1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
27 /* All Rights Reserved */
28
29 /*
30 * Portions of this source code were derived from Berkeley 4.3 BSD
31 * under license from the Regents of the University of California.
32 */
33
34 #pragma ident "%Z%%M% %I% %E% SMI"
35
36 /*
37 * VM - segment for non-faulting loads.
38 */
39
40 #include <sys/types.h>
41 #include <sys/t_lock.h>
42 #include <sys/param.h>
43 #include <sys/mman.h>
44 #include <sys/errno.h>
45 #include <sys/kmem.h>
46 #include <sys/cmn_err.h>
47 #include <sys/vnode.h>
48 #include <sys/proc.h>
49 #include <sys/conf.h>
50 #include <sys/debug.h>
51 #include <sys/archsystm.h>
52 #include <sys/lgrp.h>
53
54 #include <vm/page.h>
55 #include <vm/hat.h>
56 #include <vm/as.h>
57 #include <vm/seg.h>
58 #include <vm/vpage.h>
59
60 /*
61 * Private seg op routines.
62 */
63 static int segnf_dup(struct seg *seg, struct seg *newseg);
64 static int segnf_unmap(struct seg *seg, caddr_t addr, size_t len);
65 static void segnf_free(struct seg *seg);
66 static faultcode_t segnf_nomap(void);
67 static int segnf_setprot(struct seg *seg, caddr_t addr,
68 size_t len, uint_t prot);
69 static int segnf_checkprot(struct seg *seg, caddr_t addr,
70 size_t len, uint_t prot);
71 static void segnf_badop(void);
72 static int segnf_nop(void);
73 static int segnf_getprot(struct seg *seg, caddr_t addr,
74 size_t len, uint_t *protv);
75 static u_offset_t segnf_getoffset(struct seg *seg, caddr_t addr);
76 static int segnf_gettype(struct seg *seg, caddr_t addr);
77 static int segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp);
78 static void segnf_dump(struct seg *seg);
79 static int segnf_pagelock(struct seg *seg, caddr_t addr, size_t len,
80 struct page ***ppp, enum lock_type type, enum seg_rw rw);
81 static int segnf_setpagesize(struct seg *seg, caddr_t addr, size_t len,
82 uint_t szc);
83 static int segnf_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp);
84 static lgrp_mem_policy_info_t *segnf_getpolicy(struct seg *seg,
85 caddr_t addr);
86
87
88 struct seg_ops segnf_ops = {
89 segnf_dup,
90 segnf_unmap,
91 segnf_free,
92 (faultcode_t (*)(struct hat *, struct seg *, caddr_t, size_t,
93 enum fault_type, enum seg_rw))
94 segnf_nomap, /* fault */
95 (faultcode_t (*)(struct seg *, caddr_t))
96 segnf_nomap, /* faulta */
97 segnf_setprot,
98 segnf_checkprot,
99 (int (*)())segnf_badop, /* kluster */
100 (size_t (*)(struct seg *))NULL, /* swapout */
101 (int (*)(struct seg *, caddr_t, size_t, int, uint_t))
102 segnf_nop, /* sync */
103 (size_t (*)(struct seg *, caddr_t, size_t, char *))
104 segnf_nop, /* incore */
105 (int (*)(struct seg *, caddr_t, size_t, int, int, ulong_t *, size_t))
106 segnf_nop, /* lockop */
107 segnf_getprot,
108 segnf_getoffset,
109 segnf_gettype,
110 segnf_getvp,
111 (int (*)(struct seg *, caddr_t, size_t, uint_t))
112 segnf_nop, /* advise */
113 segnf_dump,
114 segnf_pagelock,
115 segnf_setpagesize,
116 segnf_getmemid,
117 segnf_getpolicy,
118 };
119
120 /*
121 * vnode and page for the page of zeros we use for the nf mappings.
122 */
123 static kmutex_t segnf_lock;
124 static struct vnode nfvp;
125 static struct page **nfpp;
126
127 #define addr_to_vcolor(addr) \
128 (shm_alignment) ? \
129 ((int)(((uintptr_t)(addr) & (shm_alignment - 1)) >> PAGESHIFT)) : 0
130
131 /*
132 * We try to limit the number of Non-fault segments created.
