[PATCH v2 0/5] of: generic infrastructure fixes

[PATCH v2 0/5] of: generic infrastructure fixes

[Pantelis Antoniou]

The first patch renames the *_node_sysfs methods to _node_post since
this is more accurate when more work takes place besides sysfs
tweaking when the next patch is using a hashtable for phandles.
This is a win for very large blobs with a large number of phandles.
Current we use an exhaustive search which is not optimal at all.

The third patch adds a unittest/benchmark for hashed phandles
along with figures about performance.

A long standing request of applied overlays populating
the symbol list is implemented; this allows staggered overlay
application with a symbol from a previous overlay being used
by another after it.

Finally a pr_fmt for the overlay files is used for
uncluttering the printout a bit.

Changes since v1:
* Reworked phandle hash according to maintainer requests
* Added unittest/benchmark for phandle hash
* Reworked the overlay symbol patch
* Added pr_fmt patch


Pantelis Antoniou (5):
  of: rename *_node_sysfs to _node_post
  of: Support hashtable lookups for phandles
  of: unittest: hashed phandles unitest
  of: overlay: Pick up label symbols from overlays.
  of: overlay: Add pr_fmt for clarity

 drivers/of/base.c       |  45 +++++++++++--
 drivers/of/dynamic.c    |  18 +++--
 drivers/of/of_private.h |  37 ++++++++++-
 drivers/of/overlay.c    | 173 ++++++++++++++++++++++++++++++++++++------------
 drivers/of/unittest.c   |  72 +++++++++++++++++++-
 include/linux/of.h      |   2 +
 6 files changed, 289 insertions(+), 58 deletions(-)

-- 
1.7.12

[PATCH v2 1/5] of: rename *_node_sysfs to _node_post

[Pantelis Antoniou]

Renames the *_node_sysfs methods to _node_post which is more accurate
when more work takes place besides sysfs tweaking (as in with
phandle hash management).

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
---
 drivers/of/base.c       |  4 ++--
 drivers/of/dynamic.c    | 10 +++++-----
 drivers/of/of_private.h |  4 ++--
 drivers/of/unittest.c   |  4 ++--
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 9bbca56..20bbc2f 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -156,7 +156,7 @@ int __of_add_property_sysfs(struct device_node *np, struct property *pp)
 	return rc;
 }
 
-int __of_attach_node_sysfs(struct device_node *np)
+int __of_attach_node_post(struct device_node *np)
 {
 	const char *name;
 	struct property *pp;
@@ -203,7 +203,7 @@ void __init of_core_init(void)
 		return;
 	}
 	for_each_of_allnodes(np)
-		__of_attach_node_sysfs(np);
+		__of_attach_node_post(np);
 	mutex_unlock(&of_mutex);
 
 	/* Symlink in /proc as required by userspace ABI */
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index b07fec2..34ca783 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -41,7 +41,7 @@ void of_node_put(struct device_node *node)
 }
 EXPORT_SYMBOL(of_node_put);
 
-void __of_detach_node_sysfs(struct device_node *np)
+void __of_detach_node_post(struct device_node *np)
 {
 	struct property *pp;
 
@@ -251,7 +251,7 @@ int of_attach_node(struct device_node *np)
 	__of_attach_node(np);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-	__of_attach_node_sysfs(np);
+	__of_attach_node_post(np);
 	mutex_unlock(&of_mutex);
 
 	of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
@@ -304,7 +304,7 @@ int of_detach_node(struct device_node *np)
 	__of_detach_node(np);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-	__of_detach_node_sysfs(np);
+	__of_detach_node_post(np);
 	mutex_unlock(&of_mutex);
 
 	of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
@@ -628,10 +628,10 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
 
 	switch (ce->action) {
 	case OF_RECONFIG_ATTACH_NODE:
-		__of_attach_node_sysfs(ce->np);
+		__of_attach_node_post(ce->np);
 		break;
 	case OF_RECONFIG_DETACH_NODE:
-		__of_detach_node_sysfs(ce->np);
+		__of_detach_node_post(ce->np);
 		break;
 	case OF_RECONFIG_ADD_PROPERTY:
 		/* ignore duplicate names */
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 092cba7..10b0342 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -79,9 +79,9 @@ extern void __of_update_property_sysfs(struct device_node *np,
 		struct property *newprop, struct property *oldprop);
 
 extern void __of_attach_node(struct device_node *np);
-extern int __of_attach_node_sysfs(struct device_node *np);
+extern int __of_attach_node_post(struct device_node *np);
 extern void __of_detach_node(struct device_node *np);
-extern void __of_detach_node_sysfs(struct device_node *np);
+extern void __of_detach_node_post(struct device_node *np);
 
 /* iterators for transactions, used for overlays */
 /* forward iterator */
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index e5a5ec0..7ea3689 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -931,7 +931,7 @@ static int attach_node_and_children(struct device_node *np)
 	of_node_clear_flag(np, OF_DETACHED);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-	__of_attach_node_sysfs(np);
+	__of_attach_node_post(np);
 	mutex_unlock(&of_mutex);
 
 	while (child) {
@@ -989,7 +989,7 @@ static int __init unittest_data_add(void)
 	if (!of_root) {
 		of_root = unittest_data_node;
 		for_each_of_allnodes(np)
-			__of_attach_node_sysfs(np);
+			__of_attach_node_post(np);
 		of_aliases = of_find_node_by_path("/aliases");
 		of_chosen = of_find_node_by_path("/chosen");
 		return 0;
-- 
1.7.12

[PATCH v2 2/5] of: Support hashtable lookups for phandles

[Pantelis Antoniou]

When a device tree contains a lot of phandles, resolving one
takes time because the original method uses a search against
all nodes (not just the ones with phandles).

