1 /* $NetBSD: uvm_glue.c,v 1.151 2011/07/02 01:26:29 matt 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_glue.c 8.6 (Berkeley) 1/5/94 37 * from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 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 #include <sys/cdefs.h> 65 __KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.151 2011/07/02 01:26:29 matt Exp $"); 66 67 #include "opt_kgdb.h" 68 #include "opt_kstack.h" 69 #include "opt_uvmhist.h" 70 71 /* 72 * uvm_glue.c: glue functions 73 */ 74 75 #include <sys/param.h> 76 #include <sys/kernel.h> 77 78 #include <sys/systm.h> 79 #include <sys/proc.h> 80 #include <sys/resourcevar.h> 81 #include <sys/buf.h> 82 #include <sys/syncobj.h> 83 #include <sys/cpu.h> 84 #include <sys/atomic.h> 85 #include <sys/lwp.h> 86 87 #include <uvm/uvm.h> 88 89 /* 90 * uvm_kernacc: test if kernel can access a memory region. 91 * 92 * => Currently used only by /dev/kmem driver (dev/mm.c). 93 */ 94 bool 95 uvm_kernacc(void *addr, size_t len, vm_prot_t prot) 96 { 97 vaddr_t saddr = trunc_page((vaddr_t)addr); 98 vaddr_t eaddr = round_page(saddr + len); 99 bool rv; 100 101 vm_map_lock_read(kernel_map); 102 rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot); 103 vm_map_unlock_read(kernel_map); 104 105 return rv; 106 } 107 108 #ifdef KGDB 109 /* 110 * Change protections on kernel pages from addr to addr+len 111 * (presumably so debugger can plant a breakpoint). 112 * 113 * We force the protection change at the pmap level. If we were 114 * to use vm_map_protect a change to allow writing would be lazily- 115 * applied meaning we would still take a protection fault, something 116 * we really don't want to do. It would also fragment the kernel 117 * map unnecessarily. We cannot use pmap_protect since it also won't 118 * enforce a write-enable request. Using pmap_enter is the only way 119 * we can ensure the change takes place properly. 120 */ 121 void 122 uvm_chgkprot(void *addr, size_t len, int rw) 123 { 124 vm_prot_t prot; 125 paddr_t pa; 126 vaddr_t sva, eva; 127 128 prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE; 129 eva = round_page((vaddr_t)addr + len); 130 for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) { 131 /* 132 * Extract physical address for the page. 133 */ 134 if (pmap_extract(pmap_kernel(), sva, &pa) == false) 135 panic("%s: invalid page", __func__); 136 pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED); 137 } 138 pmap_update(pmap_kernel()); 139 } 140 #endif 141 142 /* 143 * uvm_vslock: wire user memory for I/O 144 * 145 * - called from physio and sys___sysctl 146 * - XXXCDC: consider nuking this (or making it a macro?) 147 */ 148 149 int 150 uvm_vslock(struct vmspace *vs, void *addr, size_t len, vm_prot_t access_type) 151 { 152 struct vm_map *map; 153 vaddr_t start, end; 154 int error; 155 156 map = &vs->vm_map; 157 start = trunc_page((vaddr_t)addr); 158 end = round_page((vaddr_t)addr + len); 159 error = uvm_fault_wire(map, start, end, access_type, 0); 160 return error; 161 } 162 163 /* 164 * uvm_vsunlock: unwire user memory wired by uvm_vslock() 165 * 166 * - called from physio and sys___sysctl 167 * - XXXCDC: consider nuking this (or making it a macro?) 