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use NULL setpagesize segop as a shorthand for ENOTSUP
Instead of forcing every segment driver to implement a dummp function to
return (hopefully) ENOTSUP, handle NULL setpagesize segop function pointer
as "return ENOTSUP" shorthand.
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--- old/usr/src/uts/sparc/v9/vm/seg_nf.c
+++ new/usr/src/uts/sparc/v9/vm/seg_nf.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /*
22 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
23 23 * Use is subject to license terms.
24 24 */
25 25
26 26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
27 27 /* All Rights Reserved */
28 28
29 29 /*
30 30 * Portions of this source code were derived from Berkeley 4.3 BSD
31 31 * under license from the Regents of the University of California.
32 32 */
33 33
34 34 /*
35 35 * VM - segment for non-faulting loads.
36 36 */
37 37
38 38 #include <sys/types.h>
39 39 #include <sys/t_lock.h>
40 40 #include <sys/param.h>
41 41 #include <sys/mman.h>
42 42 #include <sys/errno.h>
43 43 #include <sys/kmem.h>
44 44 #include <sys/cmn_err.h>
45 45 #include <sys/vnode.h>
46 46 #include <sys/proc.h>
47 47 #include <sys/conf.h>
48 48 #include <sys/debug.h>
49 49 #include <sys/archsystm.h>
50 50 #include <sys/lgrp.h>
51 51
52 52 #include <vm/page.h>
53 53 #include <vm/hat.h>
54 54 #include <vm/as.h>
55 55 #include <vm/seg.h>
56 56 #include <vm/vpage.h>
57 57
58 58 /*
59 59 * Private seg op routines.
60 60 */
61 61 static int segnf_dup(struct seg *seg, struct seg *newseg);
62 62 static int segnf_unmap(struct seg *seg, caddr_t addr, size_t len);
63 63 static void segnf_free(struct seg *seg);
64 64 static faultcode_t segnf_nomap(void);
65 65 static int segnf_setprot(struct seg *seg, caddr_t addr,
66 66 size_t len, uint_t prot);
67 67 static int segnf_checkprot(struct seg *seg, caddr_t addr,
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68 68 size_t len, uint_t prot);
69 69 static int segnf_nop(void);
70 70 static int segnf_getprot(struct seg *seg, caddr_t addr,
71 71 size_t len, uint_t *protv);
72 72 static u_offset_t segnf_getoffset(struct seg *seg, caddr_t addr);
73 73 static int segnf_gettype(struct seg *seg, caddr_t addr);
74 74 static int segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp);
75 75 static void segnf_dump(struct seg *seg);
76 76 static int segnf_pagelock(struct seg *seg, caddr_t addr, size_t len,
77 77 struct page ***ppp, enum lock_type type, enum seg_rw rw);
78 -static int segnf_setpagesize(struct seg *seg, caddr_t addr, size_t len,
79 - uint_t szc);
80 78
81 79
82 80 struct seg_ops segnf_ops = {
83 81 .dup = segnf_dup,
84 82 .unmap = segnf_unmap,
85 83 .free = segnf_free,
86 84 .fault = (faultcode_t (*)(struct hat *, struct seg *, caddr_t,
87 85 size_t, enum fault_type, enum seg_rw))segnf_nomap,
88 86 .faulta = (faultcode_t (*)(struct seg *, caddr_t)) segnf_nomap,
89 87 .setprot = segnf_setprot,
90 88 .checkprot = segnf_checkprot,
91 89 .sync = (int (*)(struct seg *, caddr_t, size_t, int, uint_t))
92 90 segnf_nop,
93 91 .incore = (size_t (*)(struct seg *, caddr_t, size_t, char *))
94 92 segnf_nop,
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95 93 .lockop = (int (*)(struct seg *, caddr_t, size_t, int, int,
96 94 ulong_t *, size_t))segnf_nop,
97 95 .getprot = segnf_getprot,
98 96 .getoffset = segnf_getoffset,
99 97 .gettype = segnf_gettype,
100 98 .getvp = segnf_getvp,
101 99 .advise = (int (*)(struct seg *, caddr_t, size_t, uint_t))
102 100 segnf_nop,
103 101 .dump = segnf_dump,
104 102 .pagelock = segnf_pagelock,
105 - .setpagesize = segnf_setpagesize,
106 103 };
107 104
108 105 /*
109 106 * vnode and page for the page of zeros we use for the nf mappings.
