aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/boot/flatdevtree.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/boot/flatdevtree.c')
-rw-r--r--arch/powerpc/boot/flatdevtree.c880
1 files changed, 880 insertions, 0 deletions
diff --git a/arch/powerpc/boot/flatdevtree.c b/arch/powerpc/boot/flatdevtree.c
new file mode 100644
index 00000000000..c76c194715b
--- /dev/null
+++ b/arch/powerpc/boot/flatdevtree.c
@@ -0,0 +1,880 @@
+/*
+ * This program 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 program 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 program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright Pantelis Antoniou 2006
+ * Copyright (C) IBM Corporation 2006
+ *
+ * Authors: Pantelis Antoniou <pantelis@embeddedalley.com>
+ * Hollis Blanchard <hollisb@us.ibm.com>
+ * Mark A. Greer <mgreer@mvista.com>
+ * Paul Mackerras <paulus@samba.org>
+ */
+
+#include <string.h>
+#include <stddef.h>
+#include "flatdevtree.h"
+#include "flatdevtree_env.h"
+
+#define _ALIGN(x, al) (((x) + (al) - 1) & ~((al) - 1))
+
+/* Routines for keeping node ptrs returned by ft_find_device current */
+/* First entry not used b/c it would return 0 and be taken as NULL/error */
+static void *ft_node_add(struct ft_cxt *cxt, char *node)
+{
+ unsigned int i;
+
+ for (i = 1; i < cxt->nodes_used; i++) /* already there? */
+ if (cxt->node_tbl[i] == node)
+ return (void *)i;
+
+ if (cxt->nodes_used < cxt->node_max) {
+ cxt->node_tbl[cxt->nodes_used] = node;
+ return (void *)cxt->nodes_used++;
+ }
+
+ return NULL;
+}
+
+static char *ft_node_ph2node(struct ft_cxt *cxt, const void *phandle)
+{
+ unsigned int i = (unsigned int)phandle;
+
+ if (i < cxt->nodes_used)
+ return cxt->node_tbl[i];
+ return NULL;
+}
+
+static void ft_node_update_before(struct ft_cxt *cxt, char *addr, int shift)
+{
+ unsigned int i;
+
+ if (shift == 0)
+ return;
+
+ for (i = 1; i < cxt->nodes_used; i++)
+ if (cxt->node_tbl[i] < addr)
+ cxt->node_tbl[i] += shift;
+}
+
+static void ft_node_update_after(struct ft_cxt *cxt, char *addr, int shift)
+{
+ unsigned int i;
+
+ if (shift == 0)
+ return;
+
+ for (i = 1; i < cxt->nodes_used; i++)
+ if (cxt->node_tbl[i] >= addr)
+ cxt->node_tbl[i] += shift;
+}
+
+/* Struct used to return info from ft_next() */
+struct ft_atom {
+ u32 tag;
+ const char *name;
+ void *data;
+ u32 size;
+};
+
+/* Set ptrs to current one's info; return addr of next one */
+static char *ft_next(struct ft_cxt *cxt, char *p, struct ft_atom *ret)
+{
+ u32 sz;
+
+ if (p >= cxt->rgn[FT_STRUCT].start + cxt->rgn[FT_STRUCT].size)
+ return NULL;
+
+ ret->tag = be32_to_cpu(*(u32 *) p);
+ p += 4;
+
+ switch (ret->tag) { /* Tag */
+ case OF_DT_BEGIN_NODE:
+ ret->name = p;
