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