1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * Device tree based initialization code for reserved memory. 4 * 5 * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved. 6 * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd. 7 * http://www.samsung.com 8 * Author: Marek Szyprowski <m.szyprowski@samsung.com> 9 * Author: Josh Cartwright <joshc@codeaurora.org> 10 */ 11 12#define pr_fmt(fmt) "OF: reserved mem: " fmt 13 14#include <linux/err.h> 15#include <linux/libfdt.h> 16#include <linux/of.h> 17#include <linux/of_fdt.h> 18#include <linux/of_platform.h> 19#include <linux/mm.h> 20#include <linux/sizes.h> 21#include <linux/of_reserved_mem.h> 22#include <linux/sort.h> 23#include <linux/slab.h> 24#include <linux/memblock.h> 25#include <linux/kmemleak.h> 26#include <linux/cma.h> 27 28#include "of_private.h" 29 30#define MAX_RESERVED_REGIONS 64 31static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS]; 32static int reserved_mem_count; 33 34static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, 35 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap, 36 phys_addr_t *res_base) 37{ 38 phys_addr_t base; 39 int err = 0; 40 41 end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end; 42 align = !align ? SMP_CACHE_BYTES : align; 43 base = memblock_phys_alloc_range(size, align, start, end); 44 if (!base) 45 return -ENOMEM; 46 47 *res_base = base; 48 if (nomap) { 49 err = memblock_mark_nomap(base, size); 50 if (err) 51 memblock_phys_free(base, size); 52 } 53 54 kmemleak_ignore_phys(base); 55 56 return err; 57} 58 59/* 60 * fdt_reserved_mem_save_node() - save fdt node for second pass initialization 61 */ 62static void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname, 63 phys_addr_t base, phys_addr_t size) 64{ 65 struct reserved_mem *rmem = &reserved_mem[reserved_mem_count]; 66 67 if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) { 68 pr_err("not enough space for all defined regions.\n"); 69 return; 70 } 71 72 rmem->fdt_node = node; 73 rmem->name = uname; 74 rmem->base = base; 75 rmem->size = size; 76 77 reserved_mem_count++; 78 return; 79} 80 81static int __init early_init_dt_reserve_memory(phys_addr_t base, 82 phys_addr_t size, bool nomap) 83{ 84 if (nomap) { 85 /* 86 * If the memory is already reserved (by another region), we 87 * should not allow it to be marked nomap, but don't worry 88 * if the region isn't memory as it won't be mapped. 89 */ 90 if (memblock_overlaps_region(&memblock.memory, base, size) && 91 memblock_is_region_reserved(base, size)) 92 return -EBUSY; 93 94 return memblock_mark_nomap(base, size); 95 } 96 return memblock_reserve(base, size); 97} 98 99/* 100 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property 101 */ 102static int __init __reserved_mem_reserve_reg(unsigned long node, 103 const char *uname) 104{ 105 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); 106 phys_addr_t base, size; 107 int len; 108 const __be32 *prop; 109 int first = 1; 110 bool nomap; 111 112 prop = of_get_flat_dt_prop(node, "reg", &len); 113 if (!prop) 114 return -ENOENT; 115 116 if (len && len % t_len != 0) { 117 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n", 118 uname); 119 return -EINVAL; 120 } 121 122 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; 123 124 while (len >= t_len) { 125 base = dt_mem_next_cell(dt_root_addr_cells, &prop); 126 size = dt_mem_next_cell(dt_root_size_cells, &prop); 127 128 if (size && 129 early_init_dt_reserve_memory(base, size, nomap) == 0) 130 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n", 131 uname, &base, (unsigned long)(size / SZ_1M)); 132 else 133 pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n", 134 uname, &base, (unsigned long)(size / SZ_1M)); 135 136 len -= t_len; 137 if (first) { 138 fdt_reserved_mem_save_node(node, uname, base, size); 139 first = 0; 140 } 141 } 142 return 0; 143} 144 145/* 146 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided 147 * in /reserved-memory matches the values supported by the current implementation, 148 * also check if ranges property has been provided 149 */ 150static int __init __reserved_mem_check_root(unsigned long node) 151{ 152 const __be32 *prop; 153 154 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 155 if (!prop || be32_to_cpup(prop) != dt_root_size_cells) 156 return -EINVAL; 157 158 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 159 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells) 160 return -EINVAL; 161 162 prop = of_get_flat_dt_prop(node, "ranges", NULL); 163 if (!prop) 164 return -EINVAL; 165 return 0; 166} 167 168/* 169 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory 170 */ 171int __init fdt_scan_reserved_mem(void) 172{ 173 int node, child; 174 const void *fdt = initial_boot_params; 175 176 node = fdt_path_offset(fdt, "/reserved-memory"); 177 if (node < 0) 178 return -ENODEV; 179 180 if (__reserved_mem_check_root(node) != 0) { 181 pr_err("Reserved memory: unsupported node format, ignoring\n"); 182 return -EINVAL; 183 } 184 185 fdt_for_each_subnode(child, fdt, node) { 186 const char *uname; 187 int err; 188 189 if (!of_fdt_device_is_available(fdt, child)) 190 continue; 191 192 uname = fdt_get_name(fdt, child, NULL); 193 194 err = __reserved_mem_reserve_reg(child, uname); 195 if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL)) 196 fdt_reserved_mem_save_node(child, uname, 0, 0); 197 } 198 return 0; 199} 200 201/* 202 * __reserved_mem_alloc_in_range() - allocate reserved memory described with 203 * 'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing 204 * reserved regions to keep the reserved memory contiguous if possible. 205 */ 206static int __init __reserved_mem_alloc_in_range(phys_addr_t size, 207 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap, 208 phys_addr_t *res_base) 209{ 210 bool prev_bottom_up = memblock_bottom_up(); 211 bool bottom_up = false, top_down = false; 212 int ret, i; 213 214 for (i = 0; i < reserved_mem_count; i++) { 215 struct reserved_mem *rmem = &reserved_mem[i]; 216 217 /* Skip regions that were not reserved yet */ 218 if (rmem->size == 0) 219 continue; 220 221 /* 222 * If range starts next to an existing reservation, use bottom-up: 223 * |....RRRR................RRRRRRRR..............| 224 * --RRRR------ 225 */ 226 if (start >= rmem->base && start <= (rmem->base + rmem->size)) 227 bottom_up = true; 228 229 /* 230 * If range ends next to an existing reservation, use top-down: 231 * |....RRRR................RRRRRRRR..............| 232 * -------RRRR----- 233 */ 234 if (end >= rmem->base && end <= (rmem->base + rmem->size)) 235 top_down = true; 236 } 237 238 /* Change setting only if either bottom-up or top-down was selected */ 239 if (bottom_up != top_down) 240 memblock_set_bottom_up(bottom_up); 241 242 ret = early_init_dt_alloc_reserved_memory_arch(size, align, 243 start, end, nomap, res_base); 244 245 /* Restore old setting if needed */ 246 if (bottom_up != top_down) 247 memblock_set_bottom_up(prev_bottom_up); 248 249 return ret; 250} 251 252/* 253 * __reserved_mem_alloc_size() - allocate reserved memory described by 254 * 'size', 'alignment' and 'alloc-ranges' properties. 255 */ 256static int __init __reserved_mem_alloc_size(unsigned long node, 257 const char *uname, phys_addr_t *res_base, phys_addr_t *res_size) 258{ 259 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); 260 phys_addr_t start = 0, end = 0; 261 phys_addr_t base = 0, align = 0, size; 262 int len; 263 const __be32 *prop; 264 bool nomap; 265 int ret; 266 267 prop = of_get_flat_dt_prop(node, "size", &len); 268 if (!prop) 269 return -EINVAL; 270 271 if (len != dt_root_size_cells * sizeof(__be32)) { 272 pr_err("invalid size property in '%s' node.\n", uname); 273 return -EINVAL; 274 } 275 size = dt_mem_next_cell(dt_root_size_cells, &prop); 276 277 prop = of_get_flat_dt_prop(node, "alignment", &len); 278 if (prop) { 279 if (len != dt_root_addr_cells * sizeof(__be32)) { 280 pr_err("invalid alignment property in '%s' node.\n", 281 uname); 282 return -EINVAL; 283 } 284 align = dt_mem_next_cell(dt_root_addr_cells, &prop); 285 } 286 287 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; 288 289 /* Need adjust the alignment to satisfy the CMA requirement */ 290 if (IS_ENABLED(CONFIG_CMA) 291 && of_flat_dt_is_compatible(node, "shared-dma-pool") 292 && of_get_flat_dt_prop(node, "reusable", NULL) 293 && !nomap) 294 align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES); 295 296 prop = of_get_flat_dt_prop(node, "alloc-ranges", &len); 297 if (prop) { 298 299 if (len % t_len != 0) { 300 pr_err("invalid alloc-ranges property in '%s', skipping node.