[PATCH 3/3] of/flattree: use of_attach_node to build tree, and associated cleanups

From: Andres Salomon
Date: Wed Mar 09 2011 - 19:16:26 EST


Use a common function (of_attach_node) to build the device tree. This
simplifies the flat device tree creation a bit, and as an added bonus allows
us to drop a (now unused) field from the device_node struct.

There are a few minor cleanups snuck in here as well (comment additions, etc).

Signed-off-by: Andres Salomon <dilinger@xxxxxxxxxx>
---
drivers/of/fdt.c | 42 ++++++++++++++++--------------------------
include/linux/of.h | 1 -
2 files changed, 16 insertions(+), 27 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index af824e7..e70cee8 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -139,16 +139,17 @@ static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
/**
* 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
* @p: pointer to node in flat tree
* @dad: Parent struct device_node
- * @allnextpp: pointer to ->allnext from last allocated device_node
+ * @size_scan: are we figuring out amount of memory to allocate?
* @fpsize: Size of the node path up at the current depth.
*/
unsigned long unflatten_dt_node(struct boot_param_header *blob,
unsigned long mem,
unsigned long *p,
struct device_node *dad,
- struct device_node ***allnextpp,
+ bool size_scan,
unsigned long fpsize)
{
struct device_node *np;
@@ -195,7 +196,7 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,

np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
__alignof__(struct device_node));
- if (allnextpp) {
+ if (!size_scan) {
memset(np, 0, sizeof(*np));
np->full_name = ((char *)np) + sizeof(struct device_node);
if (new_format) {
@@ -217,19 +218,10 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
} else
memcpy(np->full_name, pathp, l);
prev_pp = &np->properties;
- **allnextpp = np;
- *allnextpp = &np->allnext;
- if (dad != NULL) {
- np->parent = dad;
- /* we temporarily use the next field as `last_child'*/
- if (dad->next == NULL)
- dad->child = np;
- else
- dad->next->sibling = np;
- dad->next = np;
- }
+ np->parent = dad;
kref_init(&np->kref);
}
+ /* process properties */
while (1) {
u32 sz, noff;
char *pname;
@@ -258,7 +250,7 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
l = strlen(pname) + 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property),
__alignof__(struct property));
- if (allnextpp) {
+ if (!size_scan) {
/* We accept flattened tree phandles either in
* ePAPR-style "phandle" properties, or the
* legacy "linux,phandle" properties. If both
@@ -301,7 +293,7 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
sz = (pa - ps) + 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
__alignof__(struct property));
- if (allnextpp) {
+ if (!size_scan) {
pp->name = "name";
pp->length = sz;
pp->value = pp + 1;
@@ -313,7 +305,7 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
(char *)pp->value);
}
}
- if (allnextpp) {
+ if (!size_scan) {
*prev_pp = NULL;
np->name = of_get_property(np, "name", NULL);
np->type = of_get_property(np, "device_type", NULL);
@@ -322,12 +314,14 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
np->name = "<NULL>";
if (!np->type)
np->type = "<NULL>";
+
+ of_attach_node(np);
}
while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
if (tag == OF_DT_NOP)
*p += 4;
else
- mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
+ mem = unflatten_dt_node(blob, mem, p, np, size_scan,
fpsize);
tag = be32_to_cpup((__be32 *)(*p));
}
@@ -347,16 +341,13 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
* 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
* @dt_alloc: An allocator that provides a virtual address to memory
* for the resulting tree
*/
void __unflatten_device_tree(struct boot_param_header *blob,
- struct device_node **mynodes,
void * (*dt_alloc)(u64 size, u64 align))
{
unsigned long start, mem, size;
- struct device_node **allnextp = mynodes;

pr_debug(" -> unflatten_device_tree()\n");

@@ -378,7 +369,7 @@ void __unflatten_device_tree(struct boot_param_header *blob,
/* First pass, scan for size */
start = ((unsigned long)blob) +
be32_to_cpu(blob->off_dt_struct);
- size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
+ size = unflatten_dt_node(blob, 0, &start, NULL, true, 0);
size = (size | 3) + 1;

pr_debug(" size is %lx, allocating...\n", size);
@@ -394,13 +385,12 @@ void __unflatten_device_tree(struct boot_param_header *blob,
/* Second pass, do actual unflattening */
start = ((unsigned long)blob) +
be32_to_cpu(blob->off_dt_struct);
- unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
+ unflatten_dt_node(blob, mem, &start, NULL, false, 0);
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)
pr_warning("End of tree marker overwritten: %08x\n",
be32_to_cpu(((__be32 *)mem)[size / 4]));
- *allnextp = NULL;

pr_debug(" <- unflatten_device_tree()\n");
}
@@ -423,7 +413,7 @@ void of_fdt_unflatten_tree(unsigned long *blob,
{
struct boot_param_header *device_tree =
(struct boot_param_header *)blob;
- __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
+ __unflatten_device_tree(device_tree, &kernel_tree_alloc);
}
EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);

@@ -702,7 +692,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
*/
void __init unflatten_device_tree(void)
{
- __unflatten_device_tree(initial_boot_params, &allnodes,
+ __unflatten_device_tree(initial_boot_params,
early_init_dt_alloc_memory_arch);

/* Get pointer to OF "/chosen" node for use everywhere */
diff --git a/include/linux/of.h b/include/linux/of.h
index bb36473..95754ca 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -50,7 +50,6 @@ struct device_node {
struct device_node *parent;
struct device_node *child;
struct device_node *sibling;
- struct device_node *next; /* next device of same type */
struct device_node *allnext; /* next in list of all nodes */
struct proc_dir_entry *pde; /* this node's proc directory */
struct kref kref;
--
1.7.2.3

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