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