system76-edk2/EmbeddedPkg/Library/FdtLib/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
_fdt_blocks_misordered (
  const void  *fdt,
  int         mem_rsv_size,
  int         struct_size
  )
{
  return (fdt_off_mem_rsvmap (fdt) < 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
_fdt_rw_check_header (
  void  *fdt
  )
{
  FDT_CHECK_HEADER (fdt);

  if (fdt_version (fdt) < 17) {
    return -FDT_ERR_BADVERSION;
  }

  if (_fdt_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 FDT_RW_CHECK_HEADER(fdt) \
        { \
                int __err; \
                if ((__err = _fdt_rw_check_header(fdt)) != 0) \
                        return __err; \
        }

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

static int
_fdt_splice (
  void  *fdt,
  void  *splicepoint,
  int   oldlen,
  int   newlen
  )
{
  char  *p   = splicepoint;
  char  *end = (char *)fdt + _fdt_data_size (fdt);

  if (((p + oldlen) < p) || ((p + oldlen) > end)) {
    return -FDT_ERR_BADOFFSET;
  }

  if ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt)) {
    return -FDT_ERR_BADOFFSET;
  }

  if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize (fdt))) {
    return -FDT_ERR_NOSPACE;
  }

  memmove (p + newlen, p + oldlen, end - p - oldlen);
  return 0;
}

static int
_fdt_splice_mem_rsv (
  void                      *fdt,
  struct fdt_reserve_entry  *p,
  int                       oldn,
  int                       newn
  )
{
  int  delta = (newn - oldn) * sizeof (*p);
  int  err;

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

  if ((err = _fdt_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
_fdt_splice_string (
  void  *fdt,
  int   newlen
  )
{
  void  *p = (char *)fdt
             + fdt_off_dt_strings (fdt) + fdt_size_dt_strings (fdt);
  int  err;

  if ((err = _fdt_splice (fdt, p, 0, newlen))) {
    return err;
  }

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

static int
_fdt_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 = _fdt_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;

  FDT_RW_CHECK_HEADER (fdt);

  re  = _fdt_mem_rsv_w (fdt, fdt_num_mem_rsv (fdt));
  err = _fdt_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);

  FDT_RW_CHECK_HEADER (fdt);

  if (n >= fdt_num_mem_rsv (fdt)) {
    return -FDT_ERR_NOTFOUND;
  }

  return _fdt_splice_mem_rsv (fdt, re, 1, 0);
}

static int
_fdt_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 = _fdt_splice_struct (
               fdt,
               (*prop)->data,
               FDT_TAGALIGN (oldlen),
               FDT_TAGALIGN (len)
               )))
  {
    return err;
  }

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

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

  if ((nextoffset = _fdt_check_node_offset (fdt, nodeoffset)) < 0) {
    return nextoffset;
  }

  namestroff = _fdt_find_add_string (fdt, name);
  if (namestroff < 0) {
    return namestroff;
  }

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

  err = _fdt_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_set_name (
  void        *fdt,
  int         nodeoffset,
  const char  *name
  )
{
  char  *namep;
  int   oldlen, newlen;
  int   err;

  FDT_RW_CHECK_HEADER (fdt);

  namep = (char *)(uintptr_t)fdt_get_name (fdt, nodeoffset, &oldlen);
  if (!namep) {
    return oldlen;
  }

  newlen = strlen (name);

  err = _fdt_splice_struct (
          fdt,
          namep,
          FDT_TAGALIGN (oldlen+1),
          FDT_TAGALIGN (newlen+1)
          );
  if (err) {
    return err;
  }

  memcpy (namep, name, newlen+1);
  return 0;
}

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

  FDT_RW_CHECK_HEADER (fdt);

  err = _fdt_resize_property (fdt, nodeoffset, name, len, &prop);
  if (err == -FDT_ERR_NOTFOUND) {
    err = _fdt_add_property (fdt, nodeoffset, name, len, &prop);
  }

  if (err) {
    return err;
  }

  *prop_data = prop->data;
  return 0;
}

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

  err = fdt_setprop_placeholder (fdt, nodeoffset, name, len, &prop_data);
  if (err) {
    return err;
  }

  if (len) {
    memcpy (prop_data, val, len);
  }

  return 0;
}

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

  FDT_RW_CHECK_HEADER (fdt);

  prop = fdt_get_property_w (fdt, nodeoffset, name, &oldlen);
  if (prop) {
    newlen = len + oldlen;
    err    = _fdt_splice_struct (
               fdt,
               prop->data,
               FDT_TAGALIGN (oldlen),
               FDT_TAGALIGN (newlen)
               );
    if (err) {
      return err;
    }

    prop->len = cpu_to_fdt32 (newlen);
    memcpy (prop->data + oldlen, val, len);
  } else {
    err = _fdt_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;

  FDT_RW_CHECK_HEADER (fdt);

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

  proplen = sizeof (*prop) + FDT_TAGALIGN (len);
  return _fdt_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;
  fdt32_t                 *endtag;

  FDT_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) || (tag == FDT_NOP));

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

  err = _fdt_splice_struct (fdt, nh, 0, nodelen);
  if (err) {
    return err;
  }

  nh->tag = cpu_to_fdt32 (FDT_BEGIN_NODE);
  memset (nh->name, 0, FDT_TAGALIGN (namelen+1));
  memcpy (nh->name, name, namelen);
  endtag  = (fdt32_t *)((char *)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;

  FDT_RW_CHECK_HEADER (fdt);

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

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

static void
_fdt_packblocks (
  const char  *old,
  char        *new,
  int         mem_rsv_size,
  int         struct_size
  )
{
  int  mem_rsv_off, struct_off, strings_off;

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

  memmove (new + mem_rsv_off, old + fdt_off_mem_rsvmap (old), mem_rsv_size);
  fdt_set_off_mem_rsvmap (new, mem_rsv_off);

  memmove (new + struct_off, old + fdt_off_dt_struct (old), struct_size);
  fdt_set_off_dt_struct (new, struct_off);
  fdt_set_size_dt_struct (new, struct_size);

  memmove (
    new + strings_off,
    old + fdt_off_dt_strings (old),
    fdt_size_dt_strings (old)
    );
  fdt_set_off_dt_strings (new, strings_off);
  fdt_set_size_dt_strings (new, fdt_size_dt_strings (old));
}

int
fdt_open_into (
  const void  *fdt,
  void        *buf,
  int         bufsize
  )
{
  int         err;
  int         mem_rsv_size, struct_size;
  int         newsize;
  const char  *fdtstart = fdt;
  const char  *fdtend   = fdtstart + fdt_totalsize (fdt);
  char        *tmp;

  FDT_CHECK_HEADER (fdt);

  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 (struct_size < 0) {
      return struct_size;
    }
  }

  if (!_fdt_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 = FDT_ALIGN (sizeof (struct fdt_header), 8) + mem_rsv_size
            + struct_size + fdt_size_dt_strings (fdt);

  if (bufsize < newsize) {
    return -FDT_ERR_NOSPACE;
  }

  /* First attempt to build converted tree at beginning of buffer */
  tmp = buf;
  /* But if that overlaps with the old tree... */
  if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
    /* Try right after the old tree instead */
    tmp = (char *)(uintptr_t)fdtend;
    if ((tmp + newsize) > ((char *)buf + bufsize)) {
      return -FDT_ERR_NOSPACE;
    }
  }

  _fdt_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;

  FDT_RW_CHECK_HEADER (fdt);

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

  return 0;
}