drivers/of/of_reserved_mem.c

   1 /*
   2  * Device tree based initialization code for reserved memory.
   3  *
   4  * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
   5  * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
   6  *              http://www.samsung.com
   7  * Author: Marek Szyprowski <m.szyprowski@samsung.com>
   8  * Author: Josh Cartwright <joshc@codeaurora.org>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of the
  13  * License or (at your optional) any later version of the license.
  14  */
  15
  16 #define pr_fmt(fmt)     "OF: reserved mem: " fmt
  17
  18 #include <linux/err.h>
  19 #include <linux/of.h>
  20 #include <linux/of_fdt.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/mm.h>
  23 #include <linux/sizes.h>
  24 #include <linux/of_reserved_mem.h>
  25 #include <linux/sort.h>
  26 #include <linux/slab.h>
  27
  28 #define MAX_RESERVED_REGIONS    32
  29 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
  30 static int reserved_mem_count;
  31
  32 #if defined(CONFIG_HAVE_MEMBLOCK)
  33 #include <linux/memblock.h>
  34 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  35         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  36         phys_addr_t *res_base)
  37 {
  38         phys_addr_t base;
  39         /*
  40          * We use __memblock_alloc_base() because memblock_alloc_base()
  41          * panic()s on allocation failure.
  42          */
  43         end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
  44         base = __memblock_alloc_base(size, align, end);
  45         if (!base)
  46                 return -ENOMEM;
  47
  48         /*
  49          * Check if the allocated region fits in to start..end window
  50          */
  51         if (base < start) {
  52                 memblock_free(base, size);
  53                 return -ENOMEM;
  54         }
  55
  56         *res_base = base;
  57         if (nomap)
  58                 return memblock_remove(base, size);
  59         return 0;
  60 }
  61 #else
  62 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  63         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  64         phys_addr_t *res_base)
  65 {
  66         pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
  67                   size, nomap ? " (nomap)" : "");
  68         return -ENOSYS;
  69 }
  70 #endif
  71
  72 /**
  73  * res_mem_save_node() - save fdt node for second pass initialization
  74  */
  75 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
  76                                       phys_addr_t base, phys_addr_t size)
  77 {
  78         struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
  79
  80         if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
  81                 pr_err("not enough space all defined regions.\n");
  82                 return;
  83         }
  84
  85         rmem->fdt_node = node;
  86         rmem->name = uname;
  87         rmem->base = base;
  88         rmem->size = size;
  89
  90         reserved_mem_count++;
  91         return;
  92 }
  93
  94 /**
  95  * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
  96  *                        and 'alloc-ranges' properties
  97  */
  98 static int __init __reserved_mem_alloc_size(unsigned long node,
  99         const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
 100 {
 101         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 102         phys_addr_t start = 0, end = 0;
 103         phys_addr_t base = 0, align = 0, size;
 104         int len;
 105         const __be32 *prop;
 106         int nomap;
 107         int ret;
 108
 109         prop = of_get_flat_dt_prop(node, "size", &len);
 110         if (!prop)
 111                 return -EINVAL;
 112
 113         if (len != dt_root_size_cells * sizeof(__be32)) {
 114                 pr_err("invalid size property in '%s' node.\n", uname);
 115                 return -EINVAL;
 116         }
 117         size = dt_mem_next_cell(dt_root_size_cells, &prop);
 118
 119         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 120
 121         prop = of_get_flat_dt_prop(node, "alignment", &len);
 122         if (prop) {
 123                 if (len != dt_root_addr_cells * sizeof(__be32)) {
 124                         pr_err("invalid alignment property in '%s' node.\n",
 125                                 uname);
 126                         return -EINVAL;
 127                 }
 128                 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
 129         }
 130
 131         /* Need adjust the alignment to satisfy the CMA requirement */
 132         if (IS_ENABLED(CONFIG_CMA)
 133             && of_flat_dt_is_compatible(node, "shared-dma-pool")
 134             && of_get_flat_dt_prop(node, "reusable", NULL)
 135             && !of_get_flat_dt_prop(node, "no-map", NULL)) {
 136                 unsigned long order =
 137                         max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
 138
