); |
| 429 | |
| 430 | return(submap); |
| 431 | } |
| 432 | |
| 433 | /* |
| 434 | * uvm_km_pgremove: remove pages from a kernel uvm_object and KVA. |
| 435 | */ |
| 436 | |
| 437 | void |
| 438 | uvm_km_pgremove(vaddr_t startva, vaddr_t endva) |
| 439 | { |
| 440 | struct uvm_object * const uobj = uvm_kernel_object; |
| 441 | const voff_t start = startva - vm_map_min(kernel_map); |
| 442 | const voff_t end = endva - vm_map_min(kernel_map); |
| 443 | struct vm_page *pg; |
| 444 | voff_t curoff, nextoff; |
| 445 | int swpgonlydelta = 0; |
| 446 | UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); |
| 447 | |
| 448 | KASSERT(VM_MIN_KERNEL_ADDRESS <= startva); |
| 449 | KASSERT(startva < endva); |
| 450 | KASSERT(endva <= VM_MAX_KERNEL_ADDRESS); |
| 451 | |
| 452 | mutex_enter(uobj->vmobjlock); |
| 453 | pmap_remove(pmap_kernel(), startva, endva); |
| 454 | for (curoff = start; curoff < end; curoff = nextoff) { |
| 455 | nextoff = curoff + PAGE_SIZE; |
| 456 | pg = uvm_pagelookup(uobj, curoff); |
| 457 | if (pg != NULL && pg->flags & PG_BUSY) { |
| 458 | pg->flags |= PG_WANTED; |
| 459 | UVM_UNLOCK_AND_WAIT(pg, uobj->vmobjlock, 0, |
| 460 | "km_pgrm" , 0); |
| 461 | mutex_enter(uobj->vmobjlock); |
| 462 | nextoff = curoff; |
| 463 | continue; |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | * free the swap slot, then the page. |
| 468 | */ |
| 469 | |
| 470 | if (pg == NULL && |
| 471 | uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) { |
| 472 | swpgonlydelta++; |
| 473 | } |
| 474 | uao_dropswap(uobj, curoff >> PAGE_SHIFT); |
| 475 | if (pg != NULL) { |
| 476 | mutex_enter(&uvm_pageqlock); |
| 477 | uvm_pagefree(pg); |
| 478 | mutex_exit(&uvm_pageqlock); |
| 479 | } |
| 480 | } |
| 481 | mutex_exit(uobj->vmobjlock); |
| 482 | |
| 483 | if (swpgonlydelta > 0) { |
| 484 | mutex_enter(&uvm_swap_data_lock); |
| 485 | KASSERT(uvmexp.swpgonly >= swpgonlydelta); |
| 486 | uvmexp.swpgonly -= swpgonlydelta; |
| 487 | mutex_exit(&uvm_swap_data_lock); |
| 488 | } |
| 489 | } |
| 490 | |
| 491 | |
| 492 | /* |
| 493 | * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed |
| 494 | * regions. |
| 495 | * |
| 496 | * => when you unmap a part of anonymous kernel memory you want to toss |
| 497 | * the pages right away. (this is called from uvm_unmap_...). |
| 498 | * => none of the pages will ever be busy, and none of them will ever |
| 499 | * be on the active or inactive queues (because they have no object). |
| 500 | */ |
| 501 | |
| 502 | void |
| 503 | uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end) |
| 504 | { |
| 505 | #define __PGRM_BATCH 16 |
| 506 | struct vm_page *pg; |
| 507 | paddr_t pa[__PGRM_BATCH]; |
| 508 | int npgrm, i; |
| 509 | vaddr_t va, batch_vastart; |
| 510 | |
| 511 | UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); |
| 512 | |
| 513 | KASSERT(VM_MAP_IS_KERNEL(map)); |
| 514 | KASSERTMSG(vm_map_min(map) <= start, |
| 515 | "vm_map_min(map) [%#" PRIxVADDR"] <= start [%#" PRIxVADDR"]" |
| 516 | " (size=%#" PRIxVSIZE")" , |
| 517 | vm_map_min(map), start, end - start); |
| 518 | KASSERT(start < end); |
| 519 | KASSERT(end <= vm_map_max(map)); |
| 520 | |
| 521 | for (va = start; va < end;) { |
| 522 | batch_vastart = va; |
| 523 | /* create a batch of at most __PGRM_BATCH pages to free */ |
| 524 | for (i = 0; |
| 525 | i < __PGRM_BATCH && va < end; |
| 526 | va += PAGE_SIZE) { |
| 527 | if (!pmap_extract(pmap_kernel(), va, &pa[i])) { |
| 528 | continue; |
| 529 | } |
| 530 | i++; |
| 531 | } |
| 532 | npgrm = i; |
| 533 | /* now remove the mappings */ |
| 534 | pmap_kremove(batch_vastart, va - batch_vastart); |
| 535 | /* and free the pages */ |
| 536 | for (i = 0; i < npgrm; i++) { |
| 537 | pg = PHYS_TO_VM_PAGE(pa[i]); |
| 538 | KASSERT(pg); |
