fdt_memory.c revision 1.1
1 /* $NetBSD: fdt_memory.c,v 1.1 2020/12/12 09:27:31 skrll Exp $ */ 2 3 /*- 4 * Copyright (c) 2018 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jared McNeill <jmcneill (at) invisible.ca>. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include "opt_fdt.h" 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: fdt_memory.c,v 1.1 2020/12/12 09:27:31 skrll Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/queue.h> 39 40 #include <libfdt.h> 41 #include <dev/fdt/fdtvar.h> 42 #include <dev/fdt/fdt_memory.h> 43 44 #ifndef FDT_MEMORY_RANGES 45 #define FDT_MEMORY_RANGES 256 46 #endif 47 48 struct fdt_memory_range { 49 struct fdt_memory mr_mem; 50 bool mr_used; 51 TAILQ_ENTRY(fdt_memory_range) mr_list; 52 }; 53 54 static TAILQ_HEAD(fdt_memory_rangehead, fdt_memory_range) fdt_memory_ranges = 55 TAILQ_HEAD_INITIALIZER(fdt_memory_ranges); 56 57 static struct fdt_memory_range fdt_memory_range_pool[FDT_MEMORY_RANGES]; 58 59 static struct fdt_memory_range * 60 fdt_memory_range_alloc(void) 61 { 62 for (size_t n = 0; n < FDT_MEMORY_RANGES; n++) 63 if (!fdt_memory_range_pool[n].mr_used) { 64 fdt_memory_range_pool[n].mr_used = true; 65 return &fdt_memory_range_pool[n]; 66 } 67 68 printf("%s: no free memory ranges, increase FDT_MEMORY_RANGES!\n", __func__); 69 return NULL; 70 } 71 72 static void 73 fdt_memory_range_free(struct fdt_memory_range *mr) 74 { 75 mr->mr_used = false; 76 } 77 78 /* 79 * Get all of physical memory, including holes. 80 */ 81 void 82 fdt_memory_get(uint64_t *pstart, uint64_t *pend) 83 { 84 const int memory = OF_finddevice("/memory"); 85 uint64_t cur_addr, cur_size; 86 int index; 87 88 for (index = 0; 89 fdtbus_get_reg64(memory, index, &cur_addr, &cur_size) == 0; 90 index++) { 91 fdt_memory_add_range(cur_addr, cur_size); 92 93 /* Assume the first entry is the start of memory */ 94 if (index == 0) { 95 *pstart = cur_addr; 96 *pend = cur_addr + cur_size; 97 continue; 98 } 99 if (cur_addr + cur_size > *pend) 100 *pend = cur_addr + cur_size; 101 } 102 if (index == 0) 103 panic("Cannot determine memory size"); 104 } 105 106 /* 107 * Exclude memory ranges from memory config from the device tree 108 */ 109 void 110 fdt_memory_remove_reserved(uint64_t min_addr, uint64_t max_addr) 111 { 112 uint64_t lstart = 0, lend = 0; 113 uint64_t addr, size; 114 int index, error; 115 116 const int num = fdt_num_mem_rsv(fdtbus_get_data()); 117 for (index = 0; index <= num; index++) { 118 error = fdt_get_mem_rsv(fdtbus_get_data(), index, 119 &addr, &size); 120 if (error != 0) 121 continue; 122 if (lstart <= addr && addr <= lend) { 123 size -= (lend - addr); 124 addr = lend; 125 } 126 if (size == 0) 127 continue; 128 if (addr + size <= min_addr) 129 continue; 130 if (addr >= max_addr) 131 continue; 132 if (addr < min_addr) { 133 size -= (min_addr - addr); 134 addr = min_addr; 135 } 136 if (addr + size > max_addr) 137 size = max_addr - addr; 138 fdt_memory_remove_range(addr, size); 139 lstart = addr; 140 lend = addr + size; 141 } 142 } 143 144 void 145 fdt_memory_add_range(uint64_t start, uint64_t size) 146 { 147 struct fdt_memory_range *mr, *prev, *cur, *tmp; 148 bool inserted = false; 149 150 mr = fdt_memory_range_alloc(); 151 if (mr == NULL) 152 return; 153 154 mr->mr_mem.start = start; 155 mr->mr_mem.end = start + size; 156 157 /* 158 * Add the new range to the list of sorted ranges. 