168 */ 169 170 void 171 uvm_vsunlock(struct vmspace *vs, void *addr, size_t len) 172 { 173 uvm_fault_unwire(&vs->vm_map, trunc_page((vaddr_t)addr), 174 round_page((vaddr_t)addr + len)); 175 } 176 177 /* 178 * uvm_proc_fork: fork a virtual address space 179 * 180 * - the address space is copied as per parent map's inherit values 181 */ 182 void 183 uvm_proc_fork(struct proc *p1, struct proc *p2, bool shared) 184 { 185 186 if (shared == true) { 187 p2->p_vmspace = NULL; 188 uvmspace_share(p1, p2); 189 } else { 190 p2->p_vmspace = uvmspace_fork(p1->p_vmspace); 191 } 192 193 cpu_proc_fork(p1, p2); 194 } 195 196 /* 197 * uvm_lwp_fork: fork a thread 198 * 199 * - a new PCB structure is allocated for the child process, 200 * and filled in by MD layer 201 * - if specified, the child gets a new user stack described by 202 * stack and stacksize 203 * - NOTE: the kernel stack may be at a different location in the child 204 * process, and thus addresses of automatic variables may be invalid 205 * after cpu_lwp_fork returns in the child process. We do nothing here 206 * after cpu_lwp_fork returns. 207 */ 208 void 209 uvm_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 210 void (*func)(void *), void *arg) 211 { 212 213 /* Fill stack with magic number. */ 214 kstack_setup_magic(l2); 215 216 /* 217 * cpu_lwp_fork() copy and update the pcb, and make the child ready 218 * to run. If this is a normal user fork, the child will exit 219 * directly to user mode via child_return() on its first time 220 * slice and will not return here. If this is a kernel thread, 221 * the specified entry point will be executed. 222 */ 223 cpu_lwp_fork(l1, l2, stack, stacksize, func, arg); 224 225 /* Inactive emap for new LWP. */ 226 l2->l_emap_gen = UVM_EMAP_INACTIVE; 227 } 228 229 #ifndef USPACE_ALIGN 230 #define USPACE_ALIGN 0 231 #endif 232 233 static pool_cache_t uvm_uarea_cache; 234 #if defined(__HAVE_CPU_UAREA_ROUTINES) 235 static pool_cache_t uvm_uarea_system_cache; 236 #else 237 #define uvm_uarea_system_cache uvm_uarea_cache 238 #endif 239 240 static void * 241 uarea_poolpage_alloc(struct pool *pp, int flags) 242 { 243 #if defined(PMAP_MAP_POOLPAGE) 244 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) { 245 struct vm_page *pg; 246 vaddr_t va; 247 248 pg = uvm_pagealloc(NULL, 0, NULL, 249 ((flags & PR_WAITOK) == 0 ? UVM_KMF_NOWAIT : 0)); 250 if (pg == NULL) 251 return NULL; 252 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 253 if (va == 0) 254 uvm_pagefree(pg); 255 return (void *)va; 256 } 257 #endif 258 #if defined(__HAVE_CPU_UAREA_ROUTINES) 259 void *va = cpu_uarea_alloc(false); 260 if (va) 261 return (void *)va; 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 #if defined(__HAVE_CPU_UAREA_ROUTINES) 283 if (cpu_uarea_free(addr)) 284 return; 285 #endif 286 uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz, 287 UVM_KMF_WIRED); 288 } 289 290 static struct pool_allocator uvm_uarea_allocator = { 291 .pa_alloc = uarea_poolpage_alloc, 292 .pa_free = uarea_poolpage_free, 293 .pa_pagesz = USPACE, 294 }; 295 296 #if defined(__HAVE_CPU_UAREA_ROUTINES) 297 static void * 298 uarea_system_poolpage_alloc(struct pool *pp, int flags) 299 { 300 void * const va = cpu_uarea_alloc(true); 301 if (va != NULL) 302 return va; 303 304 return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz, 305 USPACE_ALIGN, UVM_KMF_WIRED | 306 ((flags & PR_WAITOK) ? UVM_KMF_WAITVA : 307 (UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK))); 308 } 309 310 static void 311 uarea_system_poolpage_free(struct pool *pp, void *addr) 312 { 313 if (!cpu_uarea_free(addr)) 314 panic("%s: failed to free uarea %p", __func__, addr); 315 } 316 317 static struct pool_allocator uvm_uarea_system_allocator = { 318 .pa_alloc = uarea_system_poolpage_alloc, 319 .pa_free = uarea_system_poolpage_free, 320 .pa_pagesz = USPACE, 321 }; 322 #endif /* __HAVE_CPU_UAREA_ROUTINES */ 323 324 void 325 uvm_uarea_init(void) 326 { 327 int flags = PR_NOTOUCH; 328 329 /* 330 * specify PR_NOALIGN unless the alignment provided by 331 * the backend (USPACE_ALIGN) is sufficient to provide 332 * pool page size (UPSACE) alignment. 