u-boot/lib/of_live.c
Simon Glass 62b1db3377 dm: core: Add a way to convert a devicetree to a dtb
Add a way to flatten a devicetree into binary form. For livetree this
involves generating the devicetree using fdt_property() and other calls.
For flattree it simply involves providing the buffer containing the tree.

Signed-off-by: Simon Glass <sjg@chromium.org>
2023-10-06 14:38:13 -04:00

479 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* 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
*/
#define LOG_CATEGORY LOGC_DT
#include <common.h>
#include <abuf.h>
#include <log.h>
#include <linux/libfdt.h>
#include <of_live.h>
#include <malloc.h>
#include <dm/of_access.h>
#include <linux/err.h>
#include <linux/sizes.h>
enum {
BUF_STEP = SZ_64K,
};
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);
if (new_format) {
np->name = pathp;
has_name = 1;
}
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;
if (!has_name)
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 (!mem)
return NULL;
}
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;
}
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);
if (!size)
return -EFAULT;
size = ALIGN(size, 4);
debug(" size is %lx, allocating...\n", size);
/* Allocate memory for the expanded device tree */
mem = memalign(__alignof__(struct device_node), size + 4);
memset(mem, '\0', size);
/* Set up value for dm_test_livetree_align() */
*(u32 *)mem = BAD_OF_ROOT;
*(__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;
}
void of_live_free(struct device_node *root)
{
/* the tree is stored as a contiguous block of memory */
free(root);
}
int of_live_create_empty(struct device_node **rootp)
{
struct device_node *root;
root = calloc(1, sizeof(struct device_node));
if (!root)
return -ENOMEM;
root->name = strdup("");
if (!root->name) {
free(root);
return -ENOMEM;
}
root->type = "<NULL>";
root->full_name = "";
*rootp = root;
return 0;
}
static int check_space(int ret, struct abuf *buf)
{
if (ret == -FDT_ERR_NOSPACE) {
if (!abuf_realloc_inc(buf, BUF_STEP))
return log_msg_ret("spc", -ENOMEM);
ret = fdt_resize(abuf_data(buf), abuf_data(buf),
abuf_size(buf));
if (ret)
return log_msg_ret("res", -EFAULT);
return -EAGAIN;
}
return 0;
}
/**
* flatten_node() - Write out the node and its properties into a flat tree
*/
static int flatten_node(struct abuf *buf, const struct device_node *node)
{
const struct device_node *np;
const struct property *pp;
int ret;
ret = fdt_begin_node(abuf_data(buf), node->name);
ret = check_space(ret, buf);
if (ret == -EAGAIN) {
ret = fdt_begin_node(abuf_data(buf), node->name);
if (ret) {
log_debug("Internal error a %d\n", ret);
return -EFAULT;
}
}
if (ret)
return log_msg_ret("beg", ret);
/* First write out the properties */
for (pp = node->properties; !ret && pp; pp = pp->next) {
ret = fdt_property(abuf_data(buf), pp->name, pp->value,
pp->length);
ret = check_space(ret, buf);
if (ret == -EAGAIN) {
ret = fdt_property(abuf_data(buf), pp->name, pp->value,
pp->length);
}
}
/* Next write out the subnodes */
for (np = node->child; np; np = np->sibling) {
ret = flatten_node(buf, np);
if (ret)
return log_msg_ret("sub", ret);
}
ret = fdt_end_node(abuf_data(buf));
ret = check_space(ret, buf);
if (ret == -EAGAIN) {
ret = fdt_end_node(abuf_data(buf));
if (ret) {
log_debug("Internal error b %d\n", ret);
return -EFAULT;
}
}
if (ret)
return log_msg_ret("end", ret);
return 0;
}
int of_live_flatten(const struct device_node *root, struct abuf *buf)
{
int ret;
abuf_init(buf);
if (!abuf_realloc(buf, BUF_STEP))
return log_msg_ret("ini", -ENOMEM);
ret = fdt_create(abuf_data(buf), abuf_size(buf));
if (!ret)
ret = fdt_finish_reservemap(abuf_data(buf));
if (ret) {
log_debug("Failed to start FDT (err=%d)\n", ret);
return log_msg_ret("sta", -EINVAL);
}
ret = flatten_node(buf, root);
if (ret)
return log_msg_ret("flt", ret);
ret = fdt_finish(abuf_data(buf));
ret = check_space(ret, buf);
if (ret == -EAGAIN) {
ret = fdt_finish(abuf_data(buf));
if (ret) {
log_debug("Internal error c %d\n", ret);
return -EFAULT;
}
}
if (ret)
return log_msg_ret("fin", ret);
ret = fdt_pack(abuf_data(buf));
if (ret) {
log_debug("Failed to pack (err=%d)\n", ret);
return log_msg_ret("pac", -EFAULT);
}
if (!abuf_realloc(buf, fdt_totalsize(abuf_data(buf))))
return log_msg_ret("abu", -EFAULT);
return 0;
}