1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #ifdef _KERNEL
33 #include "opt_acpi.h"
34 #include "opt_ddb.h"
35 #endif
36
37 /*
38 * Routines for describing and initializing anything related to physical memory.
39 */
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/physmem.h>
45
46 #ifdef _KERNEL
47 #include <vm/vm.h>
48 #include <vm/vm_param.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_phys.h>
51 #include <vm/vm_dumpset.h>
52 #include <machine/md_var.h>
53 #else
54 #include <stdarg.h>
55 #include <stdio.h>
56 #include <string.h>
57 #endif
58
59 /*
60 * These structures are used internally to keep track of regions of physical
61 * ram, and regions within the physical ram that need to be excluded. An
62 * exclusion region can be excluded from crash dumps, from the vm pool of pages
63 * that can be allocated, or both, depending on the exclusion flags associated
64 * with the region.
65 */
66 #ifdef DEV_ACPI
67 #define MAX_HWCNT 32 /* ACPI needs more regions */
68 #define MAX_EXCNT 32
69 #else
70 #define MAX_HWCNT 16
71 #define MAX_EXCNT 16
72 #endif
73
74 #if defined(__arm__)
75 #define MAX_PHYS_ADDR 0xFFFFFFFFull
76 #elif defined(__aarch64__) || defined(__amd64__) || defined(__riscv)
77 #define MAX_PHYS_ADDR 0xFFFFFFFFFFFFFFFFull
78 #endif
79
80 struct region {
81 vm_paddr_t addr;
82 vm_size_t size;
83 uint32_t flags;
84 };
85
86 static struct region hwregions[MAX_HWCNT];
87 static struct region exregions[MAX_EXCNT];
88
89 static size_t hwcnt;
90 static size_t excnt;
91
92 /*
93 * realmem is the total number of hardware pages, excluded or not.
94 * Maxmem is one greater than the last physical page number.
95 */
96 long realmem;
97 long Maxmem;
98
99 #ifndef _KERNEL
100 static void
101 panic(const char *fmt, ...)
102 {
103 va_list va;
104
105 va_start(va, fmt);
106 vfprintf(stderr, fmt, va);
107 fprintf(stderr, "\n");
108 va_end(va);
109 __builtin_trap();
110 }
111 #endif
112
113 /*
114 * Print the contents of the physical and excluded region tables using the
115 * provided printf-like output function (which will be either printf or
116 * db_printf).
117 */
118 static void
119 physmem_dump_tables(int (*prfunc)(const char *, ...))
120 {
121 size_t i;
122 int flags;
123 uintmax_t addr, size;
124 const unsigned int mbyte = 1024 * 1024;
125
126 prfunc("Physical memory chunk(s):\n");
127 for (i = 0; i < hwcnt; ++i) {
128 addr = hwregions[i].addr;
129 size = hwregions[i].size;
130 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages)\n", addr,
131 addr + size - 1, size / mbyte, size / PAGE_SIZE);
132 }
133
134 prfunc("Excluded memory regions:\n");
135 for (i = 0; i < excnt; ++i) {
136 addr = exregions[i].addr;
137 size = exregions[i].size;
138 flags = exregions[i].flags;
139 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages) %s %s\n",
140 addr, addr + size - 1, size / mbyte, size / PAGE_SIZE,
141 (flags & EXFLAG_NOALLOC) ? "NoAlloc" : "",
142 (flags & EXFLAG_NODUMP) ? "NoDump" : "");
143 }
144
145 #ifdef DEBUG
146 prfunc("Avail lists:\n");
147 for (i = 0; phys_avail[i] != 0; ++i) {
148 prfunc(" phys_avail[%d] 0x%08x\n", i, phys_avail[i]);
149 }
150 for (i = 0; dump_avail[i] != 0; ++i) {
151 prfunc(" dump_avail[%d] 0x%08x\n", i, dump_avail[i]);
152 }
153 #endif
154 }
155
156 /*
157 * Print the contents of the static mapping table. Used for bootverbose.
