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         /*
  35          * We use __memblock_alloc_base() because memblock_alloc_base()
  36          * panic()s on allocation failure.
  37          */
  38         phys_addr_t base = __memblock_alloc_base(size, align, end);
  39         if (!base)
  40                 return -ENOMEM;
  41
  42         /*
  43          * Check if the allocated region fits in to start..end window
  44          */
  45         if (base < start) {
  46                 memblock_free(base, size);
  47                 return -ENOMEM;
  48         }
  49
  50         *res_base = base;
  51         if (nomap)
  52                 return memblock_remove(base, size);
  53         return 0;
  54 }
  55 #else
  56 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  57         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  58         phys_addr_t *res_base)
  59 {
  60         pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
  61                   size, nomap ? " (nomap)" : "");
  62         return -ENOSYS;
  63 }
  64 #endif
  65
  66 /**
  67  * res_mem_save_node() - save fdt node for second pass initialization
  68  */
  69 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
  70                                       phys_addr_t base, phys_addr_t size)
  71 {
  72         struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
  73
  74         if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
  75                 pr_err("Reserved memory: not enough space all defined regions.\n");
  76                 return;
  77         }
  78
  79         rmem->fdt_node = node;
  80         rmem->name = uname;
  81         rmem->base = base;
  82         rmem->size = size;
  83
  84         reserved_mem_count++;
  85         return;
  86 }
  87
  88 /**
  89  * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
  90  *                        and 'alloc-ranges' properties
  91  */
  92 static int __init __reserved_mem_alloc_size(unsigned long node,
  93         const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
  94 {
  95         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
  96         phys_addr_t start = 0, end = 0;
  97         phys_addr_t base = 0, align = 0, size;
  98         int len;
  99         const __be32 *prop;
 100         int nomap;
 101         int ret;
 102
 103         prop = of_get_flat_dt_prop(node, "size", &len);
 104         if (!prop)
 105                 return -EINVAL;
 106
 107         if (len != dt_root_size_cells * sizeof(__be32)) {
 108                 pr_err("Reserved memory: invalid size property in '%s' node.\n",
 109                                 uname);
 110                 return -EINVAL;
 111         }
 112         size = dt_mem_next_cell(dt_root_size_cells, &prop);
 113
 114         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 115
 116         prop = of_get_flat_dt_prop(node, "alignment", &len);
 117         if (prop) {
 118                 if (len != dt_root_addr_cells * sizeof(__be32)) {
 119                         pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
 120                                 uname);
 121                         return -EINVAL;
 122                 }
 123                 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
 124         }
 125
 126         prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 127         if (prop) {
 128
 129                 if (len % t_len != 0) {
 130                         pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
 131                                uname);
 132                         return -EINVAL;
 133                 }
 134
 135                 base = 0;
 136
 137                 while (len > 0) {
 138                         start = dt_mem_next_cell(dt_root_addr_cells, &prop);
 139                         end = start + dt_mem_next_cell(dt_root_size_cells,
 140                                                        &prop);
 141
 142                         ret = early_init_dt_alloc_reserved_memory_arch(size,
 143                                         align, start, end, nomap, &base);
 144                         if (ret == 0) {
 145                                 pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
 146                                         uname, &base,
 147                                         (unsigned long)size / SZ_1M);
 148                                 break;
 149                         }
 150                         len -= t_len;
 151                 }
 152
 153         } else {
 154                 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
 155                                                         0, 0, nomap, &base);
 156                 if (ret == 0)
 157                         pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
 158                                 uname, &base, (unsigned long)size / SZ_1M);
 159         }
 160
 161         if (base == 0) {
 162                 pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
 163                         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("Reserved memory: initialized node %s, compatible id %s\n",
 193                                 rmem->name, compat);
 194                         return 0;
 195                 }
 196         }
 197         return -ENOENT;
 198 }
 199
 200 /**
 201  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
 202  */
 203 void __init fdt_init_reserved_mem(void)
 204 {
 205         int i;
 206         for (i = 0; i < reserved_mem_count; i++) {
 207                 struct reserved_mem *rmem = &reserved_mem[i];
 208                 unsigned long node = rmem->fdt_node;
 209                 int err = 0;
 210
 211                 if (rmem->size == 0)
 212                         err = __reserved_mem_alloc_size(node, rmem->name,
 213                                                  &rmem->base, &rmem->size);
 214                 if (err == 0)
 215                         __reserved_mem_init_node(rmem);
 216         }
 217 }