1/* $NetBSD: uvm_glue.c,v 1.163 2016/05/22 09:10:37 maxv 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 1.163 2016/05/22 09:10:37 maxv 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 */
94bool
95uvm_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 */
121void
122uvm_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
149int
150uvm_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
170void
171uvm_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 */
182void
183uvm_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 */
208void
209uvm_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
233static pool_cache_t uvm_uarea_cache;
234#if defined(__HAVE_CPU_UAREA_ROUTINES)
235static pool_cache_t uvm_uarea_system_cache;
236#else
237#define uvm_uarea_system_cache uvm_uarea_cache
238#endif
239
240static void *
241uarea_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#if defined(PMAP_ALLOC_POOLPAGE)
249 pg = PMAP_ALLOC_POOLPAGE(
250 ((flags & PR_WAITOK) == 0 ? UVM_KMF_NOWAIT : 0));
251#else
252 pg = uvm_pagealloc(NULL, 0, NULL,
253 ((flags & PR_WAITOK) == 0 ? UVM_KMF_NOWAIT : 0));
254#endif
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#if defined(__HAVE_CPU_UAREA_ROUTINES)
264 void *va = cpu_uarea_alloc(false);
265 if (va)
266 return (void *)va;
267#endif
268 return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz,
269 USPACE_ALIGN, UVM_KMF_WIRED |
270 ((flags & PR_WAITOK) ? UVM_KMF_WAITVA :
271 (UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK)));
272}
273
274static void
275uarea_poolpage_free(struct pool *pp, void *addr)
276{
277#if defined(PMAP_MAP_POOLPAGE)
278 if (USPACE == PAGE_SIZE && USPACE_ALIGN == 0) {
279 paddr_t pa;
280
281 pa = PMAP_UNMAP_POOLPAGE((vaddr_t) addr);
282 KASSERT(pa != 0);
283 uvm_pagefree(PHYS_TO_VM_PAGE(pa));
284 return;
285 }
286#endif
287#if defined(__HAVE_CPU_UAREA_ROUTINES)
288 if (cpu_uarea_free(addr))
289 return;
290#endif
291 uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz,
292 UVM_KMF_WIRED);
293}
294
295static struct pool_allocator uvm_uarea_allocator = {
296 .pa_alloc = uarea_poolpage_alloc,
297 .pa_free = uarea_poolpage_free,
298 .pa_pagesz = USPACE,
299};
300
301#if defined(__HAVE_CPU_UAREA_ROUTINES)
302static void *
303uarea_system_poolpage_alloc(struct pool *pp, int flags)
304{
305 void * const va = cpu_uarea_alloc(true);
306 if (va != NULL)
307 return va;
308
309 return (void *)uvm_km_alloc(kernel_map, pp->pr_alloc->pa_pagesz,
310 USPACE_ALIGN, UVM_KMF_WIRED |
311 ((flags & PR_WAITOK) ? UVM_KMF_WAITVA :
312 (UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK)));
313}
314
315static void
316uarea_system_poolpage_free(struct pool *pp, void *addr)
317{
318 if (cpu_uarea_free(addr))
319 return;
320
321 uvm_km_free(kernel_map, (vaddr_t)addr, pp->pr_alloc->pa_pagesz,
322 UVM_KMF_WIRED);
323}
324
325static struct pool_allocator uvm_uarea_system_allocator = {
326 .pa_alloc = uarea_system_poolpage_alloc,
327 .pa_free = uarea_system_poolpage_free,
328 .pa_pagesz = USPACE,
329};
330#endif /* __HAVE_CPU_UAREA_ROUTINES */
331
332void
333uvm_uarea_init(void)
334{
335 int flags = PR_NOTOUCH;
336
337 /*
338 * specify PR_NOALIGN unless the alignment provided by
339 * the backend (USPACE_ALIGN) is sufficient to provide
340 * pool page size (UPSACE) alignment.