158 */
159 void
160 physmem_print_tables(void)
161 {
162
163 physmem_dump_tables(printf);
164 }
165
166 /*
167 * Walk the list of hardware regions, processing it against the list of
168 * exclusions that contain the given exflags, and generating an "avail list".
169 *
170 * If maxphyssz is not zero it sets upper limit, in bytes, for the total
171 * "avail list" size. Walk stops once the limit is reached and the last region
172 * is cut short if necessary.
173 *
174 * Updates the value at *pavail with the sum of all pages in all hw regions.
175 *
176 * Returns the number of pages of non-excluded memory added to the avail list.
177 */
178 static size_t
179 regions_to_avail(vm_paddr_t *avail, uint32_t exflags, size_t maxavail,
180 uint64_t maxphyssz, long *pavail, long *prealmem)
181 {
182 size_t acnt, exi, hwi;
183 uint64_t adj, end, start, xend, xstart;
184 long availmem, totalmem;
185 const struct region *exp, *hwp;
186 uint64_t availsz;
187
188 totalmem = 0;
189 availmem = 0;
190 availsz = 0;
191 acnt = 0;
192 for (hwi = 0, hwp = hwregions; hwi < hwcnt; ++hwi, ++hwp) {
193 adj = round_page(hwp->addr) - hwp->addr;
194 start = round_page(hwp->addr);
195 end = trunc_page(hwp->size + adj) + start;
196 totalmem += atop((vm_offset_t)(end - start));
197 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) {
198 /*
199 * If the excluded region does not match given flags,
200 * continue checking with the next excluded region.
201 */
202 if ((exp->flags & exflags) == 0)
203 continue;
204 xstart = exp->addr;
205 xend = exp->size + xstart;
206 /*
207 * If the excluded region ends before this hw region,
208 * continue checking with the next excluded region.
209 */
210 if (xend <= start)
211 continue;
212 /*
213 * If the excluded region begins after this hw region
214 * we're done because both lists are sorted.
215 */
216 if (xstart >= end)
217 break;
218 /*
219 * If the excluded region completely covers this hw
220 * region, shrink this hw region to zero size.
221 */
222 if ((start >= xstart) && (end <= xend)) {
223 start = xend;
224 end = xend;
225 break;
226 }
227 /*
228 * If the excluded region falls wholly within this hw
229 * region without abutting or overlapping the beginning
230 * or end, create an available entry from the leading
231 * fragment, then adjust the start of this hw region to
232 * the end of the excluded region, and continue checking
233 * the next excluded region because another exclusion
234 * could affect the remainder of this hw region.
235 */
236 if ((xstart > start) && (xend < end)) {
237
238 if ((maxphyssz != 0) &&
239 (availsz + xstart - start > maxphyssz)) {
240 xstart = maxphyssz + start - availsz;
241 }
242 if (xstart <= start)
243 continue;
244 if (acnt > 0 &&
245 avail[acnt - 1] == (vm_paddr_t)start) {
246 avail[acnt - 1] = (vm_paddr_t)xstart;
247 } else {
248 avail[acnt++] = (vm_paddr_t)start;
249 avail[acnt++] = (vm_paddr_t)xstart;
250 }
251 availsz += (xstart - start);
252 availmem += atop((vm_offset_t)(xstart - start));
253 start = xend;
254 continue;
255 }
256 /*
257 * We know the excluded region overlaps either the start
258 * or end of this hardware region (but not both), trim
259 * the excluded portion off the appropriate end.
260 */
261 if (xstart <= start)
262 start = xend;
263 else
264 end = xstart;
265 }
266 /*
267 * If the trimming actions above left a non-zero size, create an
268 * available entry for it.
