diff mbox series

[v3,6/6] of: Refactor node and property manipulation function locking

Message ID 20230801-dt-changeset-fixes-v3-6-5f0410e007dd@kernel.org
State New
Headers show
Series dt: changeset fixes and cleanups | expand

Commit Message

Rob Herring (Arm) Aug. 18, 2023, 8:41 p.m. UTC 
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.

Signed-off-by: Rob Herring <robh@kernel.org>
---
v3:
 - Rebase due to changes in prior patch
v2:
 - Re-arrange exit handling
---
 drivers/of/base.c    | 65 ++++++++++++++++++++++++++--------------------------
 drivers/of/dynamic.c | 51 +++++++++++++----------------------------
 2 files changed, 49 insertions(+), 67 deletions(-)

Comments

Andy Shevchenko Aug. 21, 2023, 10:51 a.m. UTC | #1 
On Fri, Aug 18, 2023 at 03:41:01PM -0500, Rob Herring wrote:
> 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.

With help of cleanup.h this may be made shorter and less error-prone.
Rob Herring (Arm) Aug. 21, 2023, 7 p.m. UTC | #2 
On Mon, Aug 21, 2023 at 8:19 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Rob,
>
> On Fri, Aug 18, 2023 at 10:41 PM Rob Herring <robh@kernel.org> wrote:
> > 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.
> >
> > Signed-off-by: Rob Herring <robh@kernel.org>
> > ---
> > v3:
> >  - Rebase due to changes in prior patch
>
> Thanks for your patch!
>
> > --- a/drivers/of/base.c
> > +++ b/drivers/of/base.c
>
> > @@ -1576,37 +1587,36 @@ 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)
> > -               of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
>
> The notify block should be kept.

Yes, good catch.

>
> The rest LGTM, although I have some second thoughts about more
> functions with a double underscore now taking devtree_lock().

We still take the of_mutex. :) I looked at it some and we're already
not consistent in usage of '__'. Not a great argument I know, but if
we're going to make things consistent I think we should do that
separately for the whole subsys.

Rob
diff mbox series

Patch

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 3f9ddd18ff4b..4b24bed894ad 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -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;
 }
 
@@ -1576,37 +1587,36 @@  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)
-		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
-
 	return rc;
 }
 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;
 }
 
 /**
@@ -1621,21 +1631,13 @@  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)
@@ -1649,6 +1651,9 @@  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);
 
@@ -1670,6 +1675,10 @@  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;
 }
 
@@ -1685,21 +1694,13 @@  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)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index d3ad970ad7b8..9252641de507 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -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);
@@ -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);
 }
 
 /**
@@ -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);
@@ -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;
@@ -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);
 }
 
 /**
@@ -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);
@@ -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("applying: ", 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);
@@ -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;
 }