| 539 | KASSERT(pg->uobject == NULL && pg->uanon == NULL); |
| 540 | KASSERT((pg->flags & PG_BUSY) == 0); |
| 541 | uvm_pagefree(pg); |
| 542 | } |
| 543 | } |
| 544 | #undef __PGRM_BATCH |
| 545 | } |
| 546 | |
| 547 | #if defined(DEBUG) |
| 548 | void |
| 549 | uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end) |
| 550 | { |
| 551 | struct vm_page *pg; |
| 552 | vaddr_t va; |
| 553 | paddr_t pa; |
| 554 | UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); |
| 555 | |
| 556 | KDASSERT(VM_MAP_IS_KERNEL(map)); |
| 557 | KDASSERT(vm_map_min(map) <= start); |
| 558 | KDASSERT(start < end); |
| 559 | KDASSERT(end <= vm_map_max(map)); |
| 560 | |
| 561 | for (va = start; va < end; va += PAGE_SIZE) { |
| 562 | if (pmap_extract(pmap_kernel(), va, &pa)) { |
| 563 | panic("uvm_km_check_empty: va %p has pa 0x%llx" , |
| 564 | (void *)va, (long long)pa); |
| 565 | } |
| 566 | mutex_enter(uvm_kernel_object->vmobjlock); |
| 567 | pg = uvm_pagelookup(uvm_kernel_object, |
| 568 | va - vm_map_min(kernel_map)); |
| 569 | mutex_exit(uvm_kernel_object->vmobjlock); |
| 570 | if (pg) { |
| 571 | panic("uvm_km_check_empty: " |
| 572 | "has page hashed at %p" , (const void *)va); |
| 573 | } |
| 574 | } |
| 575 | } |
| 576 | #endif /* defined(DEBUG) */ |
| 577 | |
| 578 | /* |
| 579 | * uvm_km_alloc: allocate an area of kernel memory. |
| 580 | * |
| 581 | * => NOTE: we can return 0 even if we can wait if there is not enough |
| 582 | * free VM space in the map... caller should be prepared to handle |
| 583 | * this case. |
| 584 | * => we return KVA of memory allocated |
| 585 | */ |
| 586 | |
| 587 | vaddr_t |
| 588 | uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags) |
| 589 | { |
| 590 | vaddr_t kva, loopva; |
| 591 | vaddr_t offset; |
| 592 | vsize_t loopsize; |
| 593 | struct vm_page *pg; |
| 594 | struct uvm_object *obj; |
| 595 | int pgaflags; |
| 596 | vm_prot_t prot, vaprot; |
| 597 | UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); |
| 598 | |
| 599 | KASSERT(vm_map_pmap(map) == pmap_kernel()); |
| 600 | KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || |
| 601 | (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || |
| 602 | (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); |
| 603 | KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0); |
| 604 | KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0); |
| 605 | |
| 606 | /* |
| 607 | * setup for call |
| 608 | */ |
| 609 | |
| 610 | kva = vm_map_min(map); /* hint */ |
| 611 | size = round_page(size); |
| 612 | obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL; |
| 613 | UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)" , |
| 614 | map, obj, size, flags); |
| 615 | |
| 616 | /* |
| 617 | * allocate some virtual space |
| 618 | */ |
| 619 | |
| 620 | vaprot = (flags & UVM_KMF_EXEC) ? UVM_PROT_ALL : UVM_PROT_RW; |
| 621 | if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, |
| 622 | align, UVM_MAPFLAG(vaprot, UVM_PROT_ALL, UVM_INH_NONE, |
| 623 | UVM_ADV_RANDOM, |
| 624 | (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA |
| 625 | | UVM_KMF_COLORMATCH)))) != 0)) { |
| 626 | UVMHIST_LOG(maphist, "<- done (no VM)" ,0,0,0,0); |
| 627 | return(0); |
| 628 | } |
| 629 | |
| 630 | /* |
| 631 | * if all we wanted was VA, return now |
| 632 | */ |
| 633 | |
| 634 | if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) { |
| 635 | UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)" , kva,0,0,0); |
| 636 | return(kva); |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * recover object offset from virtual address |
| 641 | */ |
| 642 | |
| 643 | offset = kva - vm_map_min(kernel_map); |
| 644 | UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x" , kva, offset,0,0); |
| 645 | |
| 646 | /* |
| 647 | * now allocate and map in the memory... note that we are the only ones |
