PKGBUILDs/alarm/dtc-overlay/dtc-dynamic-symbols-fixup-support.patch

From 61c5cdfd8e611d3a34497394098555b0b8644a31 Mon Sep 17 00:00:00 2001
From: Pantelis Antoniou <panto@antoniou-consulting.com>
Date: Fri, 4 Jan 2013 21:16:21 +0200
Subject: [PATCH] dtc: Dynamic symbols & fixup support

Enable the generation of symbol & fixup information for
usage with dynamic DT loading.

Passing the -@ option generates a __symbols__ node at the
root node of the resulting blob for any node labels used.

When using the /plugin/ tag all unresolved label references
be tracked in the __fixups__ node, while all local phandle
references will the tracked in the __local_fixups__ node.

This is sufficient to implement a dynamic DT object loader.

Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 Documentation/dts-format.txt |   7 +++
 Documentation/manual.txt     |   8 +++
 checks.c                     | 120 +++++++++++++++++++++++++++++++++++--
 dtc-lexer.l                  |   5 ++
 dtc-parser.y                 |  23 ++++++-
 dtc.c                        |   9 ++-
 dtc.h                        |  38 ++++++++++++
 flattree.c                   | 139 +++++++++++++++++++++++++++++++++++++++++++
 8 files changed, 340 insertions(+), 9 deletions(-)

diff --git a/Documentation/dts-format.txt b/Documentation/dts-format.txt
index 41741df..4da515c 100644
--- a/Documentation/dts-format.txt
+++ b/Documentation/dts-format.txt
@@ -115,7 +115,14 @@ Version 1 DTS files have the overall layout:
 
 * C style (/* ... */) and C++ style (// ...) comments are supported.
 
+Device Tree Objects
+-------------------
 
+Using the plugin tag enables dynamic tree objects.
+
+	/plugin/;
+
+For the full details please see Documentation/dt-object-internal.txt
 
 	-- David Gibson <david@gibson.dropbear.id.au>
 	-- Yoder Stuart <stuart.yoder@freescale.com>
diff --git a/Documentation/manual.txt b/Documentation/manual.txt
index 65c8540..d313715 100644
--- a/Documentation/manual.txt
+++ b/Documentation/manual.txt
@@ -133,6 +133,14 @@ Options:
 	By default the most recent version is generated.
 	Relevant for dtb and asm output only.
 
+    -@
+        Dynamic resolution mode. For non /plugin/ compilations generate
+	a __symbols__ node containing a list of all nodes with a label.
+	When /plugin/ is used, unresolved references are recorded in
+	a __fixups__ node, while local phandle references are recorded
+	in a __local_fixups__ node.
+	See Documentation/dt-object-internal.txt
+
 
 The <output_version> defines what version of the "blob" format will be
 generated.  Supported versions are 1, 2, 3, 16 and 17.  The default is
diff --git a/checks.c b/checks.c
index ee96a25..970c0a3 100644
--- a/checks.c
+++ b/checks.c
@@ -457,22 +457,93 @@ static void fixup_phandle_references(struct check *c, struct node *dt,
 				     struct node *node, struct property *prop)
 {
 	struct marker *m = prop->val.markers;
+	struct fixup *f, **fp;
+	struct fixup_entry *fe, **fep;
 	struct node *refnode;
 	cell_t phandle;
+	int has_phandle_refs;
+
+	has_phandle_refs = 0;
+	for_each_marker_of_type(m, REF_PHANDLE) {
+		has_phandle_refs = 1;
+		break;
+	}
+
+	if (!has_phandle_refs)
+		return;
 
 	for_each_marker_of_type(m, REF_PHANDLE) {
 		assert(m->offset + sizeof(cell_t) <= prop->val.len);
 
 		refnode = get_node_by_ref(dt, m->ref);
-		if (! refnode) {
+		if (!refnode && !symbol_fixup_support) {
 			FAIL(c, "Reference to non-existent node or label \"%s\"\n",
-			     m->ref);
+				m->ref);
 			continue;
 		}
 