341 */
342
343 if ((USPACE_ALIGN == 0 && USPACE != PAGE_SIZE) ||
344 (USPACE_ALIGN % USPACE) != 0) {
345 flags |= PR_NOALIGN;
346 }
347
348 uvm_uarea_cache = pool_cache_init(USPACE, USPACE_ALIGN, 0, flags,
349 "uarea", &uvm_uarea_allocator, IPL_NONE, NULL, NULL, NULL);
350#if defined(__HAVE_CPU_UAREA_ROUTINES)
351 uvm_uarea_system_cache = pool_cache_init(USPACE, USPACE_ALIGN,
352 0, flags, "uareasys", &uvm_uarea_system_allocator,
353 IPL_NONE, NULL, NULL, NULL);
354#endif
355}
356
357/*
358 * uvm_uarea_alloc: allocate a u-area
359 */
360
361vaddr_t
362uvm_uarea_alloc(void)
363{
364
365 return (vaddr_t)pool_cache_get(uvm_uarea_cache, PR_WAITOK);
366}
367
368vaddr_t
369uvm_uarea_system_alloc(struct cpu_info *ci)
370{
371#ifdef __HAVE_CPU_UAREA_ALLOC_IDLELWP
372 if (__predict_false(ci != NULL))
373 return cpu_uarea_alloc_idlelwp(ci);
374#endif
375
376 return (vaddr_t)pool_cache_get(uvm_uarea_system_cache, PR_WAITOK);
377}
378
379/*
380 * uvm_uarea_free: free a u-area
381 */
382
383void
384uvm_uarea_free(vaddr_t uaddr)
385{
386
387 pool_cache_put(uvm_uarea_cache, (void *)uaddr);
388}
389
390void
391uvm_uarea_system_free(vaddr_t uaddr)
392{
393
394 pool_cache_put(uvm_uarea_system_cache, (void *)uaddr);
395}
396
397vaddr_t
398uvm_lwp_getuarea(lwp_t *l)
399{
400
401 return (vaddr_t)l->l_addr - UAREA_PCB_OFFSET;
402}
403
404void
405uvm_lwp_setuarea(lwp_t *l, vaddr_t addr)
406{
407
408 l->l_addr = (void *)(addr + UAREA_PCB_OFFSET);
409}
410
411/*
412 * uvm_proc_exit: exit a virtual address space
413 *
414 * - borrow proc0's address space because freeing the vmspace
415 * of the dead process may block.
416 */
417
418void
419uvm_proc_exit(struct proc *p)
420{
421 struct lwp *l = curlwp; /* XXX */
422 struct vmspace *ovm;
423
424 KASSERT(p == l->l_proc);
425 ovm = p->p_vmspace;
426 KASSERT(ovm != NULL);
427
428 if (__predict_false(ovm == proc0.p_vmspace))
429 return;
430
431 /*
432 * borrow proc0's address space.
433 */
434 kpreempt_disable();
435 pmap_deactivate(l);
436 p->p_vmspace = proc0.p_vmspace;
437 pmap_activate(l);
438 kpreempt_enable();
439
440 uvmspace_free(ovm);
441}
442
443void
444uvm_lwp_exit(struct lwp *l)
445{
446 vaddr_t va = uvm_lwp_getuarea(l);
447 bool system = (l->l_flag & LW_SYSTEM) != 0;
448
449 if (system)
450 uvm_uarea_system_free(va);
451 else
452 uvm_uarea_free(va);
453#ifdef DIAGNOSTIC
454 uvm_lwp_setuarea(l, (vaddr_t)NULL);
455#endif
456}
457
458/*
459 * uvm_init_limit: init per-process VM limits
460 *
461 * - called for process 0 and then inherited by all others.
462 */
463
464void
465uvm_init_limits(struct proc *p)
466{
467
468 /*
469 * Set up the initial limits on process VM. Set the maximum
470 * resident set size to be all of (reasonably) available memory.
471 * This causes any single, large process to start random page
472 * replacement once it fills memory.
473 */
474
475 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ;
476 p->p_rlimit[RLIMIT_STACK].rlim_max = maxsmap;
477 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ;
478 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdmap;
479 p->p_rlimit[RLIMIT_AS].rlim_cur = RLIM_INFINITY;
480 p->p_rlimit[RLIMIT_AS].rlim_max = RLIM_INFINITY;
481 p->p_rlimit[RLIMIT_RSS].rlim_cur = MIN(
482 VM_MAXUSER_ADDRESS, ctob((rlim_t)uvmexp.free));
483}
484
485/*
486 * uvm_scheduler: process zero main loop.
487 */
488
489extern struct loadavg averunnable;
490
491void
492uvm_scheduler(void)
493{
494 lwp_t *l = curlwp;
495
496 lwp_lock(l);
497 l->l_priority = PRI_VM;
498 l->l_class = SCHED_FIFO;
499 lwp_unlock(l);
500
501 for (;;) {
502 sched_pstats();
503 (void)kpause("uvm", false, hz, NULL);
504 }
505}
506