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
---
 drivers/of/base.c       | 41 ++++++++++++++++++++++++++++++++++++++---
 drivers/of/dynamic.c    |  8 ++++++++
 drivers/of/of_private.h | 33 +++++++++++++++++++++++++++++++++
 include/linux/of.h      |  2 ++
 4 files changed, 81 insertions(+), 3 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 20bbc2f..436a088 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -27,6 +27,7 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/proc_fs.h>
+#include <linux/rhashtable.h>
 
 #include "of_private.h"
 
@@ -41,6 +42,18 @@ static const char *of_stdout_options;
 
 struct kset *of_kset;
 
+const struct rhashtable_params of_phandle_ht_params = {
+	.key_offset = offsetof(struct device_node, phandle), /* base offset */
+	.key_len = sizeof(phandle),
+	.head_offset = offsetof(struct device_node, ht_node),
+	.automatic_shrinking = true,
+};
+
+struct rhashtable *of_phandle_ht;
+
+/* default is false */
+bool of_phandle_ht_is_disabled;
+
 /*
  * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
  * This mutex must be held whenever modifications are being made to the
@@ -162,6 +175,12 @@ int __of_attach_node_post(struct device_node *np)
 	struct property *pp;
 	int rc;
 
+	if (of_phandle_ht_available()) {
+		rc = of_phandle_ht_insert(np);
+		WARN(rc, "insert to phandle hash fail @%s\n",
+				of_node_full_name(np));
+	}
+
 	if (!IS_ENABLED(CONFIG_SYSFS))
 		return 0;
 
@@ -194,6 +213,17 @@ void __init of_core_init(void)
 	struct device_node *np;
 	int ret;
 
+	of_phandle_ht = kzalloc(sizeof(*of_phandle_ht), GFP_KERNEL);
+	if (!of_phandle_ht) {
+		pr_warn("devicetree: Failed to allocate hashtable\n");
+		return;
+	}
+	ret = rhashtable_init(of_phandle_ht, &of_phandle_ht_params);
+	if (ret) {
+		pr_warn("devicetree: Failed to initialize hashtable\n");
+		return;
+	}
+
 	/* Create the kset, and register existing nodes */
 	mutex_lock(&of_mutex);
 	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
@@ -1073,9 +1103,14 @@ struct device_node *of_find_node_by_phandle(phandle handle)
 		return NULL;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	for_each_of_allnodes(np)
-		if (np->phandle == handle)
-			break;
+	/* when we're ready use the hash table (and not disabled) */
+	if (of_phandle_ht_available() && !of_phandle_ht_is_disabled)
+		np = of_phandle_ht_lookup(handle);
+	else { /* fallback */
+		for_each_of_allnodes(np)
+			if (np->phandle == handle)
+				break;
+	}
 	of_node_get(np);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 34ca783..931b905 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -11,6 +11,7 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/proc_fs.h>
+#include <linux/rhashtable.h>
 
 #include "of_private.h"
 
@@ -44,6 +45,13 @@ EXPORT_SYMBOL(of_node_put);
 void __of_detach_node_post(struct device_node *np)
 {
 	struct property *pp;
+	int rc;
+
+	if (of_phandle_ht_available()) {
+		rc = of_phandle_ht_remove(np);
+		WARN(rc, "remove from phandle hash fail @%s\n",
+				of_node_full_name(np));
+	}
 
 	if (!IS_ENABLED(CONFIG_SYSFS))
 		return;
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 10b0342..386ae71 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -101,4 +101,37 @@ static inline int of_overlay_init(void)
 }
 #endif
 
+extern const struct rhashtable_params of_phandle_ht_params;
+extern struct rhashtable *of_phandle_ht;
+
+/* for unittest use */
+extern bool of_phandle_ht_is_disabled;
+
+static inline bool of_phandle_ht_available(void)
+{
+	return of_phandle_ht != NULL;
+}
+
+static inline int of_phandle_ht_insert(struct device_node *np)
+{
+	if (!np || !np->phandle)
+		return 0;
+	return rhashtable_insert_fast(of_phandle_ht,
+		&np->ht_node, of_phandle_ht_params);
+}
+
+static inline int of_phandle_ht_remove(struct device_node *np)
+{
+	if (!np || !np->phandle)
+		return 0;
+	return rhashtable_remove_fast(of_phandle_ht,
+		&np->ht_node, of_phandle_ht_params);
+}
+
+static inline struct device_node *of_phandle_ht_lookup(phandle handle)
+{
+	return rhashtable_lookup_fast(of_phandle_ht,
+			&handle, of_phandle_ht_params);
+}
+
 #endif /* _LINUX_OF_PRIVATE_H */
diff --git a/include/linux/of.h b/include/linux/of.h
index 18a8e59..9de9a3f 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -25,6 +25,7 @@
 #include <linux/notifier.h>
 #include <linux/property.h>
 #include <linux/list.h>
+#include <linux/rhashtable.h>
 
 #include <asm/byteorder.h>
 #include <asm/errno.h>
@@ -52,6 +53,7 @@ struct device_node {
 	phandle phandle;
 	const char *full_name;
 	struct fwnode_handle fwnode;
+	struct rhash_head ht_node;
 
 	struct	property *properties;
 	struct	property *deadprops;	/* removed properties */
-- 
1.7.12

Re: [PATCH v2 2/5] of: Support hashtable lookups for phandles

[Rob Herring]

On Mon, May 16, 2016 at 11:52 AM, Pantelis Antoniou
<pantelis.antoniou@konsulko.com> wrote:
> When a device tree contains a lot of phandles, resolving one
> takes time because the original method uses a search against
> all nodes (not just the ones with phandles).
>
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
> ---
>  drivers/of/base.c       | 41 ++++++++++++++++++++++++++++++++++++++---
>  drivers/of/dynamic.c    |  8 ++++++++
>  drivers/of/of_private.h | 33 +++++++++++++++++++++++++++++++++
>  include/linux/of.h      |  2 ++
>  4 files changed, 81 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 20bbc2f..436a088 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -27,6 +27,7 @@
>  #include <linux/slab.h>
>  #include <linux/string.h>
>  #include <linux/proc_fs.h>
> +#include <linux/rhashtable.h>
>
>  #include "of_private.h"
>
> @@ -41,6 +42,18 @@ static const char *of_stdout_options;
>
>  struct kset *of_kset;
>
> +const struct rhashtable_params of_phandle_ht_params = {

static

> +       .key_offset = offsetof(struct device_node, phandle), /* base offset */
> +       .key_len = sizeof(phandle),
> +       .head_offset = offsetof(struct device_node, ht_node),
> +       .automatic_shrinking = true,
> +};
> +
> +struct rhashtable *of_phandle_ht;
> +
> +/* default is false */
> +bool of_phandle_ht_is_disabled;

I think this should go. The unittest alone is not enough reason to keep.