+ ret->data = (void *)(p - 4); /* start of node */
+ p += _ALIGN(strlen(p) + 1, 4);
+ break;
+ case OF_DT_PROP:
+ ret->size = sz = be32_to_cpu(*(u32 *) p);
+ ret->name = cxt->str_anchor + be32_to_cpu(*(u32 *) (p + 4));
+ ret->data = (void *)(p + 8);
+ p += 8 + _ALIGN(sz, 4);
+ break;
+ case OF_DT_END_NODE:
+ case OF_DT_NOP:
+ break;
+ case OF_DT_END:
+ default:
+ p = NULL;
+ break;
+ }
+
+ return p;
+}
+
+#define HDR_SIZE _ALIGN(sizeof(struct boot_param_header), 8)
+#define EXPAND_INCR 1024 /* alloc this much extra when expanding */
+
+/* See if the regions are in the standard order and non-overlapping */
+static int ft_ordered(struct ft_cxt *cxt)
+{
+ char *p = (char *)cxt->bph + HDR_SIZE;
+ enum ft_rgn_id r;
+
+ for (r = FT_RSVMAP; r <= FT_STRINGS; ++r) {
+ if (p > cxt->rgn[r].start)
+ return 0;
+ p = cxt->rgn[r].start + cxt->rgn[r].size;
+ }
+ return p <= (char *)cxt->bph + cxt->max_size;
+}
+
+/* Copy the tree to a newly-allocated region and put things in order */
+static int ft_reorder(struct ft_cxt *cxt, int nextra)
+{
+ unsigned long tot;
+ enum ft_rgn_id r;
+ char *p, *pend;
+ int stroff;
+
+ tot = HDR_SIZE + EXPAND_INCR;
+ for (r = FT_RSVMAP; r <= FT_STRINGS; ++r)
+ tot += cxt->rgn[r].size;
+ if (nextra > 0)
+ tot += nextra;
+ tot = _ALIGN(tot, 8);
+
+ if (!cxt->realloc)
+ return 0;
+ p = cxt->realloc(NULL, tot);
+ if (!p)
+ return 0;
+
+ memcpy(p, cxt->bph, sizeof(struct boot_param_header));
+ /* offsets get fixed up later */
+
+ cxt->bph = (struct boot_param_header *)p;
+ cxt->max_size = tot;
+ pend = p + tot;
+ p += HDR_SIZE;
+
+ memcpy(p, cxt->rgn[FT_RSVMAP].start, cxt->rgn[FT_RSVMAP].size);
+ cxt->rgn[FT_RSVMAP].start = p;
+ p += cxt->rgn[FT_RSVMAP].size;
+
+ memcpy(p, cxt->rgn[FT_STRUCT].start, cxt->rgn[FT_STRUCT].size);
+ ft_node_update_after(cxt, cxt->rgn[FT_STRUCT].start,
+ p - cxt->rgn[FT_STRUCT].start);
+ cxt->p += p - cxt->rgn[FT_STRUCT].start;
+ cxt->rgn[FT_STRUCT].start = p;
+
+ p = pend - cxt->rgn[FT_STRINGS].size;
+ memcpy(p, cxt->rgn[FT_STRINGS].start, cxt->rgn[FT_STRINGS].size);
+ stroff = cxt->str_anchor - cxt->rgn[FT_STRINGS].start;
+ cxt->rgn[FT_STRINGS].start = p;
+ cxt->str_anchor = p + stroff;
+
+ cxt->isordered = 1;
+ return 1;
+}
+
+static inline char *prev_end(struct ft_cxt *cxt, enum ft_rgn_id r)
+{
+ if (r > FT_RSVMAP)
+ return cxt->rgn[r - 1].start + cxt->rgn[r - 1].size;
+ return (char *)cxt->bph + HDR_SIZE;
+}
+
+static inline char *next_start(struct ft_cxt *cxt, enum ft_rgn_id r)
+{
+ if (r < FT_STRINGS)
+ return cxt->rgn[r + 1].start;
+ return (char *)cxt->bph + cxt->max_size;
+}
+
+/*
+ * See if we can expand region rgn by nextra bytes by using up
+ * free space after or before the region.