110 107 */
111 108 static kmutex_t segnf_lock;
112 109 static struct vnode nfvp;
113 110 static struct page **nfpp;
114 111
115 112 #define addr_to_vcolor(addr) \
116 113 (shm_alignment) ? \
117 114 ((int)(((uintptr_t)(addr) & (shm_alignment - 1)) >> PAGESHIFT)) : 0
118 115
119 116 /*
120 117 * We try to limit the number of Non-fault segments created.
121 118 * Non fault segments are created to optimize sparc V9 code which uses
122 119 * the sparc nonfaulting load ASI (ASI_PRIMARY_NOFAULT).
123 120 *
124 121 * There are several reasons why creating too many non-fault segments
125 122 * could cause problems.
126 123 *
127 124 * First, excessive allocation of kernel resources for the seg
128 125 * structures and the HAT data to map the zero pages.
129 126 *
130 127 * Secondly, creating nofault segments actually uses up user virtual
131 128 * address space. This makes it unavailable for subsequent mmap(0, ...)
132 129 * calls which use as_gap() to find empty va regions. Creation of too
133 130 * many nofault segments could thus interfere with the ability of the
134 131 * runtime linker to load a shared object.
135 132 */
136 133 #define MAXSEGFORNF (10000)
137 134 #define MAXNFSEARCH (5)
138 135
139 136
140 137 /*
141 138 * Must be called from startup()
142 139 */
143 140 void
144 141 segnf_init()
145 142 {
146 143 mutex_init(&segnf_lock, NULL, MUTEX_DEFAULT, NULL);
147 144 }
148 145
149 146
150 147 /*
151 148 * Create a no-fault segment.
152 149 *
153 150 * The no-fault segment is not technically necessary, as the code in
154 151 * nfload() in trap.c will emulate the SPARC instruction and load
155 152 * a value of zero in the destination register.
156 153 *
157 154 * However, this code tries to put a page of zero's at the nofault address
158 155 * so that subsequent non-faulting loads to the same page will not
159 156 * trap with a tlb miss.
160 157 *
161 158 * In order to help limit the number of segments we merge adjacent nofault
162 159 * segments into a single segment. If we get a large number of segments
163 160 * we'll also try to delete a random other nf segment.
164 161 */
165 162 /* ARGSUSED */
166 163 int
167 164 segnf_create(struct seg *seg, void *argsp)
168 165 {
169 166 uint_t prot;
170 167 pgcnt_t vacpgs;
171 168 u_offset_t off = 0;
172 169 caddr_t vaddr = NULL;
173 170 int i, color;
174 171 struct seg *s1;
175 172 struct seg *s2;
176 173 size_t size;
177 174 struct as *as = seg->s_as;
178 175
179 176 ASSERT(as && AS_WRITE_HELD(as, &as->a_lock));
180 177
181 178 /*
182 179 * Need a page per virtual color or just 1 if no vac.
183 180 */
184 181 mutex_enter(&segnf_lock);
185 182 if (nfpp == NULL) {
186 183 struct seg kseg;
187 184
188 185 vacpgs = 1;
189 186 if (shm_alignment > PAGESIZE) {
190 187 vacpgs = shm_alignment >> PAGESHIFT;
191 188 }
192 189
193 190 nfpp = kmem_alloc(sizeof (*nfpp) * vacpgs, KM_SLEEP);
194 191
195 192 kseg.s_as = &kas;
196 193 for (i = 0; i < vacpgs; i++, off += PAGESIZE,
197 194 vaddr += PAGESIZE) {
198 195 nfpp[i] = page_create_va(&nfvp, off, PAGESIZE,
199 196 PG_WAIT | PG_NORELOC, &kseg, vaddr);
200 197 page_io_unlock(nfpp[i]);
201 198 page_downgrade(nfpp[i]);
202 199 pagezero(nfpp[i], 0, PAGESIZE);
203 200 }
204 201 }
205 202 mutex_exit(&segnf_lock);
206 203
207 204 hat_map(as->a_hat, seg->s_base, seg->s_size, HAT_MAP);
208 205
209 206 /*
210 207 * s_data can't be NULL because of ASSERTS in the common vm code.
