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 #include <linux/err.h>
  17 #include <linux/of.h>
  18 #include <linux/of_fdt.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/mm.h>
  21 #include <linux/sizes.h>
  22 #include <linux/of_reserved_mem.h>
  23 #include <linux/sort.h>
  24
  25 #define MAX_RESERVED_REGIONS    16
  26 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
  27 static int reserved_mem_count;
  28
  29 #if defined(CONFIG_HAVE_MEMBLOCK)
  30 #include <linux/memblock.h>
  31 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  32         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  33         phys_addr_t *res_base)
  34 {
  35         /*
  36          * We use __memblock_alloc_base() because memblock_alloc_base()
  37          * panic()s on allocation failure.
  38          */
  39         phys_addr_t 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 #else
  57 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  58         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  59         phys_addr_t *res_base)
  60 {
  61         pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
  62                   size, nomap ? " (nomap)" : "");
  63         return -ENOSYS;
  64 }
  65 #endif
  66
  67 /**
  68  * res_mem_save_node() - save fdt node for second pass initialization
  69  */
  70 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
  71                                       phys_addr_t base, phys_addr_t size)
  72 {
  73         struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
  74
  75         if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
  76                 pr_err("Reserved memory: not enough space all defined regions.\n");
  77                 return;
  78         }
  79
  80         rmem->fdt_node = node;
  81         rmem->name = uname;
  82         rmem->base = base;
  83         rmem->size = size;
  84
  85         reserved_mem_count++;
  86         return;
  87 }
  88
  89 /**
  90  * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
  91  *                        and 'alloc-ranges' properties
  92  */
  93 static int __init __reserved_mem_alloc_size(unsigned long node,
  94         const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
  95 {
  96         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
  97         phys_addr_t start = 0, end = 0;
  98         phys_addr_t base = 0, align = 0, size;
  99         int len;
 100         const __be32 *prop;
 101         int nomap;
 102         int ret;
 103
 104         prop = of_get_flat_dt_prop(node, "size", &len);
 105         if (!prop)
 106                 return -EINVAL;
 107
 108         if (len != dt_root_size_cells * sizeof(__be32)) {
 109                 pr_err("Reserved memory: invalid size property in '%s' node.\n",
 110                                 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("Reserved memory: 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         prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 128         if (prop) {
 129
 130                 if (len % t_len != 0) {
 131                         pr_err("Reserved memory: 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("Reserved memory: 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("Reserved memory: 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("Reserved memory: failed to allocate memory for node '%s'\n",
 164                         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("Reserved memory: 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         return ra->base - rb->base;
 206 }
 207
 208 static void __init __rmem_check_for_overlap(void)
 209 {
 210         int i;
 211
 212         if (reserved_mem_count < 2)
 213                 return;
 214
 215         sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 216              __rmem_cmp, NULL);
 217         for (i = 0; i < reserved_mem_count - 1; i++) {
 218                 struct reserved_mem *this, *next;
 219
 220                 this = &reserved_mem[i];
 221                 next = &reserved_mem[i + 1];
 222                 if (!(this->base && next->base))
 223                         continue;
 224                 if (this->base + this->size > next->base) {
 225                         phys_addr_t this_end, next_end;
 226
 227                         this_end = this->base + this->size;
 228                         next_end = next->base + next->size;
 229                         pr_err("Reserved memory: OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 230                                this->name, &this->base, &this_end,
 231                                next->name, &next->base, &next_end);
 232                 }
 233         }
 234 }
 235
 236 /**
 237  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
 238  */
 239 void __init fdt_init_reserved_mem(void)
 240 {
 241         int i;
 242
 243         /* check for overlapping reserved regions */
 244         __rmem_check_for_overlap();
 245
 246         for (i = 0; i < reserved_mem_count; i++) {
 247                 struct reserved_mem *rmem = &reserved_mem[i];
 248                 unsigned long node = rmem->fdt_node;
 249                 int len;
 250                 const __be32 *prop;
 251                 int err = 0;
 252
 253                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 254                 if (!prop)
 255                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 256                 if (prop)
 257                         rmem->phandle = of_read_number(prop, len/4);
 258
 259                 if (rmem->size == 0)
 260                         err = __reserved_mem_alloc_size(node, rmem->name,
 261                                                  &rmem->base, &rmem->size);
 262                 if (err == 0)
 263                         __reserved_mem_init_node(rmem);
 264         }
 265 }
 266
 267 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 268 {
 269         unsigned int i;
 270
 271         if (!node->phandle)
 272                 return NULL;
 273
 274         for (i = 0; i < reserved_mem_count; i++)
 275                 if (reserved_mem[i].phandle == node->phandle)
 276                         return &reserved_mem[i];
 277         return NULL;
 278 }
 279
 280 /**
 281  * of_reserved_mem_device_init() - assign reserved memory region to given device
 282  *
 283  * This function assign memory region pointed by "memory-region" device tree
 284  * property to the given device.
 285  */
 286 int of_reserved_mem_device_init(struct device *dev)
 287 {
 288         struct reserved_mem *rmem;
 289         struct device_node *np;
 290         int ret;
 291
 292         np = of_parse_phandle(dev->of_node, "memory-region", 0);
 293         if (!np)
 294                 return -ENODEV;
 295
 296         rmem = __find_rmem(np);
 297         of_node_put(np);
 298
 299         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 300                 return -EINVAL;
 301
 302         ret = rmem->ops->device_init(rmem, dev);
 303         if (ret == 0)
 304                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 305
 306         return ret;
 307 }
 308 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
 309
 310 /**
 311  * of_reserved_mem_device_release() - release reserved memory device structures
 312  *
 313  * This function releases structures allocated for memory region handling for
 314  * the given device.
 315  */
 316 void of_reserved_mem_device_release(struct device *dev)
 317 {
 318         struct reserved_mem *rmem;
 319         struct device_node *np;
 320
 321         np = of_parse_phandle(dev->of_node, "memory-region", 0);
 322         if (!np)
 323                 return;
 324
 325         rmem = __find_rmem(np);
 326         of_node_put(np);
 327
 328         if (!rmem || !rmem->ops || !rmem->ops->device_release)
 329                 return;
 330
 331         rmem->ops->device_release(rmem, dev);
 332 }
 333 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);