+ */
+static int ft_shuffle(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
+ int nextra)
+{
+ char *p = *pp;
+ char *rgn_start, *rgn_end;
+
+ rgn_start = cxt->rgn[rgn].start;
+ rgn_end = rgn_start + cxt->rgn[rgn].size;
+ if (nextra <= 0 || rgn_end + nextra <= next_start(cxt, rgn)) {
+ /* move following stuff */
+ if (p < rgn_end) {
+ if (nextra < 0)
+ memmove(p, p - nextra, rgn_end - p + nextra);
+ else
+ memmove(p + nextra, p, rgn_end - p);
+ if (rgn == FT_STRUCT)
+ ft_node_update_after(cxt, p, nextra);
+ }
+ cxt->rgn[rgn].size += nextra;
+ if (rgn == FT_STRINGS)
+ /* assumes strings only added at beginning */
+ cxt->str_anchor += nextra;
+ return 1;
+ }
+ if (prev_end(cxt, rgn) <= rgn_start - nextra) {
+ /* move preceding stuff */
+ if (p > rgn_start) {
+ memmove(rgn_start - nextra, rgn_start, p - rgn_start);
+ if (rgn == FT_STRUCT)
+ ft_node_update_before(cxt, p, -nextra);
+ }
+ *p -= nextra;
+ cxt->rgn[rgn].start -= nextra;
+ cxt->rgn[rgn].size += nextra;
+ return 1;
+ }
+ return 0;
+}
+
+static int ft_make_space(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
+ int nextra)
+{
+ unsigned long size, ssize, tot;
+ char *str, *next;
+ enum ft_rgn_id r;
+
+ if (!cxt->isordered && !ft_reorder(cxt, nextra))
+ return 0;
+ if (ft_shuffle(cxt, pp, rgn, nextra))
+ return 1;
+
+ /* See if there is space after the strings section */
+ ssize = cxt->rgn[FT_STRINGS].size;
+ if (cxt->rgn[FT_STRINGS].start + ssize
+ < (char *)cxt->bph + cxt->max_size) {
+ /* move strings up as far as possible */
+ str = (char *)cxt->bph + cxt->max_size - ssize;
+ cxt->str_anchor += str - cxt->rgn[FT_STRINGS].start;
+ memmove(str, cxt->rgn[FT_STRINGS].start, ssize);
+ cxt->rgn[FT_STRINGS].start = str;
+ /* enough space now? */
+ if (rgn >= FT_STRUCT && ft_shuffle(cxt, pp, rgn, nextra))
+ return 1;
+ }
+
+ /* how much total free space is there following this region? */
+ tot = 0;
+ for (r = rgn; r < FT_STRINGS; ++r) {
+ char *r_end = cxt->rgn[r].start + cxt->rgn[r].size;
+ tot += next_start(cxt, rgn) - r_end;
+ }
+
+ /* cast is to shut gcc up; we know nextra >= 0 */
+ if (tot < (unsigned int)nextra) {
+ /* have to reallocate */
+ char *newp, *new_start;
+ int shift;
+
+ if (!cxt->realloc)
+ return 0;
+ size = _ALIGN(cxt->max_size + (nextra - tot) + EXPAND_INCR, 8);
+ newp = cxt->realloc(cxt->bph, size);
+ if (!newp)
+ return 0;
+ cxt->max_size = size;
+ shift = newp - (char *)cxt->bph;
+
+ if (shift) { /* realloc can return same addr */
+ cxt->bph = (struct boot_param_header *)newp;
+ ft_node_update_after(cxt, cxt->rgn[FT_STRUCT].start,
+ shift);
+ for (r = FT_RSVMAP; r <= FT_STRINGS; ++r) {
+ new_start = cxt->rgn[r].start + shift;
+ cxt->rgn[r].start = new_start;
+ }
+ *pp += shift;
+ cxt->str_anchor += shift;
