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of: Refactor node and property manipulation function locking
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All callers of __of_{add,remove,update}_property() and
__of_{attach,detach}_node() wrap the call with the devtree_lock
spinlock. Let's move the spinlock into the functions. This allows moving
the sysfs update functions into those functions as well.

Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-6-5f0410e007dd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
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Rob Herring committed Aug 21, 2023
1 parent 6701c2c commit fab610b
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Showing 2 changed files with 49 additions and 64 deletions.
62 changes: 33 additions & 29 deletions drivers/of/base.c
Original file line number Diff line number Diff line change
Expand Up @@ -1551,21 +1551,32 @@ static struct property *__of_remove_property_from_list(struct property **list, s
*/
int __of_add_property(struct device_node *np, struct property *prop)
{
int rc = 0;
unsigned long flags;
struct property **next;

raw_spin_lock_irqsave(&devtree_lock, flags);

__of_remove_property_from_list(&np->deadprops, prop);

prop->next = NULL;
next = &np->properties;
while (*next) {
if (strcmp(prop->name, (*next)->name) == 0)
if (strcmp(prop->name, (*next)->name) == 0) {
/* duplicate ! don't insert it */
return -EEXIST;

rc = -EEXIST;
goto out_unlock;
}
next = &(*next)->next;
}
*next = prop;

out_unlock:
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (rc)
return rc;

__of_add_property_sysfs(np, prop);
return 0;
}

Expand All @@ -1576,18 +1587,10 @@ int __of_add_property(struct device_node *np, struct property *prop)
*/
int of_add_property(struct device_node *np, struct property *prop)
{
unsigned long flags;
int rc;

mutex_lock(&of_mutex);

raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_add_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);

if (!rc)
__of_add_property_sysfs(np, prop);

mutex_unlock(&of_mutex);

if (!rc)
Expand All @@ -1599,14 +1602,24 @@ EXPORT_SYMBOL_GPL(of_add_property);

int __of_remove_property(struct device_node *np, struct property *prop)
{
unsigned long flags;
int rc = -ENODEV;

raw_spin_lock_irqsave(&devtree_lock, flags);

if (__of_remove_property_from_list(&np->properties, prop)) {
/* Found the property, add it to deadprops list */
prop->next = np->deadprops;
np->deadprops = prop;
return 0;
rc = 0;
}

return -ENODEV;
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (rc)
return rc;

__of_remove_property_sysfs(np, prop);
return 0;
}

/**
Expand All @@ -1621,21 +1634,13 @@ int __of_remove_property(struct device_node *np, struct property *prop)
*/
int of_remove_property(struct device_node *np, struct property *prop)
{
unsigned long flags;
int rc;

if (!prop)
return -ENODEV;

mutex_lock(&of_mutex);

raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_remove_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);

if (!rc)
__of_remove_property_sysfs(np, prop);

mutex_unlock(&of_mutex);

if (!rc)
Expand All @@ -1649,6 +1654,9 @@ int __of_update_property(struct device_node *np, struct property *newprop,
struct property **oldpropp)
{
struct property **next, *oldprop;
unsigned long flags;

raw_spin_lock_irqsave(&devtree_lock, flags);

__of_remove_property_from_list(&np->deadprops, newprop);

Expand All @@ -1670,6 +1678,10 @@ int __of_update_property(struct device_node *np, struct property *newprop,
*next = newprop;
}

raw_spin_unlock_irqrestore(&devtree_lock, flags);