> +
>  /*
>   * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
>   * This mutex must be held whenever modifications are being made to the
> @@ -162,6 +175,12 @@ int __of_attach_node_post(struct device_node *np)
>         struct property *pp;
>         int rc;
>
> +       if (of_phandle_ht_available()) {

This can never be false as this function should only get called after init.

> +               rc = of_phandle_ht_insert(np);
> +               WARN(rc, "insert to phandle hash fail @%s\n",
> +                               of_node_full_name(np));
> +       }
> +
>         if (!IS_ENABLED(CONFIG_SYSFS))
>                 return 0;
>
> @@ -194,6 +213,17 @@ void __init of_core_init(void)
>         struct device_node *np;
>         int ret;
>
> +       of_phandle_ht = kzalloc(sizeof(*of_phandle_ht), GFP_KERNEL);
> +       if (!of_phandle_ht) {
> +               pr_warn("devicetree: Failed to allocate hashtable\n");
> +               return;
> +       }
> +       ret = rhashtable_init(of_phandle_ht, &of_phandle_ht_params);
> +       if (ret) {
> +               pr_warn("devicetree: Failed to initialize hashtable\n");
> +               return;
> +       }
> +
>         /* Create the kset, and register existing nodes */
>         mutex_lock(&of_mutex);
>         of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
> @@ -1073,9 +1103,14 @@ struct device_node *of_find_node_by_phandle(phandle handle)
>                 return NULL;
>
>         raw_spin_lock_irqsave(&devtree_lock, flags);
> -       for_each_of_allnodes(np)
> -               if (np->phandle == handle)
> -                       break;
> +       /* when we're ready use the hash table (and not disabled) */
> +       if (of_phandle_ht_available() && !of_phandle_ht_is_disabled)

Just "if (of_phandle_ht)"

> +               np = of_phandle_ht_lookup(handle);
> +       else { /* fallback */
> +               for_each_of_allnodes(np)
> +                       if (np->phandle == handle)
> +                               break;
> +       }
>         of_node_get(np);
>         raw_spin_unlock_irqrestore(&devtree_lock, flags);
>         return np;
> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
> index 34ca783..931b905 100644
> --- a/drivers/of/dynamic.c
> +++ b/drivers/of/dynamic.c
> @@ -11,6 +11,7 @@
>  #include <linux/slab.h>
>  #include <linux/string.h>
>  #include <linux/proc_fs.h>
> +#include <linux/rhashtable.h>
>
>  #include "of_private.h"
>
> @@ -44,6 +45,13 @@ EXPORT_SYMBOL(of_node_put);
>  void __of_detach_node_post(struct device_node *np)
>  {
>         struct property *pp;
> +       int rc;
> +
> +       if (of_phandle_ht_available()) {

Likewise, this can't be false either.

> +               rc = of_phandle_ht_remove(np);
> +               WARN(rc, "remove from phandle hash fail @%s\n",
> +                               of_node_full_name(np));
> +       }
>
>         if (!IS_ENABLED(CONFIG_SYSFS))
>                 return;
> diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
> index 10b0342..386ae71 100644
> --- a/drivers/of/of_private.h
> +++ b/drivers/of/of_private.h
> @@ -101,4 +101,37 @@ static inline int of_overlay_init(void)
>  }
>  #endif
>
> +extern const struct rhashtable_params of_phandle_ht_params;
> +extern struct rhashtable *of_phandle_ht;
> +
> +/* for unittest use */
> +extern bool of_phandle_ht_is_disabled;
> +
> +static inline bool of_phandle_ht_available(void)
> +{
> +       return of_phandle_ht != NULL;
> +}
> +
> +static inline int of_phandle_ht_insert(struct device_node *np)
> +{
> +       if (!np || !np->phandle)
> +               return 0;
> +       return rhashtable_insert_fast(of_phandle_ht,
> +               &np->ht_node, of_phandle_ht_params);
> +}
> +
> +static inline int of_phandle_ht_remove(struct device_node *np)
> +{
> +       if (!np || !np->phandle)
> +               return 0;
> +       return rhashtable_remove_fast(of_phandle_ht,
> +               &np->ht_node, of_phandle_ht_params);
> +}
> +
> +static inline struct device_node *of_phandle_ht_lookup(phandle handle)
> +{
> +       return rhashtable_lookup_fast(of_phandle_ht,
> +                       &handle, of_phandle_ht_params);
> +}
> +
>  #endif /* _LINUX_OF_PRIVATE_H */
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 18a8e59..9de9a3f 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -25,6 +25,7 @@
>  #include <linux/notifier.h>
>  #include <linux/property.h>
>  #include <linux/list.h>
> +#include <linux/rhashtable.h>
>
>  #include <asm/byteorder.h>
>  #include <asm/errno.h>
> @@ -52,6 +53,7 @@ struct device_node {
>         phandle phandle;
>         const char *full_name;
>         struct fwnode_handle fwnode;
> +       struct rhash_head ht_node;

Place next to .phandle as both will be accessed at the same time.

>
>         struct  property *properties;
>         struct  property *deadprops;    /* removed properties */
> --
> 1.7.12
>

Re: [PATCH v2 2/5] of: Support hashtable lookups for phandles

[Pantelis Antoniou]

Hi Rob,

> On May 16, 2016, at 22:37 , Rob Herring <robherring2@gmail.com> wrote:
> 
> On Mon, May 16, 2016 at 11:52 AM, Pantelis Antoniou
> <pantelis.antoniou@konsulko.com> wrote:
>> When a device tree contains a lot of phandles, resolving one
>> takes time because the original method uses a search against
>> all nodes (not just the ones with phandles).
>> 
>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
>> ---
>> drivers/of/base.c       | 41 ++++++++++++++++++++++++++++++++++++++---
>> drivers/of/dynamic.c    |  8 ++++++++
>> drivers/of/of_private.h | 33 +++++++++++++++++++++++++++++++++
>> include/linux/of.h      |  2 ++
>> 4 files changed, 81 insertions(+), 3 deletions(-)
>> 
>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index 20bbc2f..436a088 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -27,6 +27,7 @@
>> #include <linux/slab.h>
>> #include <linux/string.h>
>> #include <linux/proc_fs.h>
>> +#include <linux/rhashtable.h>
>> 
>> #include "of_private.h"
>> 
>> @@ -41,6 +42,18 @@ static const char *of_stdout_options;
>> 
>> struct kset *of_kset;
>> 
>> +const struct rhashtable_params of_phandle_ht_params = {
> 
> static
> 

No, it won’t work. The rhashtable API requires using this at every call.