+ }
+
+ /* move strings up to the end */
+ str = newp + size - ssize;
+ cxt->str_anchor += str - cxt->rgn[FT_STRINGS].start;
+ memmove(str, cxt->rgn[FT_STRINGS].start, ssize);
+ cxt->rgn[FT_STRINGS].start = str;
+
+ if (ft_shuffle(cxt, pp, rgn, nextra))
+ return 1;
+ }
+
+ /* must be FT_RSVMAP and we need to move FT_STRUCT up */
+ if (rgn == FT_RSVMAP) {
+ next = cxt->rgn[FT_RSVMAP].start + cxt->rgn[FT_RSVMAP].size
+ + nextra;
+ ssize = cxt->rgn[FT_STRUCT].size;
+ if (next + ssize >= cxt->rgn[FT_STRINGS].start)
+ return 0; /* "can't happen" */
+ memmove(next, cxt->rgn[FT_STRUCT].start, ssize);
+ ft_node_update_after(cxt, cxt->rgn[FT_STRUCT].start, nextra);
+ cxt->rgn[FT_STRUCT].start = next;
+
+ if (ft_shuffle(cxt, pp, rgn, nextra))
+ return 1;
+ }
+
+ return 0; /* "can't happen" */
+}
+
+static void ft_put_word(struct ft_cxt *cxt, u32 v)
+{
+ *(u32 *) cxt->p = cpu_to_be32(v);
+ cxt->p += 4;
+}
+
+static void ft_put_bin(struct ft_cxt *cxt, const void *data, unsigned int sz)
+{
+ unsigned long sza = _ALIGN(sz, 4);
+
+ /* zero out the alignment gap if necessary */
+ if (sz < sza)
+ *(u32 *) (cxt->p + sza - 4) = 0;
+
+ /* copy in the data */
+ memcpy(cxt->p, data, sz);
+
+ cxt->p += sza;
+}
+
+int ft_begin_node(struct ft_cxt *cxt, const char *name)
+{
+ unsigned long nlen = strlen(name) + 1;
+ unsigned long len = 8 + _ALIGN(nlen, 4);
+
+ if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, len))
+ return -1;
+ ft_put_word(cxt, OF_DT_BEGIN_NODE);
+ ft_put_bin(cxt, name, strlen(name) + 1);
+ return 0;
+}
+
+void ft_end_node(struct ft_cxt *cxt)
+{
+ ft_put_word(cxt, OF_DT_END_NODE);
+}
+
+void ft_nop(struct ft_cxt *cxt)
+{
+ if (ft_make_space(cxt, &cxt->p, FT_STRUCT, 4))
+ ft_put_word(cxt, OF_DT_NOP);
+}
+
+#define NO_STRING 0x7fffffff
+
+static int lookup_string(struct ft_cxt *cxt, const char *name)
+{
+ char *p, *end;
+
+ p = cxt->rgn[FT_STRINGS].start;
+ end = p + cxt->rgn[FT_STRINGS].size;
+ while (p < end) {
+ if (strcmp(p, (char *)name) == 0)
+ return p - cxt->str_anchor;
+ p += strlen(p) + 1;
+ }
+
+ return NO_STRING;
+}
+
+/* lookup string and insert if not found */
+static int map_string(struct ft_cxt *cxt, const char *name)
+{
+ int off;
+ char *p;
+
+ off = lookup_string(cxt, name);
+ if (off != NO_STRING)
+ return off;
+ p = cxt->rgn[FT_STRINGS].start;
+ if (!ft_make_space(cxt, &p, FT_STRINGS, strlen(name) + 1))
+ return NO_STRING;
+ strcpy(p, name);
+ return p - cxt->str_anchor;
+}
+
+int ft_prop(struct ft_cxt *cxt, const char *name, const void *data,
+ unsigned int sz)
+{
+ int off, len;
+
+ off = lookup_string(cxt, name);
+ if (off == NO_STRING)
+ return -1;
+
+ len = 12 + _ALIGN(sz, 4);
+ if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, len))