133 * Non fault segments are created to optimize sparc V9 code which uses
134 * the sparc nonfaulting load ASI (ASI_PRIMARY_NOFAULT).
135 *
136 * There are several reasons why creating too many non-fault segments
137 * could cause problems.
138 *
139 * First, excessive allocation of kernel resources for the seg
140 * structures and the HAT data to map the zero pages.
141 *
142 * Secondly, creating nofault segments actually uses up user virtual
143 * address space. This makes it unavailable for subsequent mmap(0, ...)
144 * calls which use as_gap() to find empty va regions. Creation of too
145 * many nofault segments could thus interfere with the ability of the
146 * runtime linker to load a shared object.
147 */
148 #define MAXSEGFORNF (10000)
149 #define MAXNFSEARCH (5)
150
151
152 /*
153 * Must be called from startup()
154 */
155 void
segnf_init()156 segnf_init()
157 {
158 mutex_init(&segnf_lock, NULL, MUTEX_DEFAULT, NULL);
159 }
160
161
162 /*
163 * Create a no-fault segment.
164 *
165 * The no-fault segment is not technically necessary, as the code in
166 * nfload() in trap.c will emulate the SPARC instruction and load
167 * a value of zero in the destination register.
168 *
169 * However, this code tries to put a page of zero's at the nofault address
170 * so that subsequent non-faulting loads to the same page will not
171 * trap with a tlb miss.
172 *
173 * In order to help limit the number of segments we merge adjacent nofault
174 * segments into a single segment. If we get a large number of segments
175 * we'll also try to delete a random other nf segment.
176 */
177 /* ARGSUSED */
178 int
segnf_create(struct seg * seg,void * argsp)179 segnf_create(struct seg *seg, void *argsp)
180 {
181 uint_t prot;
182 pgcnt_t vacpgs;
183 u_offset_t off = 0;
184 caddr_t vaddr = NULL;
185 int i, color;
186 struct seg *s1;
187 struct seg *s2;
188 size_t size;
189 struct as *as = seg->s_as;
190
191 ASSERT(as && AS_WRITE_HELD(as, &as->a_lock));
192
193 /*
194 * Need a page per virtual color or just 1 if no vac.
195 */
196 mutex_enter(&segnf_lock);
197 if (nfpp == NULL) {
198 struct seg kseg;
199
200 vacpgs = 1;
201 if (shm_alignment > PAGESIZE) {
202 vacpgs = shm_alignment >> PAGESHIFT;
203 }
204
205 nfpp = kmem_alloc(sizeof (*nfpp) * vacpgs, KM_SLEEP);
206
207 kseg.s_as = &kas;
208 for (i = 0; i < vacpgs; i++, off += PAGESIZE,
209 vaddr += PAGESIZE) {
210 nfpp[i] = page_create_va(&nfvp, off, PAGESIZE,
211 PG_WAIT | PG_NORELOC, &kseg, vaddr);
212 page_io_unlock(nfpp[i]);
213 page_downgrade(nfpp[i]);
214 pagezero(nfpp[i], 0, PAGESIZE);
215 }
216 }
217 mutex_exit(&segnf_lock);
218
219 hat_map(as->a_hat, seg->s_base, seg->s_size, HAT_MAP);
220
221 /*
222 * s_data can't be NULL because of ASSERTS in the common vm code.
223 */
224 seg->s_ops = &segnf_ops;
225 seg->s_data = seg;
226 seg->s_flags |= S_PURGE;
227
228 mutex_enter(&as->a_contents);
229 as->a_flags |= AS_NEEDSPURGE;
230 mutex_exit(&as->a_contents);
231
232 prot = PROT_READ;
233 color = addr_to_vcolor(seg->s_base);
234 if (as != &kas)
235 prot |= PROT_USER;
236 hat_memload(as->a_hat, seg->s_base, nfpp[color],
237 prot | HAT_NOFAULT, HAT_LOAD);
238
239 /*
240 * At this point see if we can concatenate a segment to
241 * a non-fault segment immediately before and/or after it.