-		phandle = get_node_phandle(dt, refnode);
-		*((cell_t *)(prop->val.val + m->offset)) = cpu_to_fdt32(phandle);
+		if (!refnode) {
+			/* allocate fixup entry */
+			fe = xmalloc(sizeof(*fe));
+
+			fe->node = node;
+			fe->prop = prop;
+			fe->offset = m->offset;
+			fe->next = NULL;
+
+			/* search for an already existing fixup */
+			for_each_fixup(dt, f)
+				if (strcmp(f->ref, m->ref) == 0)
+					break;
+
+			/* no fixup found, add new */
+			if (f == NULL) {
+				f = xmalloc(sizeof(*f));
+				f->ref = m->ref;
+				f->entries = NULL;
+				f->next = NULL;
+
+				/* add it to the tree */
+				fp = &dt->fixups;
+				while (*fp)
+					fp = &(*fp)->next;
+				*fp = f;
+			}
+
+			/* and now append fixup entry */
+			fep = &f->entries;
+			while (*fep)
+				fep = &(*fep)->next;
+			*fep = fe;
+
+			/* mark the entry as unresolved */
+			phandle = 0xdeadbeef;
+		} else {
+			phandle = get_node_phandle(dt, refnode);
+
+			/* if it's a plugin, we need to record it */
+			if (symbol_fixup_support && dt->is_plugin) {
+
+				/* allocate a new local fixup entry */
+				fe = xmalloc(sizeof(*fe));
+
+				fe->node = node;
+				fe->prop = prop;
+				fe->offset = m->offset;
+				fe->next = NULL;
+
+				/* append it to the local fixups */
+				fep = &dt->local_fixups;
+				while (*fep)
+					fep = &(*fep)->next;
+				*fep = fe;
+			}
+		}
+
+		*((cell_t *)(prop->val.val + m->offset)) =
+			cpu_to_fdt32(phandle);
 	}
+
 }
 ERROR(phandle_references, NULL, NULL, fixup_phandle_references, NULL,
       &duplicate_node_names, &explicit_phandles);
@@ -651,6 +722,45 @@ static void check_obsolete_chosen_interrupt_controller(struct check *c,
 }
 TREE_WARNING(obsolete_chosen_interrupt_controller, NULL);
 
+static void check_auto_label_phandles(struct check *c, struct node *dt,
+				       struct node *node)
+{
+	struct label *l;
+	struct symbol *s, **sp;
+	int has_label;
+
+	if (!symbol_fixup_support)
+		return;
+
+	has_label = 0;
+	for_each_label(node->labels, l) {
+		has_label = 1;
+		break;
+	}
+
+	if (!has_label)
+		return;
+
+	/* force allocation of a phandle for this node */
+	(void)get_node_phandle(dt, node);
+
+	/* add the symbol */
+	for_each_label(node->labels, l) {
+
+		s = xmalloc(sizeof(*s));
+		s->label = l;
+		s->node = node;
+		s->next = NULL;
+
+		/* add it to the symbols list */
+		sp = &dt->symbols;
+		while (*sp)
+			sp = &((*sp)->next);
+		*sp = s;
+	}
+}
+NODE_WARNING(auto_label_phandles, NULL);
+
 static struct check *check_table[] = {
 	&duplicate_node_names, &duplicate_property_names,
 	&node_name_chars, &node_name_format, &property_name_chars,
@@ -669,6 +779,8 @@ static struct check *check_table[] = {
 	&avoid_default_addr_size,
 	&obsolete_chosen_interrupt_controller,
 
+	&auto_label_phandles,
+
 	&always_fail,
 };
 
diff --git a/dtc-lexer.l b/dtc-lexer.l
index 3b41bfc..78d5132 100644
--- a/dtc-lexer.l
+++ b/dtc-lexer.l
@@ -112,6 +112,11 @@ static int pop_input_file(void);
 			return DT_V1;
 		}
 