+ return -1;
+
+ ft_put_word(cxt, OF_DT_PROP);
+ ft_put_word(cxt, sz);
+ ft_put_word(cxt, off);
+ ft_put_bin(cxt, data, sz);
+ return 0;
+}
+
+int ft_prop_str(struct ft_cxt *cxt, const char *name, const char *str)
+{
+ return ft_prop(cxt, name, str, strlen(str) + 1);
+}
+
+int ft_prop_int(struct ft_cxt *cxt, const char *name, unsigned int val)
+{
+ u32 v = cpu_to_be32((u32) val);
+
+ return ft_prop(cxt, name, &v, 4);
+}
+
+/* Calculate the size of the reserved map */
+static unsigned long rsvmap_size(struct ft_cxt *cxt)
+{
+ struct ft_reserve *res;
+
+ res = (struct ft_reserve *)cxt->rgn[FT_RSVMAP].start;
+ while (res->start || res->len)
+ ++res;
+ return (char *)(res + 1) - cxt->rgn[FT_RSVMAP].start;
+}
+
+/* Calculate the size of the struct region by stepping through it */
+static unsigned long struct_size(struct ft_cxt *cxt)
+{
+ char *p = cxt->rgn[FT_STRUCT].start;
+ char *next;
+ struct ft_atom atom;
+
+ /* make check in ft_next happy */
+ if (cxt->rgn[FT_STRUCT].size == 0)
+ cxt->rgn[FT_STRUCT].size = 0xfffffffful - (unsigned long)p;
+
+ while ((next = ft_next(cxt, p, &atom)) != NULL)
+ p = next;
+ return p + 4 - cxt->rgn[FT_STRUCT].start;
+}
+
+/* add `adj' on to all string offset values in the struct area */
+static void adjust_string_offsets(struct ft_cxt *cxt, int adj)
+{
+ char *p = cxt->rgn[FT_STRUCT].start;
+ char *next;
+ struct ft_atom atom;
+ int off;
+
+ while ((next = ft_next(cxt, p, &atom)) != NULL) {
+ if (atom.tag == OF_DT_PROP) {
+ off = be32_to_cpu(*(u32 *) (p + 8));
+ *(u32 *) (p + 8) = cpu_to_be32(off + adj);
+ }
+ p = next;
+ }
+}
+
+/* start construction of the flat OF tree from scratch */
+void ft_begin(struct ft_cxt *cxt, void *blob, unsigned int max_size,
+ void *(*realloc_fn) (void *, unsigned long))
+{
+ struct boot_param_header *bph = blob;
+ char *p;
+ struct ft_reserve *pres;
+
+ /* clear the cxt */
+ memset(cxt, 0, sizeof(*cxt));
+
+ cxt->bph = bph;
+ cxt->max_size = max_size;
+ cxt->realloc = realloc_fn;
+ cxt->isordered = 1;
+
+ /* zero everything in the header area */
+ memset(bph, 0, sizeof(*bph));
+
+ bph->magic = cpu_to_be32(OF_DT_HEADER);
+ bph->version = cpu_to_be32(0x10);
+ bph->last_comp_version = cpu_to_be32(0x10);
+
+ /* start pointers */
+ cxt->rgn[FT_RSVMAP].start = p = blob + HDR_SIZE;
+ cxt->rgn[FT_RSVMAP].size = sizeof(struct ft_reserve);
+ pres = (struct ft_reserve *)p;
+ cxt->rgn[FT_STRUCT].start = p += sizeof(struct ft_reserve);
+ cxt->rgn[FT_STRUCT].size = 4;
+ cxt->rgn[FT_STRINGS].start = blob + max_size;
+ cxt->rgn[FT_STRINGS].size = 0;
+
+ /* init rsvmap and struct */
+ pres->start = 0;
+ pres->len = 0;
+ *(u32 *) p = cpu_to_be32(OF_DT_END);
+
+ cxt->str_anchor = blob;
+}
+
+/* open up an existing blob to be examined or modified */
