/*
 * 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_sw_probe_(void* fdt)
{
    if (fdt_magic(fdt) == FDT_MAGIC)
        return -FDT_ERR_BADSTATE;
    else if (fdt_magic(fdt) != FDT_SW_MAGIC)
        return -FDT_ERR_BADMAGIC;
    return 0;
}

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

/* 'memrsv' state:	Initial state after fdt_create()
 *
 * Allowed functions:
 *	fdt_add_reservmap_entry()
 *	fdt_finish_reservemap()		[moves to 'struct' state]
 */
static int fdt_sw_probe_memrsv_(void* fdt)
{
    int err = fdt_sw_probe_(fdt);
    if (err) return err;

    if (fdt_off_dt_strings(fdt) != 0) return -FDT_ERR_BADSTATE;
    return 0;
}

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

/* 'struct' state:	Enter this state after fdt_finish_reservemap()
 *
 * Allowed functions:
 *	fdt_begin_node()
 *	fdt_end_node()
 *	fdt_property*()
 *	fdt_finish()			[moves to 'complete' state]
 */
static int fdt_sw_probe_struct_(void* fdt)
{
    int err = fdt_sw_probe_(fdt);
    if (err) return err;

    if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt)) return -FDT_ERR_BADSTATE;
    return 0;
}

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

/* 'complete' state:	Enter this state after fdt_finish()
 *
 * Allowed functions: none
 */

static void* fdt_grab_space_(void* fdt, size_t len)
{
    int offset = fdt_size_dt_struct(fdt);
    int spaceleft;

    spaceleft =
        fdt_totalsize(fdt) - fdt_off_dt_struct(fdt) - fdt_size_dt_strings(fdt);

    if ((offset + len < offset) || (offset + len > spaceleft)) return NULL;

    fdt_set_size_dt_struct(fdt, offset + len);
    return fdt_offset_ptr_w_(fdt, offset);
}

int fdt_create(void* buf, int bufsize)
{
    const size_t hdrsize =
        FDT_ALIGN(sizeof(struct fdt_header), sizeof(struct fdt_reserve_entry));
    void* fdt = buf;

    if (bufsize < hdrsize) return -FDT_ERR_NOSPACE;

    memset(buf, 0, bufsize);

    fdt_set_magic(fdt, FDT_SW_MAGIC);
    fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
    fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
    fdt_set_totalsize(fdt, bufsize);

    fdt_set_off_mem_rsvmap(fdt, hdrsize);
    fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
    fdt_set_off_dt_strings(fdt, 0);

    return 0;
}

int fdt_resize(void* fdt, void* buf, int bufsize)
{
    size_t headsize, tailsize;
    char *oldtail, *newtail;

    FDT_SW_PROBE(fdt);

    headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
    tailsize = fdt_size_dt_strings(fdt);

    if ((headsize + tailsize) > fdt_totalsize(fdt)) return -FDT_ERR_INTERNAL;

    if ((headsize + tailsize) > bufsize) return -FDT_ERR_NOSPACE;

    oldtail = (char*)fdt + fdt_totalsize(fdt) - tailsize;
    newtail = (char*)buf + bufsize - tailsize;

    /* Two cases to avoid clobbering data if the old and new
     * buffers partially overlap */
    if (buf <= fdt) {
        memmove(buf, fdt, headsize);
        memmove(newtail, oldtail, tailsize);
    } else {
        memmove(newtail, oldtail, tailsize);
        memmove(buf, fdt, headsize);
    }

    fdt_set_totalsize(buf, bufsize);
    if (fdt_off_dt_strings(buf)) fdt_set_off_dt_strings(buf, bufsize);

    return 0;
}

int fdt_add_reservemap_entry(void* fdt, uint64_t addr, uint64_t size)
{
    struct fdt_reserve_entry* re;
    int offset;