211 208 */
212 209 seg->s_ops = &segnf_ops;
213 210 seg->s_data = seg;
214 211 seg->s_flags |= S_PURGE;
215 212
216 213 mutex_enter(&as->a_contents);
217 214 as->a_flags |= AS_NEEDSPURGE;
218 215 mutex_exit(&as->a_contents);
219 216
220 217 prot = PROT_READ;
221 218 color = addr_to_vcolor(seg->s_base);
222 219 if (as != &kas)
223 220 prot |= PROT_USER;
224 221 hat_memload(as->a_hat, seg->s_base, nfpp[color],
225 222 prot | HAT_NOFAULT, HAT_LOAD);
226 223
227 224 /*
228 225 * At this point see if we can concatenate a segment to
229 226 * a non-fault segment immediately before and/or after it.
230 227 */
231 228 if ((s1 = AS_SEGPREV(as, seg)) != NULL &&
232 229 s1->s_ops == &segnf_ops &&
233 230 s1->s_base + s1->s_size == seg->s_base) {
234 231 size = s1->s_size;
235 232 seg_free(s1);
236 233 seg->s_base -= size;
237 234 seg->s_size += size;
238 235 }
239 236
240 237 if ((s2 = AS_SEGNEXT(as, seg)) != NULL &&
241 238 s2->s_ops == &segnf_ops &&
242 239 seg->s_base + seg->s_size == s2->s_base) {
243 240 size = s2->s_size;
244 241 seg_free(s2);
245 242 seg->s_size += size;
246 243 }
247 244
248 245 /*
249 246 * if we already have a lot of segments, try to delete some other
250 247 * nofault segment to reduce the probability of uncontrolled segment
251 248 * creation.
252 249 *
253 250 * the code looks around quickly (no more than MAXNFSEARCH segments
254 251 * each way) for another NF segment and then deletes it.
255 252 */
256 253 if (avl_numnodes(&as->a_segtree) > MAXSEGFORNF) {
257 254 size = 0;
258 255 s2 = NULL;
259 256 s1 = AS_SEGPREV(as, seg);
260 257 while (size++ < MAXNFSEARCH && s1 != NULL) {
261 258 if (s1->s_ops == &segnf_ops)
262 259 s2 = s1;
263 260 s1 = AS_SEGPREV(s1->s_as, seg);
264 261 }
265 262 if (s2 == NULL) {
266 263 s1 = AS_SEGNEXT(as, seg);
267 264 while (size-- > 0 && s1 != NULL) {
268 265 if (s1->s_ops == &segnf_ops)
269 266 s2 = s1;
270 267 s1 = AS_SEGNEXT(as, seg);
271 268 }
272 269 }
273 270 if (s2 != NULL)
274 271 seg_unmap(s2);
275 272 }
276 273
277 274 return (0);
278 275 }
279 276
280 277 /*
281 278 * Never really need "No fault" segments, so they aren't dup'd.
282 279 */
283 280 /* ARGSUSED */
284 281 static int
285 282 segnf_dup(struct seg *seg, struct seg *newseg)
286 283 {
287 284 panic("segnf_dup");
288 285 return (0);
289 286 }
290 287
291 288 /*
292 289 * Split a segment at addr for length len.
293 290 */
294 291 static int
295 292 segnf_unmap(struct seg *seg, caddr_t addr, size_t len)
296 293 {
297 294 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
298 295
299 296 /*
300 297 * Check for bad sizes.
301 298 */
302 299 if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size ||
303 300 (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) {
304 301 cmn_err(CE_PANIC, "segnf_unmap: bad unmap size");
305 302 }
306 303
307 304 /*
308 305 * Unload any hardware translations in the range to be taken out.
309 306 */
310 307 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD_UNMAP);
311 308
312 309 if (addr == seg->s_base && len == seg->s_size) {
313 310 /*
314 311 * Freeing entire segment.
315 312 */
316 313 seg_free(seg);
317 314 } else if (addr == seg->s_base) {
318 315 /*
319 316 * Freeing the beginning of the segment.
320 317 */
321 318 seg->s_base += len;
322 319 seg->s_size -= len;
323 320 } else if (addr + len == seg->s_base + seg->s_size) {
324 321 /*
325 322 * Freeing the end of the segment.