+int ft_open(struct ft_cxt *cxt, void *blob, unsigned int max_size,
+ unsigned int max_find_device,
+ void *(*realloc_fn) (void *, unsigned long))
+{
+ struct boot_param_header *bph = blob;
+
+ /* can't cope with version < 16 */
+ if (be32_to_cpu(bph->version) < 16)
+ return -1;
+
+ /* clear the cxt */
+ memset(cxt, 0, sizeof(*cxt));
+
+ /* alloc node_tbl to track node ptrs returned by ft_find_device */
+ ++max_find_device;
+ cxt->node_tbl = realloc_fn(NULL, max_find_device * sizeof(char *));
+ if (!cxt->node_tbl)
+ return -1;
+ memset(cxt->node_tbl, 0, max_find_device * sizeof(char *));
+ cxt->node_max = max_find_device;
+ cxt->nodes_used = 1; /* don't use idx 0 b/c looks like NULL */
+
+ cxt->bph = bph;
+ cxt->max_size = max_size;
+ cxt->realloc = realloc_fn;
+
+ cxt->rgn[FT_RSVMAP].start = blob + be32_to_cpu(bph->off_mem_rsvmap);
+ cxt->rgn[FT_RSVMAP].size = rsvmap_size(cxt);
+ cxt->rgn[FT_STRUCT].start = blob + be32_to_cpu(bph->off_dt_struct);
+ cxt->rgn[FT_STRUCT].size = struct_size(cxt);
+ cxt->rgn[FT_STRINGS].start = blob + be32_to_cpu(bph->off_dt_strings);
+ cxt->rgn[FT_STRINGS].size = be32_to_cpu(bph->dt_strings_size);
+ /* Leave as '0' to force first ft_make_space call to do a ft_reorder
+ * and move dt to an area allocated by realloc.
+ cxt->isordered = ft_ordered(cxt);
+ */
+
+ cxt->p = cxt->rgn[FT_STRUCT].start;
+ cxt->str_anchor = cxt->rgn[FT_STRINGS].start;
+
+ return 0;
+}
+
+/* add a reserver physical area to the rsvmap */
+int ft_add_rsvmap(struct ft_cxt *cxt, u64 physaddr, u64 size)
+{
+ char *p;
+ struct ft_reserve *pres;
+
+ p = cxt->rgn[FT_RSVMAP].start + cxt->rgn[FT_RSVMAP].size
+ - sizeof(struct ft_reserve);
+ if (!ft_make_space(cxt, &p, FT_RSVMAP, sizeof(struct ft_reserve)))
+ return -1;
+
+ pres = (struct ft_reserve *)p;
+ pres->start = cpu_to_be64(physaddr);
+ pres->len = cpu_to_be64(size);
+
+ return 0;
+}
+
+void ft_begin_tree(struct ft_cxt *cxt)
+{
+ cxt->p = cxt->rgn[FT_STRUCT].start;
+}
+
+void ft_end_tree(struct ft_cxt *cxt)
+{
+ struct boot_param_header *bph = cxt->bph;
+ char *p, *oldstr, *str, *endp;
+ unsigned long ssize;
+ int adj;
+
+ if (!cxt->isordered)
+ return; /* we haven't touched anything */
+
+ /* adjust string offsets */
+ oldstr = cxt->rgn[FT_STRINGS].start;
+ adj = cxt->str_anchor - oldstr;
+ if (adj)
+ adjust_string_offsets(cxt, adj);
+
+ /* make strings end on 8-byte boundary */
+ ssize = cxt->rgn[FT_STRINGS].size;
+ endp = (char *)_ALIGN((unsigned long)cxt->rgn[FT_STRUCT].start
+ + cxt->rgn[FT_STRUCT].size + ssize, 8);
+ str = endp - ssize;
+
+ /* move strings down to end of structs */
+ memmove(str, oldstr, ssize);
+ cxt->str_anchor = str;
+ cxt->rgn[FT_STRINGS].start = str;
+
+ /* fill in header fields */
+ p = (char *)bph;