>> +       .key_offset = offsetof(struct device_node, phandle), /* base offset */
>> +       .key_len = sizeof(phandle),
>> +       .head_offset = offsetof(struct device_node, ht_node),
>> +       .automatic_shrinking = true,
>> +};
>> +
>> +struct rhashtable *of_phandle_ht;
>> +
>> +/* default is false */
>> +bool of_phandle_ht_is_disabled;
> 
> I think this should go. The unittest alone is not enough reason to keep.
> 

Hmm, OK.

>> +
>> /*
>>  * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
>>  * This mutex must be held whenever modifications are being made to the
>> @@ -162,6 +175,12 @@ int __of_attach_node_post(struct device_node *np)
>>        struct property *pp;
>>        int rc;
>> 
>> +       if (of_phandle_ht_available()) {
> 
> This can never be false as this function should only get called after init.
> 

How about a BUG_ON() just in case something weird is going on?

>> +               rc = of_phandle_ht_insert(np);
>> +               WARN(rc, "insert to phandle hash fail @%s\n",
>> +                               of_node_full_name(np));
>> +       }
>> +
>>        if (!IS_ENABLED(CONFIG_SYSFS))
>>                return 0;
>> 
>> @@ -194,6 +213,17 @@ void __init of_core_init(void)
>>        struct device_node *np;
>>        int ret;
>> 
>> +       of_phandle_ht = kzalloc(sizeof(*of_phandle_ht), GFP_KERNEL);
>> +       if (!of_phandle_ht) {
>> +               pr_warn("devicetree: Failed to allocate hashtable\n");
>> +               return;
>> +       }
>> +       ret = rhashtable_init(of_phandle_ht, &of_phandle_ht_params);
>> +       if (ret) {
>> +               pr_warn("devicetree: Failed to initialize hashtable\n");
>> +               return;
>> +       }
>> +
>>        /* Create the kset, and register existing nodes */
>>        mutex_lock(&of_mutex);
>>        of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
>> @@ -1073,9 +1103,14 @@ struct device_node *of_find_node_by_phandle(phandle handle)
>>                return NULL;
>> 
>>        raw_spin_lock_irqsave(&devtree_lock, flags);
>> -       for_each_of_allnodes(np)
>> -               if (np->phandle == handle)
>> -                       break;
>> +       /* when we're ready use the hash table (and not disabled) */
>> +       if (of_phandle_ht_available() && !of_phandle_ht_is_disabled)
> 
> Just "if (of_phandle_ht)”
> 

OK


>> +               np = of_phandle_ht_lookup(handle);
>> +       else { /* fallback */
>> +               for_each_of_allnodes(np)
>> +                       if (np->phandle == handle)
>> +                               break;
>> +       }
>>        of_node_get(np);
>>        raw_spin_unlock_irqrestore(&devtree_lock, flags);
>>        return np;
>> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
>> index 34ca783..931b905 100644
>> --- a/drivers/of/dynamic.c
>> +++ b/drivers/of/dynamic.c
>> @@ -11,6 +11,7 @@
>> #include <linux/slab.h>
>> #include <linux/string.h>
>> #include <linux/proc_fs.h>
>> +#include <linux/rhashtable.h>
>> 
>> #include "of_private.h"
>> 
>> @@ -44,6 +45,13 @@ EXPORT_SYMBOL(of_node_put);
>> void __of_detach_node_post(struct device_node *np)
>> {
>>        struct property *pp;
>> +       int rc;
>> +
>> +       if (of_phandle_ht_available()) {
> 
> Likewise, this can't be false either.
> 

OK

>> +               rc = of_phandle_ht_remove(np);
>> +               WARN(rc, "remove from phandle hash fail @%s\n",
>> +                               of_node_full_name(np));
>> +       }
>> 
>>        if (!IS_ENABLED(CONFIG_SYSFS))
>>                return;
>> diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
>> index 10b0342..386ae71 100644
>> --- a/drivers/of/of_private.h
>> +++ b/drivers/of/of_private.h
>> @@ -101,4 +101,37 @@ static inline int of_overlay_init(void)
>> }
>> #endif
>> 
>> +extern const struct rhashtable_params of_phandle_ht_params;
>> +extern struct rhashtable *of_phandle_ht;
>> +
>> +/* for unittest use */
>> +extern bool of_phandle_ht_is_disabled;
>> +
>> +static inline bool of_phandle_ht_available(void)
>> +{
>> +       return of_phandle_ht != NULL;
>> +}
>> +
>> +static inline int of_phandle_ht_insert(struct device_node *np)
>> +{
>> +       if (!np || !np->phandle)
>> +               return 0;
>> +       return rhashtable_insert_fast(of_phandle_ht,
>> +               &np->ht_node, of_phandle_ht_params);
>> +}
>> +
>> +static inline int of_phandle_ht_remove(struct device_node *np)
>> +{
>> +       if (!np || !np->phandle)
>> +               return 0;
>> +       return rhashtable_remove_fast(of_phandle_ht,
>> +               &np->ht_node, of_phandle_ht_params);
>> +}
>> +
>> +static inline struct device_node *of_phandle_ht_lookup(phandle handle)
>> +{
>> +       return rhashtable_lookup_fast(of_phandle_ht,
>> +                       &handle, of_phandle_ht_params);
>> +}
>> +
>> #endif /* _LINUX_OF_PRIVATE_H */
>> diff --git a/include/linux/of.h b/include/linux/of.h
>> index 18a8e59..9de9a3f 100644
>> --- a/include/linux/of.h
>> +++ b/include/linux/of.h
>> @@ -25,6 +25,7 @@
>> #include <linux/notifier.h>
>> #include <linux/property.h>
>> #include <linux/list.h>
>> +#include <linux/rhashtable.h>
>> 
>> #include <asm/byteorder.h>
>> #include <asm/errno.h>
>> @@ -52,6 +53,7 @@ struct device_node {
>>        phandle phandle;
>>        const char *full_name;
>>        struct fwnode_handle fwnode;
>> +       struct rhash_head ht_node;
> 
> Place next to .phandle as both will be accessed at the same time.
> 

OK.

