From 70161ff336674ecfd20614a9c0c61cb17a6e9e83 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Fri, 28 Nov 2014 16:03:33 +0000 Subject: [PATCH] of: Drop ->next pointer from struct device_node The ->next pointer in struct device_node is a hanger-on from when it was used to iterate over the whole tree by a particular device_type property value. Those days are long over, but the fdt unflattening code still uses it to put nodes in the unflattened tree into the same order as node in the flat tree. By reworking the unflattening code to reverse the list after unflattening all the children of a node, the pointer can be dropped which gives a small amount of memory savings. Signed-off-by: Grant Likely Acked-by: Frank Rowand Cc: Gaurav Minocha --- drivers/of/fdt.c | 24 ++++++++++++++++++------ include/linux/of.h | 1 - 2 files changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 7f6ee31..a41f9fd 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -226,12 +226,8 @@ static void * unflatten_dt_node(void *blob, prev_pp = &np->properties; 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->sibling = dad->child; + dad->child = np; } } /* process properties */ @@ -329,6 +325,22 @@ static void * unflatten_dt_node(void *blob, if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND) pr_err("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; diff --git a/include/linux/of.h b/include/linux/of.h index 8b021db..3f0f0ff 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -56,7 +56,6 @@ 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 kobject kobj; unsigned long _flags; void *data; -- 2.7.4