 139                 align = max(align, (phys_addr_t)PAGE_SIZE << order);
 140         }
 141
 142         prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 143         if (prop) {
 144
 145                 if (len % t_len != 0) {
 146                         pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
 147                                uname);
 148                         return -EINVAL;
 149                 }
 150
 151                 base = 0;
 152
 153                 while (len > 0) {
 154                         start = dt_mem_next_cell(dt_root_addr_cells, &prop);
 155                         end = start + dt_mem_next_cell(dt_root_size_cells,
 156                                                        &prop);
 157
 158                         ret = early_init_dt_alloc_reserved_memory_arch(size,
 159                                         align, start, end, nomap, &base);
 160                         if (ret == 0) {
 161                                 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
 162                                         uname, &base,
 163                                         (unsigned long)(size / SZ_1M));
 164                                 break;
 165                         }
 166                         len -= t_len;
 167                 }
 168
 169         } else {
 170                 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
 171                                                         0, 0, nomap, &base);
 172                 if (ret == 0)
 173                         pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
 174                                 uname, &base, (unsigned long)(size / SZ_1M));
 175         }
 176
 177         if (base == 0) {
 178                 pr_info("failed to allocate memory for node '%s'\n", uname);
 179                 return -ENOMEM;
 180         }
 181
 182         *res_base = base;
 183         *res_size = size;
 184
 185         return 0;
 186 }
 187
 188 static const struct of_device_id __rmem_of_table_sentinel
 189         __used __section(__reservedmem_of_table_end);
 190
 191 /**
 192  * res_mem_init_node() - call region specific reserved memory init code
 193  */
 194 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
 195 {
 196         extern const struct of_device_id __reservedmem_of_table[];
 197         const struct of_device_id *i;
 198
 199         for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
 200                 reservedmem_of_init_fn initfn = i->data;
 201                 const char *compat = i->compatible;
 202
 203                 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
 204                         continue;
 205
 206                 if (initfn(rmem) == 0) {
 207                         pr_info("initialized node %s, compatible id %s\n",
 208                                 rmem->name, compat);
 209                         return 0;
 210                 }
 211         }
 212         return -ENOENT;
 213 }
 214
 215 static int __init __rmem_cmp(const void *a, const void *b)
 216 {
 217         const struct reserved_mem *ra = a, *rb = b;
 218
 219         if (ra->base < rb->base)
 220                 return -1;
 221
 222         if (ra->base > rb->base)
 223                 return 1;
 224
 225         /*
 226          * Put the dynamic allocations (address == 0, size == 0) before static
 227          * allocations at address 0x0 so that overlap detection works
 228          * correctly.
 229          */
 230         if (ra->size < rb->size)
 231                 return -1;
 232         if (ra->size > rb->size)
 233                 return 1;
 234
 235         return 0;
 236 }
 237
 238 static void __init __rmem_check_for_overlap(void)
 239 {
 240         int i;
 241
 242         if (reserved_mem_count < 2)
 243                 return;
 244
 245         sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 246              __rmem_cmp, NULL);
 247         for (i = 0; i < reserved_mem_count - 1; i++) {
 248                 struct reserved_mem *this, *next;
 249
 250                 this = &reserved_mem[i];
 251                 next = &reserved_mem[i + 1];
 252
 253                 if (this->base + this->size > next->base) {
 254                         phys_addr_t this_end, next_end;
 255
 256                         this_end = this->base + this->size;
 257                         next_end = next->base + next->size;
 258                         pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 259                                this->name, &this->base, &this_end,
 260                                next->name, &next->base, &next_end);
 261                 }
 262         }
 263 }
 264
 265 /**
 266  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
 267  */
 268 void __init fdt_init_reserved_mem(void)
 269 {
 270         int i;
 271
 272         /* check for overlapping reserved regions */
 273         __rmem_check_for_overlap();
 274