+<*>"/plugin/"	{
+			DPRINT("Keyword: /plugin/\n");
+			return DT_PLUGIN;
+		}
+
 <*>"/memreserve/"	{
 			DPRINT("Keyword: /memreserve/\n");
 			BEGIN_DEFAULT();
diff --git a/dtc-parser.y b/dtc-parser.y
index f412460..e444acf 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y
@@ -20,6 +20,7 @@
 
 %{
 #include <stdio.h>
+#include <inttypes.h>
 
 #include "dtc.h"
 #include "srcpos.h"
@@ -56,9 +57,11 @@ static unsigned char eval_char_literal(const char *s);
 	struct node *nodelist;
 	struct reserve_info *re;
 	uint64_t integer;
+	int is_plugin;
 }
 
 %token DT_V1
+%token DT_PLUGIN
 %token DT_MEMRESERVE
 %token DT_LSHIFT DT_RSHIFT DT_LE DT_GE DT_EQ DT_NE DT_AND DT_OR
 %token DT_BITS
@@ -76,6 +79,7 @@ static unsigned char eval_char_literal(const char *s);
 
 %type <data> propdata
 %type <data> propdataprefix
+%type <is_plugin> plugindecl
 %type <re> memreserve
 %type <re> memreserves
 %type <array> arrayprefix
@@ -106,10 +110,23 @@ static unsigned char eval_char_literal(const char *s);
 %%
 
 sourcefile:
-	  DT_V1 ';' memreserves devicetree
+	  DT_V1 ';' plugindecl memreserves devicetree
 		{
-			the_boot_info = build_boot_info($3, $4,
-							guess_boot_cpuid($4));
+			$5->is_plugin = $3;
+			$5->is_root = 1;
+			the_boot_info = build_boot_info($4, $5,
+							guess_boot_cpuid($5));
+		}
+	;
+
+plugindecl:
+	/* empty */
+		{
+			$$ = 0;
+		}
+	| DT_PLUGIN ';'
+		{
+			$$ = 1;
 		}
 	;
 
diff --git a/dtc.c b/dtc.c
index e3c9653..d2f9647 100644
--- a/dtc.c
+++ b/dtc.c
@@ -29,6 +29,7 @@ int reservenum;		/* Number of memory reservation slots */
 int minsize;		/* Minimum blob size */
 int padsize;		/* Additional padding to blob */
 int phandle_format = PHANDLE_BOTH;	/* Use linux,phandle or phandle properties */
+int symbol_fixup_support = 0;
 
 static void fill_fullpaths(struct node *tree, const char *prefix)
 {
@@ -49,7 +50,7 @@ static void fill_fullpaths(struct node *tree, const char *prefix)
 
 /* Usage related data. */
 static const char usage_synopsis[] = "dtc [options] <input file>";
-static const char usage_short_opts[] = "qI:O:o:V:d:R:S:p:fb:i:H:sW:E:hv";
+static const char usage_short_opts[] = "qI:O:o:V:d:R:S:p:fb:i:H:sW:E:hv:@";
 static struct option const usage_long_opts[] = {
 	{"quiet",            no_argument, NULL, 'q'},
 	{"in-format",         a_argument, NULL, 'I'},
@@ -67,6 +68,7 @@ static struct option const usage_long_opts[] = {
 	{"phandle",           a_argument, NULL, 'H'},
 	{"warning",           a_argument, NULL, 'W'},
 	{"error",             a_argument, NULL, 'E'},
+	{"symbols",           a_argument, NULL, '@'},
 	{"help",             no_argument, NULL, 'h'},
 	{"version",          no_argument, NULL, 'v'},
 	{NULL,               no_argument, NULL, 0x0},
@@ -97,6 +99,7 @@ static const char * const usage_opts_help[] = {
 	 "\t\tboth   - Both \"linux,phandle\" and \"phandle\" properties",
 	"\n\tEnable/disable warnings (prefix with \"no-\")",
 	"\n\tEnable/disable errors (prefix with \"no-\")",
+	"\n\tSymbols and Fixups support",
 	"\n\tPrint this help and exit",
 	"\n\tPrint version and exit",
 	NULL,
@@ -184,7 +187,9 @@ int main(int argc, char *argv[])
 		case 'E':
 			parse_checks_option(false, true, optarg);
 			break;
-
+		case '@':
+			symbol_fixup_support = 1;
+			break;
 		case 'h':
 			usage(NULL);
 		default:
diff --git a/dtc.h b/dtc.h
index 264a20c..8c9059b 100644
--- a/dtc.h
+++ b/dtc.h
@@ -54,6 +54,7 @@ extern int reservenum;		/* Number of memory reservation slots */
 extern int minsize;		/* Minimum blob size */
 extern int padsize;		/* Additional padding to blob */
 extern int phandle_format;	/* Use linux,phandle or phandle properties */
+extern int symbol_fixup_support;/* enable symbols & fixup support */
 
