The device tree data structure uses a custom linked list implementation
which is baroque and prone to bugs. Replace the allnodes list with a
list_head and the common list_head accessor functions.
At the same time, move the private for_each_of_allnodes() macro into
drivers/of/base.c. It must not be used outside of the core code because
the macro doesn't take into account device tree locking.
Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Rob Herring <rob.herring@xxxxxxxxxx>
---
arch/arm/mach-vexpress/v2m.c | 2 +-
drivers/of/base.c | 126 +++++++++++++++++++-----------------
drivers/of/fdt.c | 27 ++++----
drivers/of/pdt.c | 26 +++-----
drivers/pci/hotplug/rpadlpar_core.c | 2 +-
include/linux/of.h | 9 ++-
include/linux/of_fdt.h | 3 +-
include/linux/of_pdt.h | 3 +-
8 files changed, 96 insertions(+), 102 deletions(-)
diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index 4f8b8cb17ff5..57151ba5edee 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -412,7 +412,7 @@ void __init v2m_dt_init_early(void)
vexpress_sysreg_of_early_init();
/* Confirm board type against DT property, if available */
- if (of_property_read_u32(of_allnodes, "arm,hbi", &dt_hbi) == 0) {
+ if (of_property_read_u32(of_root, "arm,hbi", &dt_hbi) == 0) {
u32 hbi = vexpress_get_hbi(VEXPRESS_SITE_MASTER);
if (WARN_ON(dt_hbi != hbi))
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 567e6e1b7921..6c0bd86b802f 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -31,14 +31,22 @@
LIST_HEAD(aliases_lookup);
-struct device_node *of_allnodes;
+LIST_HEAD(of_allnodes);
EXPORT_SYMBOL(of_allnodes);
-struct device_node *of_chosen;
-struct device_node *of_aliases;
+struct device_node *of_root = NULL;
+struct device_node *of_chosen = NULL;
+struct device_node *of_aliases = NULL;
static struct device_node *of_stdout;
static struct kset *of_kset;
+#define of_allnodes_prepare(dn) \
+ list_prepare_entry(dn, &of_allnodes, allnext)
+#define for_each_of_allnodes(dn) \
+ list_for_each_entry(dn, &of_allnodes, allnext)
+#define for_each_of_allnodes_continue(dn) \
+ list_for_each_entry_continue(dn, &of_allnodes, allnext)
+
/*
* Used to protect the of_aliases; but also overloaded to hold off addition of
* nodes to sysfs
@@ -299,7 +307,7 @@ static int __init of_init(void)
mutex_unlock(&of_aliases_mutex);
/* Symlink in /proc as required by userspace ABI */
- if (of_allnodes)
+ if (of_root)
proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
return 0;
@@ -348,18 +356,18 @@ EXPORT_SYMBOL(of_find_property);
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
-struct device_node *of_find_all_nodes(struct device_node *prev)
+struct device_node *of_find_all_nodes(struct device_node *np)
{
- struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = prev ? prev->allnext : of_allnodes;
- for (; np != NULL; np = np->allnext)
- if (of_node_get(np))
- break;
- of_node_put(prev);
+ of_node_put(np);
+ np = list_next_entry(of_allnodes_prepare(np), allnext);
+ if (&np->allnext == &of_allnodes)
+ np = NULL;
+ of_node_get(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
return np;
}
EXPORT_SYMBOL(of_find_all_nodes);
@@ -831,7 +839,7 @@ struct device_node *of_find_node_by_path(const char *path)
unsigned long flags;
if (strcmp(path, "/") == 0)
- return of_node_get(of_allnodes);
+ return of_node_get(of_root);
/* The path could begin with an alias */
if (*path != '/') {
@@ -856,7 +864,7 @@ struct device_node *of_find_node_by_path(const char *path)
/* Step down the tree matching path components */
raw_spin_lock_irqsave(&devtree_lock, flags);
if (!np)
- np = of_node_get(of_allnodes);
+ np = of_node_get(of_root);
while (np && *path == '/') {
path++; /* Increment past '/' delimiter */
np = __of_find_node_by_path(np, path);
@@ -881,16 +889,18 @@ EXPORT_SYMBOL(of_find_node_by_path);
struct device_node *of_find_node_by_name(struct device_node *from,
const char *name)
{
- struct device_node *np;
+ struct device_node *np = NULL;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext)
- if (np->name && (of_node_cmp(np->name, name) == 0)
- && of_node_get(np))
- break;
of_node_put(from);
+ from = of_allnodes_prepare(from);
+ for_each_of_allnodes_continue(from) {
+ if (from->name && (of_node_cmp(from->name, name) == 0)) {
+ np = of_node_get(from);
+ break;
+ }
+ }
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