242 */
243 if ((s1 = AS_SEGPREV(as, seg)) != NULL &&
244 s1->s_ops == &segnf_ops &&
245 s1->s_base + s1->s_size == seg->s_base) {
246 size = s1->s_size;
247 seg_free(s1);
248 seg->s_base -= size;
249 seg->s_size += size;
250 }
251
252 if ((s2 = AS_SEGNEXT(as, seg)) != NULL &&
253 s2->s_ops == &segnf_ops &&
254 seg->s_base + seg->s_size == s2->s_base) {
255 size = s2->s_size;
256 seg_free(s2);
257 seg->s_size += size;
258 }
259
260 /*
261 * if we already have a lot of segments, try to delete some other
262 * nofault segment to reduce the probability of uncontrolled segment
263 * creation.
264 *
265 * the code looks around quickly (no more than MAXNFSEARCH segments
266 * each way) for another NF segment and then deletes it.
267 */
268 if (avl_numnodes(&as->a_segtree) > MAXSEGFORNF) {
269 size = 0;
270 s2 = NULL;
271 s1 = AS_SEGPREV(as, seg);
272 while (size++ < MAXNFSEARCH && s1 != NULL) {
273 if (s1->s_ops == &segnf_ops)
274 s2 = s1;
275 s1 = AS_SEGPREV(s1->s_as, seg);
276 }
277 if (s2 == NULL) {
278 s1 = AS_SEGNEXT(as, seg);
279 while (size-- > 0 && s1 != NULL) {
280 if (s1->s_ops == &segnf_ops)
281 s2 = s1;
282 s1 = AS_SEGNEXT(as, seg);
283 }
284 }
285 if (s2 != NULL)
286 seg_unmap(s2);
287 }
288
289 return (0);
290 }
291
292 /*
293 * Never really need "No fault" segments, so they aren't dup'd.
294 */
295 /* ARGSUSED */
296 static int
segnf_dup(struct seg * seg,struct seg * newseg)297 segnf_dup(struct seg *seg, struct seg *newseg)
298 {
299 panic("segnf_dup");
300 return (0);
301 }
302
303 /*
304 * Split a segment at addr for length len.
305 */
306 static int
segnf_unmap(struct seg * seg,caddr_t addr,size_t len)307 segnf_unmap(struct seg *seg, caddr_t addr, size_t len)
308 {
309 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
310
311 /*
312 * Check for bad sizes.
313 */
314 if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size ||
315 (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) {
316 cmn_err(CE_PANIC, "segnf_unmap: bad unmap size");
317 }
318
319 /*
320 * Unload any hardware translations in the range to be taken out.
321 */
322 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD_UNMAP);
323
324 if (addr == seg->s_base && len == seg->s_size) {
325 /*
326 * Freeing entire segment.
327 */
328 seg_free(seg);
329 } else if (addr == seg->s_base) {
330 /*
331 * Freeing the beginning of the segment.
332 */
333 seg->s_base += len;
334 seg->s_size -= len;
335 } else if (addr + len == seg->s_base + seg->s_size) {
336 /*
337 * Freeing the end of the segment.
338 */
339 seg->s_size -= len;
340 } else {
341 /*
342 * The section to go is in the middle of the segment, so we
343 * have to cut it into two segments. We shrink the existing
344 * "seg" at the low end, and create "nseg" for the high end.
345 */
346 caddr_t nbase = addr + len;
347 size_t nsize = (seg->s_base + seg->s_size) - nbase;
348 struct seg *nseg;
349
350 /*
351 * Trim down "seg" before trying to stick "nseg" into the as.
352 */
353 seg->s_size = addr - seg->s_base;
354 nseg = seg_alloc(seg->s_as, nbase, nsize);
355 if (nseg == NULL)
356 cmn_err(CE_PANIC, "segnf_unmap: seg_alloc failed");
357
358 /*
359 * s_data can't be NULL because of ASSERTs in common VM code.