__of_update_property_sysfs(np, newprop, oldprop);

return 0;
}

Expand All @@ -1685,21 +1697,13 @@ int __of_update_property(struct device_node *np, struct property *newprop,
int of_update_property(struct device_node *np, struct property *newprop)
{
struct property *oldprop;
unsigned long flags;
int rc;

if (!newprop->name)
return -EINVAL;

mutex_lock(&of_mutex);

raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_update_property(np, newprop, &oldprop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);

if (!rc)
__of_update_property_sysfs(np, newprop, oldprop);

mutex_unlock(&of_mutex);

if (!rc)
Expand Down
51 changes: 16 additions & 35 deletions drivers/of/dynamic.c
Original file line number Diff line number Diff line change
Expand Up @@ -198,6 +198,9 @@ static void __of_attach_node(struct device_node *np)
{
const __be32 *phandle;
int sz;
unsigned long flags;

raw_spin_lock_irqsave(&devtree_lock, flags);

if (!of_node_check_flag(np, OF_OVERLAY)) {
np->name = __of_get_property(np, "name", NULL);
Expand All @@ -220,6 +223,10 @@ static void __of_attach_node(struct device_node *np)
np->parent->child = np;
of_node_clear_flag(np, OF_DETACHED);
np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;

raw_spin_unlock_irqrestore(&devtree_lock, flags);

__of_attach_node_sysfs(np);
}

/**
Expand All @@ -229,17 +236,12 @@ static void __of_attach_node(struct device_node *np)
int of_attach_node(struct device_node *np)
{
struct of_reconfig_data rd;
unsigned long flags;

memset(&rd, 0, sizeof(rd));
rd.dn = np;

mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
__of_attach_node(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);

__of_attach_node_sysfs(np);
mutex_unlock(&of_mutex);

of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
Expand All @@ -250,13 +252,15 @@ int of_attach_node(struct device_node *np)
void __of_detach_node(struct device_node *np)
{
struct device_node *parent;
unsigned long flags;

if (WARN_ON(of_node_check_flag(np, OF_DETACHED)))
return;
raw_spin_lock_irqsave(&devtree_lock, flags);

parent = np->parent;
if (WARN_ON(!parent))
if (WARN_ON(of_node_check_flag(np, OF_DETACHED) || !parent)) {
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return;
}

if (parent->child == np)
parent->child = np->sibling;
Expand All @@ -273,6 +277,10 @@ void __of_detach_node(struct device_node *np)

/* race with of_find_node_by_phandle() prevented by devtree_lock */
__of_phandle_cache_inv_entry(np->phandle);

raw_spin_unlock_irqrestore(&devtree_lock, flags);

__of_detach_node_sysfs(np);
}

/**
Expand All @@ -282,17 +290,12 @@ void __of_detach_node(struct device_node *np)
int of_detach_node(struct device_node *np)
{
struct of_reconfig_data rd;
unsigned long flags;

memset(&rd, 0, sizeof(rd));
rd.dn = np;

mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
__of_detach_node(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);

__of_detach_node_sysfs(np);
mutex_unlock(&of_mutex);

of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
Expand Down Expand Up @@ -564,12 +567,10 @@ static int __of_changeset_entry_notify(struct of_changeset_entry *ce,

static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
{
unsigned long flags;
int ret = 0;

of_changeset_action_debug("apply: ", ce->action, ce->np, ce->prop);

raw_spin_lock_irqsave(&devtree_lock, flags);
switch (ce->action) {
case OF_RECONFIG_ATTACH_NODE:
__of_attach_node(ce->np);
Expand All @@ -590,32 +591,12 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
default:
ret = -EINVAL;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);

if (ret) {
of_changeset_action_err("apply failed: ", ce->action, ce->np, ce->prop);
return ret;
}

switch (ce->action) {
case OF_RECONFIG_ATTACH_NODE:
__of_attach_node_sysfs(ce->np);
break;
case OF_RECONFIG_DETACH_NODE:
__of_detach_node_sysfs(ce->np);
break;
case OF_RECONFIG_ADD_PROPERTY:
/* ignore duplicate names */
__of_add_property_sysfs(ce->np, ce->prop);
break;
case OF_RECONFIG_REMOVE_PROPERTY:
__of_remove_property_sysfs(ce->np, ce->prop);
break;
case OF_RECONFIG_UPDATE_PROPERTY:
__of_update_property_sysfs(ce->np, ce->prop, ce->old_prop);
break;
}

return 0;
}

Expand Down

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