1 /* $NetBSD: uvm_glue.c,v 1.146 2011/01/14 02:06:34 rmind 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vm_glue.c 8.6 (Berkeley) 1/5/94 42 * from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 chs Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 #include <sys/cdefs.h> 70 __KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.146 2011/01/14 02:06:34 rmind Exp $"); 71 72 #include "opt_kgdb.h" 73 #include "opt_kstack.h" 74 #include "opt_uvmhist.h" 75 76 /* 77 * uvm_glue.c: glue functions 78 */ 79 80 #include <sys/param.h> 81 #include <sys/kernel.h> 82 83 #include <sys/systm.h> 84 #include <sys/proc.h> 85 #include <sys/resourcevar.h> 86 #include <sys/buf.h> 87 #include <sys/syncobj.h> 88 #include <sys/cpu.h> 89 #include <sys/atomic.h> 90 #include <sys/lwp.h> 91 92 #include <uvm/uvm.h> 93 94 /* 95 * XXXCDC: do these really belong here? 96 */ 97 98 /* 99 * uvm_kernacc: can the kernel access a region of memory 100 * 101 * - used only by /dev/kmem driver (mem.c) 102 */ 103 104 bool 105 uvm_kernacc(void *addr, size_t len, int rw) 106 { 107 bool rv; 108 vaddr_t saddr, eaddr; 109 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 110 111 saddr = trunc_page((vaddr_t)addr); 112 eaddr = round_page((vaddr_t)addr + len); 113 vm_map_lock_read(kernel_map); 114 rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot); 115 vm_map_unlock_read(kernel_map); 116 117 return(rv); 118 } 119 120 #ifdef KGDB 121 /* 122 * Change protections on kernel pages from addr to addr+len 123 * (presumably so debugger can plant a breakpoint). 124 * 125 * We force the protection change at the pmap level. If we were 126 * to use vm_map_protect a change to allow writing would be lazily- 127 * applied meaning we would still take a protection fault, something 128 * we really don't want to do. It would also fragment the kernel 129 * map unnecessarily. We cannot use pmap_protect since it also won't 130 * enforce a write-enable request. Using pmap_enter is the only way 131 * we can ensure the change takes place properly. 132 */ 133 void 134 uvm_chgkprot(void *addr, size_t len, int rw) 135 { 136 vm_prot_t prot; 137 paddr_t pa; 138 vaddr_t sva, eva; 139 140 prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE; 141 eva = round_page((vaddr_t)addr + len); 142 for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) { 143 /* 144 * Extract physical address for the page. 145 */ 146 if (pmap_extract(pmap_kernel(), sva, &pa) == false) 147 panic("%s: invalid page", __func__); 148 pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED); 149 } 150 pmap_update(pmap_kernel()); 151 } 152 #endif 153 154 /* 155 * uvm_vslock: wire user memory for I/O 156 * 157 * - called from physio and sys___sysctl 158 * - XXXCDC: consider nuking this (or making it a macro?) 159 */ 160 161 int 162 uvm_vslock(struct vmspace *vs, void *addr, size_t len, vm_prot_t access_type) 163 { 164 struct vm_map *map; 165 vaddr_t start, end; 166 int error; 167 168 map = &vs->vm_map; 169 start = trunc_page((vaddr_t)addr); 170 end = round_page((vaddr_t)addr + len); 171 error = uvm_fault_wire(map, start, end, access_type, 0); 172 return error; 173 } 174 175 /* 176 * uvm_vsunlock: unwire user memory wired by uvm_vslock() 177 * 178 * - called from physio and sys___sysctl 179 * - XXXCDC: consider nuking this (or making it a macro?) 180 */ 181 182 void 183 uvm_vsunlock(struct vmspace *vs, void *addr, size_t len) 184 { 185 uvm_fault_unwire(&vs->vm_map, trunc_page((vaddr_t)addr), 186 round_page((vaddr_t)addr + len)); 187 } 188 189 /* 190 * uvm_proc_fork: fork a virtual address space 191 * 192 * - the address space is copied as per parent map's inherit values 193 */ 194 void 195 uvm_proc_fork(struct proc *p1, struct proc *p2, bool shared) 196 { 197 198 if (shared == true) { 199 p2->p_vmspace = NULL; 200 uvmspace_share(p1, p2); 201 } else { 202 p2->p_vmspace = uvmspace_fork(p1->p_vmspace); 203 } 204 205 cpu_proc_fork(p1, p2); 206 } 207 208 /* 209 * uvm_lwp_fork: fork a thread 210 * 211 * - a new PCB structure is allocated for the child process, 212 * and filled in by MD layer 213 * - if specified, the child gets a new user stack described by 214 * stack and stacksize 215 * - NOTE: the kernel stack may be at a different location in the child 216 * process, and thus addresses of automatic variables may be invalid 217 * after cpu_lwp_fork returns in the child process. We do nothing here 218 * after cpu_lwp_fork returns. 219 */ 220 void 221 uvm_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 222 void (*func)(void *), void *arg) 223 { 224 225 /* Fill stack with magic number. */ 226 kstack_setup_magic(l2); 227 228 /* 229 * cpu_lwp_fork() copy and update the pcb, and make the child ready 230 * to run. If this is a normal user fork, the child will exit 231 * directly to user mode via child_return() on its first time 232 * slice and will not return here. If this is a kernel thread, 233 * the specified entry point will be executed. 