    FDT_SW_PROBE_MEMRSV(fdt);

    offset = fdt_off_dt_struct(fdt);
    if ((offset + sizeof(*re)) > fdt_totalsize(fdt)) return -FDT_ERR_NOSPACE;

    re = (struct fdt_reserve_entry*)((char*)fdt + offset);
    re->address = cpu_to_fdt64(addr);
    re->size = cpu_to_fdt64(size);

    fdt_set_off_dt_struct(fdt, offset + sizeof(*re));

    return 0;
}

int fdt_finish_reservemap(void* fdt)
{
    int err = fdt_add_reservemap_entry(fdt, 0, 0);

    if (err) return err;

    fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt));
    return 0;
}

int fdt_begin_node(void* fdt, const char* name)
{
    struct fdt_node_header* nh;
    int namelen;

    FDT_SW_PROBE_STRUCT(fdt);

    namelen = strlen(name) + 1;
    nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
    if (!nh) return -FDT_ERR_NOSPACE;

    nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
    memcpy(nh->name, name, namelen);
    return 0;
}

int fdt_end_node(void* fdt)
{
    fdt32_t* en;

    FDT_SW_PROBE_STRUCT(fdt);

    en = fdt_grab_space_(fdt, FDT_TAGSIZE);
    if (!en) return -FDT_ERR_NOSPACE;

    *en = cpu_to_fdt32(FDT_END_NODE);
    return 0;
}

static int fdt_find_add_string_(void* fdt, const char* s)
{
    char* strtab = (char*)fdt + fdt_totalsize(fdt);
    const char* p;
    int strtabsize = fdt_size_dt_strings(fdt);
    int len = strlen(s) + 1;
    int struct_top, offset;

    p = fdt_find_string_(strtab - strtabsize, strtabsize, s);
    if (p) return p - strtab;

    /* Add it */
    offset = -strtabsize - len;
    struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
    if (fdt_totalsize(fdt) + offset < struct_top)
        return 0; /* no more room :( */

    memcpy(strtab + offset, s, len);
    fdt_set_size_dt_strings(fdt, strtabsize + len);
    return offset;
}

int fdt_property_placeholder(void* fdt, const char* name, int len, void** valp)
{
    struct fdt_property* prop;
    int nameoff;

    FDT_SW_PROBE_STRUCT(fdt);

    nameoff = fdt_find_add_string_(fdt, name);
    if (nameoff == 0) return -FDT_ERR_NOSPACE;

    prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
    if (!prop) return -FDT_ERR_NOSPACE;

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

int fdt_property(void* fdt, const char* name, const void* val, int len)
{
    void* ptr;
    int ret;

    ret = fdt_property_placeholder(fdt, name, len, &ptr);
    if (ret) return ret;
    memcpy(ptr, val, len);
    return 0;
}

int fdt_finish(void* fdt)
{
    char* p = (char*)fdt;
    fdt32_t* end;
    int oldstroffset, newstroffset;
    uint32_t tag;
    int offset, nextoffset;

    FDT_SW_PROBE_STRUCT(fdt);

    /* Add terminator */
    end = fdt_grab_space_(fdt, sizeof(*end));
    if (!end) return -FDT_ERR_NOSPACE;
    *end = cpu_to_fdt32(FDT_END);

    /* Relocate the string table */
    oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
    newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
    memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
    fdt_set_off_dt_strings(fdt, newstroffset);

    /* Walk the structure, correcting string offsets */
    offset = 0;
    while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
        if (tag == FDT_PROP) {
            struct fdt_property* prop = fdt_offset_ptr_w_(fdt, offset);
            int nameoff;

            nameoff = fdt32_to_cpu(prop->nameoff);
            nameoff += fdt_size_dt_strings(fdt);
            prop->nameoff = cpu_to_fdt32(nameoff);
        }
        offset = nextoffset;
    }
    if (nextoffset < 0) return nextoffset;

    /* Finally, adjust the header */
    fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
    fdt_set_magic(fdt, FDT_MAGIC);
    return 0;
}
