1 /* $NetBSD: uvm_glue.c,v 1.143 2009/12/17 01:25:11 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 1.143 2009/12/17 01:25:11 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/systm.h> 82 #include <sys/proc.h> 83 #include <sys/resourcevar.h> 84 #include <sys/buf.h> 85 #include <sys/user.h> 86 #include <sys/syncobj.h> 87 #include <sys/cpu.h> 88 #include <sys/atomic.h> 89 90 #include <uvm/uvm.h> 91 92 /* 93 * XXXCDC: do these really belong here? 94 */ 95 96 /* 97 * uvm_kernacc: can the kernel access a region of memory 98 * 99 * - used only by /dev/kmem driver (mem.c) 100 */ 101 102 bool 103 uvm_kernacc(void *addr, size_t len, int rw) 104 { 105 bool rv; 106 vaddr_t saddr, eaddr; 107 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 108 109 saddr = trunc_page((vaddr_t)addr); 110 eaddr = round_page((vaddr_t)addr + len); 111 vm_map_lock_read(kernel_map); 112 rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot); 113 vm_map_unlock_read(kernel_map); 114 115 return(rv); 116 } 117 118 #ifdef KGDB 119 /* 120 * Change protections on kernel pages from addr to addr+len 121 * (presumably so debugger can plant a breakpoint). 122 * 123 * We force the protection change at the pmap level. If we were 124 * to use vm_map_protect a change to allow writing would be lazily- 125 * applied meaning we would still take a protection fault, something 126 * we really don't want to do. It would also fragment the kernel 127 * map unnecessarily. We cannot use pmap_protect since it also won't 128 * enforce a write-enable request. Using pmap_enter is the only way 129 * we can ensure the change takes place properly. 130 */ 131 void 132 uvm_chgkprot(void *addr, size_t len, int rw) 133 { 134 vm_prot_t prot; 135 paddr_t pa; 136 vaddr_t sva, eva; 137 138 prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE; 139 eva = round_page((vaddr_t)addr + len); 140 for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) { 141 /* 142 * Extract physical address for the page. 143 */ 144 if (pmap_extract(pmap_kernel(), sva, &pa) == false) 145 panic("%s: invalid page", __func__); 146 pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED); 147 } 148 pmap_update(pmap_kernel()); 149 } 150 #endif 151 152 /* 153 * uvm_vslock: wire user memory for I/O 154 * 155 * - called from physio and sys___sysctl 156 * - XXXCDC: consider nuking this (or making it a macro?) 157 */ 158 159 int 160 uvm_vslock(struct vmspace *vs, void *addr, size_t len, vm_prot_t access_type) 161 { 162 struct vm_map *map; 163 vaddr_t start, end; 164 int error; 165 166 map = &vs->vm_map; 167 start = trunc_page((vaddr_t)addr); 168 end = round_page((vaddr_t)addr + len); 169 error = uvm_fault_wire(map, start, end, access_type, 0); 170 return error; 171 } 172 173 /* 174 * uvm_vsunlock: unwire user memory wired by uvm_vslock() 175 * 176 * - called from physio and sys___sysctl 177 * - XXXCDC: consider nuking this (or making it a macro?) 178 */ 179 180 void 181 uvm_vsunlock(struct vmspace *vs, void *addr, size_t len) 182 { 183 uvm_fault_unwire(&vs->vm_map, trunc_page((vaddr_t)addr), 184 round_page((vaddr_t)addr + len)); 185 } 186 187 /* 188 * uvm_proc_fork: fork a virtual address space 189 * 190 * - the address space is copied as per parent map's inherit values 191 */ 192 void 193 uvm_proc_fork(struct proc *p1, struct proc *p2, bool shared) 194 { 195 196 if (shared == true) { 197 p2->p_vmspace = NULL; 198 uvmspace_share(p1, p2); 199 } else { 200 p2->p_vmspace = uvmspace_fork(p1->p_vmspace); 201 } 202 203 cpu_proc_fork(p1, p2); 204 } 205 206 /* 207 * uvm_lwp_fork: fork a thread 208 * 209 * - a new "user" structure is allocated for the child process 210 * [filled in by MD layer...] 211 * - if specified, the child gets a new user stack described by 212 * stack and stacksize 213 * - NOTE: the kernel stack may be at a different location in the child 214 * process, and thus addresses of automatic variables may be invalid 215 * after cpu_lwp_fork returns in the child process. We do nothing here 216 * after cpu_lwp_fork returns. 217 */ 218 void 219 uvm_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 220 void (*func)(void *), void *arg) 221 { 222 223 /* Fill stack with magic number. */ 224 kstack_setup_magic(l2); 225 226 /* 227 * cpu_lwp_fork() copy and update the pcb, and make the child ready 228 * to run. If this is a normal user fork, the child will exit 229 * directly to user mode via child_return() on its first time 230 * slice and will not return here. If this is a kernel thread, 231 * the specified entry point will be executed. 