linux/drivers/of/of_reserved_mem.c
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   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    16
  29static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
  30static int reserved_mem_count;
  31
  32#if defined(CONFIG_HAVE_MEMBLOCK)
  33#include <linux/memblock.h>
  34int __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
  62int __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 */
  75void __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 */
  98static 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 %ld 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 %ld 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
 188static 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 */
 194static 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
 215static 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        return 0;
 226}
 227
 228static void __init __rmem_check_for_overlap(void)
 229{
 230        int i;
 231
 232        if (reserved_mem_count < 2)
 233                return;
 234
 235        sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 236             __rmem_cmp, NULL);
 237        for (i = 0; i < reserved_mem_count - 1; i++) {
 238                struct reserved_mem *this, *next;
 239
 240                this = &reserved_mem[i];
 241                next = &reserved_mem[i + 1];
 242                if (!(this->base && next->base))
 243                        continue;
 244                if (this->base + this->size > next->base) {
 245                        phys_addr_t this_end, next_end;
 246
 247                        this_end = this->base + this->size;
 248                        next_end = next->base + next->size;
 249                        pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 250                               this->name, &this->base, &this_end,
 251                               next->name, &next->base, &next_end);
 252                }
 253        }
 254}
 255
 256/**
 257 * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
 258 */
 259void __init fdt_init_reserved_mem(void)
 260{
 261        int i;
 262
 263        /* check for overlapping reserved regions */
 264        __rmem_check_for_overlap();
 265
 266        for (i = 0; i < reserved_mem_count; i++) {
 267                struct reserved_mem *rmem = &reserved_mem[i];
 268                unsigned long node = rmem->fdt_node;
 269                int len;
 270                const __be32 *prop;
 271                int err = 0;
 272
 273                prop = of_get_flat_dt_prop(node, "phandle", &len);
 274                if (!prop)
 275                        prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 276                if (prop)
 277                        rmem->phandle = of_read_number(prop, len/4);
 278
 279                if (rmem->size == 0)
 280                        err = __reserved_mem_alloc_size(node, rmem->name,
 281                                                 &rmem->base, &rmem->size);
 282                if (err == 0)
 283                        __reserved_mem_init_node(rmem);
 284        }
 285}
 286
 287static inline struct reserved_mem *__find_rmem(struct device_node *node)
 288{
 289        unsigned int i;
 290
 291        if (!node->phandle)
 292                return NULL;
 293
 294        for (i = 0; i < reserved_mem_count; i++)
 295                if (reserved_mem[i].phandle == node->phandle)
 296                        return &reserved_mem[i];
 297        return NULL;
 298}
 299
 300struct rmem_assigned_device {
 301        struct device *dev;
 302        struct reserved_mem *rmem;
 303        struct list_head list;
 304};
 305
 306static LIST_HEAD(of_rmem_assigned_device_list);
 307static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
 308
 309/**
 310 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 311 *                                        given device
 312 * @dev:        Pointer to the device to configure
 313 * @np:         Pointer to the device_node with 'reserved-memory' property
 314 * @idx:        Index of selected region
 315 *
 316 * This function assigns respective DMA-mapping operations based on reserved
 317 * memory region specified by 'memory-region' property in @np node to the @dev
 318 * device. When driver needs to use more than one reserved memory region, it
 319 * should allocate child devices and initialize regions by name for each of
 320 * child device.
 321 *
 322 * Returns error code or zero on success.
 323 */
 324int of_reserved_mem_device_init_by_idx(struct device *dev,
 325                                       struct device_node *np, int idx)
 326{
 327        struct rmem_assigned_device *rd;
 328        struct device_node *target;
 329        struct reserved_mem *rmem;
 330        int ret;
 331
 332        if (!np || !dev)
 333                return -EINVAL;
 334
 335        target = of_parse_phandle(np, "memory-region", idx);
 336        if (!target)
 337                return -ENODEV;
 338
 339        rmem = __find_rmem(target);
 340        of_node_put(target);
 341
 342        if (!rmem || !rmem->ops || !rmem->ops->device_init)
 343                return -EINVAL;
 344
 345        rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
 346        if (!rd)
 347                return -ENOMEM;
 348
 349        ret = rmem->ops->device_init(rmem, dev);
 350        if (ret == 0) {
 351                rd->dev = dev;
 352                rd->rmem = rmem;
 353
 354                mutex_lock(&of_rmem_assigned_device_mutex);
 355                list_add(&rd->list, &of_rmem_assigned_device_list);
 356                mutex_unlock(&of_rmem_assigned_device_mutex);
 357                /* ensure that dma_ops is set for virtual devices
 358                 * using reserved memory
 359                 */
 360                of_dma_configure(dev, np);
 361
 362                dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 363        } else {
 364                kfree(rd);
 365        }
 366
 367        return ret;
 368}
 369EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 370
 371/**
 372 * of_reserved_mem_device_release() - release reserved memory device structures
 373 * @dev:        Pointer to the device to deconfigure
 374 *
 375 * This function releases structures allocated for memory region handling for
 376 * the given device.
 377 */
 378void of_reserved_mem_device_release(struct device *dev)
 379{
 380        struct rmem_assigned_device *rd;
 381        struct reserved_mem *rmem = NULL;
 382
 383        mutex_lock(&of_rmem_assigned_device_mutex);
 384        list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
 385                if (rd->dev == dev) {
 386                        rmem = rd->rmem;
 387                        list_del(&rd->list);
 388                        kfree(rd);
 389                        break;
 390                }
 391        }
 392        mutex_unlock(&of_rmem_assigned_device_mutex);
 393
 394        if (!rmem || !rmem->ops || !rmem->ops->device_release)
 395                return;
 396
 397        rmem->ops->device_release(rmem, dev);
 398}
 399EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 400