 275         for (i = 0; i < reserved_mem_count; i++) {
 276                 struct reserved_mem *rmem = &reserved_mem[i];
 277                 unsigned long node = rmem->fdt_node;
 278                 int len;
 279                 const __be32 *prop;
 280                 int err = 0;
 281
 282                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 283                 if (!prop)
 284                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 285                 if (prop)
 286                         rmem->phandle = of_read_number(prop, len/4);
 287
 288                 if (rmem->size == 0)
 289                         err = __reserved_mem_alloc_size(node, rmem->name,
 290                                                  &rmem->base, &rmem->size);
 291                 if (err == 0)
 292                         __reserved_mem_init_node(rmem);
 293         }
 294 }
 295
 296 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 297 {
 298         unsigned int i;
 299
 300         if (!node->phandle)
 301                 return NULL;
 302
 303         for (i = 0; i < reserved_mem_count; i++)
 304                 if (reserved_mem[i].phandle == node->phandle)
 305                         return &reserved_mem[i];
 306         return NULL;
 307 }
 308
 309 struct rmem_assigned_device {
 310         struct device *dev;
 311         struct reserved_mem *rmem;
 312         struct list_head list;
 313 };
 314
 315 static LIST_HEAD(of_rmem_assigned_device_list);
 316 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
 317
 318 /**
 319  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 320  *                                        given device
 321  * @dev:        Pointer to the device to configure
 322  * @np:         Pointer to the device_node with 'reserved-memory' property
 323  * @idx:        Index of selected region
 324  *
 325  * This function assigns respective DMA-mapping operations based on reserved
 326  * memory region specified by 'memory-region' property in @np node to the @dev
 327  * device. When driver needs to use more than one reserved memory region, it
 328  * should allocate child devices and initialize regions by name for each of
 329  * child device.
 330  *
 331  * Returns error code or zero on success.
 332  */
 333 int of_reserved_mem_device_init_by_idx(struct device *dev,
 334                                        struct device_node *np, int idx)
 335 {
 336         struct rmem_assigned_device *rd;
 337         struct device_node *target;
 338         struct reserved_mem *rmem;
 339         int ret;
 340
 341         if (!np || !dev)
 342                 return -EINVAL;
 343
 344         target = of_parse_phandle(np, "memory-region", idx);
 345         if (!target)
 346                 return -ENODEV;
 347
 348         rmem = __find_rmem(target);
 349         of_node_put(target);
 350
 351         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 352                 return -EINVAL;
 353
 354         rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
 355         if (!rd)
 356                 return -ENOMEM;
 357
 358         ret = rmem->ops->device_init(rmem, dev);
 359         if (ret == 0) {
 360                 rd->dev = dev;
 361                 rd->rmem = rmem;
 362
 363                 mutex_lock(&of_rmem_assigned_device_mutex);
 364                 list_add(&rd->list, &of_rmem_assigned_device_list);
 365                 mutex_unlock(&of_rmem_assigned_device_mutex);
 366                 /* ensure that dma_ops is set for virtual devices
 367                  * using reserved memory
 368                  */
 369                 of_dma_configure(dev, np);
 370
 371                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 372         } else {
 373                 kfree(rd);
 374         }
 375
 376         return ret;
 377 }
 378 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 379
 380 /**
 381  * of_reserved_mem_device_release() - release reserved memory device structures
 382  * @dev:        Pointer to the device to deconfigure
 383  *
 384  * This function releases structures allocated for memory region handling for
 385  * the given device.
 386  */
 387 void of_reserved_mem_device_release(struct device *dev)
 388 {
 389         struct rmem_assigned_device *rd;
 390         struct reserved_mem *rmem = NULL;
 391
 392         mutex_lock(&of_rmem_assigned_device_mutex);
 393         list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
 394                 if (rd->dev == dev) {
 395                         rmem = rd->rmem;
 396                         list_del(&rd->list);
 397                         kfree(rd);
 398                         break;
 399                 }
 400         }
 401         mutex_unlock(&of_rmem_assigned_device_mutex);
 402
 403         if (!rmem || !rmem->ops || !rmem->ops->device_release)
 404                 return;
 405
 406         rmem->ops->device_release(rmem, dev);
 407 }
 408 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);