drivers/of/of_reserved_mem.c

   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/of.h>
  16 #include <linux/of_fdt.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/mm.h>
  19 #include <linux/sizes.h>
  20 #include <linux/of_reserved_mem.h>
  21 #include <linux/sort.h>
  22 #include <linux/slab.h>
  23 #include <linux/memblock.h>
  24 #include <linux/kmemleak.h>
  25 #include <linux/cma.h>
  26
  27 #include "of_private.h"
  28
  29 #define MAX_RESERVED_REGIONS    64
  30 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
  31 static int reserved_mem_count;
  32
  33 static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  34         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  35         phys_addr_t *res_base)
  36 {
  37         phys_addr_t base;
  38         int err = 0;
  39
  40         end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
  41         align = !align ? SMP_CACHE_BYTES : align;
  42         base = memblock_phys_alloc_range(size, align, start, end);
  43         if (!base)
  44                 return -ENOMEM;
  45
  46         *res_base = base;
  47         if (nomap) {
  48                 err = memblock_mark_nomap(base, size);
  49                 if (err)
  50                         memblock_phys_free(base, size);
  51         }
  52
  53         kmemleak_ignore_phys(base);
  54
  55         return err;
  56 }
  57
  58 /*
  59  * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
  60  */
  61 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
  62                                       phys_addr_t base, phys_addr_t size)
  63 {
  64         struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
  65
  66         if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
  67                 pr_err("not enough space for all defined regions.\n");
  68                 return;
  69         }
  70
  71         rmem->fdt_node = node;
  72         rmem->name = uname;
  73         rmem->base = base;
  74         rmem->size = size;
  75
  76         reserved_mem_count++;
  77         return;
  78 }
  79
  80 /*
  81  * __reserved_mem_alloc_in_range() - allocate reserved memory described with
  82  *      'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing
  83  *      reserved regions to keep the reserved memory contiguous if possible.
  84  */
  85 static int __init __reserved_mem_alloc_in_range(phys_addr_t size,
  86         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  87         phys_addr_t *res_base)
  88 {
  89         bool prev_bottom_up = memblock_bottom_up();
  90         bool bottom_up = false, top_down = false;
  91         int ret, i;
  92
  93         for (i = 0; i < reserved_mem_count; i++) {
  94                 struct reserved_mem *rmem = &reserved_mem[i];
  95
  96                 /* Skip regions that were not reserved yet */
  97                 if (rmem->size == 0)
  98                         continue;
  99
 100                 /*
 101                  * If range starts next to an existing reservation, use bottom-up:
 102                  *      |....RRRR................RRRRRRRR..............|
 103                  *             --RRRR------
 104                  */
 105                 if (start >= rmem->base && start <= (rmem->base + rmem->size))
 106                         bottom_up = true;
 107
 108                 /*
 109                  * If range ends next to an existing reservation, use top-down:
 110                  *      |....RRRR................RRRRRRRR..............|
 111                  *                    -------RRRR-----
 112                  */
 113                 if (end >= rmem->base && end <= (rmem->base + rmem->size))
 114                         top_down = true;
 115         }
 116
 117         /* Change setting only if either bottom-up or top-down was selected */
 118         if (bottom_up != top_down)
 119                 memblock_set_bottom_up(bottom_up);
 120
 121         ret = early_init_dt_alloc_reserved_memory_arch(size, align,
 122                         start, end, nomap, res_base);
 123
 124         /* Restore old setting if needed */
 125         if (bottom_up != top_down)
 126                 memblock_set_bottom_up(prev_bottom_up);
 127
 128         return ret;
 129 }
 130
 131 /*
 132  * __reserved_mem_alloc_size() - allocate reserved memory described by
 133  *      'size', 'alignment'  and 'alloc-ranges' properties.