234 */ 235 cpu_lwp_fork(l1, l2, stack, stacksize, func, arg); 236 237 /* Inactive emap for new LWP. */ 238 l2->l_emap_gen = UVM_EMAP_INACTIVE; 239 } 240 241 #ifndef USPACE_ALIGN 242 #define USPACE_ALIGN 0 243 #endif 244 245 static pool_cache_t uvm_uarea_cache; 246 247 static void * 248 uarea_poolpage_alloc(struct pool *pp, int flags) 249 { 250 #if defined(PMAP_MAP_POOLPAGE) 251 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) { 252 struct vm_page *pg; 253 vaddr_t va; 254 255 pg = uvm_pagealloc(NULL, 0, NULL, 256 ((flags & PR_WAITOK) == 0 ? UVM_KMF_NOWAIT : 0)); 257 if (pg == NULL) 258 return NULL; 259 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 260 if (va == 0) 261 uvm_pagefree(pg); 262 return (void *)va; 263 } 264 #endif 265 return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz, 266 USPACE_ALIGN, UVM_KMF_WIRED | 267 ((flags & PR_WAITOK) ? UVM_KMF_WAITVA : 268 (UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK))); 269 } 270 271 static void 272 uarea_poolpage_free(struct pool *pp, void *addr) 273 { 274 #if defined(PMAP_MAP_POOLPAGE) 275 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) { 276 paddr_t pa; 277 278 pa = PMAP_UNMAP_POOLPAGE((vaddr_t) addr); 279 KASSERT(pa != 0); 280 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 281 return; 282 } 283 #endif 284 uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz, 285 UVM_KMF_WIRED); 286 } 287 288 static struct pool_allocator uvm_uarea_allocator = { 289 .pa_alloc = uarea_poolpage_alloc, 290 .pa_free = uarea_poolpage_free, 291 .pa_pagesz = USPACE, 292 }; 293 294 void 295 uvm_uarea_init(void) 296 { 297 int flags = PR_NOTOUCH; 298 299 /* 300 * specify PR_NOALIGN unless the alignment provided by 301 * the backend (USPACE_ALIGN) is sufficient to provide 302 * pool page size (UPSACE) alignment. 303 */ 304 305 if ((USPACE_ALIGN == 0 && USPACE != PAGE_SIZE) || 306 (USPACE_ALIGN % USPACE) != 0) { 307 flags |= PR_NOALIGN; 308 } 309 310 uvm_uarea_cache = pool_cache_init(USPACE, USPACE_ALIGN, 0, flags, 311 "uarea", &uvm_uarea_allocator, IPL_NONE, NULL, NULL, NULL); 312 } 313 314 /* 315 * uvm_uarea_alloc: allocate a u-area 316 */ 317 318 vaddr_t 319 uvm_uarea_alloc(void) 320 { 321 322 return (vaddr_t)pool_cache_get(uvm_uarea_cache, PR_WAITOK); 323 } 324 325 /* 326 * uvm_uarea_free: free a u-area 327 */ 328 329 void 330 uvm_uarea_free(vaddr_t uaddr) 331 { 332 333 pool_cache_put(uvm_uarea_cache, (void *)uaddr); 334 } 335 336 vaddr_t 337 uvm_lwp_getuarea(lwp_t *l) 338 { 339 340 return (vaddr_t)l->l_addr - UAREA_PCB_OFFSET; 341 } 342 343 void 344 uvm_lwp_setuarea(lwp_t *l, vaddr_t addr) 345 { 346 347 l->l_addr = (void *)(addr + UAREA_PCB_OFFSET); 348 } 349 350 /* 351 * uvm_proc_exit: exit a virtual address space 352 * 353 * - borrow proc0's address space because freeing the vmspace 354 * of the dead process may block. 355 */ 356 357 void 358 uvm_proc_exit(struct proc *p) 359 { 360 struct lwp *l = curlwp; /* XXX */ 361 struct vmspace *ovm; 362 363 KASSERT(p == l->l_proc); 364 ovm = p->p_vmspace; 365 366 /* 367 * borrow proc0's address space. 368 */ 369 KPREEMPT_DISABLE(l); 370 pmap_deactivate(l); 371 p->p_vmspace = proc0.p_vmspace; 372 pmap_activate(l); 373 KPREEMPT_ENABLE(l); 374 375 uvmspace_free(ovm); 376 } 377 378 void 379 uvm_lwp_exit(struct lwp *l) 380 { 381 vaddr_t va = uvm_lwp_getuarea(l); 382 383 uvm_uarea_free(va); 384 #ifdef DIAGNOSTIC 385 uvm_lwp_setuarea(l, (vaddr_t)NULL); 386 #endif 387 } 388 389 /* 390 * uvm_init_limit: init per-process VM limits 391 * 392 * - called for process 0 and then inherited by all others. 393 */ 394 395 void 396 uvm_init_limits(struct proc *p) 397 { 398 399 /* 400 * Set up the initial limits on process VM. Set the maximum 401 * resident set size to be all of (reasonably) available memory. 402 * This causes any single, large process to start random page 403 * replacement once it fills memory. 404 */ 405 406 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 407 p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap; 408 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 409 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap; 410 p->p_rlimit[RLIMIT_AS].rlim_cur = RLIM_INFINITY; 411 p->p_rlimit[RLIMIT_AS].rlim_max = RLIM_INFINITY; 412 p->p_rlimit[RLIMIT_RSS].rlim_cur = MIN( 413 VM_MAXUSER_ADDRESS, ctob((rlim_t)uvmexp.free)); 414 } 415 416 /* 417 * uvm_scheduler: process zero main loop. 418 */ 419 420 extern struct loadavg averunnable; 421 422 void 423 uvm_scheduler(void) 424 { 425 lwp_t *l = curlwp; 426 427 lwp_lock(l); 428 l->l_priority = PRI_VM; 429 l->l_class = SCHED_FIFO; 430 lwp_unlock(l); 431 432 for (;;) { 433 sched_pstats(); 434 (void)kpause("uvm", false, hz, NULL); 435 } 436 } 437