1 /*-
2 * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>
3 * All rights excluded.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include "opt_ddb.h"
31
32 /*
33 * Routines for describing and initializing anything related to physical memory.
34 */
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <vm/vm.h>
39 #include <machine/md_var.h>
40 #include <machine/physmem.h>
41
42 /*
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
47 * with the region.
48 */
49 #define MAX_HWCNT 10
50 #define MAX_EXCNT 10
51
52 struct region {
53 vm_paddr_t addr;
54 vm_size_t size;
55 uint32_t flags;
56 };
57
58 static struct region hwregions[MAX_HWCNT];
59 static struct region exregions[MAX_EXCNT];
60
61 static size_t hwcnt;
62 static size_t excnt;
63
64 /*
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
70 * entries.
71 *
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.
75 *
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.
80 *
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).
83 */
84 #define MAX_AVAIL_REGIONS (MAX_HWCNT * 2)
85 #define MAX_AVAIL_ENTRIES (MAX_AVAIL_REGIONS * 2)
86
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. */
89
90 /*
91 * realmem is the total number of hardware pages, excluded or not.
92 * Maxmem is one greater than the last physical page number.
93 */
94 long realmem;
95 long Maxmem;
96
97 /* The address at which the kernel was loaded. Set early in initarm(). */
98 vm_paddr_t arm_physmem_kernaddr;
99
100 /*
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
103 * db_printf).
104 */
105 static void
physmem_dump_tables(int (* prfunc)(const char *,...))106 physmem_dump_tables(int (*prfunc)(const char *, ...))
107 {
108 int flags, i;
109 uintmax_t addr, size;
110 const unsigned int mbyte = 1024 * 1024;
111
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);
118 }
119
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" : "");
129 }
130
131 #ifdef DEBUG
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]);
135 }
136 for (i = 0; dump_avail[i] != 0; ++i) {
137 prfunc(" dump_avail[%d] 0x%08x\n", i, dump_avail[i]);
138 }
139 #endif
140 }
141
142 /*
143 * Print the contents of the static mapping table. Used for bootverbose.
144 */
145 void
arm_physmem_print_tables()146 arm_physmem_print_tables()
147 {
148
149 physmem_dump_tables(printf);
150 }
151
152 /*
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".
155 *
156 * Updates the value at *pavail with the sum of all pages in all hw regions.
157 *
158 * Returns the number of pages of non-excluded memory added to the avail list.
159 */
160 static size_t
regions_to_avail(vm_paddr_t * avail,uint32_t exflags,long * pavail)161 regions_to_avail(vm_paddr_t *avail, uint32_t exflags, long *pavail)
162 {
163 size_t acnt, exi, hwi;
164 vm_paddr_t end, start, xend, xstart;
165 long availmem;
166 const struct region *exp, *hwp;
167
168 realmem = 0;
169 availmem = 0;
170 acnt = 0;
171 for (hwi = 0, hwp = hwregions; hwi < hwcnt; ++hwi, ++hwp) {
172 start = hwp->addr;
173 end = hwp->size + start;
174 realmem += arm32_btop(end - start);
175 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) {
176 /*
177 * If the excluded region does not match given flags,
178 * continue checking with the next excluded region.
179 */
180 if ((exp->flags & exflags) == 0)
181 continue;
182 xstart = exp->addr;
183 xend = exp->size + xstart;
184 /*
185 * If the excluded region ends before this hw region,
186 * continue checking with the next excluded region.
187 */
188 if (xend <= start)
189 continue;
190 /*
191 * If the excluded region begins after this hw region
192 * we're done because both lists are sorted.
193 */
194 if (xstart >= end)
195 break;
196 /*
197 * If the excluded region completely covers this hw
198 * region, shrink this hw region to zero size.
199 */
200 if ((start >= xstart) && (end <= xend)) {
201 start = xend;
202 end = xend;
203 break;
204 }
205 /*
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.
