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