\n", 301 uname); 302 return -EINVAL; 303 } 304 305 base = 0; 306 307 while (len > 0) { 308 start = dt_mem_next_cell(dt_root_addr_cells, &prop); 309 end = start + dt_mem_next_cell(dt_root_size_cells, 310 &prop); 311 312 ret = __reserved_mem_alloc_in_range(size, align, 313 start, end, nomap, &base); 314 if (ret == 0) { 315 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n", 316 uname, &base, 317 (unsigned long)(size / SZ_1M)); 318 break; 319 } 320 len -= t_len; 321 } 322 323 } else { 324 ret = early_init_dt_alloc_reserved_memory_arch(size, align, 325 0, 0, nomap, &base); 326 if (ret == 0) 327 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n", 328 uname, &base, (unsigned long)(size / SZ_1M)); 329 } 330 331 if (base == 0) { 332 pr_err("failed to allocate memory for node '%s': size %lu MiB\n", 333 uname, (unsigned long)(size / SZ_1M)); 334 return -ENOMEM; 335 } 336 337 *res_base = base; 338 *res_size = size; 339 340 return 0; 341} 342 343static const struct of_device_id __rmem_of_table_sentinel 344 __used __section("__reservedmem_of_table_end"); 345 346/* 347 * __reserved_mem_init_node() - call region specific reserved memory init code 348 */ 349static int __init __reserved_mem_init_node(struct reserved_mem *rmem) 350{ 351 extern const struct of_device_id __reservedmem_of_table[]; 352 const struct of_device_id *i; 353 int ret = -ENOENT; 354 355 for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) { 356 reservedmem_of_init_fn initfn = i->data; 357 const char *compat = i->compatible; 358 359 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat)) 360 continue; 361 362 ret = initfn(rmem); 363 if (ret == 0) { 364 pr_info("initialized node %s, compatible id %s\n", 365 rmem->name, compat); 366 break; 367 } 368 } 369 return ret; 370} 371 372static int __init __rmem_cmp(const void *a, const void *b) 373{ 374 const struct reserved_mem *ra = a, *rb = b; 375 376 if (ra->base < rb->base) 377 return -1; 378 379 if (ra->base > rb->base) 380 return 1; 381 382 /* 383 * Put the dynamic allocations (address == 0, size == 0) before static 384 * allocations at address 0x0 so that overlap detection works 385 * correctly. 386 */ 387 if (ra->size < rb->size) 388 return -1; 389 if (ra->size > rb->size) 390 return 1; 391 392 if (ra->fdt_node < rb->fdt_node) 393 return -1; 394 if (ra->fdt_node > rb->fdt_node) 395 return 1; 396 397 return 0; 398} 399 400static void __init __rmem_check_for_overlap(void) 401{ 402 int i; 403 404 if (reserved_mem_count < 2) 405 return; 406 407 sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]), 408 __rmem_cmp, NULL); 409 for (i = 0; i < reserved_mem_count - 1; i++) { 410 struct reserved_mem *this, *next; 411 412 this = &reserved_mem[i]; 413 next = &reserved_mem[i + 1]; 414 415 if (this->base + this->size > next->base) { 416 phys_addr_t this_end, next_end; 417 418 this_end = this->base + this->size; 419 next_end = next->base + next->size; 420 pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n", 421 this->name, &this->base, &this_end, 422 next->name, &next->base, &next_end); 423 } 424 } 425} 426 427/** 428 * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions 429 */ 430void __init fdt_init_reserved_mem(void) 431{ 432 int i; 433 434 /* check for overlapping reserved regions */ 435 __rmem_check_for_overlap(); 436 437 for (i = 0; i < reserved_mem_count; i++) { 438 struct reserved_mem *rmem = &reserved_mem[i]; 439 unsigned long node = rmem->fdt_node; 440 int len; 441 const __be32 *prop; 442 int err = 0; 443 bool nomap; 444 445 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; 446 prop = of_get_flat_dt_prop(node, "phandle", &len); 447 if (!prop) 448 prop = of_get_flat_dt_prop(node, "linux,phandle", &len); 449 if (prop) 450 rmem->phandle = of_read_number(prop, len/4); 451 452 if (rmem->size == 0) 453 err = __reserved_mem_alloc_size(node, rmem->name, 454 &rmem->base, &rmem->size); 455 if (err == 0) { 456 err = __reserved_mem_init_node(rmem); 457 if (err != 0 && err != -ENOENT) { 458 pr_info("node %s compatible matching fail\n", 459 rmem->name); 460 if (nomap) 461 memblock_clear_nomap(rmem->base, rmem->size); 462 else 463 memblock_phys_free(rmem->base, 464 rmem->size); 465 } else { 466 phys_addr_t end = rmem->base + rmem->size - 1; 467 bool reusable = 468 (of_get_flat_dt_prop(node, "reusable", NULL)) != NULL; 469 470 pr_info("%pa..