1 /* $NetBSD: uvm_glue.c,v 1.147 2011/02/02 15:25:27 chuck 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 1.147 2011/02/02 15:25:27 chuck 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 * XXXCDC: do these really belong here? 91 */ 92 93 /* 94 * uvm_kernacc: can the kernel access a region of memory 95 * 96 * - used only by /dev/kmem driver (mem.c) 97 */ 98 99 bool 100 uvm_kernacc(void *addr, size_t len, int rw) 101 { 102 bool rv; 103 vaddr_t saddr, eaddr; 104 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 105 106 saddr = trunc_page((vaddr_t)addr); 107 eaddr = round_page((vaddr_t)addr + len); 108 vm_map_lock_read(kernel_map); 109 rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot); 110 vm_map_unlock_read(kernel_map); 111 112 return(rv); 113 } 114 115 #ifdef KGDB 116 /* 117 * Change protections on kernel pages from addr to addr+len 118 * (presumably so debugger can plant a breakpoint). 119 * 120 * We force the protection change at the pmap level. If we were 121 * to use vm_map_protect a change to allow writing would be lazily- 122 * applied meaning we would still take a protection fault, something 123 * we really don't want to do. It would also fragment the kernel 124 * map unnecessarily. We cannot use pmap_protect since it also won't 125 * enforce a write-enable request. Using pmap_enter is the only way 126 * we can ensure the change takes place properly. 127 */ 128 void 129 uvm_chgkprot(void *addr, size_t len, int rw) 130 { 131 vm_prot_t prot; 132 paddr_t pa; 133 vaddr_t sva, eva; 134 135 prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE; 136 eva = round_page((vaddr_t)addr + len); 137 for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) { 138 /* 139 * Extract physical address for the page. 140 */ 141 if (pmap_extract(pmap_kernel(), sva, &pa) == false) 142 panic("%s: invalid page", __func__); 143 pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED); 144 } 145 pmap_update(pmap_kernel()); 146 } 147 #endif 148 149 /* 150 * uvm_vslock: wire user memory for I/O 151 * 152 * - called from physio and sys___sysctl 153 * - XXXCDC: consider nuking this (or making it a macro?) 154 */ 155 156 int 157 uvm_vslock(struct vmspace *vs, void *addr, size_t len, vm_prot_t access_type) 158 { 159 struct vm_map *map; 160 vaddr_t start, end; 161 int error; 162 163 map = &vs->vm_map; 164 start = trunc_page((vaddr_t)addr); 165 end = round_page((vaddr_t)addr + len); 166 error = uvm_fault_wire(map, start, end, access_type, 0); 167 return error; 168 } 169 170 /* 171 * uvm_vsunlock: unwire user memory wired by uvm_vslock() 172 * 173 * - called from physio and sys___sysctl 174 * - XXXCDC: consider nuking this (or making it a macro?) 175 */ 176 177 void 178 uvm_vsunlock(struct vmspace *vs, void *addr, size_t len) 179 { 180 uvm_fault_unwire(&vs->vm_map, trunc_page((vaddr_t)addr), 181 round_page((vaddr_t)addr + len)); 182 } 183 184 /* 185 * uvm_proc_fork: fork a virtual address space 186 * 187 * - the address space is copied as per parent map's inherit values 188 */ 189 void 190 uvm_proc_fork(struct proc *p1, struct proc *p2, bool shared) 191 { 192 193 if (shared == true) { 194 p2->p_vmspace = NULL; 195 uvmspace_share(p1, p2); 196 } else { 197 p2->p_vmspace = uvmspace_fork(p1->p_vmspace); 198 } 199 200 cpu_proc_fork(p1, p2); 201 } 202 203 /* 204 * uvm_lwp_fork: fork a thread 205 * 206 * - a new PCB structure is allocated for the child process, 207 * and filled in by MD layer 208 * - if specified, the child gets a new user stack described by 209 * stack and stacksize 210 * - NOTE: the kernel stack may be at a different location in the child 211 * process, and thus addresses of automatic variables may be invalid 212 * after cpu_lwp_fork returns in the child process. We do nothing here 213 * after cpu_lwp_fork returns. 214 */ 215 void 216 uvm_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 217 void (*func)(void *), void *arg) 218 { 219 220 /* Fill stack with magic number. */ 221 kstack_setup_magic(l2); 222 223 /* 224 * cpu_lwp_fork() copy and update the pcb, and make the child ready 225 * to run. If this is a normal user fork, the child will exit 226 * directly to user mode via child_return() on its first time 227 * slice and will not return here. If this is a kernel thread, 228 * the specified entry point will be executed. 