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("$FreeBSD$");
35 * Routines for describing and initializing anything related to physical memory.
38 #include <sys/param.h>
39 #include <sys/systm.h>
41 #include <machine/md_var.h>
42 #include <machine/physmem.h>
45 * These structures are used internally to keep track of regions of physical
46 * ram, and regions within the physical ram that need to be excluded. An
47 * exclusion region can be excluded from crash dumps, from the vm pool of pages
48 * that can be allocated, or both, depending on the exclusion flags associated
54 #define MAX_PHYS_ADDR 0xFFFFFFFFull
62 static struct region hwregions[MAX_HWCNT];
63 static struct region exregions[MAX_EXCNT];
69 * These "avail lists" are globals used to communicate physical memory layout to
70 * other parts of the kernel. Within the arrays, each value is the starting
71 * address of a contiguous area of physical address space. The values at even
72 * indexes are areas that contain usable memory and the values at odd indexes
73 * are areas that aren't usable. Each list is terminated by a pair of zero
76 * dump_avail tells the dump code what regions to include in a crash dump, and
77 * phys_avail is the way we hand all the remaining physical ram we haven't used
78 * in early kernel init over to the vm system for allocation management.
80 * We size these arrays to hold twice as many available regions as we allow for
81 * hardware memory regions, to allow for the fact that exclusions can split a
82 * hardware region into two or more available regions. In the real world there
83 * will typically be one or two hardware regions and two or three exclusions.
85 * Each available region in this list occupies two array slots (the start of the
86 * available region and the start of the unavailable region that follows it).
88 #define MAX_AVAIL_REGIONS (MAX_HWCNT * 2)
89 #define MAX_AVAIL_ENTRIES (MAX_AVAIL_REGIONS * 2)
91 vm_paddr_t phys_avail[MAX_AVAIL_ENTRIES + 2]; /* +2 to allow for a pair */
92 vm_paddr_t dump_avail[MAX_AVAIL_ENTRIES + 2]; /* of zeroes to terminate. */
95 * realmem is the total number of hardware pages, excluded or not.
96 * Maxmem is one greater than the last physical page number.
101 /* The address at which the kernel was loaded. Set early in initarm(). */
102 vm_paddr_t arm_physmem_kernaddr;
105 * Print the contents of the physical and excluded region tables using the
106 * provided printf-like output function (which will be either printf or
110 physmem_dump_tables(int (*prfunc)(const char *, ...))
113 uintmax_t addr, size;
114 const unsigned int mbyte = 1024 * 1024;
116 prfunc("Physical memory chunk(s):\n");
117 for (i = 0; i < hwcnt; ++i) {
118 addr = hwregions[i].addr;
119 size = hwregions[i].size;
120 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages)\n", addr,
121 addr + size - 1, size / mbyte, size / PAGE_SIZE);
124 prfunc("Excluded memory regions:\n");
125 for (i = 0; i < excnt; ++i) {
126 addr = exregions[i].addr;
127 size = exregions[i].size;
128 flags = exregions[i].flags;
129 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages) %s %s\n",
130 addr, addr + size - 1, size / mbyte, size / PAGE_SIZE,
131 (flags & EXFLAG_NOALLOC) ? "NoAlloc" : "",
132 (flags & EXFLAG_NODUMP) ? "NoDump" : "");
136 prfunc("Avail lists:\n");
137 for (i = 0; phys_avail[i] != 0; ++i) {
138 prfunc(" phys_avail[%d] 0x%08x\n", i, phys_avail[i]);
140 for (i = 0; dump_avail[i] != 0; ++i) {
141 prfunc(" dump_avail[%d] 0x%08x\n", i, dump_avail[i]);
147 * Print the contents of the static mapping table. Used for bootverbose.
150 arm_physmem_print_tables(void)
153 physmem_dump_tables(printf);
157 * Walk the list of hardware regions, processing it against the list of
158 * exclusions that contain the given exflags, and generating an "avail list".
160 * Updates the value at *pavail with the sum of all pages in all hw regions.
162 * Returns the number of pages of non-excluded memory added to the avail list.
165 regions_to_avail(vm_paddr_t *avail, uint32_t exflags, long *pavail)
167 size_t acnt, exi, hwi;
168 uint64_t end, start, xend, xstart;
170 const struct region *exp, *hwp;
175 for (hwi = 0, hwp = hwregions; hwi < hwcnt; ++hwi, ++hwp) {
177 end = hwp->size + start;
178 realmem += arm32_btop((vm_offset_t)(end - start));
179 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) {
181 * If the excluded region does not match given flags,
182 * continue checking with the next excluded region.
