physmem.c revision 293061
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: head/sys/arm/arm/physmem.c 293061 2016-01-02 22:00:52Z ian $"); 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 52struct region { 53 vm_paddr_t addr; 54 vm_size_t size; 55 uint32_t flags; 56}; 57 58static struct region hwregions[MAX_HWCNT]; 59static struct region exregions[MAX_EXCNT]; 60 61static size_t hwcnt; 62static 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 87vm_paddr_t phys_avail[MAX_AVAIL_ENTRIES + 2]; /* +2 to allow for a pair */ 88vm_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 */ 94long realmem; 95long Maxmem; 96 97/* The address at which the kernel was loaded. Set early in initarm(). */ 98vm_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 */ 105static void 106physmem_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 */ 145void 146arm_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 */ 160static size_t 161regions_to_avail(vm_paddr_t *avail, uint32_t exflags, long *pavail) 162{ 163 size_t acnt, exi, hwi; 164 uint64_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((vm_offset_t)(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++] = (vm_paddr_t)start; 216 avail[acnt++] = (vm_paddr_t)xstart; 217 availmem += 218 arm32_btop((vm_offset_t)(xstart - start)); 219 start = xend; 220 continue; 221 } 222 /* 223 * We know the excluded region overlaps either the start 224 * or end of this hardware region (but not both), trim 225 * the excluded portion off the appropriate end. 226 */ 227 if (xstart <= start) 228 start = xend; 229 else 230 end = xstart; 231 } 232 /* 233 * If the trimming actions above left a non-zero size, create an 234 * available entry for it. 235 */ 236 if (end > start) { 237 avail[acnt++] = (vm_paddr_t)start; 238 avail[acnt++] = (vm_paddr_t)end; 239 availmem += arm32_btop((vm_offset_t)(end - start)); 240 } 241 if (acnt >= MAX_AVAIL_ENTRIES) 242 panic("Not enough space in the dump/phys_avail arrays"); 243 } 244 245 if (pavail) 246 *pavail = availmem; 247 return (acnt); 248} 249 250/* 251 * Insertion-sort a new entry into a regions list; sorted by start address. 252 */ 253static void 254insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr, 255 vm_size_t size, uint32_t flags) 256{ 257 size_t i; 258 struct region *ep, *rp; 259 260 ep = regions + rcnt; 261 for (i = 0, rp = regions; i < rcnt; ++i, ++rp) { 262 if (addr < rp->addr) { 263 bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp)); 264 break; 265 } 266 } 267 rp->addr = addr; 268 rp->size = size; 269 rp->flags = flags; 270} 271 272/* 273 * Add a hardware memory region. 274 */ 275void 276arm_physmem_hardware_region(vm_paddr_t pa, vm_size_t sz) 277{ 278 vm_offset_t adj; 279 280 /* 281 * Filter out the page at PA 0x00000000. The VM can't handle it, as 282 * pmap_extract() == 0 means failure. 283 */ 284 if (pa == 0) { 285 pa = PAGE_SIZE; 286 sz -= PAGE_SIZE; 287 } 288 289 /* 290 * Round the starting address up to a page boundary, and truncate the 291 * ending page down to a page boundary. 292 */ 293 adj = round_page(pa) - pa; 294 pa = round_page(pa); 295 sz = trunc_page(sz - adj); 296 297 if (hwcnt < nitems(hwregions)) 298 insert_region(hwregions, hwcnt++, pa, sz, 0); 299} 300 301/* 302 * Add an exclusion region. 303 */ 304void arm_physmem_exclude_region(vm_paddr_t pa, vm_size_t sz, uint32_t exflags) 305{ 306 vm_offset_t adj; 307 308 /* 309 * Truncate the starting address down to a page boundary, and round the 310 * ending page up to a page boundary. 311 */ 312 adj = pa - trunc_page(pa); 313 pa = trunc_page(pa); 314 sz = round_page(sz + adj); 315 316 if (excnt < nitems(exregions)) 317 insert_region(exregions, excnt++, pa, sz, exflags); 318} 319 320/* 321 * Process all the regions added earlier into the global avail lists. 322 * 323 * Updates the kernel global 'physmem' with the number of physical pages 324 * available for use (all pages not in any exclusion region). 325 * 326 * Updates the kernel global 'Maxmem' with the page number one greater then the 327 * last page of physical memory in the system. 328 */ 329void 330arm_physmem_init_kernel_globals(void) 331{ 332 size_t nextidx; 333 334 regions_to_avail(dump_avail, EXFLAG_NODUMP, NULL); 335 nextidx = regions_to_avail(phys_avail, EXFLAG_NOALLOC, &physmem); 336 if (nextidx == 0) 337 panic("No memory entries in phys_avail"); 338 Maxmem = atop(phys_avail[nextidx - 1]); 339} 340 341#ifdef DDB 342#include <ddb/ddb.h> 343 344DB_SHOW_COMMAND(physmem, db_show_physmem) 345{ 346 347 physmem_dump_tables(db_printf); 348} 349 350#endif /* DDB */ 351 352