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fdt_rw.c

/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 * libfdt is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 *
 *  a) This library is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of the
 *     License, or (at your option) any later version.
 *
 *     This library is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public
 *     License along with this library; if not, write to the Free
 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *     MA 02110-1301 USA
 *
 * Alternatively,
 *
 *  b) Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *     1. Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *     2. Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "libfdt_env.h"

#include <fdt.h>
#include <libfdt.h>

#include "libfdt_internal.h"

static int _blocks_misordered(const void *fdt,
                        int mem_rsv_size, int struct_size)
{
      return (fdt_off_mem_rsvmap(fdt) < ALIGN(sizeof(struct fdt_header), 8))
            || (fdt_off_dt_struct(fdt) <
                (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
            || (fdt_off_dt_strings(fdt) <
                (fdt_off_dt_struct(fdt) + struct_size))
            || (fdt_totalsize(fdt) <
                (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
}

static int rw_check_header(void *fdt)
{
      int err;

      if ((err = fdt_check_header(fdt)))
            return err;
      if (fdt_version(fdt) < 17)
            return -FDT_ERR_BADVERSION;
      if (_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
                         fdt_size_dt_struct(fdt)))
            return -FDT_ERR_BADLAYOUT;
      if (fdt_version(fdt) > 17)
            fdt_set_version(fdt, 17);

      return 0;
}

#define RW_CHECK_HEADER(fdt) \
      { \
            int err; \
            if ((err = rw_check_header(fdt)) != 0) \
                  return err; \
      }

static inline int _blob_data_size(void *fdt)
{
      return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
}

static int _blob_splice(void *fdt, void *p, int oldlen, int newlen)
{
      void *end = fdt + _blob_data_size(fdt);

      if (((p + oldlen) < p) || ((p + oldlen) > end))
            return -FDT_ERR_BADOFFSET;
      if ((end - oldlen + newlen) > (fdt + fdt_totalsize(fdt)))
            return -FDT_ERR_NOSPACE;
      memmove(p + newlen, p + oldlen, end - p - oldlen);
      return 0;
}

static int _blob_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
                        int oldn, int newn)
{
      int delta = (newn - oldn) * sizeof(*p);
      int err;
      err = _blob_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
      if (err)
            return err;
      fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
      fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
      return 0;
}

static int _blob_splice_struct(void *fdt, void *p,
                         int oldlen, int newlen)
{
      int delta = newlen - oldlen;
      int err;

      if ((err = _blob_splice(fdt, p, oldlen, newlen)))
            return err;

      fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
      fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
      return 0;
}

static int _blob_splice_string(void *fdt, int newlen)
{
      void *p = fdt + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
      int err;

      if ((err = _blob_splice(fdt, p, 0, newlen)))
            return err;

      fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
      return 0;
}

static int _find_add_string(void *fdt, const char *s)
{
      char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
      const char *p;
      char *new;
      int len = strlen(s) + 1;
      int err;

      p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
      if (p)
            /* found it */
            return (p - strtab);

      new = strtab + fdt_size_dt_strings(fdt);
      err = _blob_splice_string(fdt, len);
      if (err)
            return err;

      memcpy(new, s, len);
      return (new - strtab);
}

int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
{
      struct fdt_reserve_entry *re;
      int err;

      if ((err = rw_check_header(fdt)))
            return err;

      re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
      err = _blob_splice_mem_rsv(fdt, re, 0, 1);
      if (err)
            return err;

      re->address = cpu_to_fdt64(address);
      re->size = cpu_to_fdt64(size);
      return 0;
}

int fdt_del_mem_rsv(void *fdt, int n)
{
      struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
      int err;

      if ((err = rw_check_header(fdt)))
            return err;
      if (n >= fdt_num_mem_rsv(fdt))
            return -FDT_ERR_NOTFOUND;

      err = _blob_splice_mem_rsv(fdt, re, 1, 0);
      if (err)
            return err;
      return 0;
}

static int _resize_property(void *fdt, int nodeoffset, const char *name, int len,
                      struct fdt_property **prop)
{
      int oldlen;
      int err;

      *prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
      if (! (*prop))
            return oldlen;

      if ((err = _blob_splice_struct(fdt, (*prop)->data,
                               ALIGN(oldlen, FDT_TAGSIZE),
                               ALIGN(len, FDT_TAGSIZE))))
            return err;

      (*prop)->len = cpu_to_fdt32(len);
      return 0;
}

static int _add_property(void *fdt, int nodeoffset, const char *name, int len,
                   struct fdt_property **prop)
{
      uint32_t tag;
      int proplen;
      int nextoffset;
      int namestroff;
      int err;

      tag = fdt_next_tag(fdt, nodeoffset, &nextoffset);
      if (tag != FDT_BEGIN_NODE)
            return -FDT_ERR_BADOFFSET;

      namestroff = _find_add_string(fdt, name);
      if (namestroff < 0)
            return namestroff;

      *prop = _fdt_offset_ptr_w(fdt, nextoffset);
      proplen = sizeof(**prop) + ALIGN(len, FDT_TAGSIZE);

      err = _blob_splice_struct(fdt, *prop, 0, proplen);
      if (err)
            return err;