@@ -911,16 +921,18 @@ EXPORT_SYMBOL(of_find_node_by_name);
struct device_node *of_find_node_by_type(struct device_node *from,
const char *type)
{
- struct device_node *np;
+ struct device_node *np = NULL;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext)
- if (np->type && (of_node_cmp(np->type, type) == 0)
- && of_node_get(np))
- break;
of_node_put(from);
+ from = of_allnodes_prepare(from);
+ for_each_of_allnodes_continue(from) {
+ if (from->type && (of_node_cmp(from->type, type) == 0)) {
+ np = of_node_get(from);
+ break;
+ }
+ }
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
@@ -943,18 +955,20 @@ EXPORT_SYMBOL(of_find_node_by_type);
struct device_node *of_find_compatible_node(struct device_node *from,
const char *type, const char *compatible)
{
- struct device_node *np;
+ struct device_node *np = NULL;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext) {
- if (__of_device_is_compatible(np, compatible, type, NULL) &&
- of_node_get(np))
+ of_node_put(from);
+ from = of_allnodes_prepare(from);
+ for_each_of_allnodes_continue(from) {
+ if (__of_device_is_compatible(from, compatible, type, NULL)) {
+ np = of_node_get(from);
break;
+ }
}
- of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
return np;
}
EXPORT_SYMBOL(of_find_compatible_node);
@@ -974,22 +988,22 @@ EXPORT_SYMBOL(of_find_compatible_node);
struct device_node *of_find_node_with_property(struct device_node *from,
const char *prop_name)
{
- struct device_node *np;
+ struct device_node *np = NULL;
struct property *pp;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext) {
- for (pp = np->properties; pp; pp = pp->next) {
+ of_node_put(from);
+ from = of_allnodes_prepare(from);
+ for_each_of_allnodes_continue(from) {
+ for (pp = from->properties; pp; pp = pp->next) {
if (of_prop_cmp(pp->name, prop_name) == 0) {
- of_node_get(np);
+ np = of_node_get(from);
goto out;
}
}
}
-out:
- of_node_put(from);
+ out:
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
@@ -1054,7 +1068,7 @@ struct device_node *of_find_matching_node_and_match(struct device_node *from,
const struct of_device_id *matches,
const struct of_device_id **match)
{
- struct device_node *np;
+ struct device_node *np = NULL;
const struct of_device_id *m;
unsigned long flags;
@@ -1062,16 +1076,16 @@ struct device_node *of_find_matching_node_and_match(struct device_node *from,
*match = NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext) {
- m = __of_match_node(matches, np);
- if (m && of_node_get(np)) {
+ of_node_put(from);
+ from = of_allnodes_prepare(from);
+ for_each_of_allnodes_continue(from) {
+ if ((m = __of_match_node(matches, from))) {
+ np = of_node_get(from);
if (match)
*match = m;
break;
}
}
- of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
@@ -1113,14 +1127,16 @@ EXPORT_SYMBOL_GPL(of_modalias_node);
*/
struct device_node *of_find_node_by_phandle(phandle handle)
{
- struct device_node *np;
+ struct device_node *tmp, *np = NULL;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- for (np = of_allnodes; np; np = np->allnext)
- if (np->phandle == handle)
+ for_each_of_allnodes(tmp) {
+ if (tmp->phandle == handle) {
+ np = of_node_get(tmp);
break;
- of_node_get(np);
+ }
+ }
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
@@ -1959,10 +1975,9 @@ int of_attach_node(struct device_node *np)
return rc;
raw_spin_lock_irqsave(&devtree_lock, flags);
+ list_add_tail(&np->allnext, &of_allnodes);
np->sibling = np->parent->child;
- np->allnext = of_allnodes;
np->parent->child = np;
- of_allnodes = np;
of_node_clear_flag(np, OF_DETACHED);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
@@ -2000,16 +2015,7 @@ int of_detach_node(struct device_node *np)
return rc;
}
- if (of_allnodes == np)
- of_allnodes = np->allnext;
- else {
- struct device_node *prev;
- for (prev = of_allnodes;
- prev->allnext != np;
- prev = prev->allnext)
- ;
- prev->allnext = np->allnext;
- }
+ list_del(&np->allnext);
if (parent->child == np)
parent->child = np->sibling;
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 17be90f5445f..6876ac3d4b30 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -96,14 +96,14 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size,
* @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
+ * @allnext: list of ->allnext from this tree
* @fpsize: Size of the node path up at the current depth.
