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
  25 #define MAX_RESERVED_REGIONS    64
  26 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
  27 static int reserved_mem_count;
  28
  29 static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  30         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  31         phys_addr_t *res_base)
  32 {
  33         phys_addr_t base;
  34
  35         end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
  36         align = !align ? SMP_CACHE_BYTES : align;
  37         base = memblock_find_in_range(start, end, size, align);
  38         if (!base)
  39                 return -ENOMEM;
  40
  41         *res_base = base;
  42         if (nomap)
  43                 return memblock_remove(base, size);
  44
  45         return memblock_reserve(base, size);
  46 }
  47
  48 /**
  49  * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
  50  */
  51 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
  52                                       phys_addr_t base, phys_addr_t size)
  53 {
  54         struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
  55
  56         if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
  57                 pr_err("not enough space for all defined regions.\n");
  58                 return;
  59         }
  60
  61         rmem->fdt_node = node;
  62         rmem->name = uname;
  63         rmem->base = base;
  64         rmem->size = size;
  65
  66         reserved_mem_count++;
  67         return;
  68 }
  69
  70 /**
  71  * __reserved_mem_alloc_size() - allocate reserved memory described by
  72  *      'size', 'alignment'  and 'alloc-ranges' properties.
  73  */
  74 static int __init __reserved_mem_alloc_size(unsigned long node,
  75         const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
  76 {
  77         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
  78         phys_addr_t start = 0, end = 0;
  79         phys_addr_t base = 0, align = 0, size;
  80         int len;
  81         const __be32 *prop;
  82         bool nomap;
  83         int ret;
  84
  85         prop = of_get_flat_dt_prop(node, "size", &len);
  86         if (!prop)
  87                 return -EINVAL;
  88
  89         if (len != dt_root_size_cells * sizeof(__be32)) {
  90                 pr_err("invalid size property in '%s' node.\n", uname);
  91                 return -EINVAL;
  92         }
  93         size = dt_mem_next_cell(dt_root_size_cells, &prop);
  94
  95         prop = of_get_flat_dt_prop(node, "alignment", &len);
  96         if (prop) {
  97                 if (len != dt_root_addr_cells * sizeof(__be32)) {
  98                         pr_err("invalid alignment property in '%s' node.\n",
  99                                 uname);
 100                         return -EINVAL;
 101                 }
 102                 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
 103         }
 104
 105         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 106
 107         /* Need adjust the alignment to satisfy the CMA requirement */
 108         if (IS_ENABLED(CONFIG_CMA)
 109             && of_flat_dt_is_compatible(node, "shared-dma-pool")
 110             && of_get_flat_dt_prop(node, "reusable", NULL)
 111             && !nomap) {
 112                 unsigned long order =
 113                         max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
 114
 115                 align = max(align, (phys_addr_t)PAGE_SIZE << order);
 116         }
 117
 118         prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 119         if (prop) {
 120
 121                 if (len % t_len != 0) {
 122                         pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
 123                                uname);
 124                         return -EINVAL;
 125                 }
 126
 127                 base = 0;
 128
 129                 while (len > 0) {
 130                         start = dt_mem_next_cell(dt_root_addr_cells, &prop);
 131                         end = start + dt_mem_next_cell(dt_root_size_cells,
 132                                                        &prop);
 133
 134                         ret = early_init_dt_alloc_reserved_memory_arch(size,
 135                                         align, start, end, nomap, &base);
 136                         if (ret == 0) {
 137                                 pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
 138                                         uname, &base,
 139                                         (unsigned long)size / SZ_1M);
 140                                 break;
 141                         }
 142                         len -= t_len;
 143                 }
 144
 145         } else {
 146                 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
 147                                                         0, 0, nomap, &base);
 148                 if (ret == 0)
 149                         pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
 150                                 uname, &base, (unsigned long)size / SZ_1M);
 151         }
 152
 153         if (base == 0) {
 154                 pr_info("failed to allocate memory for node '%s'\n", uname);
 155                 return -ENOMEM;
 156         }
 157
 158         *res_base = base;
 159         *res_size = size;
 160
 161         return 0;
 162 }
 163
 164 static const struct of_device_id __rmem_of_table_sentinel