%pa (%lu KiB) %s %s %s\n", 471 &rmem->base, &end, (unsigned long)(rmem->size / SZ_1K), 472 nomap ? "nomap" : "map", 473 reusable ? "reusable" : "non-reusable", 474 rmem->name ? rmem->name : "unknown"); 475 } 476 } 477 } 478} 479 480static inline struct reserved_mem *__find_rmem(struct device_node *node) 481{ 482 unsigned int i; 483 484 if (!node->phandle) 485 return NULL; 486 487 for (i = 0; i < reserved_mem_count; i++) 488 if (reserved_mem[i].phandle == node->phandle) 489 return &reserved_mem[i]; 490 return NULL; 491} 492 493struct rmem_assigned_device { 494 struct device *dev; 495 struct reserved_mem *rmem; 496 struct list_head list; 497}; 498 499static LIST_HEAD(of_rmem_assigned_device_list); 500static DEFINE_MUTEX(of_rmem_assigned_device_mutex); 501 502/** 503 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to 504 * given device 505 * @dev: Pointer to the device to configure 506 * @np: Pointer to the device_node with 'reserved-memory' property 507 * @idx: Index of selected region 508 * 509 * This function assigns respective DMA-mapping operations based on reserved 510 * memory region specified by 'memory-region' property in @np node to the @dev 511 * device. When driver needs to use more than one reserved memory region, it 512 * should allocate child devices and initialize regions by name for each of 513 * child device. 514 * 515 * Returns error code or zero on success. 516 */ 517int of_reserved_mem_device_init_by_idx(struct device *dev, 518 struct device_node *np, int idx) 519{ 520 struct rmem_assigned_device *rd; 521 struct device_node *target; 522 struct reserved_mem *rmem; 523 int ret; 524 525 if (!np || !dev) 526 return -EINVAL; 527 528 target = of_parse_phandle(np, "memory-region", idx); 529 if (!target) 530 return -ENODEV; 531 532 if (!of_device_is_available(target)) { 533 of_node_put(target); 534 return 0; 535 } 536 537 rmem = __find_rmem(target); 538 of_node_put(target); 539 540 if (!rmem || !rmem->ops || !rmem->ops->device_init) 541 return -EINVAL; 542 543 rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL); 544 if (!rd) 545 return -ENOMEM; 546 547 ret = rmem->ops->device_init(rmem, dev); 548 if (ret == 0) { 549 rd->dev = dev; 550 rd->rmem = rmem; 551 552 mutex_lock(&of_rmem_assigned_device_mutex); 553 list_add(&rd->list, &of_rmem_assigned_device_list); 554 mutex_unlock(&of_rmem_assigned_device_mutex); 555 556 dev_info(dev, "assigned reserved memory node %s\n", rmem->name); 557 } else { 558 kfree(rd); 559 } 560 561 return ret; 562} 563EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx); 564 565/** 566 * of_reserved_mem_device_init_by_name() - assign named reserved memory region 567 * to given device 568 * @dev: pointer to the device to configure 569 * @np: pointer to the device node with 'memory-region' property 570 * @name: name of the selected memory region 571 * 572 * Returns: 0 on success or a negative error-code on failure. 573 */ 574int of_reserved_mem_device_init_by_name(struct device *dev, 575 struct device_node *np, 576 const char *name) 577{ 578 int idx = of_property_match_string(np, "memory-region-names", name); 579 580 return of_reserved_mem_device_init_by_idx(dev, np, idx); 581} 582EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name); 583 584/** 585 * of_reserved_mem_device_release() - release reserved memory device structures 586 * @dev: Pointer to the device to deconfigure 587 * 588 * This function releases structures allocated for memory region handling for 589 * the given device. 590 */ 591void of_reserved_mem_device_release(struct device *dev) 592{ 593 struct rmem_assigned_device *rd, *tmp; 594 LIST_HEAD(release_list); 595 596 mutex_lock(&of_rmem_assigned_device_mutex); 597 list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) { 598 if (rd->dev == dev) 599 list_move_tail(&rd->list, &release_list); 600 } 601 mutex_unlock(&of_rmem_assigned_device_mutex); 602 603 list_for_each_entry_safe(rd, tmp, &release_list, list) { 604 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release) 605 rd->rmem->ops->device_release(rd->rmem, dev); 606 607 kfree(rd); 608 } 609} 610EXPORT_SYMBOL_GPL(of_reserved_mem_device_release); 611 612/** 613 * of_reserved_mem_lookup() - acquire reserved_mem from a device node 614 * @np: node pointer of the desired reserved-memory region 615 * 616 * This function allows drivers to acquire a reference to the reserved_mem 617 * struct based on a device node handle. 618 * 619 * Returns a reserved_mem reference, or NULL on error. 620 */ 621struct reserved_mem *of_reserved_mem_lookup(struct device_node *np) 622{ 623 const char *name; 624 int i; 625 626 if (!np->full_name) 627 return NULL; 628 629 name = kbasename(np->full_name); 630 for (i = 0; i < reserved_mem_count; i++) 631 if (!strcmp(reserved_mem[i].name, name)) 632 return &reserved_mem[i]; 633 634 return NULL; 635} 636EXPORT_SYMBOL_GPL(of_reserved_mem_lookup); 637