232 */ 233 cpu_lwp_fork(l1, l2, stack, stacksize, func, arg); 234 235 /* Inactive emap for new LWP. */ 236 l2->l_emap_gen = UVM_EMAP_INACTIVE; 237 } 238 239 #ifndef USPACE_ALIGN 240 #define USPACE_ALIGN 0 241 #endif 242 243 static pool_cache_t uvm_uarea_cache; 244 245 static void * 246 uarea_poolpage_alloc(struct pool *pp, int flags) 247 { 248 #if defined(PMAP_MAP_POOLPAGE) 249 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) { 250 struct vm_page *pg; 251 vaddr_t va; 252 253 pg = uvm_pagealloc(NULL, 0, NULL, 254 ((flags & PR_WAITOK) == 0 ? UVM_KMF_NOWAIT : 0)); 255 if (pg == NULL) 256 return NULL; 257 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 258 if (va == 0) 259 uvm_pagefree(pg); 260 return (void *)va; 261 } 262 #endif 263 return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz, 264 USPACE_ALIGN, UVM_KMF_WIRED | 265 ((flags & PR_WAITOK) ? UVM_KMF_WAITVA : 266 (UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK))); 267 } 268 269 static void 270 uarea_poolpage_free(struct pool *pp, void *addr) 271 { 272 #if defined(PMAP_MAP_POOLPAGE) 273 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) { 274 paddr_t pa; 275 276 pa = PMAP_UNMAP_POOLPAGE((vaddr_t) addr); 277 KASSERT(pa != 0); 278 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 279 return; 280 } 281 #endif 282 uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz, 283 UVM_KMF_WIRED); 284 } 285 286 static struct pool_allocator uvm_uarea_allocator = { 287 .pa_alloc = uarea_poolpage_alloc, 288 .pa_free = uarea_poolpage_free, 289 .pa_pagesz = USPACE, 290 }; 291 292 void 293 uvm_uarea_init(void) 294 { 295 int flags = PR_NOTOUCH; 296 297 /* 298 * specify PR_NOALIGN unless the alignment provided by 299 * the backend (USPACE_ALIGN) is sufficient to provide 300 * pool page size (UPSACE) alignment. 301 */ 302 303 if ((USPACE_ALIGN == 0 && USPACE != PAGE_SIZE) || 304 (USPACE_ALIGN % USPACE) != 0) { 305 flags |= PR_NOALIGN; 306 } 307 308 uvm_uarea_cache = pool_cache_init(USPACE, USPACE_ALIGN, 0, flags, 309 "uarea", &uvm_uarea_allocator, IPL_NONE, NULL, NULL, NULL); 310 } 311 312 /* 313 * uvm_uarea_alloc: allocate a u-area 314 */ 315 316 vaddr_t 317 uvm_uarea_alloc(void) 318 { 319 320 return (vaddr_t)pool_cache_get(uvm_uarea_cache, PR_WAITOK); 321 } 322 323 /* 324 * uvm_uarea_free: free a u-area 325 */ 326 327 void 328 uvm_uarea_free(vaddr_t uaddr) 329 { 330 331 pool_cache_put(uvm_uarea_cache, (void *)uaddr); 332 } 333 334 vaddr_t 335 uvm_lwp_getuarea(lwp_t *l) 336 { 337 338 return (vaddr_t)l->l_addr - UAREA_USER_OFFSET; 339 } 340 341 void 342 uvm_lwp_setuarea(lwp_t *l, vaddr_t addr) 343 { 344 345 l->l_addr = (void *)(addr + UAREA_USER_OFFSET); 346 } 347 348 /* 349 * uvm_proc_exit: exit a virtual address space 350 * 351 * - borrow proc0's address space because freeing the vmspace 352 * of the dead process may block. 353 */ 354 355 void 356 uvm_proc_exit(struct proc *p) 357 { 358 struct lwp *l = curlwp; /* XXX */ 359 struct vmspace *ovm; 360 361 KASSERT(p == l->l_proc); 362 ovm = p->p_vmspace; 363 364 /* 365 * borrow proc0's address space. 366 */ 367 KPREEMPT_DISABLE(l); 368 pmap_deactivate(l); 369 p->p_vmspace = proc0.p_vmspace; 370 pmap_activate(l); 371 KPREEMPT_ENABLE(l); 372 373 uvmspace_free(ovm); 374 } 375 376 void 377 uvm_lwp_exit(struct lwp *l) 378 { 379 vaddr_t va = uvm_lwp_getuarea(l); 380 381 uvm_uarea_free(va); 382 #ifdef DIAGNOSTIC 383 uvm_lwp_setuarea(l, (vaddr_t)NULL); 384 #endif 385 } 386 387 /* 388 * uvm_init_limit: init per-process VM limits 389 * 390 * - called for process 0 and then inherited by all others. 391 */ 392 393 void 394 uvm_init_limits(struct proc *p) 395 { 396 397 /* 398 * Set up the initial limits on process VM. Set the maximum 399 * resident set size to be all of (reasonably) available memory. 400 * This causes any single, large process to start random page 401 * replacement once it fills memory. 402 */ 403 404 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 405 p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap; 406 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 407 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap; 408 p->p_rlimit[RLIMIT_AS].rlim_cur = RLIM_INFINITY; 409 p->p_rlimit[RLIMIT_AS].rlim_max = RLIM_INFINITY; 410 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(uvmexp.free); 411 } 412 413 /* 414 * uvm_scheduler: process zero main loop. 415 */ 416 void 417 uvm_scheduler(void) 418 { 419 lwp_t *l = curlwp; 420 421 lwp_lock(l); 422 l->l_priority = PRI_VM; 423 l->l_class = SCHED_FIFO; 424 lwp_unlock(l); 425 426 for (;;) { 427 /* XXX/TODO: move some workload to this LWP? */ 428 (void)kpause("uvm", false, 0, NULL); 429 } 430 } 431