Commit 8b50d526 authored by Simon Glass's avatar Simon Glass

dm: Add a function to create a 'live' device tree

This function converts the flat device tree into a hierarchical one with
C structures and pointers. This is easier to access.
Signed-off-by: default avatarSimon Glass <sjg@chromium.org>
parent 644ec0a9
/*
* Copyright (c) 2017 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*
* Support for a 'live' (as opposed to flat) device tree
*/
#ifndef _OF_LIVE_H
#define _OF_LIVE_H
struct device_node;
/**
* of_live_build() - build a live (hierarchical) tree from a flat DT
*
* @fdt_blob: Input tree to convert
* @rootp: Returns live tree that was created
* @return 0 if OK, -ve on error
*/
int of_live_build(const void *fdt_blob, struct device_node **rootp);
#endif
......@@ -15,6 +15,7 @@ obj-$(CONFIG_ZLIB) += zlib/
obj-$(CONFIG_BZIP2) += bzip2/
obj-$(CONFIG_TIZEN) += tizen/
obj-$(CONFIG_FIT) += libfdt/
obj-$(CONFIG_OF_LIVE) += of_live.o
obj-$(CONFIG_CMD_DHRYSTONE) += dhry/
obj-$(CONFIG_AES) += aes.o
......
/*
* Copyright 2009 Benjamin Herrenschmidt, IBM Corp
* benh@kernel.crashing.org
*
* Based on parts of drivers/of/fdt.c from Linux v4.9
* Modifications for U-Boot
* Copyright (c) 2017 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <libfdt.h>
#include <of_live.h>
#include <malloc.h>
#include <dm/of_access.h>
#include <linux/err.h>
DECLARE_GLOBAL_DATA_PTR;
static void *unflatten_dt_alloc(void **mem, unsigned long size,
unsigned long align)
{
void *res;
*mem = PTR_ALIGN(*mem, align);
res = *mem;
*mem += size;
return res;
}
/**
* unflatten_dt_node() - Alloc and populate a device_node from the flat tree
* @blob: The parent device tree blob
* @mem: Memory chunk to use for allocating device nodes and properties
* @poffset: pointer to node in flat tree
* @dad: Parent struct device_node
* @nodepp: The device_node tree created by the call
* @fpsize: Size of the node path up at t05he current depth.
* @dryrun: If true, do not allocate device nodes but still calculate needed
* memory size
*/
static void *unflatten_dt_node(const void *blob, void *mem, int *poffset,
struct device_node *dad,
struct device_node **nodepp,
unsigned long fpsize, bool dryrun)
{
const __be32 *p;
struct device_node *np;
struct property *pp, **prev_pp = NULL;
const char *pathp;
int l;
unsigned int allocl;
static int depth;
int old_depth;
int offset;
int has_name = 0;
int new_format = 0;
pathp = fdt_get_name(blob, *poffset, &l);
if (!pathp)
return mem;
allocl = ++l;
/*
* version 0x10 has a more compact unit name here instead of the full
* path. we accumulate the full path size using "fpsize", we'll rebuild
* it later. We detect this because the first character of the name is
* not '/'.
*/
if ((*pathp) != '/') {
new_format = 1;
if (fpsize == 0) {
/*
* root node: special case. fpsize accounts for path
* plus terminating zero. root node only has '/', so
* fpsize should be 2, but we want to avoid the first
* level nodes to have two '/' so we use fpsize 1 here
*/
fpsize = 1;
allocl = 2;
l = 1;
pathp = "";
} else {
/*
* account for '/' and path size minus terminal 0
* already in 'l'
*/
fpsize += l;
allocl = fpsize;
}
}
np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
__alignof__(struct device_node));
if (!dryrun) {
char *fn;
fn = (char *)np + sizeof(*np);
np->full_name = fn;
if (new_format) {
/* rebuild full path for new format */
if (dad && dad->parent) {
strcpy(fn, dad->full_name);
#ifdef DEBUG
if ((strlen(fn) + l + 1) != allocl) {
debug("%s: p: %d, l: %d, a: %d\n",
pathp, (int)strlen(fn), l,
allocl);
}
#endif
fn += strlen(fn);
}
*(fn++) = '/';
}
memcpy(fn, pathp, l);
prev_pp = &np->properties;
if (dad != NULL) {
np->parent = dad;
np->sibling = dad->child;
dad->child = np;
}
}
/* process properties */
for (offset = fdt_first_property_offset(blob, *poffset);
(offset >= 0);
(offset = fdt_next_property_offset(blob, offset))) {
const char *pname;
int sz;
p = fdt_getprop_by_offset(blob, offset, &pname, &sz);
if (!p) {
offset = -FDT_ERR_INTERNAL;
break;
}
if (pname == NULL) {
debug("Can't find property name in list !\n");
break;
}
if (strcmp(pname, "name") == 0)
has_name = 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property),