*/
static void * unflatten_dt_node(void *blob,
void *mem,
int *poffset,
struct device_node *dad,
- struct device_node ***allnextpp,
+ struct list_head *allnext,
unsigned long fpsize)
{
const __be32 *p;
@@ -151,7 +151,7 @@ static void * unflatten_dt_node(void *blob,
np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
__alignof__(struct device_node));
- if (allnextpp) {
+ if (allnext) {
char *fn;
of_node_init(np);
np->full_name = fn = ((char *)np) + sizeof(*np);
@@ -173,8 +173,7 @@ static void * unflatten_dt_node(void *blob,
memcpy(fn, pathp, l);
prev_pp = &np->properties;
- **allnextpp = np;
- *allnextpp = &np->allnext;
+ list_add_tail(&np->allnext, allnext);
if (dad != NULL) {
np->parent = dad;
/* we temporarily use the next field as `last_child'*/
@@ -205,7 +204,7 @@ static void * unflatten_dt_node(void *blob,
has_name = 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property),
__alignof__(struct property));
- if (allnextpp) {
+ if (allnext) {
/* We accept flattened tree phandles either in
* ePAPR-style "phandle" properties, or the
* legacy "linux,phandle" properties. If both
@@ -247,7 +246,7 @@ static void * unflatten_dt_node(void *blob,
sz = (pa - ps) + 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
__alignof__(struct property));
- if (allnextpp) {
+ if (allnext) {
pp->name = "name";
pp->length = sz;
pp->value = pp + 1;
@@ -259,7 +258,7 @@ static void * unflatten_dt_node(void *blob,
(char *)pp->value);
}
}
- if (allnextpp) {
+ if (allnext) {
*prev_pp = NULL;
np->name = of_get_property(np, "name", NULL);
np->type = of_get_property(np, "device_type", NULL);
@@ -275,7 +274,7 @@ static void * unflatten_dt_node(void *blob,
if (depth < 0)
depth = 0;
while (*poffset > 0 && depth > old_depth)
- mem = unflatten_dt_node(blob, mem, poffset, np, allnextpp,
+ mem = unflatten_dt_node(blob, mem, poffset, np, allnext,
fpsize);
if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
@@ -297,13 +296,12 @@ static void * unflatten_dt_node(void *blob,
* for the resulting tree
*/
static void __unflatten_device_tree(void *blob,
- struct device_node **mynodes,
+ struct list_head *allnext,
void * (*dt_alloc)(u64 size, u64 align))
{
unsigned long size;
int start;
void *mem;
- struct device_node **allnextp = mynodes;
pr_debug(" -> unflatten_device_tree()\n");
@@ -339,11 +337,10 @@ static void __unflatten_device_tree(void *blob,
/* Second pass, do actual unflattening */
start = 0;
- unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
+ unflatten_dt_node(blob, mem, &start, NULL, allnext, 0);
if (be32_to_cpup(mem + size) != 0xdeadbeef)
pr_warning("End of tree marker overwritten: %08x\n",
be32_to_cpup(mem + size));
- *allnextp = NULL;
pr_debug(" <- unflatten_device_tree()\n");
}
@@ -361,8 +358,7 @@ static void *kernel_tree_alloc(u64 size, u64 align)
* pointers of the nodes so the normal device-tree walking functions
* can be used.
*/
-void of_fdt_unflatten_tree(unsigned long *blob,
- struct device_node **mynodes)
+void of_fdt_unflatten_tree(unsigned long *blob, struct list_head *mynodes)
{
__unflatten_device_tree(blob, mynodes, &kernel_tree_alloc);
}
@@ -904,6 +900,7 @@ void __init unflatten_device_tree(void)
{
__unflatten_device_tree(initial_boot_params, &of_allnodes,
early_init_dt_alloc_memory_arch);
+ of_root = list_first_entry_or_null(&of_allnodes, struct device_node, allnext);
/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
of_alias_scan(early_init_dt_alloc_memory_arch);
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 36b4035881b0..38dd814870b4 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -25,8 +25,7 @@
static struct of_pdt_ops *of_pdt_prom_ops __initdata;
-void __initdata (*of_pdt_build_more)(struct device_node *dp,
- struct device_node ***nextp);
+void __initdata (*of_pdt_build_more)(struct device_node *dp);
#if defined(CONFIG_SPARC)
unsigned int of_pdt_unique_id __initdata;
@@ -192,8 +191,7 @@ static struct device_node * __init of_pdt_create_node(phandle node,
}
static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
- phandle node,
- struct device_node ***nextp)
+ phandle node)
{
struct device_node *ret = NULL, *prev_sibling = NULL;
struct device_node *dp;
@@ -210,16 +208,15 @@ static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