 134  */
 135 static int __init __reserved_mem_alloc_size(unsigned long node,
 136         const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
 137 {
 138         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 139         phys_addr_t start = 0, end = 0;
 140         phys_addr_t base = 0, align = 0, size;
 141         int len;
 142         const __be32 *prop;
 143         bool nomap;
 144         int ret;
 145
 146         prop = of_get_flat_dt_prop(node, "size", &len);
 147         if (!prop)
 148                 return -EINVAL;
 149
 150         if (len != dt_root_size_cells * sizeof(__be32)) {
 151                 pr_err("invalid size property in '%s' node.\n", uname);
 152                 return -EINVAL;
 153         }
 154         size = dt_mem_next_cell(dt_root_size_cells, &prop);
 155
 156         prop = of_get_flat_dt_prop(node, "alignment", &len);
 157         if (prop) {
 158                 if (len != dt_root_addr_cells * sizeof(__be32)) {
 159                         pr_err("invalid alignment property in '%s' node.\n",
 160                                 uname);
 161                         return -EINVAL;
 162                 }
 163                 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
 164         }
 165
 166         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 167
 168         /* Need adjust the alignment to satisfy the CMA requirement */
 169         if (IS_ENABLED(CONFIG_CMA)
 170             && of_flat_dt_is_compatible(node, "shared-dma-pool")
 171             && of_get_flat_dt_prop(node, "reusable", NULL)
 172             && !nomap)
 173                 align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES);
 174
 175         prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 176         if (prop) {
 177
 178                 if (len % t_len != 0) {
 179                         pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
 180                                uname);
 181                         return -EINVAL;
 182                 }
 183
 184                 base = 0;
 185
 186                 while (len > 0) {
 187                         start = dt_mem_next_cell(dt_root_addr_cells, &prop);
 188                         end = start + dt_mem_next_cell(dt_root_size_cells,
 189                                                        &prop);
 190
 191                         ret = __reserved_mem_alloc_in_range(size, align,
 192                                         start, end, nomap, &base);
 193                         if (ret == 0) {
 194                                 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
 195                                         uname, &base,
 196                                         (unsigned long)(size / SZ_1M));
 197                                 break;
 198                         }
 199                         len -= t_len;
 200                 }
 201
 202         } else {
 203                 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
 204                                                         0, 0, nomap, &base);
 205                 if (ret == 0)
 206                         pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
 207                                 uname, &base, (unsigned long)(size / SZ_1M));
 208         }
 209
 210         if (base == 0) {
 211                 pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
 212                        uname, (unsigned long)(size / SZ_1M));
 213                 return -ENOMEM;
 214         }
 215
 216         *res_base = base;
 217         *res_size = size;
 218
 219         return 0;
 220 }
 221
 222 static const struct of_device_id __rmem_of_table_sentinel
 223         __used __section("__reservedmem_of_table_end");
 224
 225 /*
 226  * __reserved_mem_init_node() - call region specific reserved memory init code
 227  */
 228 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
 229 {
 230         extern const struct of_device_id __reservedmem_of_table[];
 231         const struct of_device_id *i;
 232         int ret = -ENOENT;
 233
 234         for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
 235                 reservedmem_of_init_fn initfn = i->data;
 236                 const char *compat = i->compatible;
 237
 238                 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
 239                         continue;
 240
 241                 ret = initfn(rmem);
 242                 if (ret == 0) {
 243                         pr_info("initialized node %s, compatible id %s\n",
 244                                 rmem->name, compat);
 245                         break;
 246                 }
 247         }
 248         return ret;
 249 }
 250
 251 static int __init __rmem_cmp(const void *a, const void *b)
 252 {
 253         const struct reserved_mem *ra = a, *rb = b;
 254
 255         if (ra->base < rb->base)
 256                 return -1;
 257
 258         if (ra->base > rb->base)
 259                 return 1;
 260
 261         /*
 262          * Put the dynamic allocations (address == 0, size == 0) before static
 263          * allocations at address 0x0 so that overlap detection works
 264          * correctly.
