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>
42 #include <machine/md_var.h>
43 #include <arm/include/physmem.h>
46 * These structures are used internally to keep track of regions of physical
47 * ram, and regions within the physical ram that need to be excluded. An
48 * exclusion region can be excluded from crash dumps, from the vm pool of pages
49 * that can be allocated, or both, depending on the exclusion flags associated
53 #define MAX_HWCNT 32 /* ACPI needs more regions */
61 #define MAX_PHYS_ADDR 0xFFFFFFFFull
62 #define pm_btop(x) arm32_btop(x)
63 #elif defined(__aarch64__)
64 #define MAX_PHYS_ADDR 0xFFFFFFFFFFFFFFFFull
65 #define pm_btop(x) arm64_btop(x)
74 static struct region hwregions[MAX_HWCNT];
75 static struct region exregions[MAX_EXCNT];
81 * These "avail lists" are globals used to communicate physical memory layout to
82 * other parts of the kernel. Within the arrays, each value is the starting
83 * address of a contiguous area of physical address space. The values at even
84 * indexes are areas that contain usable memory and the values at odd indexes
85 * are areas that aren't usable. Each list is terminated by a pair of zero
88 * dump_avail tells the dump code what regions to include in a crash dump, and
89 * phys_avail is the way we hand all the remaining physical ram we haven't used
90 * in early kernel init over to the vm system for allocation management.
92 * We size these arrays to hold twice as many available regions as we allow for
93 * hardware memory regions, to allow for the fact that exclusions can split a
94 * hardware region into two or more available regions. In the real world there
95 * will typically be one or two hardware regions and two or three exclusions.
97 * Each available region in this list occupies two array slots (the start of the
98 * available region and the start of the unavailable region that follows it).
100 #define MAX_AVAIL_REGIONS (MAX_HWCNT * 2)
101 #define MAX_AVAIL_ENTRIES (MAX_AVAIL_REGIONS * 2)
103 vm_paddr_t phys_avail[MAX_AVAIL_ENTRIES + 2]; /* +2 to allow for a pair */
104 vm_paddr_t dump_avail[MAX_AVAIL_ENTRIES + 2]; /* of zeroes to terminate. */
107 * realmem is the total number of hardware pages, excluded or not.
108 * Maxmem is one greater than the last physical page number.
113 /* The address at which the kernel was loaded. Set early in initarm(). */
114 vm_paddr_t arm_physmem_kernaddr;
117 * Print the contents of the physical and excluded region tables using the
118 * provided printf-like output function (which will be either printf or
122 physmem_dump_tables(int (*prfunc)(const char *, ...))
125 uintmax_t addr, size;
126 const unsigned int mbyte = 1024 * 1024;
128 prfunc("Physical memory chunk(s):\n");
129 for (i = 0; i < hwcnt; ++i) {
130 addr = hwregions[i].addr;
131 size = hwregions[i].size;
132 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages)\n", addr,
133 addr + size - 1, size / mbyte, size / PAGE_SIZE);
136 prfunc("Excluded memory regions:\n");
137 for (i = 0; i < excnt; ++i) {
138 addr = exregions[i].addr;
139 size = exregions[i].size;
140 flags = exregions[i].flags;
141 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages) %s %s\n",
142 addr, addr + size - 1, size / mbyte, size / PAGE_SIZE,
143 (flags & EXFLAG_NOALLOC) ? "NoAlloc" : "",
144 (flags & EXFLAG_NODUMP) ? "NoDump" : "");
148 prfunc("Avail lists:\n");
149 for (i = 0; phys_avail[i] != 0; ++i) {
150 prfunc(" phys_avail[%d] 0x%08x\n", i, phys_avail[i]);
152 for (i = 0; dump_avail[i] != 0; ++i) {
153 prfunc(" dump_avail[%d] 0x%08x\n", i, dump_avail[i]);
159 * Print the contents of the static mapping table. Used for bootverbose.
162 arm_physmem_print_tables(void)
165 physmem_dump_tables(printf);
169 * Walk the list of hardware regions, processing it against the list of
170 * exclusions that contain the given exflags, and generating an "avail list".
172 * Updates the value at *pavail with the sum of all pages in all hw regions.
174 * Returns the number of pages of non-excluded memory added to the avail list.
177 regions_to_avail(vm_paddr_t *avail, uint32_t exflags, size_t maxavail,
178 long *pavail, long *prealmem)
180 size_t acnt, exi, hwi;
181 uint64_t end, start, xend, xstart;
182 long availmem, totalmem;
183 const struct region *exp, *hwp;
188 for (hwi = 0, hwp = hwregions; hwi < hwcnt; ++hwi, ++hwp) {
190 end = hwp->size + start;
191 totalmem += pm_btop((vm_offset_t)(end - start));
192 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) {
194 * If the excluded region does not match given flags,
195 * continue checking with the next excluded region.
197 if ((exp->flags & exflags) == 0)
200 xend = exp->size + xstart;
202 * If the excluded region ends before this hw region,
203 * continue checking with the next excluded region.