269 */
270 if (end > start) {
271 if ((maxphyssz != 0) &&
272 (availsz + end - start > maxphyssz)) {
273 end = maxphyssz + start - availsz;
274 }
275 if (end <= start)
276 break;
277
278 if (acnt > 0 && avail[acnt - 1] == (vm_paddr_t)start) {
279 avail[acnt - 1] = (vm_paddr_t)end;
280 } else {
281 avail[acnt++] = (vm_paddr_t)start;
282 avail[acnt++] = (vm_paddr_t)end;
283 }
284 availsz += end - start;
285 availmem += atop((vm_offset_t)(end - start));
286 }
287 if (acnt >= maxavail)
288 panic("Not enough space in the dump/phys_avail arrays");
289 }
290
291 if (pavail != NULL)
292 *pavail = availmem;
293 if (prealmem != NULL)
294 *prealmem = totalmem;
295 return (acnt);
296 }
297
298 /*
299 * Check if the region at idx can be merged with the region above it.
300 */
301 static size_t
302 merge_upper_regions(struct region *regions, size_t rcnt, size_t idx)
303 {
304 struct region *lower, *upper;
305 vm_paddr_t lend, uend;
306 size_t i, mergecnt, movecnt;
307
308 lower = ®ions[idx];
309 lend = lower->addr + lower->size;
310
311 /*
312 * Continue merging in upper entries as long as we have entries to
313 * merge; the new block could have spanned more than one, although one
314 * is likely the common case.
315 */
316 for (i = idx + 1; i < rcnt; i++) {
317 upper = ®ions[i];
318 if (lend < upper->addr || lower->flags != upper->flags)
319 break;
320
321 uend = upper->addr + upper->size;
322 if (uend > lend) {
323 lower->size += uend - lend;
324 lend = lower->addr + lower->size;
325 }
326
327 if (uend >= lend) {
328 /*
329 * If we didn't move past the end of the upper region,
330 * then we don't need to bother checking for another
331 * merge because it would have been done already. Just
332 * increment i once more to maintain the invariant that
333 * i is one past the last entry merged.
334 */
335 i++;
336 break;
337 }
338 }
339
340 /*
341 * We merged in the entries from [idx + 1, i); physically move the tail
342 * end at [i, rcnt) if we need to.
343 */
344 mergecnt = i - (idx + 1);
345 if (mergecnt > 0) {
346 movecnt = rcnt - i;
347 if (movecnt == 0) {
348 /* Merged all the way to the end, just decrease rcnt. */
349 rcnt = idx + 1;
350 } else {
351 memmove(®ions[idx + 1], ®ions[idx + mergecnt + 1],
352 movecnt * sizeof(*regions));
353 rcnt -= mergecnt;
354 }
355 }
356 return (rcnt);
357 }
358
359 /*
360 * Insertion-sort a new entry into a regions list; sorted by start address.
361 */
362 static size_t
363 insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr,
364 vm_size_t size, uint32_t flags)
365 {
366 size_t i;
367 vm_paddr_t nend, rend;
368 struct region *ep, *rp;
369
370 nend = addr + size;
371 ep = regions + rcnt;
372 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) {
373 if (flags == rp->flags) {
374 rend = rp->addr + rp->size;
375 if (addr <= rp->addr && nend >= rp->addr) {
376 /*
377 * New mapping overlaps at the beginning, shift
378 * for any difference in the beginning then
379 * shift if the new mapping extends past.
380 */
381 rp->size += rp->addr - addr;
382 rp->addr = addr;
383 if (nend > rend) {
384 rp->size += nend - rend;
385 rcnt = merge_upper_regions(regions,
386 rcnt, i);
387 }
388 return (rcnt);
389 } else if (addr <= rend && nend > rp->addr) {
390 /*
391 * New mapping is either entirely contained
392 * within or it's overlapping at the end.
393 */
394 if (nend > rend) {
395 rp->size += nend - rend;
396 rcnt = merge_upper_regions(regions,
397 rcnt, i);
398 }
399 return (rcnt);
400 }
401 }
402 if (addr < rp->addr) {
403 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp));
404 break;
405 }
406 }
407 rp->addr = addr;
408 rp->size = size;
409 rp->flags = flags;
410 rcnt++;
411
412 return (rcnt);
413 }
414
415 /*
416 * Add a hardware memory region.
417 */
418 void
419 physmem_hardware_region(uint64_t pa, uint64_t sz)
420 {
421 /*
422 * Filter out the page at PA 0x00000000. The VM can't handle it, as
423 * pmap_extract() == 0 means failure.
