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    32
  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  * res_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 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  * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
  72  *                        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         int 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         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
  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         /* 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             && !of_get_flat_dt_prop(node, "no-map", NULL)) {
 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  * res_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
 175         for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
 176                 reservedmem_of_init_fn initfn = i->data;
 177                 const char *compat = i->compatible;
 178
 179                 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
 180                         continue;
 181
 182                 if (initfn(rmem) == 0) {
 183                         pr_info("initialized node %s, compatible id %s\n",
 184                                 rmem->name, compat);
 185                         return 0;
 186                 }
 187         }
 188         return -ENOENT;
 189 }
 190
 191 static int __init __rmem_cmp(const void *a, const void *b)
 192 {
 193         const struct reserved_mem *ra = a, *rb = b;
 194
 195         if (ra->base < rb->base)
 196                 return -1;
 197
 198         if (ra->base > rb->base)
 199                 return 1;
 200
 201         return 0;
 202 }
 203
 204 static void __init __rmem_check_for_overlap(void)
 205 {
 206         int i;
 207
 208         if (reserved_mem_count < 2)
 209                 return;
 210
 211         sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 212              __rmem_cmp, NULL);
 213         for (i = 0; i < reserved_mem_count - 1; i++) {
 214                 struct reserved_mem *this, *next;
 215
 216                 this = &reserved_mem[i];
 217                 next = &reserved_mem[i + 1];
 218                 if (!(this->base && next->base))
 219                         continue;
 220                 if (this->base + this->size > next->base) {
 221                         phys_addr_t this_end, next_end;
 222
 223                         this_end = this->base + this->size;
 224                         next_end = next->base + next->size;
 225                         pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 226                                this->name, &this->base, &this_end,
 227                                next->name, &next->base, &next_end);
 228                 }
 229         }
 230 }
 231
 232 /**
 233  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
 234  */
 235 void __init fdt_init_reserved_mem(void)
 236 {
 237         int i;
 238
 239         /* check for overlapping reserved regions */
 240         __rmem_check_for_overlap();
 241
 242         for (i = 0; i < reserved_mem_count; i++) {
 243                 struct reserved_mem *rmem = &reserved_mem[i];
 244                 unsigned long node = rmem->fdt_node;
 245                 int len;
 246                 const __be32 *prop;
 247                 int err = 0;
 248
 249                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 250                 if (!prop)
 251                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 252                 if (prop)
 253                         rmem->phandle = of_read_number(prop, len/4);
 254
 255                 if (rmem->size == 0)
 256                         err = __reserved_mem_alloc_size(node, rmem->name,
 257                                                  &rmem->base, &rmem->size);
 258                 if (err == 0)
 259                         __reserved_mem_init_node(rmem);
 260         }
 261 }
 262
 263 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 264 {
 265         unsigned int i;
 266
 267         if (!node->phandle)
 268                 return NULL;
 269
 270         for (i = 0; i < reserved_mem_count; i++)
 271                 if (reserved_mem[i].phandle == node->phandle)
 272                         return &reserved_mem[i];
 273         return NULL;
 274 }
 275
 276 struct rmem_assigned_device {
 277         struct device *dev;
 278         struct reserved_mem *rmem;
 279         struct list_head list;
 280 };
 281
 282 static LIST_HEAD(of_rmem_assigned_device_list);
 283 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
 284
 285 /**
 286  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 287  *                                        given device
 288  * @dev:        Pointer to the device to configure
 289  * @np:         Pointer to the device_node with 'reserved-memory' property
 290  * @idx:        Index of selected region
 291  *
 292  * This function assigns respective DMA-mapping operations based on reserved
 293  * memory region specified by 'memory-region' property in @np node to the @dev
 294  * device. When driver needs to use more than one reserved memory region, it
 295  * should allocate child devices and initialize regions by name for each of
 296  * child device.
 297  *
 298  * Returns error code or zero on success.
 299  */
 300 int of_reserved_mem_device_init_by_idx(struct device *dev,
 301                                        struct device_node *np, int idx)
 302 {
 303         struct rmem_assigned_device *rd;
 304         struct device_node *target;
 305         struct reserved_mem *rmem;
 306         int ret;
 307
 308         if (!np || !dev)
 309                 return -EINVAL;
 310
 311         target = of_parse_phandle(np, "memory-region", idx);
 312         if (!target)
 313                 return -ENODEV;
 314
 315         rmem = __find_rmem(target);
 316         of_node_put(target);
 317
 318         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 319                 return -EINVAL;
 320
 321         rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
 322         if (!rd)
 323                 return -ENOMEM;
 324
 325         ret = rmem->ops->device_init(rmem, dev);
 326         if (ret == 0) {
 327                 rd->dev = dev;
 328                 rd->rmem = rmem;
 329
 330                 mutex_lock(&of_rmem_assigned_device_mutex);
 331                 list_add(&rd->list, &of_rmem_assigned_device_list);
 332                 mutex_unlock(&of_rmem_assigned_device_mutex);
 333
 334                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 335         } else {
 336                 kfree(rd);
 337         }
 338
 339         return ret;
 340 }
 341 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 342
 343 /**
 344  * of_reserved_mem_device_release() - release reserved memory device structures
 345  * @dev:        Pointer to the device to deconfigure
 346  *
 347  * This function releases structures allocated for memory region handling for
 348  * the given device.
 349  */
 350 void of_reserved_mem_device_release(struct device *dev)
 351 {
 352         struct rmem_assigned_device *rd;
 353         struct reserved_mem *rmem = NULL;
 354
 355         mutex_lock(&of_rmem_assigned_device_mutex);
 356         list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
 357                 if (rd->dev == dev) {
 358                         rmem = rd->rmem;
 359                         list_del(&rd->list);
 360                         kfree(rd);
 361                         break;
 362                 }
 363         }
 364         mutex_unlock(&of_rmem_assigned_device_mutex);
 365
 366         if (!rmem || !rmem->ops || !rmem->ops->device_release)
 367                 return;
 368
 369         rmem->ops->device_release(rmem, dev);
 370 }
 371 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 372
 373 /**
 374  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
 375  * @np:         node pointer of the desired reserved-memory region
 376  *
 377  * This function allows drivers to acquire a reference to the reserved_mem
 378  * struct based on a device node handle.
 379  *
 380  * Returns a reserved_mem reference, or NULL on error.
 381  */
 382 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
 383 {
 384         const char *name;
 385         int i;
 386
 387         if (!np->full_name)
 388                 return NULL;
 389
 390         name = kbasename(np->full_name);
 391         for (i = 0; i < reserved_mem_count; i++)
 392                 if (!strcmp(reserved_mem[i].name, name))
 393                         return &reserved_mem[i];
 394
 395         return NULL;
 396 }
 397 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);