184 if ((exp->flags & exflags) == 0)
187 xend = exp->size + xstart;
189 * If the excluded region ends before this hw region,
190 * continue checking with the next excluded region.
195 * If the excluded region begins after this hw region
196 * we're done because both lists are sorted.
201 * If the excluded region completely covers this hw
202 * region, shrink this hw region to zero size.
204 if ((start >= xstart) && (end <= xend)) {
210 * If the excluded region falls wholly within this hw
211 * region without abutting or overlapping the beginning
212 * or end, create an available entry from the leading
213 * fragment, then adjust the start of this hw region to
214 * the end of the excluded region, and continue checking
215 * the next excluded region because another exclusion
216 * could affect the remainder of this hw region.
218 if ((xstart > start) && (xend < end)) {
219 avail[acnt++] = (vm_paddr_t)start;
220 avail[acnt++] = (vm_paddr_t)xstart;
222 arm32_btop((vm_offset_t)(xstart - start));
227 * We know the excluded region overlaps either the start
228 * or end of this hardware region (but not both), trim
229 * the excluded portion off the appropriate end.
237 * If the trimming actions above left a non-zero size, create an
238 * available entry for it.
241 avail[acnt++] = (vm_paddr_t)start;
242 avail[acnt++] = (vm_paddr_t)end;
243 availmem += arm32_btop((vm_offset_t)(end - start));
245 if (acnt >= MAX_AVAIL_ENTRIES)
246 panic("Not enough space in the dump/phys_avail arrays");
255 * Insertion-sort a new entry into a regions list; sorted by start address.
258 insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr,
259 vm_size_t size, uint32_t flags)
262 struct region *ep, *rp;
265 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) {
266 if (addr < rp->addr) {
267 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp));
277 * Add a hardware memory region.
280 arm_physmem_hardware_region(uint64_t pa, uint64_t sz)
285 * Filter out the page at PA 0x00000000. The VM can't handle it, as
286 * pmap_extract() == 0 means failure.
293 } else if (pa > MAX_PHYS_ADDR) {
294 /* This range is past usable memory, ignore it */
299 * Also filter out the page at the end of the physical address space --
300 * if addr is non-zero and addr+size is zero we wrapped to the next byte
301 * beyond what vm_paddr_t can express. That leads to a NULL pointer
302 * deref early in startup; work around it by leaving the last page out.
304 * XXX This just in: subtract out a whole megabyte, not just 1 page.
305 * Reducing the size by anything less than 1MB results in the NULL
306 * pointer deref in _vm_map_lock_read(). Better to give up a megabyte
307 * than leave some folks with an unusable system while we investigate.
309 if ((pa + sz) > (MAX_PHYS_ADDR - 1024 * 1024)) {
310 sz = MAX_PHYS_ADDR - pa + 1;
311 if (sz <= 1024 * 1024)
317 * Round the starting address up to a page boundary, and truncate the
318 * ending page down to a page boundary.
320 adj = round_page(pa) - pa;
322 sz = trunc_page(sz - adj);
324 if (sz > 0 && hwcnt < nitems(hwregions))
325 insert_region(hwregions, hwcnt++, pa, sz, 0);
329 * Add an exclusion region.
331 void arm_physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags)
336 * Truncate the starting address down to a page boundary, and round the
337 * ending page up to a page boundary.
339 adj = pa - trunc_page(pa);
341 sz = round_page(sz + adj);
343 if (excnt < nitems(exregions))
344 insert_region(exregions, excnt++, pa, sz, exflags);
348 * Process all the regions added earlier into the global avail lists.
350 * Updates the kernel global 'physmem' with the number of physical pages
351 * available for use (all pages not in any exclusion region).
353 * Updates the kernel global 'Maxmem' with the page number one greater then the
354 * last page of physical memory in the system.
357 arm_physmem_init_kernel_globals(void)
361 regions_to_avail(dump_avail, EXFLAG_NODUMP, NULL);
362 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC, &physmem);
364 panic("No memory entries in phys_avail");
365 Maxmem = atop(phys_avail[nextidx - 1]);
371 DB_SHOW_COMMAND(physmem, db_show_physmem)
374 physmem_dump_tables(db_printf);