>> 
>>        struct  property *properties;
>>        struct  property *deadprops;    /* removed properties */
>> --
>> 1.7.12

Regards

— Pantelis

[PATCH v2 3/5] of: unittest: hashed phandles unitest

[Pantelis Antoniou]

Add a benchmarking hashed phandles unittest which report what kind
of speed up we get switching to hashed phandle lookups.

 ### dt-test ### the hash method is 8.2 times faster than the original

On the beaglebone we perform about 1877 phandle lookups until that
point in the unittest. Each non-hashed lookup takes about 23us when
the cash is hot, while the hash lookup takes about 3us.

For those 1877 lookup we get a speedup in the boot sequence of
1877 * (23 - 3) = 37.5ms, which is not spectacular but there's no
point in wasting cycles and energy.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
---
 drivers/of/unittest.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 7ea3689..59cad84 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -25,6 +25,9 @@
 
 #include <linux/bitops.h>
 
+#include <linux/timekeeping.h>
+#include <linux/random.h>
+
 #include "of_private.h"
 
 static struct unittest_results {
@@ -2266,6 +2269,70 @@ out:
 static inline void __init of_unittest_overlay(void) { }
 #endif
 
+#define PHANDLE_LOOKUPS	1000
+
+static void __init of_unittest_phandle_hash(void)
+{
+	struct device_node *node;
+	phandle max_phandle;
+	u32 ph;
+	unsigned long flags;
+	int i, j, total;
+	ktime_t start, end;
+	s64 dur[2];
+	int dec, frac;
+
+	/* test only available when hashing is available */
+	if (!of_phandle_ht_available()) {
+		pr_warn("phandle hash test requires hash to be initialized\n");
+		return;
+	}
+
+	/* find the maximum phandle of the tree */
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	max_phandle = 0;
+	total = 0;
+	for_each_of_allnodes(node) {
+		if (node->phandle != (phandle)-1U &&
+				node->phandle > max_phandle)
+			max_phandle = node->phandle;
+		total++;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	max_phandle++;
+
+	pr_debug("phandle: max-phandle #%u, #%d total nodes\n",
+			(u32)max_phandle, total);
+
+	/* perform random lookups using the hash */
+	for (j = 0; j < 2; j++) {
+
+		/* disabled for pass #0, enabled for pass #1 */
+		of_phandle_ht_is_disabled = j == 0;
+
+		start = ktime_get_raw();
+		for (i = 0; i < PHANDLE_LOOKUPS; i++) {
+			ph = prandom_u32() % max_phandle;
+			node = of_find_node_by_phandle(ph);
+			of_node_put(node);
+		}
+		end = ktime_get_raw();
+
+		dur[j] = ktime_to_us(end) - ktime_to_us(start);
+		pr_debug("#%d lookups in %lld us (%s)\n",
+				PHANDLE_LOOKUPS, dur[j],
+				j == 0 ? "original" : "hashed");
+	}
+
+	unittest(dur[0] > dur[1], "Non hashing phandles are faster!?");
+
+	dec = (int)div64_s64(dur[0] * 10 + 5, dur[1]);
+	frac = dec % 10;
+	dec /= 10;
+	pr_info("the hash method is %d.%d times faster than the original\n",
+			dec, frac);
+}
+
 static int __init of_unittest(void)
 {
 	struct device_node *np;
@@ -2300,6 +2367,7 @@ static int __init of_unittest(void)
 	of_unittest_match_node();
 	of_unittest_platform_populate();
 	of_unittest_overlay();
+	of_unittest_phandle_hash();
 
 	/* Double check linkage after removing testcase data */
 	of_unittest_check_tree_linkage();
-- 
1.7.12

Re: [PATCH v2 3/5] of: unittest: hashed phandles unitest

[Geert Uytterhoeven]

On Mon, May 16, 2016 at 6:52 PM, Pantelis Antoniou
<pantelis.antoniou@konsulko.com> wrote:
> Add a benchmarking hashed phandles unittest which report what kind
> of speed up we get switching to hashed phandle lookups.
>
>  ### dt-test ### the hash method is 8.2 times faster than the original
>
> On the beaglebone we perform about 1877 phandle lookups until that
> point in the unittest. Each non-hashed lookup takes about 23us when
> the cash is hot, while the hash lookup takes about 3us.

cache

> For those 1877 lookup we get a speedup in the boot sequence of
> 1877 * (23 - 3) = 37.5ms, which is not spectacular but there's no
> point in wasting cycles and energy.
>
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
> ---
>  drivers/of/unittest.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
>
> diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
> index 7ea3689..59cad84 100644
> --- a/drivers/of/unittest.c
> +++ b/drivers/of/unittest.c
> @@ -25,6 +25,9 @@
>
>  #include <linux/bitops.h>
>
> +#include <linux/timekeeping.h>
> +#include <linux/random.h>
> +
>  #include "of_private.h"
>
>  static struct unittest_results {
> @@ -2266,6 +2269,70 @@ out:
>  static inline void __init of_unittest_overlay(void) { }
>  #endif
>
> +#define PHANDLE_LOOKUPS        1000
> +
> +static void __init of_unittest_phandle_hash(void)
> +{
> +       struct device_node *node;
> +       phandle max_phandle;
> +       u32 ph;
> +       unsigned long flags;
> +       int i, j, total;

unsigned int

> +       ktime_t start, end;
> +       s64 dur[2];

No idea why ktime_to_us() returns s64 i.s.o. u64...

> +       int dec, frac;

unsigned int?

> +       /* test only available when hashing is available */
> +       if (!of_phandle_ht_available()) {
> +               pr_warn("phandle hash test requires hash to be initialized\n");
> +               return;
> +       }
> +
> +       /* find the maximum phandle of the tree */
> +       raw_spin_lock_irqsave(&devtree_lock, flags);
> +       max_phandle = 0;
> +       total = 0;
> +       for_each_of_allnodes(node) {
> +               if (node->phandle != (phandle)-1U &&

Drop the "U" suffix?

> +                               node->phandle > max_phandle)
> +                       max_phandle = node->phandle;
> +               total++;
> +       }
> +       raw_spin_unlock_irqrestore(&devtree_lock, flags);
> +       max_phandle++;
> +
> +       pr_debug("phandle: max-phandle #%u, #%d total nodes\n",
> +                       (u32)max_phandle, total);

phandle is already u32, so no need for the cast.