326 323 */
327 324 seg->s_size -= len;
328 325 } else {
329 326 /*
330 327 * The section to go is in the middle of the segment, so we
331 328 * have to cut it into two segments. We shrink the existing
332 329 * "seg" at the low end, and create "nseg" for the high end.
333 330 */
334 331 caddr_t nbase = addr + len;
335 332 size_t nsize = (seg->s_base + seg->s_size) - nbase;
336 333 struct seg *nseg;
337 334
338 335 /*
339 336 * Trim down "seg" before trying to stick "nseg" into the as.
340 337 */
341 338 seg->s_size = addr - seg->s_base;
342 339 nseg = seg_alloc(seg->s_as, nbase, nsize);
343 340 if (nseg == NULL)
344 341 cmn_err(CE_PANIC, "segnf_unmap: seg_alloc failed");
345 342
346 343 /*
347 344 * s_data can't be NULL because of ASSERTs in common VM code.
348 345 */
349 346 nseg->s_ops = seg->s_ops;
350 347 nseg->s_data = nseg;
351 348 nseg->s_flags |= S_PURGE;
352 349 mutex_enter(&seg->s_as->a_contents);
353 350 seg->s_as->a_flags |= AS_NEEDSPURGE;
354 351 mutex_exit(&seg->s_as->a_contents);
355 352 }
356 353
357 354 return (0);
358 355 }
359 356
360 357 /*
361 358 * Free a segment.
362 359 */
363 360 static void
364 361 segnf_free(struct seg *seg)
365 362 {
366 363 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
367 364 }
368 365
369 366 /*
370 367 * No faults allowed on segnf.
371 368 */
372 369 static faultcode_t
373 370 segnf_nomap(void)
374 371 {
375 372 return (FC_NOMAP);
376 373 }
377 374
378 375 /* ARGSUSED */
379 376 static int
380 377 segnf_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
381 378 {
382 379 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
383 380 return (EACCES);
384 381 }
385 382
386 383 /* ARGSUSED */
387 384 static int
388 385 segnf_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
389 386 {
390 387 uint_t sprot;
391 388 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
392 389
393 390 sprot = seg->s_as == &kas ? PROT_READ : PROT_READ|PROT_USER;
394 391 return ((prot & sprot) == prot ? 0 : EACCES);
395 392 }
396 393
397 394 static int
398 395 segnf_nop(void)
399 396 {
400 397 return (0);
401 398 }
402 399
403 400 static int
404 401 segnf_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
405 402 {
406 403 size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1;
407 404 size_t p;
408 405 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
409 406
410 407 for (p = 0; p < pgno; ++p)
411 408 protv[p] = PROT_READ;
412 409 return (0);
413 410 }
414 411
415 412 /* ARGSUSED */
416 413 static u_offset_t
417 414 segnf_getoffset(struct seg *seg, caddr_t addr)
418 415 {
419 416 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
420 417
421 418 return ((u_offset_t)0);
422 419 }
423 420
424 421 /* ARGSUSED */
425 422 static int
426 423 segnf_gettype(struct seg *seg, caddr_t addr)
427 424 {
428 425 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
429 426
430 427 return (MAP_SHARED);
431 428 }
432 429
433 430 /* ARGSUSED */
434 431 static int
435 432 segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
436 433 {
437 434 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
438 435
439 436 *vpp = &nfvp;
440 437 return (0);
441 438 }
442 439
443 440 /*
444 441 * segnf pages are not dumped, so we just return
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445 442 */
446 443 /* ARGSUSED */
447 444 static void
448 445 segnf_dump(struct seg *seg)
449 446 {}
450 447
451 448 /*ARGSUSED*/
452 449 static int
453 450 segnf_pagelock(struct seg *seg, caddr_t addr, size_t len,
454 451 struct page ***ppp, enum lock_type type, enum seg_rw rw)
455 -{
456 - return (ENOTSUP);
457 -}
458 -
459 -/*ARGSUSED*/
460 -static int
461 -segnf_setpagesize(struct seg *seg, caddr_t addr, size_t len,
462 - uint_t szc)
463 452 {
464 453 return (ENOTSUP);
465 454 }
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