xref: /gem5/ext/libfdt/fdt_rw.c

/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 *     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 <fdt.h>
#include <libfdt.h>

#include "libfdt_env.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 ((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);
        int err;

        FDT_RW_CHECK_HEADER(fdt);

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

        err = _fdt_splice_mem_rsv(fdt, re, 1, 0);
        if (err)
                return err;
        return 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(void *fdt, int nodeoffset, const char *name,
                const void *val, int len)
{
        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;

        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;
}