+ bph->totalsize = cpu_to_be32(endp - p);
+ bph->off_mem_rsvmap = cpu_to_be32(cxt->rgn[FT_RSVMAP].start - p);
+ bph->off_dt_struct = cpu_to_be32(cxt->rgn[FT_STRUCT].start - p);
+ bph->off_dt_strings = cpu_to_be32(cxt->rgn[FT_STRINGS].start - p);
+ bph->dt_strings_size = cpu_to_be32(ssize);
+}
+
+void *ft_find_device(struct ft_cxt *cxt, const char *srch_path)
+{
+ char *node;
+
+ /* require absolute path */
+ if (srch_path[0] != '/')
+ return NULL;
+ node = ft_find_descendent(cxt, cxt->rgn[FT_STRUCT].start, srch_path);
+ return ft_node_add(cxt, node);
+}
+
+void *ft_find_descendent(struct ft_cxt *cxt, void *top, const char *srch_path)
+{
+ struct ft_atom atom;
+ char *p;
+ const char *cp, *q;
+ int cl;
+ int depth = -1;
+ int dmatch = 0;
+ const char *path_comp[FT_MAX_DEPTH];
+
+ cp = srch_path;
+ cl = 0;
+ p = top;
+
+ while ((p = ft_next(cxt, p, &atom)) != NULL) {
+ switch (atom.tag) {
+ case OF_DT_BEGIN_NODE:
+ ++depth;
+ if (depth != dmatch)
+ break;
+ cxt->genealogy[depth] = atom.data;
+ cxt->genealogy[depth + 1] = NULL;
+ if (depth && !(strncmp(atom.name, cp, cl) == 0
+ && (atom.name[cl] == '/'
+ || atom.name[cl] == '\0'
+ || atom.name[cl] == '@')))
+ break;
+ path_comp[dmatch] = cp;
+ /* it matches so far, advance to next path component */
+ cp += cl;
+ /* skip slashes */
+ while (*cp == '/')
+ ++cp;
+ /* we're done if this is the end of the string */
+ if (*cp == 0)
+ return atom.data;
+ /* look for end of this component */
+ q = strchr(cp, '/');
+ if (q)
+ cl = q - cp;
+ else
+ cl = strlen(cp);
+ ++dmatch;
+ break;
+ case OF_DT_END_NODE:
+ if (depth == 0)
+ return NULL;
+ if (dmatch > depth) {
+ --dmatch;
+ cl = cp - path_comp[dmatch] - 1;
+ cp = path_comp[dmatch];
+ while (cl > 0 && cp[cl - 1] == '/')
+ --cl;
+ }
+ --depth;
+ break;
+ }
+ }
+ return NULL;
+}
+
+void *ft_get_parent(struct ft_cxt *cxt, const void *phandle)
+{
+ void *node;
+ int d;
+ struct ft_atom atom;
+ char *p;
+
+ node = ft_node_ph2node(cxt, phandle);
+ if (node == NULL)
+ return NULL;
+
+ for (d = 0; cxt->genealogy[d] != NULL; ++d)
+ if (cxt->genealogy[d] == node)
+ return cxt->genealogy[d > 0 ? d - 1 : 0];
+
+ /* have to do it the hard way... */
+ p = cxt->rgn[FT_STRUCT].start;
+ d = 0;
+ while ((p = ft_next(cxt, p, &atom)) != NULL) {
+ switch (atom.tag) {
+ case OF_DT_BEGIN_NODE:
+ cxt->genealogy[d] = atom.data;
+ if (node == atom.data) {
+ /* found it */
+ cxt->genealogy[d + 1] = NULL;
+ return d > 0 ? cxt->genealogy[d - 1] : node;
+ }
+ ++d;
+ break;
+ case OF_DT_END_NODE:
+ --d;
+ break;
+ }
+ }
+ return NULL;
+}
+
+int ft_get_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
+ void *buf, const unsigned int buflen)
+{
+ struct ft_atom atom;
+ void *node;
+ char *p;
+ int depth;
+ unsigned int size;