229 */ 230 cpu_lwp_fork(l1, l2, stack, stacksize, func, arg); 231 232 /* Inactive emap for new LWP. */ 233 l2->l_emap_gen = UVM_EMAP_INACTIVE; 234 } 235 236 #ifndef USPACE_ALIGN 237 #define USPACE_ALIGN 0 238 #endif 239 240 static pool_cache_t uvm_uarea_cache; 241 242 static void * 243 uarea_poolpage_alloc(struct pool *pp, int flags) 244 { 245 #if defined(PMAP_MAP_POOLPAGE) 246 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) { 247 struct vm_page *pg; 248 vaddr_t va; 249 250 pg = uvm_pagealloc(NULL, 0, NULL, 251 ((flags & PR_WAITOK) == 0 ? UVM_KMF_NOWAIT : 0)); 252 if (pg == NULL) 253 return NULL; 254 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 255 if (va == 0) 256 uvm_pagefree(pg); 257 return (void *)va; 258 } 259 #endif 260 return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz, 261 USPACE_ALIGN, UVM_KMF_WIRED | 262 ((flags & PR_WAITOK) ? UVM_KMF_WAITVA : 263 (UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK))); 264 } 265 266 static void 267 uarea_poolpage_free(struct pool *pp, void *addr) 268 { 269 #if defined(PMAP_MAP_POOLPAGE) 270 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) { 271 paddr_t pa; 272 273 pa = PMAP_UNMAP_POOLPAGE((vaddr_t) addr); 274 KASSERT(pa != 0); 275 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 276 return; 277 } 278 #endif 279 uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz, 280 UVM_KMF_WIRED); 281 } 282 283 static struct pool_allocator uvm_uarea_allocator = { 284 .pa_alloc = uarea_poolpage_alloc, 285 .pa_free = uarea_poolpage_free, 286 .pa_pagesz = USPACE, 287 }; 288 289 void 290 uvm_uarea_init(void) 291 { 292 int flags = PR_NOTOUCH; 293 294 /* 295 * specify PR_NOALIGN unless the alignment provided by 296 * the backend (USPACE_ALIGN) is sufficient to provide 297 * pool page size (UPSACE) alignment. 298 */ 299 300 if ((USPACE_ALIGN == 0 && USPACE != PAGE_SIZE) || 301 (USPACE_ALIGN % USPACE) != 0) { 302 flags |= PR_NOALIGN; 303 } 304 305 uvm_uarea_cache = pool_cache_init(USPACE, USPACE_ALIGN, 0, flags, 306 "uarea", &uvm_uarea_allocator, IPL_NONE, NULL, NULL, NULL); 307 } 308 309 /* 310 * uvm_uarea_alloc: allocate a u-area 311 */ 312 313 vaddr_t 314 uvm_uarea_alloc(void) 315 { 316 317 return (vaddr_t)pool_cache_get(uvm_uarea_cache, PR_WAITOK); 318 } 319 320 /* 321 * uvm_uarea_free: free a u-area 322 */ 323 324 void 325 uvm_uarea_free(vaddr_t uaddr) 326 { 327 328 pool_cache_put(uvm_uarea_cache, (void *)uaddr); 329 } 330 331 vaddr_t 332 uvm_lwp_getuarea(lwp_t *l) 333 { 334 335 return (vaddr_t)l->l_addr - UAREA_PCB_OFFSET; 336 } 337 338 void 339 uvm_lwp_setuarea(lwp_t *l, vaddr_t addr) 340 { 341 342 l->l_addr = (void *)(addr + UAREA_PCB_OFFSET); 343 } 344 345 /* 346 * uvm_proc_exit: exit a virtual address space 347 * 348 * - borrow proc0's address space because freeing the vmspace 349 * of the dead process may block. 350 */ 351 352 void 353 uvm_proc_exit(struct proc *p) 354 { 355 struct lwp *l = curlwp; /* XXX */ 356 struct vmspace *ovm; 357 358 KASSERT(p == l->l_proc); 359 ovm = p->p_vmspace; 360 361 /* 362 * borrow proc0's address space. 363 */ 364 KPREEMPT_DISABLE(l); 365 pmap_deactivate(l); 366 p->p_vmspace = proc0.p_vmspace; 367 pmap_activate(l); 368 KPREEMPT_ENABLE(l); 369 370 uvmspace_free(ovm); 371 } 372 373 void 374 uvm_lwp_exit(struct lwp *l) 375 { 376 vaddr_t va = uvm_lwp_getuarea(l); 377 378 uvm_uarea_free(va); 379 #ifdef DIAGNOSTIC 380 uvm_lwp_setuarea(l, (vaddr_t)NULL); 381 #endif 382 } 383 384 /* 385 * uvm_init_limit: init per-process VM limits 386 * 387 * - called for process 0 and then inherited by all others. 388 */ 389 390 void 391 uvm_init_limits(struct proc *p) 392 { 393 394 /* 395 * Set up the initial limits on process VM. Set the maximum 396 * resident set size to be all of (reasonably) available memory. 397 * This causes any single, large process to start random page 398 * replacement once it fills memory. 399 */ 400 401 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 402 p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap; 403 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 404 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap; 405 p->p_rlimit[RLIMIT_AS].rlim_cur = RLIM_INFINITY; 406 p->p_rlimit[RLIMIT_AS].rlim_max = RLIM_INFINITY; 407 p->p_rlimit[RLIMIT_RSS].rlim_cur = MIN( 408 VM_MAXUSER_ADDRESS, ctob((rlim_t)uvmexp.free)); 409 } 410 411 /* 412 * uvm_scheduler: process zero main loop. 413 */ 414 415 extern struct loadavg averunnable; 416 417 void 418 uvm_scheduler(void) 419 { 420 lwp_t *l = curlwp; 421 422 lwp_lock(l); 423 l->l_priority = PRI_VM; 424 l->l_class = SCHED_FIFO; 425 lwp_unlock(l); 426 427 for (;;) { 428 sched_pstats(); 429 (void)kpause("uvm", false, hz, NULL); 430 } 431 } 432