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