213 */
214 if ((xstart > start) && (xend < end)) {
215 avail[acnt++] = start;
216 avail[acnt++] = xstart;
217 availmem += arm32_btop(xstart - start);
218 start = xend;
219 continue;
220 }
221 /*
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.
225 */
226 if (xstart <= start)
227 start = xend;
228 else
229 end = xstart;
230 }
231 /*
232 * If the trimming actions above left a non-zero size, create an
233 * available entry for it.
234 */
235 if (end > start) {
236 avail[acnt++] = start;
237 avail[acnt++] = end;
238 availmem += arm32_btop(end - start);
239 }
240 if (acnt >= MAX_AVAIL_ENTRIES)
241 panic("Not enough space in the dump/phys_avail arrays");
242 }
243
244 if (pavail)
245 *pavail = availmem;
246 return (acnt);
247 }
248
249 /*
250 * Insertion-sort a new entry into a regions list; sorted by start address.
251 */
252 static void
insert_region(struct region * regions,size_t rcnt,vm_paddr_t addr,vm_size_t size,uint32_t flags)253 insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr,
254 vm_size_t size, uint32_t flags)
255 {
256 size_t i;
257 struct region *ep, *rp;
258
259 ep = regions + rcnt;
260 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) {
261 if (addr < rp->addr) {
262 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp));
263 break;
264 }
265 }
266 rp->addr = addr;
267 rp->size = size;
268 rp->flags = flags;
269 }
270
271 /*
272 * Add a hardware memory region.
273 */
274 void
arm_physmem_hardware_region(vm_paddr_t pa,vm_size_t sz)275 arm_physmem_hardware_region(vm_paddr_t pa, vm_size_t sz)
276 {
277 vm_offset_t adj;
278
279 /*
280 * Filter out the page at PA 0x00000000. The VM can't handle it, as
281 * pmap_extract() == 0 means failure.
282 */
283 if (pa == 0) {
284 pa = PAGE_SIZE;
285 sz -= PAGE_SIZE;
286 }
287
288 /*
289 * Round the starting address up to a page boundary, and truncate the
290 * ending page down to a page boundary.
291 */
292 adj = round_page(pa) - pa;
293 pa = round_page(pa);
294 sz = trunc_page(sz - adj);
295
296 if (hwcnt < nitems(hwregions))
297 insert_region(hwregions, hwcnt++, pa, sz, 0);
298 }
299
300 /*
301 * Add an exclusion region.
302 */
arm_physmem_exclude_region(vm_paddr_t pa,vm_size_t sz,uint32_t exflags)303 void arm_physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags)
304 {
305 vm_offset_t adj;
306
307 /*
308 * Truncate the starting address down to a page boundary, and round the
309 * ending page up to a page boundary.
310 */
311 adj = pa - trunc_page(pa);
312 pa = trunc_page(pa);
313 sz = round_page(sz + adj);
314
315 if (excnt < nitems(exregions))
316 insert_region(exregions, excnt++, pa, sz, exflags);
317 }
318
319 /*
320 * Process all the regions added earlier into the global avail lists.
321 *
322 * Updates the kernel global 'physmem' with the number of physical pages
323 * available for use (all pages not in any exclusion region).
324 *
325 * Updates the kernel global 'Maxmem' with the page number one greater then the
326 * last page of physical memory in the system.
327 */
328 void
arm_physmem_init_kernel_globals(void)329 arm_physmem_init_kernel_globals(void)
330 {
331 size_t nextidx;
332
333 regions_to_avail(dump_avail, EXFLAG_NODUMP, NULL);
334 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC, &physmem);
335 if (nextidx == 0)
336 panic("No memory entries in phys_avail");
337 Maxmem = atop(phys_avail[nextidx - 1]);
338 }
339
340 #ifdef DDB
341 #include <ddb/ddb.h>
342
DB_SHOW_COMMAND(physmem,db_show_physmem)343 DB_SHOW_COMMAND(physmem, db_show_physmem)
344 {
345
346 physmem_dump_tables(db_printf);
347 }
348
349 #endif /* DDB */
350
351