1/*- 2 * Copyright (c) 2014 Ian Lepore <ian@freebsd.org> 3 * All rights reserved. 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: stable/11/sys/arm/arm/physmem.c 338694 2018-09-15 18:01:15Z markj $"); 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 16 50#define MAX_EXCNT 16 51 52#define MAX_PHYS_ADDR 0xFFFFFFFFull 53 54struct region { 55 vm_paddr_t addr; 56 vm_size_t size; 57 uint32_t flags; 58}; 59 60static struct region hwregions[MAX_HWCNT]; 61static struct region exregions[MAX_EXCNT]; 62 63static size_t hwcnt; 64static size_t excnt; 65 66/* 67 * These "avail lists" are globals used to communicate physical memory layout to 68 * other parts of the kernel. Within the arrays, each value is the starting 69 * address of a contiguous area of physical address space. The values at even 70 * indexes are areas that contain usable memory and the values at odd indexes 71 * are areas that aren't usable. Each list is terminated by a pair of zero 72 * entries. 73 * 74 * dump_avail tells the dump code what regions to include in a crash dump, and 75 * phys_avail is the way we hand all the remaining physical ram we haven't used 76 * in early kernel init over to the vm system for allocation management. 77 * 78 * We size these arrays to hold twice as many available regions as we allow for 79 * hardware memory regions, to allow for the fact that exclusions can split a 80 * hardware region into two or more available regions. In the real world there 81 * will typically be one or two hardware regions and two or three exclusions. 82 * 83 * Each available region in this list occupies two array slots (the start of the 84 * available region and the start of the unavailable region that follows it). 85 */ 86#define MAX_AVAIL_REGIONS (MAX_HWCNT * 2) 87#define MAX_AVAIL_ENTRIES (MAX_AVAIL_REGIONS * 2) 88 89vm_paddr_t phys_avail[MAX_AVAIL_ENTRIES + 2]; /* +2 to allow for a pair */ 90vm_paddr_t dump_avail[MAX_AVAIL_ENTRIES + 2]; /* of zeroes to terminate. */ 91 92/* 93 * realmem is the total number of hardware pages, excluded or not. 94 * Maxmem is one greater than the last physical page number. 95 */ 96long realmem; 97long Maxmem; 98 99/* The address at which the kernel was loaded. Set early in initarm(). */ 100vm_paddr_t arm_physmem_kernaddr; 101 102/* 103 * Print the contents of the physical and excluded region tables using the 104 * provided printf-like output function (which will be either printf or 105 * db_printf). 106 */ 107static void 108physmem_dump_tables(int (*prfunc)(const char *, ...)) 109{ 110 int flags, i; 111 uintmax_t addr, size; 112 const unsigned int mbyte = 1024 * 1024; 113 114 prfunc("Physical memory chunk(s):\n"); 115 for (i = 0; i < hwcnt; ++i) { 116 addr = hwregions[i].addr; 117 size = hwregions[i].size; 118 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages)\n", addr, 119 addr + size - 1, size / mbyte, size / PAGE_SIZE); 120 } 121 122 prfunc("Excluded memory regions:\n"); 123 for (i = 0; i < excnt; ++i) { 124 addr = exregions[i].addr; 125 size = exregions[i].size; 126 flags = exregions[i].flags; 127 prfunc(" 0x%08jx - 0x%08jx, %5ju MB (%7ju pages) %s %s\n", 128 addr, addr + size - 1, size / mbyte, size / PAGE_SIZE, 129 (flags & EXFLAG_NOALLOC) ? "NoAlloc" : "", 130 (flags & EXFLAG_NODUMP) ? "NoDump" : ""); 131 } 132 133#ifdef DEBUG 134 prfunc("Avail lists:\n"); 135 for (i = 0; phys_avail[i] != 0; ++i) { 136 prfunc(" phys_avail[%d] 0x%08x\n", i, phys_avail[i]); 137 } 138 for (i = 0; dump_avail[i] != 0; ++i) { 139 prfunc(" dump_avail[%d] 0x%08x\n", i, dump_avail[i]); 140 } 141#endif 142} 143 144/* 145 * Print the contents of the static mapping table. Used for bootverbose. 146 */ 147void 148arm_physmem_print_tables(void) 149{ 150 151 physmem_dump_tables(printf); 152} 153 154/* 155 * Walk the list of hardware regions, processing it against the list of 156 * exclusions that contain the given exflags, and generating an "avail list". 157 * 158 * Updates the value at *pavail with the sum of all pages in all hw regions. 159 * 160 * Returns the number of pages of non-excluded memory added to the avail list. 161 */ 162static size_t 163regions_to_avail(vm_paddr_t *avail, uint32_t exflags, long *pavail) 164{ 165 size_t acnt, exi, hwi; 166 uint64_t end, start, xend, xstart; 167 long availmem; 168 const struct region *exp, *hwp; 169 170 realmem = 0; 171 availmem = 0; 172 acnt = 0; 173 for (hwi = 0, hwp = hwregions; hwi < hwcnt; ++hwi, ++hwp) { 174 start = hwp->addr; 175 end = hwp->size + start; 176 realmem += arm32_btop((vm_offset_t)(end - start)); 177 for (exi = 0, exp = exregions; exi < excnt; ++exi, ++exp) { 178 /* 179 * If the excluded region does not match given flags, 180 * continue checking with the next excluded region. 181 */ 182 if ((exp->flags & exflags) == 0) 183 continue; 184 xstart = exp->addr; 185 xend = exp->size + xstart; 186 /* 187 * If the excluded region ends before this hw region, 188 * continue checking with the next excluded region. 189 */ 190 if (xend <= start) 191 continue; 192 /* 193 * If the excluded region begins after this hw region 194 * we're done because both lists are sorted. 