2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
36 * Routines for describing and initializing anything related to physical memory.
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/physmem.h>
43 #include <vm/vm_param.h>
44 #include <vm/vm_page.h>
45 #include <vm/vm_phys.h>
46 #include <vm/vm_dumpset.h>
47 #include <machine/md_var.h>
50 * These structures are used internally to keep track of regions of physical
51 * ram, and regions within the physical ram that need to be excluded. An
52 * exclusion region can be excluded from crash dumps, from the vm pool of pages
53 * that can be allocated, or both, depending on the exclusion flags associated
57 #define MAX_HWCNT 32 /* ACPI needs more regions */
65 #define MAX_PHYS_ADDR 0xFFFFFFFFull
66 #elif defined(__aarch64__) || defined(__riscv)
67 #define MAX_PHYS_ADDR 0xFFFFFFFFFFFFFFFFull
76 static struct region hwregions[MAX_HWCNT];
77 static struct region exregions[MAX_EXCNT];
83 * realmem is the total number of hardware pages, excluded or not.
84 * Maxmem is one greater than the last physical page number.
90 * Print the contents of the physical and excluded region tables using the
91 * provided printf-like output function (which will be either printf or
95 physmem_dump_tables(int (*prfunc)(const char *, ...))
99 const unsigned int mbyte = 1024 * 1024;
101 prfunc("Physical memory chunk(s):\n");
102 for (i = 0; i < hwcnt; ++i) {
103 addr = hwregions[i].addr;
104 size = hwregions[i].size;
105 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages)\n", addr,
106 addr + size - 1, size / mbyte, size / PAGE_SIZE);
109 prfunc("Excluded memory regions:\n");
110 for (i = 0; i < excnt; ++i) {
111 addr = exregions[i].addr;
112 size = exregions[i].size;
113 flags = exregions[i].flags;
114 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages) %s %s\n",
115 addr, addr + size - 1, size / mbyte, size / PAGE_SIZE,
116 (flags & EXFLAG_NOALLOC) ? "NoAlloc" : "",
117 (flags & EXFLAG_NODUMP) ? "NoDump" : "");
121 prfunc("Avail lists:\n");
122 for (i = 0; phys_avail[i] != 0; ++i) {
123 prfunc(" phys_avail[%d] 0x%08x\n", i, phys_avail[i]);
125 for (i = 0; dump_avail[i] != 0; ++i) {
126 prfunc(" dump_avail[%d] 0x%08x\n", i, dump_avail[i]);
132 * Print the contents of the static mapping table. Used for bootverbose.
135 physmem_print_tables(void)
138 physmem_dump_tables(printf);
142 * Walk the list of hardware regions, processing it against the list of
143 * exclusions that contain the given exflags, and generating an "avail list".
145 * Updates the value at *pavail with the sum of all pages in all hw regions.
147 * Returns the number of pages of non-excluded memory added to the avail list.
150 regions_to_avail(vm_paddr_t *avail, uint32_t exflags, size_t maxavail,
151 long *pavail, long *prealmem)
153 size_t acnt, exi, hwi;
154 uint64_t end, start, xend, xstart;
155 long availmem, totalmem;
156 const struct region *exp, *hwp;
161 for (hwi = 0, hwp = hwregions; hwi < hwcnt; ++hwi, ++hwp) {
163 end = hwp->size + start;
164 totalmem += atop((vm_offset_t)(end - start));
165 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) {
167 * If the excluded region does not match given flags,
168 * continue checking with the next excluded region.
170 if ((exp->flags & exflags) == 0)
173 xend = exp->size + xstart;
175 * If the excluded region ends before this hw region,
176 * continue checking with the next excluded region.
181 * If the excluded region begins after this hw region
182 * we're done because both lists are sorted.
187 * If the excluded region completely covers this hw
188 * region, shrink this hw region to zero size.
190 if ((start >= xstart) && (end <= xend)) {
196 * If the excluded region falls wholly within this hw
197 * region without abutting or overlapping the beginning
198 * or end, create an available entry from the leading
199 * fragment, then adjust the start of this hw region to
200 * the end of the excluded region, and continue checking
201 * the next excluded region because another exclusion
202 * could affect the remainder of this hw region.
