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