drivers/of/of_reserved_mem.c

   1 /*
   2  * Device tree based initialization code for reserved memory.
   3  *
   4  * Copyright (c) 2013, 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
  24 #define MAX_RESERVED_REGIONS    16
  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("Reserved memory: 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("Reserved memory: invalid size property in '%s' node.\n",
 111                                 uname);
 112                 return -EINVAL;
 113         }
 114         size = dt_mem_next_cell(dt_root_size_cells, &prop);
 115
 116         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 117
 118         prop = of_get_flat_dt_prop(node, "alignment", &len);
 119         if (prop) {
 120                 if (len != dt_root_addr_cells * sizeof(__be32)) {
 121                         pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
 122                                 uname);
 123                         return -EINVAL;
 124                 }
 125                 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
 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("Reserved memory: 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("Reserved memory: 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("Reserved memory: 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("Reserved memory: failed to allocate memory for node '%s'\n",
 165                         uname);
 166                 return -ENOMEM;
 167         }
 168
 169         *res_base = base;
 170         *res_size = size;
 171
 172         return 0;
 173 }
 174
 175 static const struct of_device_id __rmem_of_table_sentinel
 176         __used __section(__reservedmem_of_table_end);
 177
 178 /**
 179  * res_mem_init_node() - call region specific reserved memory init code
 180  */
 181 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
 182 {
 183         extern const struct of_device_id __reservedmem_of_table[];
 184         const struct of_device_id *i;
 185
 186         for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
 187                 reservedmem_of_init_fn initfn = i->data;
 188                 const char *compat = i->compatible;
 189
 190                 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
 191                         continue;
 192
 193                 if (initfn(rmem) == 0) {
 194                         pr_info("Reserved memory: initialized node %s, compatible id %s\n",
 195                                 rmem->name, compat);
 196                         return 0;
 197                 }
 198         }
 199         return -ENOENT;
 200 }
 201
 202 /**
 203  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
 204  */
 205 void __init fdt_init_reserved_mem(void)
 206 {
 207         int i;
 208         for (i = 0; i < reserved_mem_count; i++) {
 209                 struct reserved_mem *rmem = &reserved_mem[i];
 210                 unsigned long node = rmem->fdt_node;
 211                 int len;
 212                 const __be32 *prop;
 213                 int err = 0;
 214
 215                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 216                 if (!prop)
 217                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 218                 if (prop)
 219                         rmem->phandle = of_read_number(prop, len/4);
 220
 221                 if (rmem->size == 0)
 222                         err = __reserved_mem_alloc_size(node, rmem->name,
 223                                                  &rmem->base, &rmem->size);
 224                 if (err == 0)
 225                         __reserved_mem_init_node(rmem);
 226         }
 227 }
 228
 229 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 230 {
 231         unsigned int i;
 232
 233         if (!node->phandle)
 234                 return NULL;
 235
 236         for (i = 0; i < reserved_mem_count; i++)
 237                 if (reserved_mem[i].phandle == node->phandle)
 238                         return &reserved_mem[i];
 239         return NULL;
 240 }
 241
 242 /**
 243  * of_reserved_mem_device_init() - assign reserved memory region to given device
 244  *
 245  * This function assign memory region pointed by "memory-region" device tree
 246  * property to the given device.
 247  */
 248 int of_reserved_mem_device_init(struct device *dev)
 249 {
 250         struct reserved_mem *rmem;
 251         struct device_node *np;
 252         int ret;
 253
 254         np = of_parse_phandle(dev->of_node, "memory-region", 0);
 255         if (!np)
 256                 return -ENODEV;
 257
 258         rmem = __find_rmem(np);
 259         of_node_put(np);
 260
 261         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 262                 return -EINVAL;
 263
 264         ret = rmem->ops->device_init(rmem, dev);
 265         if (ret == 0)
 266                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 267
 268         return ret;
 269 }
 270 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
 271
 272 /**
 273  * of_reserved_mem_device_release() - release reserved memory device structures
 274  *
 275  * This function releases structures allocated for memory region handling for
 276  * the given device.
 277  */
 278 void of_reserved_mem_device_release(struct device *dev)
 279 {
 280         struct reserved_mem *rmem;
 281         struct device_node *np;
 282
 283         np = of_parse_phandle(dev->of_node, "memory-region", 0);
 284         if (!np)
 285                 return;
 286
 287         rmem = __find_rmem(np);
 288         of_node_put(np);
 289
 290         if (!rmem || !rmem->ops || !rmem->ops->device_release)
 291                 return;
 292
 293         rmem->ops->device_release(rmem, dev);
 294 }
 295 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);