physmem.c revision 278730
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: stable/10/sys/arm/arm/physmem.c 278730 2015-02-13 23:30:48Z 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 kernel global 'realmem' with the sum of all pages in 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 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 */ 252static void 253insert_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 */ 274void 275arm_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 */ 303void 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 */ 328void 329arm_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 343DB_SHOW_COMMAND(physmem, db_show_physmem) 344{ 345 346 physmem_dump_tables(db_printf); 347} 348 349#endif /* DDB */ 350 351