ret = dp;
prev_sibling = dp;
- *(*nextp) = dp;
- *nextp = &dp->allnext;
+ list_add_tail(&of_allnodes, &np->allnext);
dp->full_name = of_pdt_build_full_name(dp);
dp->child = of_pdt_build_tree(dp,
- of_pdt_prom_ops->getchild(node), nextp);
+ of_pdt_prom_ops->getchild(node));
if (of_pdt_build_more)
- of_pdt_build_more(dp, nextp);
+ of_pdt_build_more(dp);
node = of_pdt_prom_ops->getsibling(node);
}
@@ -234,20 +231,17 @@ static void * __init kernel_tree_alloc(u64 size, u64 align)
void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
{
- struct device_node **nextp;
-
BUG_ON(!ops);
of_pdt_prom_ops = ops;
- of_allnodes = of_pdt_create_node(root_node, NULL);
+ of_root = of_pdt_create_node(root_node, NULL);
#if defined(CONFIG_SPARC)
- of_allnodes->path_component_name = "";
+ of_root->path_component_name = "";
#endif
- of_allnodes->full_name = "/";
+ of_root->full_name = "/";
- nextp = &of_allnodes->allnext;
- of_allnodes->child = of_pdt_build_tree(of_allnodes,
- of_pdt_prom_ops->getchild(of_allnodes->phandle), &nextp);
+ list_add_tail(&of_allnodes, &of_root->allnext);
+ of_root->child = of_pdt_build_tree(of_root, of_pdt_prom_ops->getchild(of_root->phandle));
/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
of_alias_scan(kernel_tree_alloc);
diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
index 4fcdeedda31b..e25e4d1ec241 100644
--- a/drivers/pci/hotplug/rpadlpar_core.c
+++ b/drivers/pci/hotplug/rpadlpar_core.c
@@ -68,7 +68,7 @@ static struct device_node *find_php_slot_pci_node(char *drc_name,
char *type;
int rc;
- while ((np = of_find_node_by_name(np, "pci"))) {
+ for_each_node_by_name(np, "pci") {
rc = rpaphp_get_drc_props(np, NULL, &name, &type, NULL);
if (rc == 0)
if (!strcmp(drc_name, name) && !strcmp(drc_type, type))
diff --git a/include/linux/of.h b/include/linux/of.h
index 3bad8d106e0e..e082db3c284f 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -56,7 +56,7 @@ struct device_node {
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 list_head allnext;
struct kobject kobj;
unsigned long _flags;
void *data;
@@ -110,14 +110,15 @@ static inline void of_node_put(struct device_node *node) { }
#ifdef CONFIG_OF
/* Pointer for first entry in chain of all nodes. */
-extern struct device_node *of_allnodes;
+extern struct list_head of_allnodes;
+extern struct device_node *of_root;
extern struct device_node *of_chosen;
extern struct device_node *of_aliases;
extern raw_spinlock_t devtree_lock;
static inline bool of_have_populated_dt(void)
{
- return of_allnodes != NULL;
+ return !list_empty(&of_allnodes);
}
static inline bool of_node_is_root(const struct device_node *node)
@@ -208,8 +209,6 @@ static inline const char *of_node_full_name(const struct device_node *np)
return np ? np->full_name : "<no-node>";
}
-#define for_each_of_allnodes(dn) \
- for (dn = of_allnodes; dn; dn = dn->allnext)
extern struct device_node *of_find_node_by_name(struct device_node *from,
const char *name);
extern struct device_node *of_find_node_by_type(struct device_node *from,
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 5c0ab057eecf..efa7615a1ce9 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -35,8 +35,7 @@ extern int of_fdt_is_compatible(const void *blob,
const char *compat);
extern int of_fdt_match(const void *blob, unsigned long node,
const char *const *compat);
-extern void of_fdt_unflatten_tree(unsigned long *blob,
- struct device_node **mynodes);
+extern void of_fdt_unflatten_tree(unsigned long *blob, struct list_head *mynodes);
/* TBD: Temporary export of fdt globals - remove when code fully merged */
extern int __initdata dt_root_addr_cells;
diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
index c65a18a0cfdf..7e09244bb679 100644
--- a/include/linux/of_pdt.h
+++ b/include/linux/of_pdt.h
@@ -39,7 +39,6 @@ extern void *prom_early_alloc(unsigned long size);
/* for building the device tree */
extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);
-extern void (*of_pdt_build_more)(struct device_node *dp,
- struct device_node ***nextp);
+extern void (*of_pdt_build_more)(struct device_node *dp);
#endif /* _LINUX_OF_PDT_H */
--
1.9.1
--
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