2 * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
33 * Routines for describing and initializing anything related to physical memory.
36 #include <sys/param.h>
37 #include <sys/systm.h>
39 #include <machine/md_var.h>
40 #include <machine/physmem.h>
43 * These structures are used internally to keep track of regions of physical
44 * ram, and regions within the physical ram that need to be excluded. An
45 * exclusion region can be excluded from crash dumps, from the vm pool of pages
46 * that can be allocated, or both, depending on the exclusion flags associated
58 static struct region hwregions[MAX_HWCNT];
59 static struct region exregions[MAX_EXCNT];
65 * These "avail lists" are globals used to communicate physical memory layout to
66 * other parts of the kernel. Within the arrays, each value is the starting
67 * address of a contiguous area of physical address space. The values at even
68 * indexes are areas that contain usable memory and the values at odd indexes
69 * are areas that aren't usable. Each list is terminated by a pair of zero
72 * dump_avail tells the dump code what regions to include in a crash dump, and
73 * phys_avail is the way we hand all the remaining physical ram we haven't used
74 * in early kernel init over to the vm system for allocation management.
76 * We size these arrays to hold twice as many available regions as we allow for
77 * hardware memory regions, to allow for the fact that exclusions can split a
78 * hardware region into two or more available regions. In the real world there
79 * will typically be one or two hardware regions and two or three exclusions.
81 * Each available region in this list occupies two array slots (the start of the
82 * available region and the start of the unavailable region that follows it).
84 #define MAX_AVAIL_REGIONS (MAX_HWCNT * 2)
85 #define MAX_AVAIL_ENTRIES (MAX_AVAIL_REGIONS * 2)
87 vm_paddr_t phys_avail[MAX_AVAIL_ENTRIES + 2]; /* +2 to allow for a pair */
88 vm_paddr_t dump_avail[MAX_AVAIL_ENTRIES + 2]; /* of zeroes to terminate. */
91 * realmem is the total number of hardware pages, excluded or not.
92 * Maxmem is one greater than the last physical page number.
97 /* The address at which the kernel was loaded. Set early in initarm(). */
98 vm_paddr_t arm_physmem_kernaddr;
101 * Print the contents of the physical and excluded region tables using the
102 * provided printf-like output function (which will be either printf or
106 physmem_dump_tables(int (*prfunc)(const char *, ...))
109 uintmax_t addr, size;
110 const unsigned int mbyte = 1024 * 1024;
112 prfunc("Physical memory chunk(s):\n");
113 for (i = 0; i < hwcnt; ++i) {
114 addr = hwregions[i].addr;
115 size = hwregions[i].size;
116 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages)\n", addr,
117 addr + size - 1, size / mbyte, size / PAGE_SIZE);
120 prfunc("Excluded memory regions:\n");
121 for (i = 0; i < excnt; ++i) {
122 addr = exregions[i].addr;
123 size = exregions[i].size;
124 flags = exregions[i].flags;
125 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages) %s %s\n",
126 addr, addr + size - 1, size / mbyte, size / PAGE_SIZE,
127 (flags & EXFLAG_NOALLOC) ? "NoAlloc" : "",
128 (flags & EXFLAG_NODUMP) ? "NoDump" : "");
132 prfunc("Avail lists:\n");
133 for (i = 0; phys_avail[i] != 0; ++i) {
134 prfunc(" phys_avail[%d] 0x%08x\n", i, phys_avail[i]);
136 for (i = 0; dump_avail[i] != 0; ++i) {
137 prfunc(" dump_avail[%d] 0x%08x\n", i, dump_avail[i]);
143 * Print the contents of the static mapping table. Used for bootverbose.
146 arm_physmem_print_tables()
149 physmem_dump_tables(printf);
153 * Walk the list of hardware regions, processing it against the list of
154 * exclusions that contain the given exflags, and generating an "avail list".
156 * Updates the value at *pavail with the sum of all pages in all hw regions.
158 * Returns the number of pages of non-excluded memory added to the avail list.
161 regions_to_avail(vm_paddr_t *avail, uint32_t exflags, long *pavail)
163 size_t acnt, exi, hwi;
164 vm_paddr_t end, start, xend, xstart;
166 const struct region *exp, *hwp;
171 for (hwi = 0, hwp = hwregions; hwi < hwcnt; ++hwi, ++hwp) {
173 end = hwp->size + start;
174 realmem += arm32_btop(end - start);
175 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) {
177 * If the excluded region does not match given flags,
178 * continue checking with the next excluded region.
180 if ((exp->flags & exflags) == 0)
183 xend = exp->size + xstart;
185 * If the excluded region ends before this hw region,
186 * continue checking with the next excluded region.
191 * If the excluded region begins after this hw region
192 * we're done because both lists are sorted.
197 * If the excluded region completely covers this hw
198 * region, shrink this hw region to zero size.
200 if ((start >= xstart) && (end <= xend)) {
206 * If the excluded region falls wholly within this hw
207 * region without abutting or overlapping the beginning
208 * or end, create an available entry from the leading
209 * fragment, then adjust the start of this hw region to
210 * the end of the excluded region, and continue checking
211 * the next excluded region because another exclusion
212 * could affect the remainder of this hw region.
214 if ((xstart > start) && (xend < end)) {
215 avail[acnt++] = start;
216 avail[acnt++] = xstart;
217 availmem += arm32_btop(xstart - start);
222 * We know the excluded region overlaps either the start
223 * or end of this hardware region (but not both), trim
224 * the excluded portion off the appropriate end.
232 * If the trimming actions above left a non-zero size, create an
233 * available entry for it.
236 avail[acnt++] = start;
238 availmem += arm32_btop(end - start);
240 if (acnt >= MAX_AVAIL_ENTRIES)
241 panic("Not enough space in the dump/phys_avail arrays");
250 * Insertion-sort a new entry into a regions list; sorted by start address.
253 insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr,
254 vm_size_t size, uint32_t flags)
257 struct region *ep, *rp;
260 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) {
261 if (addr < rp->addr) {
262 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp));
272 * Add a hardware memory region.
275 arm_physmem_hardware_region(vm_paddr_t pa, vm_size_t sz)
280 * Filter out the page at PA 0x00000000. The VM can't handle it, as
281 * pmap_extract() == 0 means failure.
289 * Round the starting address up to a page boundary, and truncate the
290 * ending page down to a page boundary.
292 adj = round_page(pa) - pa;
294 sz = trunc_page(sz - adj);
296 if (hwcnt < nitems(hwregions))
297 insert_region(hwregions, hwcnt++, pa, sz, 0);
301 * Add an exclusion region.
303 void arm_physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags)
308 * Truncate the starting address down to a page boundary, and round the
309 * ending page up to a page boundary.
311 adj = pa - trunc_page(pa);
313 sz = round_page(sz + adj);
315 if (excnt < nitems(exregions))
316 insert_region(exregions, excnt++, pa, sz, exflags);
320 * Process all the regions added earlier into the global avail lists.
322 * Updates the kernel global 'physmem' with the number of physical pages
323 * available for use (all pages not in any exclusion region).
325 * Updates the kernel global 'Maxmem' with the page number one greater then the
326 * last page of physical memory in the system.
329 arm_physmem_init_kernel_globals(void)
333 regions_to_avail(dump_avail, EXFLAG_NODUMP, NULL);
334 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC, &physmem);
336 panic("No memory entries in phys_avail");
337 Maxmem = atop(phys_avail[nextidx - 1]);
343 DB_SHOW_COMMAND(physmem, db_show_physmem)
346 physmem_dump_tables(db_printf);