424 */
425 if (pa == 0) {
426 if (sz <= PAGE_SIZE)
427 return;
428 pa = PAGE_SIZE;
429 sz -= PAGE_SIZE;
430 } else if (pa > MAX_PHYS_ADDR) {
431 /* This range is past usable memory, ignore it */
432 return;
433 }
434
435 /*
436 * Also filter out the page at the end of the physical address space --
437 * if addr is non-zero and addr+size is zero we wrapped to the next byte
438 * beyond what vm_paddr_t can express. That leads to a NULL pointer
439 * deref early in startup; work around it by leaving the last page out.
440 *
441 * XXX This just in: subtract out a whole megabyte, not just 1 page.
442 * Reducing the size by anything less than 1MB results in the NULL
443 * pointer deref in _vm_map_lock_read(). Better to give up a megabyte
444 * than leave some folks with an unusable system while we investigate.
445 */
446 if ((pa + sz) > (MAX_PHYS_ADDR - 1024 * 1024)) {
447 sz = MAX_PHYS_ADDR - pa + 1;
448 if (sz <= 1024 * 1024)
449 return;
450 sz -= 1024 * 1024;
451 }
452
453 if (sz > 0 && hwcnt < nitems(hwregions))
454 hwcnt = insert_region(hwregions, hwcnt, pa, sz, 0);
455 }
456
457 /*
458 * Add an exclusion region.
459 */
460 void
461 physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags)
462 {
463 vm_offset_t adj;
464
465 /*
466 * Truncate the starting address down to a page boundary, and round the
467 * ending page up to a page boundary.
468 */
469 adj = pa - trunc_page(pa);
470 pa = trunc_page(pa);
471 sz = round_page(sz + adj);
472
473 if (excnt >= nitems(exregions))
474 panic("failed to exclude region %#jx-%#jx", (uintmax_t)pa,
475 (uintmax_t)(pa + sz));
476 excnt = insert_region(exregions, excnt, pa, sz, exflags);
477 }
478
479 size_t
480 physmem_avail(vm_paddr_t *avail, size_t maxavail)
481 {
482
483 return (regions_to_avail(avail, EXFLAG_NOALLOC, maxavail, 0, NULL, NULL));
484 }
485
486 bool
487 physmem_excluded(vm_paddr_t pa, vm_size_t sz)
488 {
489 const struct region *exp;
490 size_t exi;
491
492 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) {
493 if (pa < exp->addr || pa + sz > exp->addr + exp->size)
494 continue;
495 return (true);
496 }
497 return (false);
498 }
499
500 #ifdef _KERNEL
501 /*
502 * Process all the regions added earlier into the global avail lists.
503 *
504 * Updates the kernel global 'physmem' with the number of physical pages
505 * available for use (all pages not in any exclusion region).
506 *
507 * Updates the kernel global 'Maxmem' with the page number one greater then the
508 * last page of physical memory in the system.
509 */
510 void
511 physmem_init_kernel_globals(void)
512 {
513 size_t nextidx;
514 u_long hwphyssz;
515
516 hwphyssz = 0;
517 TUNABLE_ULONG_FETCH("hw.physmem", &hwphyssz);
518
519 regions_to_avail(dump_avail, EXFLAG_NODUMP, PHYS_AVAIL_ENTRIES,
520 hwphyssz, NULL, NULL);
521 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC,
522 PHYS_AVAIL_ENTRIES, hwphyssz, &physmem, &realmem);
523 if (nextidx == 0)
524 panic("No memory entries in phys_avail");
525 Maxmem = atop(phys_avail[nextidx - 1]);
526 }
527 #endif
528
529 #ifdef DDB
530 #include <ddb/ddb.h>
531
532 DB_SHOW_COMMAND_FLAGS(physmem, db_show_physmem, DB_CMD_MEMSAFE)
533 {
534
535 physmem_dump_tables(db_printf);
536 }
537
538 #endif /* DDB */
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