1 /* $NetBSD: uvm_pglist.c,v 1.18 2001/09/15 20:36:47 chs Exp $ */ 2 3 /*- 4 * Copyright (c) 1997 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * uvm_pglist.c: pglist functions 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/malloc.h> 47 #include <sys/proc.h> 48 49 #include <uvm/uvm.h> 50 51 #ifdef VM_PAGE_ALLOC_MEMORY_STATS 52 #define STAT_INCR(v) (v)++ 53 #define STAT_DECR(v) do { \ 54 if ((v) == 0) \ 55 printf("%s:%d -- Already 0!\n", __FILE__, __LINE__); \ 56 else \ 57 (v)--; \ 58 } while (0) 59 u_long uvm_pglistalloc_npages; 60 #else 61 #define STAT_INCR(v) 62 #define STAT_DECR(v) 63 #endif 64 65 /* 66 * uvm_pglistalloc: allocate a list of pages 67 * 68 * => allocated pages are placed at the tail of rlist. rlist is 69 * assumed to be properly initialized by caller. 70 * => returns 0 on success or errno on failure 71 * => XXX: implementation allocates only a single segment, also 72 * might be able to better advantage of vm_physeg[]. 73 * => doesn't take into account clean non-busy pages on inactive list 74 * that could be used(?) 75 * => params: 76 * size the size of the allocation, rounded to page size. 77 * low the low address of the allowed allocation range. 78 * high the high address of the allowed allocation range. 79 * alignment memory must be aligned to this power-of-two boundary. 80 * boundary no segment in the allocation may cross this 81 * power-of-two boundary (relative to zero). 82 */ 83 84 int 85 uvm_pglistalloc(size, low, high, alignment, boundary, rlist, nsegs, waitok) 86 psize_t size; 87 paddr_t low, high, alignment, boundary; 88 struct pglist *rlist; 89 int nsegs, waitok; 90 { 91 paddr_t try, idxpa, lastidxpa; 92 int psi; 93 struct vm_page *pgs, *pg; 94 int s, tryidx, idx, pgflidx, end, error, free_list, color; 95 u_long pagemask; 96 #ifdef DEBUG 97 struct vm_page *tp; 98 #endif 99 100 KASSERT((alignment & (alignment - 1)) == 0); 101 KASSERT((boundary & (boundary - 1)) == 0); 102 103 /* 104 * Our allocations are always page granularity, so our alignment 105 * must be, too. 106 */ 107 108 if (alignment < PAGE_SIZE) 109 alignment = PAGE_SIZE; 110 size = round_page(size); 111 try = roundup(low, alignment); 112 if (boundary != 0 && boundary < size) 113 return (EINVAL); 114 pagemask = ~(boundary - 1); 115 116 /* Default to "lose". */ 117 error = ENOMEM; 118 119 /* 120 * Block all memory allocation and lock the free list. 121 */ 122 123 s = uvm_lock_fpageq(); 124 125 /* Are there even any free pages? */ 126 if (uvmexp.free <= (uvmexp.reserve_pagedaemon + uvmexp.reserve_kernel)) 127 goto out; 128 129 for (;; try += alignment) { 130 if (try + size > high) { 131 132 /* 133 * We've run past the allowable range. 134 */ 135 136 goto out; 137 } 138 139 /* 140 * Make sure this is a managed physical page. 141 */ 142 143 if ((psi = vm_physseg_find(atop(try), &idx)) == -1) 144 continue; /* managed? */ 145 if (vm_physseg_find(atop(try + size), NULL) != psi) 146 continue; /* end must be in this segment */ 147 tryidx = idx; 148 end = idx + (size / PAGE_SIZE); 149 pgs = vm_physmem[psi].pgs; 150 151 /* 152 * Found a suitable starting page. See of the range is free. 153 */ 154 155 for (; idx < end; idx++) { 156 if (VM_PAGE_IS_FREE(&pgs[idx]) == 0) { 157 break; 158 } 159 idxpa = VM_PAGE_TO_PHYS(&pgs[idx]); 160 if (idx > tryidx) { 161 lastidxpa = VM_PAGE_TO_PHYS(&pgs[idx - 1]); 162 if ((lastidxpa + PAGE_SIZE) != idxpa) { 163 164 /* 165 * Region not contiguous. 166 */ 167 168 break; 169 } 170 if (boundary != 0 && 171 ((lastidxpa ^ idxpa) & pagemask) != 0) { 172 173 /* 174 * Region crosses boundary. 175 */ 176 177 break; 178 } 179 } 180 } 181 if (idx == end) { 182 break; 183 } 184 } 185 186 #if PGFL_NQUEUES != 2 187 #error uvm_pglistalloc needs to be updated 188 #endif 189 190 /* 191 * we have a chunk of memory that conforms to the requested constraints. 192 */ 193 idx = tryidx; 194 while (idx < end) { 195 pg = &pgs[idx]; 196 free_list = uvm_page_lookup_freelist(pg); 197 color = VM_PGCOLOR_BUCKET(pg); 198 pgflidx = (pg->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN; 199 #ifdef DEBUG 200 for (tp = TAILQ_FIRST(&uvm.page_free[ 201 free_list].pgfl_buckets[color].pgfl_queues[pgflidx]); 202 tp != NULL; 203 tp = TAILQ_NEXT(tp, pageq)) { 204 if (tp == pg) 205 break; 206 } 207 if (tp == NULL) 208 panic("uvm_pglistalloc: page not on freelist"); 209 #endif 210 TAILQ_REMOVE(&uvm.page_free[free_list].pgfl_buckets[ 211 color].pgfl_queues[pgflidx], pg, pageq); 212 uvmexp.free--; 213 if (pg->flags & PG_ZERO) 214 uvmexp.zeropages--; 215 pg->flags = PG_CLEAN; 216 pg->pqflags = 0; 217 pg->uobject = NULL; 218 pg->uanon = NULL; 219 TAILQ_INSERT_TAIL(rlist, pg, pageq); 220 idx++; 221 STAT_INCR(uvm_pglistalloc_npages); 222 } 223 error = 0; 224 225 out: 226 /* 227 * check to see if we need to generate some free pages waking 228 * the pagedaemon. 229 */ 230 231 UVM_KICK_PDAEMON(); 232 uvm_unlock_fpageq(s); 233 return (error); 234 } 235 236 /* 237 * uvm_pglistfree: free a list of pages 238 * 239 * => pages should already be unmapped 240 */ 241 242 void 243 uvm_pglistfree(list) 244 struct pglist *list; 245 { 246 struct vm_page *pg; 247 int s; 248 249 /* 250 * Lock the free list and free each page. 251 */ 252 253 s = uvm_lock_fpageq(); 254 while ((pg = TAILQ_FIRST(list)) != NULL) { 255 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 256 TAILQ_REMOVE(list, pg, pageq); 257 pg->pqflags = PQ_FREE; 258 TAILQ_INSERT_TAIL(&uvm.page_free[uvm_page_lookup_freelist(pg)]. 259 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. 260 pgfl_queues[PGFL_UNKNOWN], pg, pageq); 261 uvmexp.free++; 262 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 263 uvm.page_idle_zero = vm_page_zero_enable; 264 STAT_DECR(uvm_pglistalloc_npages); 265 } 266 uvm_unlock_fpageq(s); 267 } 268