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         /*
 204          * Put the dynamic allocations (address == 0, size == 0) before static
 205          * allocations at address 0x0 so that overlap detection works
 206          * correctly.
 207          */
 208         if (ra->size < rb->size)
 209                 return -1;
 210         if (ra->size > rb->size)
 211                 return 1;
 212
 213         return 0;
 214 }
 215
 216 static void __init __rmem_check_for_overlap(void)
 217 {
 218         int i;
 219
 220         if (reserved_mem_count < 2)
 221                 return;
 222
 223         sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 224              __rmem_cmp, NULL);
 225         for (i = 0; i < reserved_mem_count - 1; i++) {
 226                 struct reserved_mem *this, *next;
 227
 228                 this = &reserved_mem[i];
 229                 next = &reserved_mem[i + 1];
 230
 231                 if (this->base + this->size > next->base) {
 232                         phys_addr_t this_end, next_end;
 233
 234                         this_end = this->base + this->size;
 235                         next_end = next->base + next->size;
 236                         pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 237                                this->name, &this->base, &this_end,
 238                                next->name, &next->base, &next_end);
 239                 }
 240         }
 241 }
 242
 243 /**
 244  * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
 245  */
 246 void __init fdt_init_reserved_mem(void)
 247 {
 248         int i;
 249
 250         /* check for overlapping reserved regions */
 251         __rmem_check_for_overlap();
 252
 253         for (i = 0; i < reserved_mem_count; i++) {
 254                 struct reserved_mem *rmem = &reserved_mem[i];
 255                 unsigned long node = rmem->fdt_node;
 256                 int len;
 257                 const __be32 *prop;
 258                 int err = 0;
 259                 bool nomap;
 260
 261                 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 262                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 263                 if (!prop)
 264                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 265                 if (prop)
 266                         rmem->phandle = of_read_number(prop, len/4);
 267
 268                 if (rmem->size == 0)
 269                         err = __reserved_mem_alloc_size(node, rmem->name,
 270                                                  &rmem->base, &rmem->size);
 271                 if (err == 0) {
 272                         err = __reserved_mem_init_node(rmem);
 273                         if (err != 0 && err != -ENOENT) {
 274                                 pr_info("node %s compatible matching fail\n",
 275                                         rmem->name);
 276                                 memblock_free(rmem->base, rmem->size);
 277                                 if (nomap)
 278                                         memblock_add(rmem->base, rmem->size);
 279                         }
 280                 }
 281         }
 282 }
 283
 284 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 285 {
 286         unsigned int i;
 287
 288         if (!node->phandle)
 289                 return NULL;
 290
 291         for (i = 0; i < reserved_mem_count; i++)
 292                 if (reserved_mem[i].phandle == node->phandle)
 293                         return &reserved_mem[i];
 294         return NULL;
 295 }
 296
 297 struct rmem_assigned_device {
 298         struct device *dev;
 299         struct reserved_mem *rmem;
 300         struct list_head list;
 301 };
 302
 303 static LIST_HEAD(of_rmem_assigned_device_list);
 304 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
 305
 306 /**
 307  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 308  *                                        given device
 309  * @dev:        Pointer to the device to configure
 310  * @np:         Pointer to the device_node with 'reserved-memory' property
 311  * @idx:        Index of selected region
 312  *
 313  * This function assigns respective DMA-mapping operations based on reserved
 314  * memory region specified by 'memory-region' property in @np node to the @dev
 315  * device. When driver needs to use more than one reserved memory region, it
 316  * should allocate child devices and initialize regions by name for each of
 317  * child device.
 318  *
 319  * Returns error code or zero on success.
 320  */
 321 int of_reserved_mem_device_init_by_idx(struct device *dev,
 322                                        struct device_node *np, int idx)
 323 {
 324         struct rmem_assigned_device *rd;
 325         struct device_node *target;
 326         struct reserved_mem *rmem;
 327         int ret;
 328
 329         if (!np || !dev)
 330                 return -EINVAL;
 331
 332         target = of_parse_phandle(np, "memory-region", idx);
 333         if (!target)
 334                 return -ENODEV;
 335
 336         if (!of_device_is_available(target)) {
 337                 of_node_put(target);
 338                 return 0;
 339         }
 340
 341         rmem = __find_rmem(target);
 342         of_node_put(target);
 343
 344         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 345                 return -EINVAL;
 346
 347         rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
 348         if (!rd)
 349                 return -ENOMEM;
 350
 351         ret = rmem->ops->device_init(rmem, dev);
 352         if (ret == 0) {
 353                 rd->dev = dev;
 354                 rd->rmem = rmem;
 355
 356                 mutex_lock(&of_rmem_assigned_device_mutex);
 357                 list_add(&rd->list, &of_rmem_assigned_device_list);
 358                 mutex_unlock(&of_rmem_assigned_device_mutex);
 359
 360                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 361         } else {
 362                 kfree(rd);
 363         }
 364
 365         return ret;
 366 }
 367 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 368
 369 /**
 370  * of_reserved_mem_device_init_by_name() - assign named reserved memory region
 371  *                                         to given device
 372  * @dev: pointer to the device to configure
 373  * @np: pointer to the device node with 'memory-region' property
 374  * @name: name of the selected memory region
 375  *
 376  * Returns: 0 on success or a negative error-code on failure.
 377  */
 378 int of_reserved_mem_device_init_by_name(struct device *dev,
 379                                         struct device_node *np,
 380                                         const char *name)
 381 {
 382         int idx = of_property_match_string(np, "memory-region-names", name);
 383
 384         return of_reserved_mem_device_init_by_idx(dev, np, idx);
 385 }
 386 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
 387
 388 /**
 389  * of_reserved_mem_device_release() - release reserved memory device structures
 390  * @dev:        Pointer to the device to deconfigure
 391  *
 392  * This function releases structures allocated for memory region handling for
 393  * the given device.
 394  */
 395 void of_reserved_mem_device_release(struct device *dev)
 396 {
 397         struct rmem_assigned_device *rd, *tmp;
 398         LIST_HEAD(release_list);
 399
 400         mutex_lock(&of_rmem_assigned_device_mutex);
 401         list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
 402                 if (rd->dev == dev)
 403                         list_move_tail(&rd->list, &release_list);
 404         }
 405         mutex_unlock(&of_rmem_assigned_device_mutex);
 406
 407         list_for_each_entry_safe(rd, tmp, &release_list, list) {
 408                 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
 409                         rd->rmem->ops->device_release(rd->rmem, dev);
 410
 411                 kfree(rd);
 412         }
 413 }
 414 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 415
 416 /**
 417  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
 418  * @np:         node pointer of the desired reserved-memory region
 419  *
 420  * This function allows drivers to acquire a reference to the reserved_mem
 421  * struct based on a device node handle.
 422  *
 423  * Returns a reserved_mem reference, or NULL on error.
 424  */
 425 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
 426 {
 427         const char *name;
 428         int i;
 429
 430         if (!np->full_name)
 431                 return NULL;
 432
 433         name = kbasename(np->full_name);
 434         for (i = 0; i < reserved_mem_count; i++)
 435                 if (!strcmp(reserved_mem[i].name, name))
 436                         return &reserved_mem[i];
 437
 438         return NULL;
 439 }
 440 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);