 265          */
 266         if (ra->size < rb->size)
 267                 return -1;
 268         if (ra->size > rb->size)
 269                 return 1;
 270
 271         if (ra->fdt_node < rb->fdt_node)
 272                 return -1;
 273         if (ra->fdt_node > rb->fdt_node)
 274                 return 1;
 275
 276         return 0;
 277 }
 278
 279 static void __init __rmem_check_for_overlap(void)
 280 {
 281         int i;
 282
 283         if (reserved_mem_count < 2)
 284                 return;
 285
 286         sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 287              __rmem_cmp, NULL);
 288         for (i = 0; i < reserved_mem_count - 1; i++) {
 289                 struct reserved_mem *this, *next;
 290
 291                 this = &reserved_mem[i];
 292                 next = &reserved_mem[i + 1];
 293
 294                 if (this->base + this->size > next->base) {
 295                         phys_addr_t this_end, next_end;
 296
 297                         this_end = this->base + this->size;
 298                         next_end = next->base + next->size;
 299                         pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 300                                this->name, &this->base, &this_end,
 301                                next->name, &next->base, &next_end);
 302                 }
 303         }
 304 }
 305
 306 /**
 307  * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
 308  */
 309 void __init fdt_init_reserved_mem(void)
 310 {
 311         int i;
 312
 313         /* check for overlapping reserved regions */
 314         __rmem_check_for_overlap();
 315
 316         for (i = 0; i < reserved_mem_count; i++) {
 317                 struct reserved_mem *rmem = &reserved_mem[i];
 318                 unsigned long node = rmem->fdt_node;
 319                 int len;
 320                 const __be32 *prop;
 321                 int err = 0;
 322                 bool nomap;
 323
 324                 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 325                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 326                 if (!prop)
 327                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 328                 if (prop)
 329                         rmem->phandle = of_read_number(prop, len/4);
 330
 331                 if (rmem->size == 0)
 332                         err = __reserved_mem_alloc_size(node, rmem->name,
 333                                                  &rmem->base, &rmem->size);
 334                 if (err == 0) {
 335                         err = __reserved_mem_init_node(rmem);
 336                         if (err != 0 && err != -ENOENT) {
 337                                 pr_info("node %s compatible matching fail\n",
 338                                         rmem->name);
 339                                 if (nomap)
 340                                         memblock_clear_nomap(rmem->base, rmem->size);
 341                                 else
 342                                         memblock_phys_free(rmem->base,
 343                                                            rmem->size);
 344                         } else {
 345                                 phys_addr_t end = rmem->base + rmem->size - 1;
 346                                 bool reusable =
 347                                         (of_get_flat_dt_prop(node, "reusable", NULL)) != NULL;
 348
 349                                 pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
 350                                         &rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
 351                                         nomap ? "nomap" : "map",
 352                                         reusable ? "reusable" : "non-reusable",
 353                                         rmem->name ? rmem->name : "unknown");
 354                         }
 355                 }
 356         }
 357 }
 358
 359 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 360 {
 361         unsigned int i;
 362
 363         if (!node->phandle)
 364                 return NULL;
 365
 366         for (i = 0; i < reserved_mem_count; i++)
 367                 if (reserved_mem[i].phandle == node->phandle)
 368                         return &reserved_mem[i];
 369         return NULL;
 370 }
 371
 372 struct rmem_assigned_device {
 373         struct device *dev;
 374         struct reserved_mem *rmem;
 375         struct list_head list;
 376 };
 377
 378 static LIST_HEAD(of_rmem_assigned_device_list);
 379 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
 380
 381 /**
 382  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 383  *                                        given device
 384  * @dev:        Pointer to the device to configure
 385  * @np:         Pointer to the device_node with 'reserved-memory' property
 386  * @idx:        Index of selected region
 387  *
 388  * This function assigns respective DMA-mapping operations based on reserved
 389  * memory region specified by 'memory-region' property in @np node to the @dev
 390  * device. When driver needs to use more than one reserved memory region, it
 391  * should allocate child devices and initialize regions by name for each of
 392  * child device.