159 */ 160 TAILQ_FOREACH(cur, &fdt_memory_ranges, mr_list) 161 if (mr->mr_mem.start <= cur->mr_mem.start) { 162 TAILQ_INSERT_BEFORE(cur, mr, mr_list); 163 inserted = true; 164 break; 165 } 166 if (!inserted) 167 TAILQ_INSERT_TAIL(&fdt_memory_ranges, mr, mr_list); 168 169 /* 170 * Remove overlaps. 171 */ 172 TAILQ_FOREACH_SAFE(mr, &fdt_memory_ranges, mr_list, tmp) { 173 prev = TAILQ_PREV(mr, fdt_memory_rangehead, mr_list); 174 if (prev && prev->mr_mem.end > mr->mr_mem.start) { 175 mr->mr_mem.start = prev->mr_mem.end; 176 if (mr->mr_mem.start >= mr->mr_mem.end) { 177 TAILQ_REMOVE(&fdt_memory_ranges, mr, mr_list); 178 fdt_memory_range_free(mr); 179 } 180 } 181 } 182 183 /* 184 * Combine adjacent ranges. 185 */ 186 TAILQ_FOREACH_SAFE(mr, &fdt_memory_ranges, mr_list, tmp) { 187 prev = TAILQ_PREV(mr, fdt_memory_rangehead, mr_list); 188 if (prev && prev->mr_mem.end == mr->mr_mem.start) { 189 prev->mr_mem.end = mr->mr_mem.end; 190 TAILQ_REMOVE(&fdt_memory_ranges, mr, mr_list); 191 fdt_memory_range_free(mr); 192 } 193 } 194 } 195 196 void 197 fdt_memory_remove_range(uint64_t start, uint64_t size) 198 { 199 struct fdt_memory_range *mr, *next, *tmp; 200 const uint64_t end = start + size; 201 202 TAILQ_FOREACH_SAFE(mr, &fdt_memory_ranges, mr_list, tmp) { 203 if (start <= mr->mr_mem.start && end >= mr->mr_mem.end) { 204 /* 205 * Removed range completely covers this range, 206 * just remove it. 207 */ 208 TAILQ_REMOVE(&fdt_memory_ranges, mr, mr_list); 209 fdt_memory_range_free(mr); 210 } else if (start > mr->mr_mem.start && end < mr->mr_mem.end) { 211 /* 212 * Removed range is completely contained by this range, 213 * split it. 214 */ 215 next = fdt_memory_range_alloc(); 216 if (next == NULL) 217 panic("fdt_memory_remove_range"); 218 next->mr_mem.start = end; 219 next->mr_mem.end = mr->mr_mem.end; 220 mr->mr_mem.end = start; 221 TAILQ_INSERT_AFTER(&fdt_memory_ranges, mr, next, mr_list); 222 } else if (start <= mr->mr_mem.start && end > mr->mr_mem.start && end < mr->mr_mem.end) { 223 /* 224 * Partial overlap at the beginning of the range. 225 */ 226 mr->mr_mem.start = end; 227 } else if (start > mr->mr_mem.start && start < mr->mr_mem.end && end >= mr->mr_mem.end) { 228 /* 229 * Partial overlap at the end of the range. 230 */ 231 mr->mr_mem.end = start; 232 } 233 KASSERT(mr->mr_mem.start < mr->mr_mem.end); 234 } 235 } 236 237 void 238 fdt_memory_foreach(void (*fn)(const struct fdt_memory *, void *), void *arg) 239 { 240 struct fdt_memory_range *mr; 241 242 TAILQ_FOREACH(mr, &fdt_memory_ranges, mr_list) 243 fn(&mr->mr_mem, arg); 244 } 245
Indexes created Mon Sep 22 13:09:51 GMT 2025