__alignof__(struct property));
if (!dryrun) {
/*
* We accept flattened tree phandles either in
* ePAPR-style "phandle" properties, or the
* legacy "linux,phandle" properties. If both
* appear and have different values, things
* will get weird. Don't do that. */
if ((strcmp(pname, "phandle") == 0) ||
(strcmp(pname, "linux,phandle") == 0)) {
if (np->phandle == 0)
np->phandle = be32_to_cpup(p);
}
/*
* And we process the "ibm,phandle" property
* used in pSeries dynamic device tree
* stuff */
if (strcmp(pname, "ibm,phandle") == 0)
np->phandle = be32_to_cpup(p);
pp->name = (char *)pname;
pp->length = sz;
pp->value = (__be32 *)p;
*prev_pp = pp;
prev_pp = &pp->next;
}
}
/*
* with version 0x10 we may not have the name property, recreate
* it here from the unit name if absent
*/
if (!has_name) {
const char *p1 = pathp, *ps = pathp, *pa = NULL;
int sz;
while (*p1) {
if ((*p1) == '@')
pa = p1;
if ((*p1) == '/')
ps = p1 + 1;
p1++;
}
if (pa < ps)
pa = p1;
sz = (pa - ps) + 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
__alignof__(struct property));
if (!dryrun) {
pp->name = "name";
pp->length = sz;
pp->value = pp + 1;
*prev_pp = pp;
prev_pp = &pp->next;
memcpy(pp->value, ps, sz - 1);
((char *)pp->value)[sz - 1] = 0;
debug("fixed up name for %s -> %s\n", pathp,
(char *)pp->value);
}
}
if (!dryrun) {
*prev_pp = NULL;
np->name = of_get_property(np, "name", NULL);
np->type = of_get_property(np, "device_type", NULL);
if (!np->name)
np->name = "<NULL>";
if (!np->type)
np->type = "<NULL>"; }
old_depth = depth;
*poffset = fdt_next_node(blob, *poffset, &depth);
if (depth < 0)
depth = 0;
while (*poffset > 0 && depth > old_depth)
mem = unflatten_dt_node(blob, mem, poffset, np, NULL,
fpsize, dryrun);
if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND) {
debug("unflatten: error %d processing FDT\n", *poffset);
return NULL;
}
/*
* Reverse the child list. Some drivers assumes node order matches .dts
* node order
*/
if (!dryrun && np->child) {
struct device_node *child = np->child;
np->child = NULL;
while (child) {
struct device_node *next = child->sibling;
child->sibling = np->child;
np->child = child;
child = next;
}
}
if (nodepp)
*nodepp = np;
return mem;
}
/**
* unflatten_device_tree() - create tree of device_nodes from flat blob
*
* unflattens a device-tree, creating the
* tree of struct device_node. It also fills the "name" and "type"
* pointers of the nodes so the normal device-tree walking functions
* can be used.
* @blob: The blob to expand
* @mynodes: The device_node tree created by the call
* @return 0 if OK, -ve on error
*/
static int unflatten_device_tree(const void *blob,
struct device_node **mynodes)
{
unsigned long size;
int start;
void *mem;
debug(" -> unflatten_device_tree()\n");
if (!blob) {
debug("No device tree pointer\n");
return -EINVAL;
}
debug("Unflattening device tree:\n");
debug("magic: %08x\n", fdt_magic(blob));
debug("size: %08x\n", fdt_totalsize(blob));
debug("version: %08x\n", fdt_version(blob));
if (fdt_check_header(blob)) {
debug("Invalid device tree blob header\n");
return -EINVAL;
}
/* First pass, scan for size */
start = 0;
size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL,
0, true);
size = ALIGN(size, 4);
debug(" size is %lx, allocating...\n", size);
/* Allocate memory for the expanded device tree */
mem = malloc(size + 4);
memset(mem, '\0', size);
*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
debug(" unflattening %p...\n", mem);
/* Second pass, do actual unflattening */
start = 0;
unflatten_dt_node(blob, mem, &start, NULL, mynodes, 0, false);
if (be32_to_cpup(mem + size) != 0xdeadbeef) {
debug("End of tree marker overwritten: %08x\n",
be32_to_cpup(mem + size));
return -ENOSPC;
}
debug(" <- unflatten_device_tree()\n");
return 0;
}
int of_live_build(const void *fdt_blob, struct device_node **rootp)
{
int ret;
debug("%s: start\n", __func__);
ret = unflatten_device_tree(fdt_blob, rootp);
if (ret) {
debug("Failed to create live tree: err=%d\n", ret);
return ret;
}
ret = of_alias_scan();
if (ret) {
debug("Failed to scan live tree aliases: err=%d\n", ret);
return ret;
}
debug("%s: stop\n", __func__);
return ret;
}
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