 165         __used __section("__reservedmem_of_table_end");
 166
 167 /**
 168  * __reserved_mem_init_node() - call region specific reserved memory init code
 169  */
 170 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
 171 {
 172         extern const struct of_device_id __reservedmem_of_table[];
 173         const struct of_device_id *i;
 174         int ret = -ENOENT;
 175
 176         for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
 177                 reservedmem_of_init_fn initfn = i->data;
 178                 const char *compat = i->compatible;
 179
 180                 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
 181                         continue;
 182
 183                 ret = initfn(rmem);
 184                 if (ret == 0) {
 185                         pr_info("initialized node %s, compatible id %s\n",
 186                                 rmem->name, compat);
 187                         break;
 188                 }
 189         }
 190         return ret;
 191 }
 192
 193 static int __init __rmem_cmp(const void *a, const void *b)
 194 {
 195         const struct reserved_mem *ra = a, *rb = b;
 196
 197         if (ra->base < rb->base)
 198                 return -1;
 199
 200         if (ra->base > rb->base)
 201                 return 1;
 202
 203         return 0;
 204 }
 205
 206 static void __init __rmem_check_for_overlap(void)
 207 {
 208         int i;
 209
 210         if (reserved_mem_count < 2)
 211                 return;
 212
 213         sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 214              __rmem_cmp, NULL);
 215         for (i = 0; i < reserved_mem_count - 1; i++) {
 216                 struct reserved_mem *this, *next;
 217
 218                 this = &reserved_mem[i];
 219                 next = &reserved_mem[i + 1];
 220                 if (!(this->base && next->base))
 221                         continue;
 222                 if (this->base + this->size > next->base) {
 223                         phys_addr_t this_end, next_end;
 224
 225                         this_end = this->base + this->size;
 226                         next_end = next->base + next->size;
 227                         pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 228                                this->name, &this->base, &this_end,
 229                                next->name, &next->base, &next_end);
 230                 }
 231         }
 232 }
 233
 234 /**
 235  * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
 236  */
 237 void __init fdt_init_reserved_mem(void)
 238 {
 239         int i;
 240
 241         /* check for overlapping reserved regions */
 242         __rmem_check_for_overlap();
 243
 244         for (i = 0; i < reserved_mem_count; i++) {
 245                 struct reserved_mem *rmem = &reserved_mem[i];
 246                 unsigned long node = rmem->fdt_node;
 247                 int len;
 248                 const __be32 *prop;
 249                 int err = 0;
 250                 bool nomap;
 251
 252                 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 253                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 254                 if (!prop)
 255                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 256                 if (prop)
 257                         rmem->phandle = of_read_number(prop, len/4);
 258
 259                 if (rmem->size == 0)
 260                         err = __reserved_mem_alloc_size(node, rmem->name,
 261                                                  &rmem->base, &rmem->size);
 262                 if (err == 0) {
 263                         err = __reserved_mem_init_node(rmem);
 264                         if (err != 0 && err != -ENOENT) {
 265                                 pr_info("node %s compatible matching fail\n",
 266                                         rmem->name);
 267                                 memblock_free(rmem->base, rmem->size);
 268                                 if (nomap)
 269                                         memblock_add(rmem->base, rmem->size);
 270                         }
 271                 }
 272         }
 273 }
 274
 275 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 276 {
 277         unsigned int i;
 278
 279         if (!node->phandle)
 280                 return NULL;
 281
 282         for (i = 0; i < reserved_mem_count; i++)
 283                 if (reserved_mem[i].phandle == node->phandle)
 284                         return &reserved_mem[i];
 285         return NULL;
 286 }
 287
 288 struct rmem_assigned_device {
 289         struct device *dev;
 290         struct reserved_mem *rmem;
 291         struct list_head list;
 292 };
 293
 294 static LIST_HEAD(of_rmem_assigned_device_list);
 295 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
 296
 297 /**
 298  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 299  *                                        given device
 300  * @dev:        Pointer to the device to configure
 301  * @np:         Pointer to the device_node with 'reserved-memory' property
 302  * @idx:        Index of selected region
 303  *
 304  * This function assigns respective DMA-mapping operations based on reserved
 305  * memory region specified by 'memory-region' property in @np node to the @dev
 306  * device. When driver needs to use more than one reserved memory region, it
 307  * should allocate child devices and initialize regions by name for each of
 308  * child device.