| 648 | * whom should ever get a handle on this area of VM. |
| 649 | */ |
| 650 | |
| 651 | loopva = kva; |
| 652 | loopsize = size; |
| 653 | |
| 654 | pgaflags = UVM_FLAG_COLORMATCH; |
| 655 | if (flags & UVM_KMF_NOWAIT) |
| 656 | pgaflags |= UVM_PGA_USERESERVE; |
| 657 | if (flags & UVM_KMF_ZERO) |
| 658 | pgaflags |= UVM_PGA_ZERO; |
| 659 | prot = VM_PROT_READ | VM_PROT_WRITE; |
| 660 | if (flags & UVM_KMF_EXEC) |
| 661 | prot |= VM_PROT_EXECUTE; |
| 662 | while (loopsize) { |
| 663 | KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), |
| 664 | "loopva=%#" PRIxVADDR, loopva); |
| 665 | |
| 666 | pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags, |
| 667 | #ifdef UVM_KM_VMFREELIST |
| 668 | UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST |
| 669 | #else |
| 670 | UVM_PGA_STRAT_NORMAL, 0 |
| 671 | #endif |
| 672 | ); |
| 673 | |
| 674 | /* |
| 675 | * out of memory? |
| 676 | */ |
| 677 | |
| 678 | if (__predict_false(pg == NULL)) { |
| 679 | if ((flags & UVM_KMF_NOWAIT) || |
| 680 | ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) { |
| 681 | /* free everything! */ |
| 682 | uvm_km_free(map, kva, size, |
| 683 | flags & UVM_KMF_TYPEMASK); |
| 684 | return (0); |
| 685 | } else { |
| 686 | uvm_wait("km_getwait2" ); /* sleep here */ |
| 687 | continue; |
| 688 | } |
| 689 | } |
| 690 | |
| 691 | pg->flags &= ~PG_BUSY; /* new page */ |
| 692 | UVM_PAGE_OWN(pg, NULL); |
| 693 | |
| 694 | /* |
| 695 | * map it in |
| 696 | */ |
| 697 | |
| 698 | pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), |
| 699 | prot, PMAP_KMPAGE); |
| 700 | loopva += PAGE_SIZE; |
| 701 | offset += PAGE_SIZE; |
| 702 | loopsize -= PAGE_SIZE; |
| 703 | } |
| 704 | |
| 705 | pmap_update(pmap_kernel()); |
| 706 | |
| 707 | UVMHIST_LOG(maphist,"<- done (kva=0x%x)" , kva,0,0,0); |
| 708 | return(kva); |
| 709 | } |
| 710 | |
| 711 | /* |
| 712 | * uvm_km_protect: change the protection of an allocated area |
| 713 | */ |
| 714 | |
| 715 | int |
| 716 | uvm_km_protect(struct vm_map *map, vaddr_t addr, vsize_t size, vm_prot_t prot) |
| 717 | { |
| 718 | return uvm_map_protect(map, addr, addr + round_page(size), prot, false); |
| 719 | } |
| 720 | |
| 721 | /* |
| 722 | * uvm_km_free: free an area of kernel memory |
| 723 | */ |
| 724 | |
| 725 | void |
| 726 | uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags) |
| 727 | { |
| 728 | UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); |
| 729 | |
| 730 | KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || |
| 731 | (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || |
| 732 | (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); |
| 733 | KASSERT((addr & PAGE_MASK) == 0); |
| 734 | KASSERT(vm_map_pmap(map) == pmap_kernel()); |
| 735 | |
| 736 | size = round_page(size); |
| 737 | |
| 738 | if (flags & UVM_KMF_PAGEABLE) { |
| 739 | uvm_km_pgremove(addr, addr + size); |
| 740 | } else if (flags & UVM_KMF_WIRED) { |
| 741 | /* |
| 742 | * Note: uvm_km_pgremove_intrsafe() extracts mapping, thus |
| 743 | * remove it after. See comment below about KVA visibility. |
| 744 | */ |
| 745 | uvm_km_pgremove_intrsafe(map, addr, addr + size); |
| 746 | } |
| 747 | |
| 748 | /* |
| 749 | * Note: uvm_unmap_remove() calls pmap_update() for us, before |
| 750 | * KVA becomes globally available. |
| 751 | */ |
| 752 | |
| 753 | uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY); |
| 754 | } |
| 755 | |
| 756 | /* Sanity; must specify both or none. */ |
| 757 | #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ |
| 758 | (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) |
| 759 | #error Must specify MAP and UNMAP together. |
| 760 | #endif |
| 761 | |
| 762 | int |
| 763 | uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, |