195 */ 196 if (xstart >= end) 197 break; 198 /* 199 * If the excluded region completely covers this hw 200 * region, shrink this hw region to zero size. 201 */ 202 if ((start >= xstart) && (end <= xend)) { 203 start = xend; 204 end = xend; 205 break; 206 } 207 /* 208 * If the excluded region falls wholly within this hw 209 * region without abutting or overlapping the beginning 210 * or end, create an available entry from the leading 211 * fragment, then adjust the start of this hw region to 212 * the end of the excluded region, and continue checking 213 * the next excluded region because another exclusion 214 * could affect the remainder of this hw region. 215 */ 216 if ((xstart > start) && (xend < end)) { 217 avail[acnt++] = (vm_paddr_t)start; 218 avail[acnt++] = (vm_paddr_t)xstart; 219 availmem += 220 arm32_btop((vm_offset_t)(xstart - start)); 221 start = xend; 222 continue; 223 } 224 /* 225 * We know the excluded region overlaps either the start 226 * or end of this hardware region (but not both), trim 227 * the excluded portion off the appropriate end. 228 */ 229 if (xstart <= start) 230 start = xend; 231 else 232 end = xstart; 233 } 234 /* 235 * If the trimming actions above left a non-zero size, create an 236 * available entry for it. 237 */ 238 if (end > start) { 239 avail[acnt++] = (vm_paddr_t)start; 240 avail[acnt++] = (vm_paddr_t)end; 241 availmem += arm32_btop((vm_offset_t)(end - start)); 242 } 243 if (acnt >= MAX_AVAIL_ENTRIES) 244 panic("Not enough space in the dump/phys_avail arrays"); 245 } 246 247 if (pavail) 248 *pavail = availmem; 249 return (acnt); 250} 251 252/* 253 * Insertion-sort a new entry into a regions list; sorted by start address. 254 */ 255static void 256insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr, 257 vm_size_t size, uint32_t flags) 258{ 259 size_t i; 260 struct region *ep, *rp; 261 262 ep = regions + rcnt; 263 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) { 264 if (addr < rp->addr) { 265 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp)); 266 break; 267 } 268 } 269 rp->addr = addr; 270 rp->size = size; 271 rp->flags = flags; 272} 273 274/* 275 * Add a hardware memory region. 276 */ 277void 278arm_physmem_hardware_region(uint64_t pa, uint64_t sz) 279{ 280 vm_offset_t adj; 281 282 /* 283 * Filter out the page at PA 0x00000000. The VM can't handle it, as 284 * pmap_extract() == 0 means failure. 285 */ 286 if (pa == 0) { 287 if (sz <= PAGE_SIZE) 288 return; 289 pa = PAGE_SIZE; 290 sz -= PAGE_SIZE; 291 } else if (pa > MAX_PHYS_ADDR) { 292 /* This range is past usable memory, ignore it */ 293 return; 294 } 295 296 /* 297 * Also filter out the page at the end of the physical address space -- 298 * if addr is non-zero and addr+size is zero we wrapped to the next byte 299 * beyond what vm_paddr_t can express. That leads to a NULL pointer 300 * deref early in startup; work around it by leaving the last page out. 301 * 302 * XXX This just in: subtract out a whole megabyte, not just 1 page. 303 * Reducing the size by anything less than 1MB results in the NULL 304 * pointer deref in _vm_map_lock_read(). Better to give up a megabyte 305 * than leave some folks with an unusable system while we investigate. 306 */ 307 if ((pa + sz) > (MAX_PHYS_ADDR - 1024 * 1024)) { 308 sz = MAX_PHYS_ADDR - pa + 1; 309 if (sz <= 1024 * 1024) 310 return; 311 sz -= 1024 * 1024; 312 } 313 314 /* 315 * Round the starting address up to a page boundary, and truncate the 316 * ending page down to a page boundary. 317 */ 318 adj = round_page(pa) - pa; 319 pa = round_page(pa); 320 sz = trunc_page(sz - adj); 321 322 if (sz > 0 && hwcnt < nitems(hwregions)) 323 insert_region(hwregions, hwcnt++, pa, sz, 0); 324} 325 326/* 327 * Add an exclusion region. 328 */ 329void 330arm_physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags) 331{ 332 vm_offset_t adj; 333 334 /* 335 * Truncate the starting address down to a page boundary, and round the 336 * ending page up to a page boundary. 337 */ 338 adj = pa - trunc_page(pa); 339 pa = trunc_page(pa); 340 sz = round_page(sz + adj); 341 342 if (excnt >= nitems(exregions)) 343 panic("failed to exclude region %#jx-%#jx", (uintmax_t)pa, 344 (uintmax_t)(pa + sz)); 345 insert_region(exregions, excnt++, pa, sz, exflags); 346} 347 348/* 349 * Process all the regions added earlier into the global avail lists. 350 * 351 * Updates the kernel global 'physmem' with the number of physical pages 352 * available for use (all pages not in any exclusion region). 353 * 354 * Updates the kernel global 'Maxmem' with the page number one greater then the 355 * last page of physical memory in the system. 356 */ 357void 358arm_physmem_init_kernel_globals(void) 359{ 360 size_t nextidx; 361 362 regions_to_avail(dump_avail, EXFLAG_NODUMP, NULL); 363 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC, &physmem); 364 if (nextidx == 0) 365 panic("No memory entries in phys_avail"); 366 Maxmem = atop(phys_avail[nextidx - 1]); 367} 368 369#ifdef DDB 370#include <ddb/ddb.h> 371 372DB_SHOW_COMMAND(physmem, db_show_physmem) 373{ 374 375 physmem_dump_tables(db_printf); 376} 377 378#endif /* DDB */ 379 380