> +
> +       /* perform random lookups using the hash */
> +       for (j = 0; j < 2; j++) {
> +
> +               /* disabled for pass #0, enabled for pass #1 */
> +               of_phandle_ht_is_disabled = j == 0;
> +
> +               start = ktime_get_raw();
> +               for (i = 0; i < PHANDLE_LOOKUPS; i++) {
> +                       ph = prandom_u32() % max_phandle;
> +                       node = of_find_node_by_phandle(ph);
> +                       of_node_put(node);
> +               }
> +               end = ktime_get_raw();
> +
> +               dur[j] = ktime_to_us(end) - ktime_to_us(start);
> +               pr_debug("#%d lookups in %lld us (%s)\n",

$u

> +                               PHANDLE_LOOKUPS, dur[j],
> +                               j == 0 ? "original" : "hashed");
> +       }
> +
> +       unittest(dur[0] > dur[1], "Non hashing phandles are faster!?");
> +
> +       dec = (int)div64_s64(dur[0] * 10 + 5, dur[1]);

I'd expect div64_u64(), if not for ktime_to_us() returning s64...

> +       frac = dec % 10;
> +       dec /= 10;
> +       pr_info("the hash method is %d.%d times faster than the original\n",

%u.%u once dec and frac are unsigned.

> +                       dec, frac);
> +}

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 3/5] of: unittest: hashed phandles unitest

[Rob Herring]

On Mon, May 16, 2016 at 11:52 AM, Pantelis Antoniou
<pantelis.antoniou@konsulko.com> wrote:
> Add a benchmarking hashed phandles unittest which report what kind
> of speed up we get switching to hashed phandle lookups.
>
>  ### dt-test ### the hash method is 8.2 times faster than the original
>
> On the beaglebone we perform about 1877 phandle lookups until that
> point in the unittest. Each non-hashed lookup takes about 23us when
> the cash is hot, while the hash lookup takes about 3us.
>
> For those 1877 lookup we get a speedup in the boot sequence of
> 1877 * (23 - 3) = 37.5ms, which is not spectacular but there's no
> point in wasting cycles and energy.
>
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
> ---
>  drivers/of/unittest.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
>
> diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
> index 7ea3689..59cad84 100644
> --- a/drivers/of/unittest.c
> +++ b/drivers/of/unittest.c
> @@ -25,6 +25,9 @@
>
>  #include <linux/bitops.h>
>
> +#include <linux/timekeeping.h>
> +#include <linux/random.h>
> +
>  #include "of_private.h"
>
>  static struct unittest_results {
> @@ -2266,6 +2269,70 @@ out:
>  static inline void __init of_unittest_overlay(void) { }
>  #endif
>
> +#define PHANDLE_LOOKUPS        1000
> +
> +static void __init of_unittest_phandle_hash(void)
> +{
> +       struct device_node *node;
> +       phandle max_phandle;
> +       u32 ph;
> +       unsigned long flags;
> +       int i, j, total;
> +       ktime_t start, end;
> +       s64 dur[2];
> +       int dec, frac;
> +
> +       /* test only available when hashing is available */
> +       if (!of_phandle_ht_available()) {
> +               pr_warn("phandle hash test requires hash to be initialized\n");
> +               return;

As the point of the unittest is to test the core DT code, this should
be a test fail.

> +       }
> +
> +       /* find the maximum phandle of the tree */
> +       raw_spin_lock_irqsave(&devtree_lock, flags);
> +       max_phandle = 0;
> +       total = 0;
> +       for_each_of_allnodes(node) {
> +               if (node->phandle != (phandle)-1U &&
> +                               node->phandle > max_phandle)
> +                       max_phandle = node->phandle;
> +               total++;
> +       }
> +       raw_spin_unlock_irqrestore(&devtree_lock, flags);
> +       max_phandle++;
> +
> +       pr_debug("phandle: max-phandle #%u, #%d total nodes\n",
> +                       (u32)max_phandle, total);
> +
> +       /* perform random lookups using the hash */
> +       for (j = 0; j < 2; j++) {
> +
> +               /* disabled for pass #0, enabled for pass #1 */
> +               of_phandle_ht_is_disabled = j == 0;

I'm not wild about having this variable leaked from the core code just
for the unit test. Yet another step away from the unittest being a
module.

I think you should just measure current performance and users can
revert the hash table if they want to measure the slow path.

Rob

[PATCH v2 4/5] of: overlay: Pick up label symbols from overlays.

[Pantelis Antoniou]

Insert overlay symbols to the base tree when applied.
This makes it possible to apply an overlay that references a label
that a previously inserted overlay had.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
---
 drivers/of/overlay.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index a274d65..89ebb70 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -8,6 +8,7 @@
  * modify it under the terms of the GNU General Public License
  * version 2 as published by the Free Software Foundation.
  */
+
 #undef DEBUG
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -514,6 +515,91 @@ static int of_free_overlay_info(struct of_overlay *ov)
 	return 0;
 }
 
+static int of_overlay_add_symbols(
+		struct device_node *tree,
+		struct of_overlay *ov)
+{
+	struct of_overlay_info *ovinfo;
+	struct device_node *root_sym = NULL;
+	struct device_node *child = NULL;
+	struct property *prop;
+	const char *path, *s;
+	char *new_path;
+	int i, len, err;
+
+	/* both may fail (if no fixups are required) */
+	root_sym = of_find_node_by_path("/__symbols__");
+	child = of_get_child_by_name(tree, "__symbols__");
+
+	err = 0;
+	/* do nothing if either is NULL */
+	if (!root_sym || !child)
+		goto out;
+
+	for_each_property_of_node(child, prop) {
+
+		/* skip properties added automatically */
+		if (of_prop_cmp(prop->name, "name") == 0)
+			continue;
+
+		err = of_property_read_string(child,
+				prop->name, &path);
+		if (err != 0) {
+			pr_err("Could not find symbol '%s'\n", prop->name);
+			continue;
+		}
+
+		/* now find fragment index */
+		s = path;
+
+		/* compare paths to find fragment index */
+		for (i = 0, ovinfo = NULL, len = -1; i < ov->count; i++) {
+			ovinfo = &ov->ovinfo_tab[i];
+
+			pr_debug("#%d: overlay->name=%s target->name=%s\n",
+					i, ovinfo->overlay->full_name,
+					ovinfo->target->full_name);
+
+			len = strlen(ovinfo->overlay->full_name);
+			if (strncasecmp(path, ovinfo->overlay->full_name,
+						len) == 0 && path[len] == '/')
+				break;
+		}
+
+		if (i >= ov->count)
+			continue;
+
+		pr_debug("found target at #%d\n", i);
+		new_path = kasprintf(GFP_KERNEL, "%s%s",
+				ovinfo->target->full_name,
+				path + len);
+		if (!new_path) {
+			pr_err("Failed to allocate propname for \"%s\"\n",
+					prop->name);
+			err = -ENOMEM;
+			break;
+		}
+
+		err = of_changeset_add_property_string(&ov->cset, root_sym,
+				prop->name, new_path);
+
+		/* free always */
+		kfree(new_path);
+
+		if (err) {
+			pr_err("Failed to add property for \"%s\"\n",
+					prop->name);
+			break;
+		}
+	}
+
+out:
+	of_node_put(child);
+	of_node_put(root_sym);
+
+	return err;
+}
+
 static LIST_HEAD(ov_list);
 static DEFINE_IDR(ov_idr);
 
