[U-Boot] [PATCH 06/22] dm: Add a function to create a 'live' device tree
Simon Glass
sjg at chromium.org
Wed Jan 18 06:51:42 CET 2017
This function converts the flat device tree into a hierarchical one with
C structures and pointers. This is easier to access.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
include/livetree.h | 22 ++++
lib/Makefile | 2 +-
lib/livetree.c | 320 +++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 343 insertions(+), 1 deletion(-)
create mode 100644 include/livetree.h
create mode 100644 lib/livetree.c
diff --git a/include/livetree.h b/include/livetree.h
new file mode 100644
index 00000000000..aa0a8687c1b
--- /dev/null
+++ b/include/livetree.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg at chromium.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * Support for a 'live' (as opposed to flat) device tree
+ */
+
+#ifndef _LIVETREE_H
+#define _LIVETREE_H
+
+/**
+ * livetree_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 livetree_build(const void *fdt_blob, struct device_node **rootp);
+
+#endif
diff --git a/lib/Makefile b/lib/Makefile
index d07a062483a..1c76c59374d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -15,7 +15,7 @@ obj-$(CONFIG_ZLIB) += zlib/
obj-$(CONFIG_BZIP2) += bzip2/
obj-$(CONFIG_TIZEN) += tizen/
obj-$(CONFIG_FIT) += libfdt/
-obj-$(CONFIG_OF_LIVE) += of_access.o
+obj-$(CONFIG_OF_LIVE) += livetree.o of_access.o
obj-$(CONFIG_CMD_DHRYSTONE) += dhry/
obj-$(CONFIG_AES) += aes.o
diff --git a/lib/livetree.c b/lib/livetree.c
new file mode 100644
index 00000000000..a1dd3320940
--- /dev/null
+++ b/lib/livetree.c
@@ -0,0 +1,320 @@
+/*
+ * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
+ * benh at 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 <livetree.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);
+
+ if (!np->name)
+ np->name = "<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)
+ printf("unflatten: error %d processing FDT\n", *poffset);
+
+ /*
+ * 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)) {
+ printf("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) {
+ printf("End of tree marker overwritten: %08x\n",
+ be32_to_cpup(mem + size));
+ }
+
+ debug(" <- unflatten_device_tree()\n");
+
+ return 0;
+}
+
+int livetree_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 livetree: err=%d\n", ret);
+ debug("%s: stop\n", __func__);
+
+ return ret;
+}
--
2.11.0.483.g087da7b7c-goog
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