 #define PHANDLE_LEGACY	0x1
 #define PHANDLE_EPAPR	0x2
@@ -132,6 +133,25 @@ struct label {
 	struct label *next;
 };
 
+struct fixup_entry {
+	int offset;
+	struct node *node;
+	struct property *prop;
+	struct fixup_entry *next;
+};
+
+struct fixup {
+	char *ref;
+	struct fixup_entry *entries;
+	struct fixup *next;
+};
+
+struct symbol {
+	struct label *label;
+	struct node *node;
+	struct symbol *next;
+};
+
 struct property {
 	int deleted;
 	char *name;
@@ -158,6 +178,12 @@ struct node {
 	int addr_cells, size_cells;
 
 	struct label *labels;
+
+	int is_root;
+	int is_plugin;
+	struct fixup *fixups;
+	struct symbol *symbols;
+	struct fixup_entry *local_fixups;
 };
 
 #define for_each_label_withdel(l0, l) \
@@ -181,6 +207,18 @@ struct node {
 	for_each_child_withdel(n, c) \
 		if (!(c)->deleted)
 
+#define for_each_fixup(n, f) \
+	for ((f) = (n)->fixups; (f); (f) = (f)->next)
+
+#define for_each_fixup_entry(f, fe) \
+	for ((fe) = (f)->entries; (fe); (fe) = (fe)->next)
+
+#define for_each_symbol(n, s) \
+	for ((s) = (n)->symbols; (s); (s) = (s)->next)
+
+#define for_each_local_fixup_entry(n, fe) \
+	for ((fe) = (n)->local_fixups; (fe); (fe) = (fe)->next)
+
 void add_label(struct label **labels, char *label);
 void delete_labels(struct label **labels);
 
diff --git a/flattree.c b/flattree.c
index 665dad7..6237715 100644
--- a/flattree.c
+++ b/flattree.c
@@ -262,6 +262,12 @@ static void flatten_tree(struct node *tree, struct emitter *emit,
 	struct property *prop;
 	struct node *child;
 	int seen_name_prop = 0;
+	struct symbol *sym;
+	struct fixup *f;
+	struct fixup_entry *fe;
+	char *name, *s;
+	const char *fullpath;
+	int namesz, nameoff, vallen;
 
 	if (tree->deleted)
 		return;
@@ -310,6 +316,139 @@ static void flatten_tree(struct node *tree, struct emitter *emit,
 		flatten_tree(child, emit, etarget, strbuf, vi);
 	}
 