 393  *
 394  * Returns error code or zero on success.
 395  */
 396 int of_reserved_mem_device_init_by_idx(struct device *dev,
 397                                        struct device_node *np, int idx)
 398 {
 399         struct rmem_assigned_device *rd;
 400         struct device_node *target;
 401         struct reserved_mem *rmem;
 402         int ret;
 403
 404         if (!np || !dev)
 405                 return -EINVAL;
 406
 407         target = of_parse_phandle(np, "memory-region", idx);
 408         if (!target)
 409                 return -ENODEV;
 410
 411         if (!of_device_is_available(target)) {
 412                 of_node_put(target);
 413                 return 0;
 414         }
 415
 416         rmem = __find_rmem(target);
 417         of_node_put(target);
 418
 419         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 420                 return -EINVAL;
 421
 422         rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
 423         if (!rd)
 424                 return -ENOMEM;
 425
 426         ret = rmem->ops->device_init(rmem, dev);
 427         if (ret == 0) {
 428                 rd->dev = dev;
 429                 rd->rmem = rmem;
 430
 431                 mutex_lock(&of_rmem_assigned_device_mutex);
 432                 list_add(&rd->list, &of_rmem_assigned_device_list);
 433                 mutex_unlock(&of_rmem_assigned_device_mutex);
 434
 435                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 436         } else {
 437                 kfree(rd);
 438         }
 439
 440         return ret;
 441 }
 442 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 443
 444 /**
 445  * of_reserved_mem_device_init_by_name() - assign named reserved memory region
 446  *                                         to given device
 447  * @dev: pointer to the device to configure
 448  * @np: pointer to the device node with 'memory-region' property
 449  * @name: name of the selected memory region
 450  *
 451  * Returns: 0 on success or a negative error-code on failure.
 452  */
 453 int of_reserved_mem_device_init_by_name(struct device *dev,
 454                                         struct device_node *np,
 455                                         const char *name)
 456 {
 457         int idx = of_property_match_string(np, "memory-region-names", name);
 458
 459         return of_reserved_mem_device_init_by_idx(dev, np, idx);
 460 }
 461 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
 462
 463 /**
 464  * of_reserved_mem_device_release() - release reserved memory device structures
 465  * @dev:        Pointer to the device to deconfigure
 466  *
 467  * This function releases structures allocated for memory region handling for
 468  * the given device.
 469  */
 470 void of_reserved_mem_device_release(struct device *dev)
 471 {
 472         struct rmem_assigned_device *rd, *tmp;
 473         LIST_HEAD(release_list);
 474
 475         mutex_lock(&of_rmem_assigned_device_mutex);
 476         list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
 477                 if (rd->dev == dev)
 478                         list_move_tail(&rd->list, &release_list);
 479         }
 480         mutex_unlock(&of_rmem_assigned_device_mutex);
 481
 482         list_for_each_entry_safe(rd, tmp, &release_list, list) {
 483                 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
 484                         rd->rmem->ops->device_release(rd->rmem, dev);
 485
 486                 kfree(rd);
 487         }
 488 }
 489 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 490
 491 /**
 492  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
 493  * @np:         node pointer of the desired reserved-memory region
 494  *
 495  * This function allows drivers to acquire a reference to the reserved_mem
 496  * struct based on a device node handle.
 497  *
 498  * Returns a reserved_mem reference, or NULL on error.
 499  */
 500 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
 501 {
 502         const char *name;
 503         int i;
 504
 505         if (!np->full_name)
 506                 return NULL;
 507
 508         name = kbasename(np->full_name);
 509         for (i = 0; i < reserved_mem_count; i++)
 510                 if (!strcmp(reserved_mem[i].name, name))
 511                         return &reserved_mem[i];
 512
 513         return NULL;
 514 }
 515 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);