[PATCH 2/3] fdt.c: Refactor unflatten_dt_node

Stephen Neuendorffer stephen.neuendorffer at xilinx.com
Thu Nov 18 06:15:44 EST 2010


unflatten_dt_node is a helper function that does most of the work to
convert a device tree blob into tree of device nodes.  This code
now uses a passed-in blob instead of using the single boot-time blob,
allowing it to be called in more contexts.

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer at xilinx.com>
---
 drivers/of/fdt.c |  251 +++++++++++++++++++++++++++---------------------------
 1 files changed, 127 insertions(+), 124 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 6ae207a..c448b2f 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -101,120 +101,7 @@ int fdt_is_compatible(unsigned long node, const char *compat,
 	return 0;
 }
 
-/* Everything below here references initial_boot_params directly. */
-int __initdata dt_root_addr_cells;
-int __initdata dt_root_size_cells;
-
-struct boot_param_header *initial_boot_params;
-
-char *find_flat_dt_string(u32 offset)
-{
-	return ((char *)initial_boot_params) +
-		be32_to_cpu(initial_boot_params->off_dt_strings) + offset;
-}
-
-/**
- * of_scan_flat_dt - scan flattened tree blob and call callback on each.
- * @it: callback function
- * @data: context data pointer
- *
- * This function is used to scan the flattened device-tree, it is
- * used to extract the memory information at boot before we can
- * unflatten the tree
- */
-int __init of_scan_flat_dt(int (*it)(unsigned long node,
-				     const char *uname, int depth,
-				     void *data),
-			   void *data)
-{
-	unsigned long p = ((unsigned long)initial_boot_params) +
-		be32_to_cpu(initial_boot_params->off_dt_struct);
-	int rc = 0;
-	int depth = -1;
-
-	do {
-		u32 tag = be32_to_cpup((__be32 *)p);
-		char *pathp;
-
-		p += 4;
-		if (tag == OF_DT_END_NODE) {
-			depth--;
-			continue;
-		}
-		if (tag == OF_DT_NOP)
-			continue;
-		if (tag == OF_DT_END)
-			break;
-		if (tag == OF_DT_PROP) {
-			u32 sz = be32_to_cpup((__be32 *)p);
-			p += 8;
-			if (be32_to_cpu(initial_boot_params->version) < 0x10)
-				p = ALIGN(p, sz >= 8 ? 8 : 4);
-			p += sz;
-			p = ALIGN(p, 4);
-			continue;
-		}
-		if (tag != OF_DT_BEGIN_NODE) {
-			pr_err("Invalid tag %x in flat device tree!\n", tag);
-			return -EINVAL;
-		}
-		depth++;
-		pathp = (char *)p;
-		p = ALIGN(p + strlen(pathp) + 1, 4);
-		if ((*pathp) == '/') {
-			char *lp, *np;
-			for (lp = NULL, np = pathp; *np; np++)
-				if ((*np) == '/')
-					lp = np+1;
-			if (lp != NULL)
-				pathp = lp;
-		}
-		rc = it(p, pathp, depth, data);
-		if (rc != 0)
-			break;
-	} while (1);
-
-	return rc;
-}
-
-/**
- * of_get_flat_dt_root - find the root node in the flat blob
- */
-unsigned long __init of_get_flat_dt_root(void)
-{
-	unsigned long p = ((unsigned long)initial_boot_params) +
-		be32_to_cpu(initial_boot_params->off_dt_struct);
-
-	while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
-		p += 4;
-	BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
-	p += 4;
-	return ALIGN(p + strlen((char *)p) + 1, 4);
-}
-
-/**
- * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
- *
- * This function can be used within scan_flattened_dt callback to get
- * access to properties
- */
-void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
-				 unsigned long *size)
-{
-	return fdt_get_property(node, name, size, initial_boot_params);
-}
-
-/**
- * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
- * @node: node to test
- * @compat: compatible string to compare with compatible list.
- */
-int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
-{
-	return fdt_is_compatible(node, compat, initial_boot_params);
-}
-
-static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
+static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
 				       unsigned long align)
 {
 	void *res;
@@ -232,12 +119,14 @@ static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
  * @dad: Parent struct device_node
  * @allnextpp: pointer to ->allnext from last allocated device_node
  * @fpsize: Size of the node path up at the current depth.
+ * @blob: The parent device tree blob
  */
-unsigned long __init unflatten_dt_node(unsigned long mem,
-					unsigned long *p,
-					struct device_node *dad,
-					struct device_node ***allnextpp,
-					unsigned long fpsize)
+unsigned long unflatten_dt_node(unsigned long mem,
+				unsigned long *p,
+				struct device_node *dad,
+				struct device_node ***allnextpp,
+				unsigned long fpsize,
+				struct boot_param_header *blob)
 {
 	struct device_node *np;
 	struct property *pp, **prev_pp = NULL;
@@ -333,10 +222,10 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
 		sz = be32_to_cpup((__be32 *)(*p));
 		noff = be32_to_cpup((__be32 *)((*p) + 4));
 		*p += 8;
-		if (be32_to_cpu(initial_boot_params->version) < 0x10)
+		if (be32_to_cpu(blob->version) < 0x10)
 			*p = ALIGN(*p, sz >= 8 ? 8 : 4);
 
