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