+
+ node = ft_node_ph2node(cxt, phandle);
+ if (node == NULL)
+ return -1;
+
+ depth = 0;
+ p = (char *)node;
+
+ while ((p = ft_next(cxt, p, &atom)) != NULL) {
+ switch (atom.tag) {
+ case OF_DT_BEGIN_NODE:
+ ++depth;
+ break;
+ case OF_DT_PROP:
+ if ((depth != 1) || strcmp(atom.name, propname))
+ break;
+ size = min(atom.size, buflen);
+ memcpy(buf, atom.data, size);
+ return atom.size;
+ case OF_DT_END_NODE:
+ if (--depth <= 0)
+ return -1;
+ }
+ }
+ return -1;
+}
+
+int ft_set_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
+ const void *buf, const unsigned int buflen)
+{
+ struct ft_atom atom;
+ void *node;
+ char *p, *next;
+ int nextra, depth;
+
+ node = ft_node_ph2node(cxt, phandle);
+ if (node == NULL)
+ return -1;
+
+ depth = 0;
+ p = node;
+
+ while ((next = ft_next(cxt, p, &atom)) != NULL) {
+ switch (atom.tag) {
+ case OF_DT_BEGIN_NODE:
+ ++depth;
+ break;
+ case OF_DT_END_NODE:
+ if (--depth > 0)
+ break;
+ /* haven't found the property, insert here */
+ cxt->p = p;
+ return ft_prop(cxt, propname, buf, buflen);
+ case OF_DT_PROP:
+ if ((depth != 1) || strcmp(atom.name, propname))
+ break;
+ /* found an existing property, overwrite it */
+ nextra = _ALIGN(buflen, 4) - _ALIGN(atom.size, 4);
+ cxt->p = atom.data;
+ if (nextra && !ft_make_space(cxt, &cxt->p, FT_STRUCT,
+ nextra))
+ return -1;
+ *(u32 *) (cxt->p - 8) = cpu_to_be32(buflen);
+ ft_put_bin(cxt, buf, buflen);
+ return 0;
+ }
+ p = next;
+ }
+ return -1;
+}
+
+int ft_del_prop(struct ft_cxt *cxt, const void *phandle, const char *propname)
+{
+ struct ft_atom atom;
+ void *node;
+ char *p, *next;
+ int size;
+
+ node = ft_node_ph2node(cxt, phandle);
+ if (node == NULL)
+ return -1;
+
+ p = node;
+ while ((next = ft_next(cxt, p, &atom)) != NULL) {
+ switch (atom.tag) {
+ case OF_DT_BEGIN_NODE:
+ case OF_DT_END_NODE:
+ return -1;
+ case OF_DT_PROP:
+ if (strcmp(atom.name, propname))
+ break;
+ /* found the property, remove it */
+ size = 12 + -_ALIGN(atom.size, 4);
+ cxt->p = p;
+ if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, -size))
+ return -1;
+ return 0;
+ }
+ p = next;
+ }
+ return -1;
+}
+
+void *ft_create_node(struct ft_cxt *cxt, const void *parent, const char *path)
+{
+ struct ft_atom atom;
+ char *p, *next;
+ int depth = 0;
+
+ p = cxt->rgn[FT_STRUCT].start;
+ while ((next = ft_next(cxt, p, &atom)) != NULL) {
+ switch (atom.tag) {
+ case OF_DT_BEGIN_NODE:
+ ++depth;
+ if (depth == 1 && strcmp(atom.name, path) == 0)
+ /* duplicate node path, return error */
+ return NULL;
+ break;
+ case OF_DT_END_NODE:
+ --depth;
+ if (depth > 0)
+ break;
+ /* end of node, insert here */
+ cxt->p = p;
+ ft_begin_node(cxt, path);
+ ft_end_node(cxt);
+ return p;
+ }
+ p = next;
+ }
+ return NULL;
+}