 309  *
 310  * Returns error code or zero on success.
 311  */
 312 int of_reserved_mem_device_init_by_idx(struct device *dev,
 313                                        struct device_node *np, int idx)
 314 {
 315         struct rmem_assigned_device *rd;
 316         struct device_node *target;
 317         struct reserved_mem *rmem;
 318         int ret;
 319
 320         if (!np || !dev)
 321                 return -EINVAL;
 322
 323         target = of_parse_phandle(np, "memory-region", idx);
 324         if (!target)
 325                 return -ENODEV;
 326
 327         if (!of_device_is_available(target)) {
 328                 of_node_put(target);
 329                 return 0;
 330         }
 331
 332         rmem = __find_rmem(target);
 333         of_node_put(target);
 334
 335         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 336                 return -EINVAL;
 337
 338         rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
 339         if (!rd)
 340                 return -ENOMEM;
 341
 342         ret = rmem->ops->device_init(rmem, dev);
 343         if (ret == 0) {
 344                 rd->dev = dev;
 345                 rd->rmem = rmem;
 346
 347                 mutex_lock(&of_rmem_assigned_device_mutex);
 348                 list_add(&rd->list, &of_rmem_assigned_device_list);
 349                 mutex_unlock(&of_rmem_assigned_device_mutex);
 350
 351                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 352         } else {
 353                 kfree(rd);
 354         }
 355
 356         return ret;
 357 }
 358 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 359
 360 /**
 361  * of_reserved_mem_device_init_by_name() - assign named reserved memory region
 362  *                                         to given device
 363  * @dev: pointer to the device to configure
 364  * @np: pointer to the device node with 'memory-region' property
 365  * @name: name of the selected memory region
 366  *
 367  * Returns: 0 on success or a negative error-code on failure.
 368  */
 369 int of_reserved_mem_device_init_by_name(struct device *dev,
 370                                         struct device_node *np,
 371                                         const char *name)
 372 {
 373         int idx = of_property_match_string(np, "memory-region-names", name);
 374
 375         return of_reserved_mem_device_init_by_idx(dev, np, idx);
 376 }
 377 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
 378
 379 /**
 380  * of_reserved_mem_device_release() - release reserved memory device structures
 381  * @dev:        Pointer to the device to deconfigure
 382  *
 383  * This function releases structures allocated for memory region handling for
 384  * the given device.
 385  */
 386 void of_reserved_mem_device_release(struct device *dev)
 387 {
 388         struct rmem_assigned_device *rd, *tmp;
 389         LIST_HEAD(release_list);
 390
 391         mutex_lock(&of_rmem_assigned_device_mutex);
 392         list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
 393                 if (rd->dev == dev)
 394                         list_move_tail(&rd->list, &release_list);
 395         }
 396         mutex_unlock(&of_rmem_assigned_device_mutex);
 397
 398         list_for_each_entry_safe(rd, tmp, &release_list, list) {
 399                 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
 400                         rd->rmem->ops->device_release(rd->rmem, dev);
 401
 402                 kfree(rd);
 403         }
 404 }
 405 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 406
 407 /**
 408  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
 409  * @np:         node pointer of the desired reserved-memory region
 410  *
 411  * This function allows drivers to acquire a reference to the reserved_mem
 412  * struct based on a device node handle.
 413  *
 414  * Returns a reserved_mem reference, or NULL on error.
 415  */
 416 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
 417 {
 418         const char *name;
 419         int i;
 420
 421         if (!np->full_name)
 422                 return NULL;
 423
 424         name = kbasename(np->full_name);
 425         for (i = 0; i < reserved_mem_count; i++)
 426                 if (!strcmp(reserved_mem[i].name, name))
 427                         return &reserved_mem[i];
 428
 429         return NULL;
 430 }
 431 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);