360 */
361 nseg->s_ops = seg->s_ops;
362 nseg->s_data = nseg;
363 nseg->s_flags |= S_PURGE;
364 mutex_enter(&seg->s_as->a_contents);
365 seg->s_as->a_flags |= AS_NEEDSPURGE;
366 mutex_exit(&seg->s_as->a_contents);
367 }
368
369 return (0);
370 }
371
372 /*
373 * Free a segment.
374 */
375 static void
segnf_free(struct seg * seg)376 segnf_free(struct seg *seg)
377 {
378 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
379 }
380
381 /*
382 * No faults allowed on segnf.
383 */
384 static faultcode_t
segnf_nomap(void)385 segnf_nomap(void)
386 {
387 return (FC_NOMAP);
388 }
389
390 /* ARGSUSED */
391 static int
segnf_setprot(struct seg * seg,caddr_t addr,size_t len,uint_t prot)392 segnf_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
393 {
394 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
395 return (EACCES);
396 }
397
398 /* ARGSUSED */
399 static int
segnf_checkprot(struct seg * seg,caddr_t addr,size_t len,uint_t prot)400 segnf_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
401 {
402 uint_t sprot;
403 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
404
405 sprot = seg->s_as == &kas ? PROT_READ : PROT_READ|PROT_USER;
406 return ((prot & sprot) == prot ? 0 : EACCES);
407 }
408
409 static void
segnf_badop(void)410 segnf_badop(void)
411 {
412 panic("segnf_badop");
413 /*NOTREACHED*/
414 }
415
416 static int
segnf_nop(void)417 segnf_nop(void)
418 {
419 return (0);
420 }
421
422 static int
segnf_getprot(struct seg * seg,caddr_t addr,size_t len,uint_t * protv)423 segnf_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
424 {
425 size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1;
426 size_t p;
427 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
428
429 for (p = 0; p < pgno; ++p)
430 protv[p] = PROT_READ;
431 return (0);
432 }
433
434 /* ARGSUSED */
435 static u_offset_t
segnf_getoffset(struct seg * seg,caddr_t addr)436 segnf_getoffset(struct seg *seg, caddr_t addr)
437 {
438 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
439
440 return ((u_offset_t)0);
441 }
442
443 /* ARGSUSED */
444 static int
segnf_gettype(struct seg * seg,caddr_t addr)445 segnf_gettype(struct seg *seg, caddr_t addr)
446 {
447 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
448
449 return (MAP_SHARED);
450 }
451
452 /* ARGSUSED */
453 static int
segnf_getvp(struct seg * seg,caddr_t addr,struct vnode ** vpp)454 segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
455 {
456 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
457
458 *vpp = &nfvp;
459 return (0);
460 }
461
462 /*
463 * segnf pages are not dumped, so we just return
464 */
465 /* ARGSUSED */
466 static void
segnf_dump(struct seg * seg)467 segnf_dump(struct seg *seg)
468 {}
469
470 /*ARGSUSED*/
471 static int
segnf_pagelock(struct seg * seg,caddr_t addr,size_t len,struct page *** ppp,enum lock_type type,enum seg_rw rw)472 segnf_pagelock(struct seg *seg, caddr_t addr, size_t len,
473 struct page ***ppp, enum lock_type type, enum seg_rw rw)
474 {
475 return (ENOTSUP);
476 }
477
478 /*ARGSUSED*/
479 static int
segnf_setpagesize(struct seg * seg,caddr_t addr,size_t len,uint_t szc)480 segnf_setpagesize(struct seg *seg, caddr_t addr, size_t len,
481 uint_t szc)
482 {
483 return (ENOTSUP);
484 }
485
486 /*ARGSUSED*/
487 static int
segnf_getmemid(struct seg * seg,caddr_t addr,memid_t * memidp)488 segnf_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
489 {
490 return (ENODEV);
491 }
492
493 /*ARGSUSED*/
494 static lgrp_mem_policy_info_t *
segnf_getpolicy(struct seg * seg,caddr_t addr)495 segnf_getpolicy(struct seg *seg, caddr_t addr)
496 {
497 return (NULL);
498 }
499