@@ -642,6 +728,13 @@ static int __of_overlay_create(struct device_node *tree,
 		goto err_abort_trans;
 	}
 
+	err = of_overlay_add_symbols(tree, ov);
+	if (err) {
+		pr_err("%s: of_overlay_add_symbols() failed for tree@%s\n",
+				__func__, tree->full_name);
+		goto err_abort_trans;
+	}
+
 	/* apply the changeset */
 	err = __of_changeset_apply(&ov->cset);
 	if (err) {
-- 
1.7.12

Re: [PATCH v2 4/5] of: overlay: Pick up label symbols from overlays.

[Geert Uytterhoeven]

On Mon, May 16, 2016 at 6:52 PM, Pantelis Antoniou
<pantelis.antoniou@konsulko.com> wrote:
> Insert overlay symbols to the base tree when applied.
> This makes it possible to apply an overlay that references a label
> that a previously inserted overlay had.
>
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>

This patch hasn't changed, so I think you can keep my
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 4/5] of: overlay: Pick up label symbols from overlays.

[Pantelis Antoniou]

Hi Geert,

> On May 16, 2016, at 22:06 , Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> 
> On Mon, May 16, 2016 at 6:52 PM, Pantelis Antoniou
> <pantelis.antoniou@konsulko.com> wrote:
>> Insert overlay symbols to the base tree when applied.
>> This makes it possible to apply an overlay that references a label
>> that a previously inserted overlay had.
>> 
>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
> 
> This patch hasn't changed, so I think you can keep my

It’s been tweaked slightly that’s why I dropped your tested-by
signoff. Could you test this version again please to verify it
works for you?

> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
> Gr{oetje,eeting}s,
> 
>                        Geert
> 

Regards

— Pantelis

> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                -- Linus Torvalds

Re: [PATCH v2 4/5] of: overlay: Pick up label symbols from overlays.

[Geert Uytterhoeven]

Hi Pantelis,

On Mon, May 16, 2016 at 9:27 PM, Pantelis Antoniou
<pantelis.antoniou@konsulko.com> wrote:
>> On May 16, 2016, at 22:06 , Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>> On Mon, May 16, 2016 at 6:52 PM, Pantelis Antoniou
>> <pantelis.antoniou@konsulko.com> wrote:
>>> Insert overlay symbols to the base tree when applied.
>>> This makes it possible to apply an overlay that references a label
>>> that a previously inserted overlay had.
>>>
>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
>>
>> This patch hasn't changed, so I think you can keep my
>
> It’s been tweaked slightly that’s why I dropped your tested-by
> signoff. Could you test this version again please to verify it
> works for you?

Oh, I missed that you did make some changes...

Will test again and report back to you...

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 4/5] of: overlay: Pick up label symbols from overlays.

[Geert Uytterhoeven]

On Mon, May 16, 2016 at 9:40 PM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> On Mon, May 16, 2016 at 9:27 PM, Pantelis Antoniou
> <pantelis.antoniou@konsulko.com> wrote:
>>> On May 16, 2016, at 22:06 , Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>>> On Mon, May 16, 2016 at 6:52 PM, Pantelis Antoniou
>>> <pantelis.antoniou@konsulko.com> wrote:
>>>> Insert overlay symbols to the base tree when applied.
>>>> This makes it possible to apply an overlay that references a label
>>>> that a previously inserted overlay had.
>>>>
>>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
>>>
>>> This patch hasn't changed, so I think you can keep my
>>
>> It’s been tweaked slightly that’s why I dropped your tested-by
>> signoff. Could you test this version again please to verify it
>> works for you?
>
> Oh, I missed that you did make some changes...
>
> Will test again and report back to you...

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH v2 5/5] of: overlay: Add pr_fmt for clarity

[Pantelis Antoniou]

There are a bunch of pr_.*() messages in the file, use a common pr_fmt
for making them a little bit shorter.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
---
 drivers/of/overlay.c | 84 ++++++++++++++++++++++++----------------------------
 1 file changed, 38 insertions(+), 46 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 89ebb70..eecd6d2 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -9,6 +9,8 @@
  * version 2 as published by the Free Software Foundation.
  */
 
+#define pr_fmt(fmt) "overlay: %s() " fmt, __func__
+
 #undef DEBUG
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -175,8 +177,8 @@ static int of_overlay_apply_one(struct of_overlay *ov,
 	for_each_property_of_node(overlay, prop) {
 		ret = of_overlay_apply_single_property(ov, target, prop);
 		if (ret) {
-			pr_err("%s: Failed to apply prop @%s/%s\n",
-				__func__, target->full_name, prop->name);
+			pr_err("Failed to apply prop @%s/%s\n",
+				target->full_name, prop->name);
 			return ret;
 		}
 	}
@@ -184,9 +186,8 @@ static int of_overlay_apply_one(struct of_overlay *ov,
 	for_each_child_of_node(overlay, child) {
 		ret = of_overlay_apply_single_device_node(ov, target, child);
 		if (ret != 0) {
-			pr_err("%s: Failed to apply single node @%s/%s\n",
-					__func__, target->full_name,
-					child->name);
+			pr_err("Failed to apply single node @%s/%s\n",
+					target->full_name, child->name);
 			of_node_put(child);
 			return ret;
 		}
@@ -214,8 +215,8 @@ static int of_overlay_apply(struct of_overlay *ov)
 