333 */ 334 335 if ((USPACE_ALIGN == 0 && USPACE != PAGE_SIZE) || 336 (USPACE_ALIGN % USPACE) != 0) { 337 flags |= PR_NOALIGN; 338 } 339 340 uvm_uarea_cache = pool_cache_init(USPACE, USPACE_ALIGN, 0, flags, 341 "uarea", &uvm_uarea_allocator, IPL_NONE, NULL, NULL, NULL); 342 #if defined(__HAVE_CPU_UAREA_ROUTINES) 343 uvm_uarea_system_cache = pool_cache_init(USPACE, USPACE_ALIGN, 344 0, flags, "uareasys", &uvm_uarea_system_allocator, 345 IPL_NONE, NULL, NULL, NULL); 346 #endif 347 } 348 349 /* 350 * uvm_uarea_alloc: allocate a u-area 351 */ 352 353 vaddr_t 354 uvm_uarea_alloc(void) 355 { 356 357 return (vaddr_t)pool_cache_get(uvm_uarea_cache, PR_WAITOK); 358 } 359 360 vaddr_t 361 uvm_uarea_system_alloc(void) 362 { 363 364 return (vaddr_t)pool_cache_get(uvm_uarea_system_cache, PR_WAITOK); 365 } 366 367 /* 368 * uvm_uarea_free: free a u-area 369 */ 370 371 void 372 uvm_uarea_free(vaddr_t uaddr) 373 { 374 375 pool_cache_put(uvm_uarea_cache, (void *)uaddr); 376 } 377 378 void 379 uvm_uarea_system_free(vaddr_t uaddr) 380 { 381 382 pool_cache_put(uvm_uarea_system_cache, (void *)uaddr); 383 } 384 385 vaddr_t 386 uvm_lwp_getuarea(lwp_t *l) 387 { 388 389 return (vaddr_t)l->l_addr - UAREA_PCB_OFFSET; 390 } 391 392 void 393 uvm_lwp_setuarea(lwp_t *l, vaddr_t addr) 394 { 395 396 l->l_addr = (void *)(addr + UAREA_PCB_OFFSET); 397 } 398 399 /* 400 * uvm_proc_exit: exit a virtual address space 401 * 402 * - borrow proc0's address space because freeing the vmspace 403 * of the dead process may block. 404 */ 405 406 void 407 uvm_proc_exit(struct proc *p) 408 { 409 struct lwp *l = curlwp; /* XXX */ 410 struct vmspace *ovm; 411 412 KASSERT(p == l->l_proc); 413 ovm = p->p_vmspace; 414 415 /* 416 * borrow proc0's address space. 417 */ 418 KPREEMPT_DISABLE(l); 419 pmap_deactivate(l); 420 p->p_vmspace = proc0.p_vmspace; 421 pmap_activate(l); 422 KPREEMPT_ENABLE(l); 423 424 uvmspace_free(ovm); 425 } 426 427 void 428 uvm_lwp_exit(struct lwp *l) 429 { 430 vaddr_t va = uvm_lwp_getuarea(l); 431 bool system = (l->l_flag & LW_SYSTEM) != 0; 432 433 if (system) 434 uvm_uarea_system_free(va); 435 else 436 uvm_uarea_free(va); 437 #ifdef DIAGNOSTIC 438 uvm_lwp_setuarea(l, (vaddr_t)NULL); 439 #endif 440 } 441 442 /* 443 * uvm_init_limit: init per-process VM limits 444 * 445 * - called for process 0 and then inherited by all others. 446 */ 447 448 void 449 uvm_init_limits(struct proc *p) 450 { 451 452 /* 453 * Set up the initial limits on process VM. Set the maximum 454 * resident set size to be all of (reasonably) available memory. 455 * This causes any single, large process to start random page 456 * replacement once it fills memory. 457 */ 458 459 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 460 p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap; 461 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 462 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap; 463 p->p_rlimit[RLIMIT_AS].rlim_cur = RLIM_INFINITY; 464 p->p_rlimit[RLIMIT_AS].rlim_max = RLIM_INFINITY; 465 p->p_rlimit[RLIMIT_RSS].rlim_cur = MIN( 466 VM_MAXUSER_ADDRESS, ctob((rlim_t)uvmexp.free)); 467 } 468 469 /* 470 * uvm_scheduler: process zero main loop. 471 */ 472 473 extern struct loadavg averunnable; 474 475 void 476 uvm_scheduler(void) 477 { 478 lwp_t *l = curlwp; 479 480 lwp_lock(l); 481 l->l_priority = PRI_VM; 482 l->l_class = SCHED_FIFO; 483 lwp_unlock(l); 484 485 for (;;) { 486 sched_pstats(); 487 (void)kpause("uvm", false, hz, NULL); 488 } 489 } 490