| 764 | vmem_addr_t *addr) |
| 765 | { |
| 766 | struct vm_page *pg; |
| 767 | vmem_addr_t va; |
| 768 | int rc; |
| 769 | vaddr_t loopva; |
| 770 | vsize_t loopsize; |
| 771 | |
| 772 | size = round_page(size); |
| 773 | |
| 774 | #if defined(PMAP_MAP_POOLPAGE) |
| 775 | if (size == PAGE_SIZE) { |
| 776 | again: |
| 777 | #ifdef PMAP_ALLOC_POOLPAGE |
| 778 | pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ? |
| 779 | 0 : UVM_PGA_USERESERVE); |
| 780 | #else |
| 781 | pg = uvm_pagealloc(NULL, 0, NULL, |
| 782 | (flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE); |
| 783 | #endif /* PMAP_ALLOC_POOLPAGE */ |
| 784 | if (__predict_false(pg == NULL)) { |
| 785 | if (flags & VM_SLEEP) { |
| 786 | uvm_wait("plpg" ); |
| 787 | goto again; |
| 788 | } |
| 789 | return ENOMEM; |
| 790 | } |
| 791 | va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); |
| 792 | if (__predict_false(va == 0)) { |
| 793 | uvm_pagefree(pg); |
| 794 | return ENOMEM; |
| 795 | } |
| 796 | *addr = va; |
| 797 | return 0; |
| 798 | } |
| 799 | #endif /* PMAP_MAP_POOLPAGE */ |
| 800 | |
| 801 | rc = vmem_alloc(vm, size, flags, &va); |
| 802 | if (rc != 0) |
| 803 | return rc; |
| 804 | |
| 805 | #ifdef PMAP_GROWKERNEL |
| 806 | /* |
| 807 | * These VA allocations happen independently of uvm_map |
| 808 | * so this allocation must not extend beyond the current limit. |
| 809 | */ |
| 810 | KASSERTMSG(uvm_maxkaddr >= va + size, |
| 811 | "%#" PRIxVADDR" %#" PRIxPTR" %#zx" , |
| 812 | uvm_maxkaddr, va, size); |
| 813 | #endif |
| 814 | |
| 815 | loopva = va; |
| 816 | loopsize = size; |
| 817 | |
| 818 | while (loopsize) { |
| 819 | #ifdef DIAGNOSTIC |
| 820 | paddr_t pa; |
| 821 | #endif |
| 822 | KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, &pa), |
| 823 | "loopva=%#" PRIxVADDR" loopsize=%#" PRIxVSIZE |
| 824 | " pa=%#" PRIxPADDR" vmem=%p" , |
| 825 | loopva, loopsize, pa, vm); |
| 826 | |
| 827 | pg = uvm_pagealloc(NULL, loopva, NULL, |
| 828 | UVM_FLAG_COLORMATCH |
| 829 | | ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE)); |
| 830 | if (__predict_false(pg == NULL)) { |
| 831 | if (flags & VM_SLEEP) { |
| 832 | uvm_wait("plpg" ); |
| 833 | continue; |
| 834 | } else { |
| 835 | uvm_km_pgremove_intrsafe(kernel_map, va, |
| 836 | va + size); |
| 837 | vmem_free(vm, va, size); |
| 838 | return ENOMEM; |
| 839 | } |
| 840 | } |
| 841 | |
| 842 | pg->flags &= ~PG_BUSY; /* new page */ |
| 843 | UVM_PAGE_OWN(pg, NULL); |
| 844 | pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), |
| 845 | VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); |
| 846 | |
| 847 | loopva += PAGE_SIZE; |
| 848 | loopsize -= PAGE_SIZE; |
| 849 | } |
| 850 | pmap_update(pmap_kernel()); |
| 851 | |
| 852 | *addr = va; |
| 853 | |
| 854 | return 0; |
| 855 | } |
| 856 | |
| 857 | void |
| 858 | uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size) |
| 859 | { |
| 860 | |
| 861 | size = round_page(size); |
| 862 | #if defined(PMAP_UNMAP_POOLPAGE) |
| 863 | if (size == PAGE_SIZE) { |
| 864 | paddr_t pa; |
| 865 | |
| 866 | pa = PMAP_UNMAP_POOLPAGE(addr); |
| 867 | uvm_pagefree(PHYS_TO_VM_PAGE(pa)); |
| 868 | return; |
| 869 | } |
| 870 | #endif /* PMAP_UNMAP_POOLPAGE */ |
| 871 | uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size); |
| 872 | pmap_update(pmap_kernel()); |
| 873 | |
| 874 | vmem_free(vm, addr, size); |
| 875 | } |
| 876 | |
| 877 | bool |
| 878 | uvm_km_va_starved_p(void) |
| 879 | { |
| 880 | vmem_size_t total; |
| 881 | vmem_size_t free; |
| 882 | |
| 883 | if (kmem_arena == NULL) |
| 884 | return false; |
| 885 | |
| 886 | total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE); |
| 887 | free = vmem_size(kmem_arena, VMEM_FREE); |
| 888 | |
| 889 | return (free < (total / 10)); |
| 890 | } |
| 891 | |