+	if (!symbol_fixup_support)
+		goto no_symbols;
+
+	/* add the symbol nodes (if any) */
+	if (tree->symbols) {
+
+		emit->beginnode(etarget, NULL);
+		emit->string(etarget, "__symbols__", 0);
+		emit->align(etarget, sizeof(cell_t));
+
+		for_each_symbol(tree, sym) {
+
+			vallen = strlen(sym->node->fullpath);
+
+			nameoff = stringtable_insert(strbuf, sym->label->label);
+
+			emit->property(etarget, NULL);
+			emit->cell(etarget, vallen + 1);
+			emit->cell(etarget, nameoff);
+
+			if ((vi->flags & FTF_VARALIGN) && vallen >= 8)
+				emit->align(etarget, 8);
+
+			emit->string(etarget, sym->node->fullpath,
+					strlen(sym->node->fullpath));
+			emit->align(etarget, sizeof(cell_t));
+		}
+
+		emit->endnode(etarget, NULL);
+	}
+
+	/* add the fixup nodes */
+	if (tree->fixups) {
+
+		/* emit the external fixups */
+		emit->beginnode(etarget, NULL);
+		emit->string(etarget, "__fixups__", 0);
+		emit->align(etarget, sizeof(cell_t));
+
+		for_each_fixup(tree, f) {
+
+			namesz = 0;
+			for_each_fixup_entry(f, fe) {
+				fullpath = fe->node->fullpath;
+				if (fullpath[0] == '\0')
+					fullpath = "/";
+				namesz += strlen(fullpath) + 1;
+			      	namesz += strlen(fe->prop->name) + 1;
+				namesz += 32;	/* space for :<number> + '\0' */
+			}
+
+			name = xmalloc(namesz);
+
+			s = name;
+			for_each_fixup_entry(f, fe) {
+				fullpath = fe->node->fullpath;
+				if (fullpath[0] == '\0')
+					fullpath = "/";
+				snprintf(s, name + namesz - s, "%s:%s:%d",
+						fullpath,
+						fe->prop->name, fe->offset);
+				s += strlen(s) + 1;
+			}
+
+			nameoff = stringtable_insert(strbuf, f->ref);
+			vallen = s - name - 1;
+
+			emit->property(etarget, NULL);
+			emit->cell(etarget, vallen + 1);
+			emit->cell(etarget, nameoff);
+
+			if ((vi->flags & FTF_VARALIGN) && vallen >= 8)
+				emit->align(etarget, 8);
+
+			emit->string(etarget, name, vallen);
+			emit->align(etarget, sizeof(cell_t));
+
+			free(name);
+		}
+
+		emit->endnode(etarget, tree->labels);
+	}
+
+	/* add the local fixup property */
+	if (tree->local_fixups) {
+
+		/* emit the external fixups */
+		emit->beginnode(etarget, NULL);
+		emit->string(etarget, "__local_fixups__", 0);
+		emit->align(etarget, sizeof(cell_t));
+
+		namesz = 0;
+		for_each_local_fixup_entry(tree, fe) {
+			fullpath = fe->node->fullpath;
+			if (fullpath[0] == '\0')
+				fullpath = "/";
+			namesz += strlen(fullpath) + 1;
+			namesz += strlen(fe->prop->name) + 1;
+			namesz += 32;	/* space for :<number> + '\0' */
+		}
+
+		name = xmalloc(namesz);
+
+		s = name;
+		for_each_local_fixup_entry(tree, fe) {
+			fullpath = fe->node->fullpath;
+			if (fullpath[0] == '\0')
+				fullpath = "/";
+			snprintf(s, name + namesz - s, "%s:%s:%d",
+					fullpath, fe->prop->name,
+					fe->offset);
+			s += strlen(s) + 1;
+		}
+
+		nameoff = stringtable_insert(strbuf, "fixup");
+		vallen = s - name - 1;
+
+		emit->property(etarget, NULL);
+		emit->cell(etarget, vallen + 1);
+		emit->cell(etarget, nameoff);
+
+		if ((vi->flags & FTF_VARALIGN) && vallen >= 8)
+			emit->align(etarget, 8);
+
+		emit->string(etarget, name, vallen);
+		emit->align(etarget, sizeof(cell_t));
+
+		free(name);
+
+		emit->endnode(etarget, tree->labels);
+	}
+
+no_symbols:
 	emit->endnode(etarget, tree->labels);
 }
 
-- 
1.8.3.1