-		pname = find_flat_dt_string(noff);
+		pname = fdt_get_string(noff, blob);
 		if (pname == NULL) {
 			pr_info("Can't find property name in list !\n");
 			break;
@@ -415,7 +304,8 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
 		if (tag == OF_DT_NOP)
 			*p += 4;
 		else
-			mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
+			mem = unflatten_dt_node(mem, p, np, allnextpp,
+						fpsize, blob);
 		tag = be32_to_cpup((__be32 *)(*p));
 	}
 	if (tag != OF_DT_END_NODE) {
@@ -426,6 +316,119 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
 	return mem;
 }
 
+/* Everything below here references initial_boot_params directly. */
+int __initdata dt_root_addr_cells;
+int __initdata dt_root_size_cells;
+
+struct boot_param_header *initial_boot_params;
+
+char *find_flat_dt_string(u32 offset)
+{
+	return ((char *)initial_boot_params) +
+		be32_to_cpu(initial_boot_params->off_dt_strings) + offset;
+}
+
+/**
+ * of_scan_flat_dt - scan flattened tree blob and call callback on each.
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan the flattened device-tree, it is
+ * used to extract the memory information at boot before we can
+ * unflatten the tree
+ */
+int __init of_scan_flat_dt(int (*it)(unsigned long node,
+				     const char *uname, int depth,
+				     void *data),
+			   void *data)
+{
+	unsigned long p = ((unsigned long)initial_boot_params) +
+		be32_to_cpu(initial_boot_params->off_dt_struct);
+	int rc = 0;
+	int depth = -1;
+
+	do {
+		u32 tag = be32_to_cpup((__be32 *)p);
+		char *pathp;
+
+		p += 4;
+		if (tag == OF_DT_END_NODE) {
+			depth--;
+			continue;
+		}
+		if (tag == OF_DT_NOP)
+			continue;
+		if (tag == OF_DT_END)
+			break;
+		if (tag == OF_DT_PROP) {
+			u32 sz = be32_to_cpup((__be32 *)p);
+			p += 8;
+			if (be32_to_cpu(initial_boot_params->version) < 0x10)
+				p = ALIGN(p, sz >= 8 ? 8 : 4);
+			p += sz;
+			p = ALIGN(p, 4);
+			continue;
+		}
+		if (tag != OF_DT_BEGIN_NODE) {
+			pr_err("Invalid tag %x in flat device tree!\n", tag);
+			return -EINVAL;
+		}
+		depth++;
+		pathp = (char *)p;
+		p = ALIGN(p + strlen(pathp) + 1, 4);
+		if ((*pathp) == '/') {
+			char *lp, *np;
+			for (lp = NULL, np = pathp; *np; np++)
+				if ((*np) == '/')
+					lp = np+1;
+			if (lp != NULL)
+				pathp = lp;
+		}
+		rc = it(p, pathp, depth, data);
+		if (rc != 0)
+			break;
+	} while (1);
+
+	return rc;
+}
+
+/**
+ * of_get_flat_dt_root - find the root node in the flat blob
+ */
+unsigned long __init of_get_flat_dt_root(void)
+{
+	unsigned long p = ((unsigned long)initial_boot_params) +
+		be32_to_cpu(initial_boot_params->off_dt_struct);
+
+	while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
+		p += 4;
+	BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
+	p += 4;
+	return ALIGN(p + strlen((char *)p) + 1, 4);
+}
+
+/**
+ * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
+ *
+ * This function can be used within scan_flattened_dt callback to get
+ * access to properties
+ */
+void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
+				 unsigned long *size)
+{
+	return fdt_get_property(node, name, size, initial_boot_params);
+}
+
+/**
+ * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ */
+int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+{
+	return fdt_is_compatible(node, compat, initial_boot_params);
+}
+
 #ifdef CONFIG_BLK_DEV_INITRD
 /**
  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
@@ -607,7 +610,7 @@ void __init unflatten_device_tree(void)
 	/* First pass, scan for size */
 	start = ((unsigned long)initial_boot_params) +
 		be32_to_cpu(initial_boot_params->off_dt_struct);
-	size = unflatten_dt_node(0, &start, NULL, NULL, 0);
+	size = unflatten_dt_node(0, &start, NULL, NULL, 0, initial_boot_params);
 	size = (size | 3) + 1;
 
 	pr_debug("  size is %lx, allocating...\n", size);
@@ -624,7 +627,7 @@ void __init unflatten_device_tree(void)
 	/* Second pass, do actual unflattening */
 	start = ((unsigned long)initial_boot_params) +
 		be32_to_cpu(initial_boot_params->off_dt_struct);
-	unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
+	unflatten_dt_node(mem, &start, NULL, &allnextp, 0, initial_boot_params);
 	if (be32_to_cpup((__be32 *)start) != OF_DT_END)
 		pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
 	if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
-- 
1.5.6.6



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