208 * If the excluded region begins after this hw region
209 * we're done because both lists are sorted.
214 * If the excluded region completely covers this hw
215 * region, shrink this hw region to zero size.
217 if ((start >= xstart) && (end <= xend)) {
223 * If the excluded region falls wholly within this hw
224 * region without abutting or overlapping the beginning
225 * or end, create an available entry from the leading
226 * fragment, then adjust the start of this hw region to
227 * the end of the excluded region, and continue checking
228 * the next excluded region because another exclusion
229 * could affect the remainder of this hw region.
231 if ((xstart > start) && (xend < end)) {
233 avail[acnt - 1] == (vm_paddr_t)start) {
234 avail[acnt - 1] = (vm_paddr_t)xstart;
236 avail[acnt++] = (vm_paddr_t)start;
237 avail[acnt++] = (vm_paddr_t)xstart;
240 pm_btop((vm_offset_t)(xstart - start));
245 * We know the excluded region overlaps either the start
246 * or end of this hardware region (but not both), trim
247 * the excluded portion off the appropriate end.
255 * If the trimming actions above left a non-zero size, create an
256 * available entry for it.
259 if (acnt > 0 && avail[acnt - 1] == (vm_paddr_t)start) {
260 avail[acnt - 1] = (vm_paddr_t)end;
262 avail[acnt++] = (vm_paddr_t)start;
263 avail[acnt++] = (vm_paddr_t)end;
265 availmem += pm_btop((vm_offset_t)(end - start));
267 if (acnt >= maxavail)
268 panic("Not enough space in the dump/phys_avail arrays");
273 if (prealmem != NULL)
274 *prealmem = totalmem;
279 * Insertion-sort a new entry into a regions list; sorted by start address.
282 insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr,
283 vm_size_t size, uint32_t flags)
286 struct region *ep, *rp;
289 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) {
290 if (rp->addr == addr && rp->size == size) /* Pure dup. */
292 if (flags == rp->flags) {
293 if (addr + size == rp->addr) {
297 } else if (rp->addr + rp->size == addr) {
302 if (addr < rp->addr) {
303 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp));
316 * Add a hardware memory region.
319 arm_physmem_hardware_region(uint64_t pa, uint64_t sz)
324 * Filter out the page at PA 0x00000000. The VM can't handle it, as
325 * pmap_extract() == 0 means failure.
332 } else if (pa > MAX_PHYS_ADDR) {
333 /* This range is past usable memory, ignore it */
338 * Also filter out the page at the end of the physical address space --
339 * if addr is non-zero and addr+size is zero we wrapped to the next byte
340 * beyond what vm_paddr_t can express. That leads to a NULL pointer
341 * deref early in startup; work around it by leaving the last page out.
343 * XXX This just in: subtract out a whole megabyte, not just 1 page.
344 * Reducing the size by anything less than 1MB results in the NULL
345 * pointer deref in _vm_map_lock_read(). Better to give up a megabyte
346 * than leave some folks with an unusable system while we investigate.
348 if ((pa + sz) > (MAX_PHYS_ADDR - 1024 * 1024)) {
349 sz = MAX_PHYS_ADDR - pa + 1;
350 if (sz <= 1024 * 1024)
356 * Round the starting address up to a page boundary, and truncate the
357 * ending page down to a page boundary.
359 adj = round_page(pa) - pa;
361 sz = trunc_page(sz - adj);
363 if (sz > 0 && hwcnt < nitems(hwregions))
364 hwcnt = insert_region(hwregions, hwcnt, pa, sz, 0);
368 * Add an exclusion region.
371 arm_physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags)
376 * Truncate the starting address down to a page boundary, and round the
377 * ending page up to a page boundary.
379 adj = pa - trunc_page(pa);
381 sz = round_page(sz + adj);
383 if (excnt >= nitems(exregions))
384 panic("failed to exclude region %#jx-%#jx", (uintmax_t)pa,
385 (uintmax_t)(pa + sz));
386 excnt = insert_region(exregions, excnt, pa, sz, exflags);
390 arm_physmem_avail(vm_paddr_t *avail, size_t maxavail)
393 return (regions_to_avail(avail, EXFLAG_NOALLOC, maxavail, NULL, NULL));
397 * Process all the regions added earlier into the global avail lists.
399 * Updates the kernel global 'physmem' with the number of physical pages
400 * available for use (all pages not in any exclusion region).
402 * Updates the kernel global 'Maxmem' with the page number one greater then the
403 * last page of physical memory in the system.
406 arm_physmem_init_kernel_globals(void)
410 regions_to_avail(dump_avail, EXFLAG_NODUMP, MAX_AVAIL_ENTRIES, NULL,
412 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC,
413 MAX_AVAIL_ENTRIES, &physmem, &realmem);
415 panic("No memory entries in phys_avail");
416 Maxmem = atop(phys_avail[nextidx - 1]);
422 DB_SHOW_COMMAND(physmem, db_show_physmem)
425 physmem_dump_tables(db_printf);