      (*prop)->tag = cpu_to_fdt32(FDT_PROP);
      (*prop)->nameoff = cpu_to_fdt32(namestroff);
      (*prop)->len = cpu_to_fdt32(len);
      return 0;
}

int fdt_setprop(void *fdt, int nodeoffset, const char *name,
            const void *val, int len)
{
      struct fdt_property *prop;
      int err;

      if ((err = rw_check_header(fdt)))
            return err;

      err = _resize_property(fdt, nodeoffset, name, len, &prop);
      if (err == -FDT_ERR_NOTFOUND)
            err = _add_property(fdt, nodeoffset, name, len, &prop);
      if (err)
            return err;

      memcpy(prop->data, val, len);
      return 0;
}

int fdt_delprop(void *fdt, int nodeoffset, const char *name)
{
      struct fdt_property *prop;
      int len, proplen;

      RW_CHECK_HEADER(fdt);

      prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
      if (! prop)
            return len;

      proplen = sizeof(*prop) + ALIGN(len, FDT_TAGSIZE);
      return _blob_splice_struct(fdt, prop, proplen, 0);
}

int fdt_add_subnode_namelen(void *fdt, int parentoffset,
                      const char *name, int namelen)
{
      struct fdt_node_header *nh;
      int offset, nextoffset;
      int nodelen;
      int err;
      uint32_t tag;
      uint32_t *endtag;

      RW_CHECK_HEADER(fdt);

      offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
      if (offset >= 0)
            return -FDT_ERR_EXISTS;
      else if (offset != -FDT_ERR_NOTFOUND)
            return offset;

      /* Try to place the new node after the parent's properties */
      fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
      do {
            offset = nextoffset;
            tag = fdt_next_tag(fdt, offset, &nextoffset);
      } while (tag == FDT_PROP);

      nh = _fdt_offset_ptr_w(fdt, offset);
      nodelen = sizeof(*nh) + ALIGN(namelen+1, FDT_TAGSIZE) + FDT_TAGSIZE;

      err = _blob_splice_struct(fdt, nh, 0, nodelen);
      if (err)
            return err;

      nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
      memset(nh->name, 0, ALIGN(namelen+1, FDT_TAGSIZE));
      memcpy(nh->name, name, namelen);
      endtag = (uint32_t *)((void *)nh + nodelen - FDT_TAGSIZE);
      *endtag = cpu_to_fdt32(FDT_END_NODE);

      return offset;
}

int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
{
      return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
}

int fdt_del_node(void *fdt, int nodeoffset)
{
      int endoffset;

      RW_CHECK_HEADER(fdt);

      endoffset = _fdt_node_end_offset(fdt, nodeoffset);
      if (endoffset < 0)
            return endoffset;

      return _blob_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
                           endoffset - nodeoffset, 0);
}

static void _packblocks(const void *fdt, void *buf,
                   int mem_rsv_size, int struct_size)
{
      int mem_rsv_off, struct_off, strings_off;

      mem_rsv_off = ALIGN(sizeof(struct fdt_header), 8);
      struct_off = mem_rsv_off + mem_rsv_size;
      strings_off = struct_off + struct_size;

      memmove(buf + mem_rsv_off, fdt + fdt_off_mem_rsvmap(fdt), mem_rsv_size);
      fdt_set_off_mem_rsvmap(buf, mem_rsv_off);

      memmove(buf + struct_off, fdt + fdt_off_dt_struct(fdt), struct_size);
      fdt_set_off_dt_struct(buf, struct_off);
      fdt_set_size_dt_struct(buf, struct_size);

      memmove(buf + strings_off, fdt + fdt_off_dt_strings(fdt),
            fdt_size_dt_strings(fdt));
      fdt_set_off_dt_strings(buf, strings_off);
      fdt_set_size_dt_strings(buf, fdt_size_dt_strings(fdt));
}

int fdt_open_into(const void *fdt, void *buf, int bufsize)
{
      int err;
      int mem_rsv_size, struct_size;
      int newsize;
      void *tmp;

      err = fdt_check_header(fdt);
      if (err)
            return err;

      mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
            * sizeof(struct fdt_reserve_entry);

      if (fdt_version(fdt) >= 17) {
            struct_size = fdt_size_dt_struct(fdt);
      } else {
            struct_size = 0;
            while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
                  ;
      }

      if (!_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
            /* no further work necessary */
            err = fdt_move(fdt, buf, bufsize);
            if (err)
                  return err;
            fdt_set_version(buf, 17);
            fdt_set_size_dt_struct(buf, struct_size);
            fdt_set_totalsize(buf, bufsize);
            return 0;
      }

      /* Need to reorder */
      newsize = ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
            + struct_size + fdt_size_dt_strings(fdt);

      if (bufsize < newsize)
            return -FDT_ERR_NOSPACE;

      if (((buf + newsize) <= fdt)
          || (buf >= (fdt + fdt_totalsize(fdt)))) {
            tmp = buf;
      } else {
            tmp = (void *)fdt + fdt_totalsize(fdt);
            if ((tmp + newsize) > (buf + bufsize))
                  return -FDT_ERR_NOSPACE;
      }

      _packblocks(fdt, tmp, mem_rsv_size, struct_size);
      memmove(buf, tmp, newsize);

      fdt_set_magic(buf, FDT_MAGIC);
      fdt_set_totalsize(buf, bufsize);
      fdt_set_version(buf, 17);
      fdt_set_last_comp_version(buf, 16);
      fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));

      return 0;
}

int fdt_pack(void *fdt)
{
      int mem_rsv_size;
      int err;

      err = rw_check_header(fdt);
      if (err)
            return err;

      mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
            * sizeof(struct fdt_reserve_entry);
      _packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
      fdt_set_totalsize(fdt, _blob_data_size(fdt));

      return 0;
}

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