204 if ((xstart > start) && (xend < end)) {
206 avail[acnt - 1] == (vm_paddr_t)start) {
207 avail[acnt - 1] = (vm_paddr_t)xstart;
209 avail[acnt++] = (vm_paddr_t)start;
210 avail[acnt++] = (vm_paddr_t)xstart;
212 availmem += atop((vm_offset_t)(xstart - start));
217 * We know the excluded region overlaps either the start
218 * or end of this hardware region (but not both), trim
219 * the excluded portion off the appropriate end.
227 * If the trimming actions above left a non-zero size, create an
228 * available entry for it.
231 if (acnt > 0 && avail[acnt - 1] == (vm_paddr_t)start) {
232 avail[acnt - 1] = (vm_paddr_t)end;
234 avail[acnt++] = (vm_paddr_t)start;
235 avail[acnt++] = (vm_paddr_t)end;
237 availmem += atop((vm_offset_t)(end - start));
239 if (acnt >= maxavail)
240 panic("Not enough space in the dump/phys_avail arrays");
245 if (prealmem != NULL)
246 *prealmem = totalmem;
251 * Insertion-sort a new entry into a regions list; sorted by start address.
254 insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr,
255 vm_size_t size, uint32_t flags)
258 struct region *ep, *rp;
261 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) {
262 if (rp->addr == addr && rp->size == size) /* Pure dup. */
264 if (flags == rp->flags) {
265 if (addr + size == rp->addr) {
269 } else if (rp->addr + rp->size == addr) {
274 if (addr < rp->addr) {
275 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp));
288 * Add a hardware memory region.
291 physmem_hardware_region(uint64_t pa, uint64_t sz)
296 * Filter out the page at PA 0x00000000. The VM can't handle it, as
297 * pmap_extract() == 0 means failure.
304 } else if (pa > MAX_PHYS_ADDR) {
305 /* This range is past usable memory, ignore it */
310 * Also filter out the page at the end of the physical address space --
311 * if addr is non-zero and addr+size is zero we wrapped to the next byte
312 * beyond what vm_paddr_t can express. That leads to a NULL pointer
313 * deref early in startup; work around it by leaving the last page out.
315 * XXX This just in: subtract out a whole megabyte, not just 1 page.
316 * Reducing the size by anything less than 1MB results in the NULL
317 * pointer deref in _vm_map_lock_read(). Better to give up a megabyte
318 * than leave some folks with an unusable system while we investigate.
320 if ((pa + sz) > (MAX_PHYS_ADDR - 1024 * 1024)) {
321 sz = MAX_PHYS_ADDR - pa + 1;
322 if (sz <= 1024 * 1024)
328 * Round the starting address up to a page boundary, and truncate the
329 * ending page down to a page boundary.
331 adj = round_page(pa) - pa;
333 sz = trunc_page(sz - adj);
335 if (sz > 0 && hwcnt < nitems(hwregions))
336 hwcnt = insert_region(hwregions, hwcnt, pa, sz, 0);
340 * Add an exclusion region.
343 physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags)
348 * Truncate the starting address down to a page boundary, and round the
349 * ending page up to a page boundary.
351 adj = pa - trunc_page(pa);
353 sz = round_page(sz + adj);
355 if (excnt >= nitems(exregions))
356 panic("failed to exclude region %#jx-%#jx", (uintmax_t)pa,
357 (uintmax_t)(pa + sz));
358 excnt = insert_region(exregions, excnt, pa, sz, exflags);
362 physmem_avail(vm_paddr_t *avail, size_t maxavail)
365 return (regions_to_avail(avail, EXFLAG_NOALLOC, maxavail, NULL, NULL));
369 * Process all the regions added earlier into the global avail lists.
371 * Updates the kernel global 'physmem' with the number of physical pages
372 * available for use (all pages not in any exclusion region).
374 * Updates the kernel global 'Maxmem' with the page number one greater then the
375 * last page of physical memory in the system.
378 physmem_init_kernel_globals(void)
382 regions_to_avail(dump_avail, EXFLAG_NODUMP, PHYS_AVAIL_ENTRIES, NULL,
384 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC,
385 PHYS_AVAIL_ENTRIES, &physmem, &realmem);
387 panic("No memory entries in phys_avail");
388 Maxmem = atop(phys_avail[nextidx - 1]);
394 DB_SHOW_COMMAND(physmem, db_show_physmem)
397 physmem_dump_tables(db_printf);