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