OF: convert devtree lock from rw_lock to raw spinlock
With the locking cleanup in place (from "OF: Fixup resursive
locking code paths"), we can now do the conversion from the
rw_lock to a raw spinlock as required for preempt-rt.
The previous cleanup and this conversion were originally
separate since they predated when mainline got raw spinlock (in
commit c2f21ce2e31286a "locking: Implement new raw_spinlock").
So, at that point in time, the cleanup was considered plausible
for mainline, but not this conversion. In any case, we've kept
them separate as it makes for easier review and better bisection.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[PG: taken from preempt-rt, update subject & add a commit log]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 16ee7a0..f86be55 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -55,7 +55,7 @@
/* use when traversing tree through the allnext, child, sibling,
* or parent members of struct device_node.
*/
-DEFINE_RWLOCK(devtree_lock);
+DEFINE_RAW_SPINLOCK(devtree_lock);
int of_n_addr_cells(struct device_node *np)
{
@@ -188,10 +188,11 @@
int *lenp)
{
struct property *pp;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
pp = __of_find_property(np, name, lenp);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return pp;
}
@@ -209,13 +210,13 @@
{
struct device_node *np;
- read_lock(&devtree_lock);
+ raw_spin_lock(&devtree_lock);
np = prev ? prev->allnext : of_allnodes;
for (; np != NULL; np = np->allnext)
if (of_node_get(np))
break;
of_node_put(prev);
- read_unlock(&devtree_lock);
+ raw_spin_unlock(&devtree_lock);
return np;
}
EXPORT_SYMBOL(of_find_all_nodes);
@@ -274,11 +275,12 @@
int of_device_is_compatible(const struct device_node *device,
const char *compat)
{
+ unsigned long flags;
int res;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
res = __of_device_is_compatible(device, compat);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return res;
}
EXPORT_SYMBOL(of_device_is_compatible);
@@ -340,13 +342,14 @@
struct device_node *of_get_parent(const struct device_node *node)
{
struct device_node *np;
+ unsigned long flags;
if (!node)
return NULL;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
np = of_node_get(node->parent);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_get_parent);
@@ -365,14 +368,15 @@
struct device_node *of_get_next_parent(struct device_node *node)
{
struct device_node *parent;
+ unsigned long flags;
if (!node)
return NULL;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
parent = of_node_get(node->parent);
of_node_put(node);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return parent;
}
@@ -388,14 +392,15 @@
struct device_node *prev)
{
struct device_node *next;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
next = prev ? prev->sibling : node->child;
for (; next; next = next->sibling)
if (of_node_get(next))
break;
of_node_put(prev);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
EXPORT_SYMBOL(of_get_next_child);
@@ -413,7 +418,7 @@
{
struct device_node *next;
- read_lock(&devtree_lock);
+ raw_spin_lock(&devtree_lock);
next = prev ? prev->sibling : node->child;
for (; next; next = next->sibling) {
if (!of_device_is_available(next))
@@ -422,7 +427,7 @@
break;
}
of_node_put(prev);
- read_unlock(&devtree_lock);
+ raw_spin_unlock(&devtree_lock);
return next;
}
EXPORT_SYMBOL(of_get_next_available_child);
@@ -460,14 +465,15 @@
struct device_node *of_find_node_by_path(const char *path)
{
struct device_node *np = of_allnodes;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
for (; np; np = np->allnext) {
if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
&& of_node_get(np))
break;
}
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_path);
@@ -487,15 +493,16 @@
const char *name)
{
struct device_node *np;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ 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);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_name);
@@ -516,15 +523,16 @@
const char *type)
{
struct device_node *np;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ 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);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_type);
@@ -547,8 +555,9 @@
const char *type, const char *compatible)
{
struct device_node *np;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
np = from ? from->allnext : of_allnodes;
for (; np; np = np->allnext) {
if (type
@@ -559,7 +568,7 @@
break;
}
of_node_put(from);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_compatible_node);
@@ -581,8 +590,9 @@
{
struct device_node *np;
struct property *pp;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ 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) {
@@ -594,7 +604,7 @@
}
out:
of_node_put(from);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_with_property);
@@ -635,10 +645,11 @@
const struct device_node *node)
{
const struct of_device_id *match;
+ unsigned long flags;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
match = __of_match_node(matches, node);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return match;
}
EXPORT_SYMBOL(of_match_node);
@@ -662,11 +673,12 @@
{
struct device_node *np;
const struct of_device_id *m;
+ unsigned long flags;
if (match)
*match = NULL;
- read_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
np = from ? from->allnext : of_allnodes;
for (; np; np = np->allnext) {
m = __of_match_node(matches, np);
@@ -677,7 +689,7 @@
}
}
of_node_put(from);
- read_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_matching_node_and_match);
@@ -720,12 +732,12 @@
{
struct device_node *np;
- read_lock(&devtree_lock);
+ raw_spin_lock(&devtree_lock);
for (np = of_allnodes; np; np = np->allnext)
if (np->phandle == handle)
break;
of_node_get(np);
- read_unlock(&devtree_lock);
+ raw_spin_unlock(&devtree_lock);
return np;
}
EXPORT_SYMBOL(of_find_node_by_phandle);
@@ -1197,18 +1209,18 @@
return rc;
prop->next = NULL;
- write_lock_irqsave(&devtree_lock, flags);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
while (*next) {
if (strcmp(prop->name, (*next)->name) == 0) {
/* duplicate ! don't insert it */
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return -1;
}
next = &(*next)->next;
}
*next = prop;
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
#ifdef CONFIG_PROC_DEVICETREE
/* try to add to proc as well if it was initialized */
@@ -1238,7 +1250,7 @@
if (rc)
return rc;
- write_lock_irqsave(&devtree_lock, flags);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
while (*next) {
if (*next == prop) {
@@ -1251,7 +1263,7 @@
}
next = &(*next)->next;
}
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!found)
return -ENODEV;
@@ -1291,7 +1303,7 @@
if (!oldprop)
return of_add_property(np, newprop);
- write_lock_irqsave(&devtree_lock, flags);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
while (*next) {
if (*next == oldprop) {
@@ -1305,7 +1317,7 @@
}
next = &(*next)->next;
}
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!found)
return -ENODEV;
@@ -1378,12 +1390,12 @@
if (rc)
return rc;
- write_lock_irqsave(&devtree_lock, flags);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
np->sibling = np->parent->child;
np->allnext = of_allnodes;
np->parent->child = np;
of_allnodes = np;
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
of_add_proc_dt_entry(np);
return 0;
@@ -1426,17 +1438,17 @@
if (rc)
return rc;
- write_lock_irqsave(&devtree_lock, flags);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
if (of_node_check_flag(np, OF_DETACHED)) {
/* someone already detached it */
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return rc;
}
parent = np->parent;
if (!parent) {
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return rc;
}
@@ -1463,7 +1475,7 @@
}
of_node_set_flag(np, OF_DETACHED);
- write_unlock_irqrestore(&devtree_lock, flags);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
of_remove_proc_dt_entry(np);
return rc;