 		err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay);
 		if (err != 0) {
-			pr_err("%s: overlay failed '%s'\n",
-				__func__, ovinfo->target->full_name);
+			pr_err("overlay failed '%s'\n",
+				ovinfo->target->full_name);
 			return err;
 		}
 	}
@@ -237,8 +238,7 @@ static struct device_node *find_target_node_direct(struct of_overlay *ov,
 	if (ret == 0) {
 		target = of_find_node_by_phandle(val);
 		if (!target) {
-			pr_err("%s: Could not find target phandle 0x%x\n",
-					__func__, val);
+			pr_err("Could not find target phandle 0x%x\n", val);
 			return NULL;
 		}
 		goto check_root;
@@ -251,8 +251,8 @@ static struct device_node *find_target_node_direct(struct of_overlay *ov,
 		if (!ov->target_root) {
 			target = of_find_node_by_path(path);
 			if (!target)
-				pr_err("%s: Could not find target path \"%s\"\n",
-						__func__, path);
+				pr_err("Could not find target path \"%s\"\n",
+						path);
 			return target;
 		}
 
@@ -265,8 +265,7 @@ static struct device_node *find_target_node_direct(struct of_overlay *ov,
 					of_node_full_name(ov->target_root),
 					*path ? "/" : "", path);
 			if (!newpath) {
-				pr_err("%s: Could not allocate \"%s%s%s\"\n",
-					__func__,
+				pr_err("Could not allocate \"%s%s%s\"\n",
 					of_node_full_name(ov->target_root),
 					*path ? "/" : "", path);
 				return NULL;
@@ -280,8 +279,7 @@ static struct device_node *find_target_node_direct(struct of_overlay *ov,
 		/* target is an alias, need to check */
 		target = of_find_node_by_path(path);
 		if (!target) {
-			pr_err("%s: Could not find alias \"%s\"\n",
-					__func__, path);
+			pr_err("Could not find alias \"%s\"\n", path);
 			return NULL;
 		}
 		goto check_root;
@@ -298,8 +296,8 @@ check_root:
 		if (np == ov->target_root)
 			return target;
 	}
-	pr_err("%s: target \"%s\" not under target_root \"%s\"\n",
-			__func__, of_node_full_name(target),
+	pr_err("target \"%s\" not under target_root \"%s\"\n",
+			of_node_full_name(target),
 			of_node_full_name(ov->target_root));
 	/* target is not under target_root */
 	of_node_put(target);
@@ -331,8 +329,7 @@ static struct device_node *find_target_node(struct of_overlay *ov,
 
 	target_indirect = of_get_child_by_name(info_node, "target-indirect");
 	if (!target_indirect) {
-		pr_err("%s: Failed to find target-indirect node at %s\n",
-				__func__,
+		pr_err("Failed to find target-indirect node at %s\n",
 				of_node_full_name(info_node));
 		return NULL;
 	}
@@ -340,8 +337,8 @@ static struct device_node *find_target_node(struct of_overlay *ov,
 	indirect = of_get_child_by_name(target_indirect, ov->indirect_id);
 	of_node_put(target_indirect);
 	if (!indirect) {
-		pr_err("%s: Failed to find indirect child node \"%s\" at %s\n",
-				__func__, ov->indirect_id,
+		pr_err("Failed to find indirect child node \"%s\" at %s\n",
+				ov->indirect_id,
 				of_node_full_name(info_node));
 		return NULL;
 	}
@@ -349,8 +346,8 @@ static struct device_node *find_target_node(struct of_overlay *ov,
 	target = find_target_node_direct(ov, indirect);
 
 	if (!target) {
-		pr_err("%s: Failed to find target for \"%s\" at %s\n",
-				__func__, ov->indirect_id,
+		pr_err("Failed to find target for \"%s\" at %s\n",
+				ov->indirect_id,
 				of_node_full_name(indirect));
 	}
 	of_node_put(indirect);
@@ -705,8 +702,7 @@ static int __of_overlay_create(struct device_node *tree,
 
 	id = idr_alloc(&ov_idr, ov, 0, 0, GFP_KERNEL);
 	if (id < 0) {
-		pr_err("%s: idr_alloc() failed for tree@%s\n",
-				__func__, tree->full_name);
+		pr_err("idr_alloc() failed for tree@%s\n", tree->full_name);
 		err = id;
 		goto err_destroy_trans;
 	}
@@ -715,46 +711,46 @@ static int __of_overlay_create(struct device_node *tree,
 	/* build the overlay info structures */
 	err = of_build_overlay_info(ov, tree);
 	if (err) {
-		pr_err("%s: of_build_overlay_info() failed for tree@%s\n",
-				__func__, tree->full_name);
+		pr_err("of_build_overlay_info() failed for tree@%s\n",
+				tree->full_name);
 		goto err_free_idr;
 	}
 
 	/* apply the overlay */
 	err = of_overlay_apply(ov);
 	if (err) {
-		pr_err("%s: of_overlay_apply() failed for tree@%s\n",
-				__func__, tree->full_name);
+		pr_err("of_overlay_apply() failed for tree@%s\n",
+				tree->full_name);
 		goto err_abort_trans;
 	}
 
 	err = of_overlay_add_symbols(tree, ov);
 	if (err) {
-		pr_err("%s: of_overlay_add_symbols() failed for tree@%s\n",
-				__func__, tree->full_name);
+		pr_err("of_overlay_add_symbols() failed for tree@%s\n",
+				tree->full_name);
 		goto err_abort_trans;
 	}
 
 	/* apply the changeset */
 	err = __of_changeset_apply(&ov->cset);
 	if (err) {
-		pr_err("%s: __of_changeset_apply() failed for tree@%s\n",
-				__func__, tree->full_name);
+		pr_err("__of_changeset_apply() failed for tree@%s\n",
+				tree->full_name);
 		goto err_revert_overlay;
 	}
 
 	ov->kobj.kset = ov_kset;
 	err = kobject_add(&ov->kobj, NULL, "%d", id);
 	if (err != 0) {
-		pr_err("%s: kobject_add() failed for tree@%s\n",
-				__func__, tree->full_name);
+		pr_err("kobject_add() failed for tree@%s\n",
+				tree->full_name);
 		goto err_cancel_overlay;
 	}
 
 	err = sysfs_create_groups(&ov->kobj, ov->attr_groups);
 	if (err != 0) {
-		pr_err("%s: sysfs_create_groups() failed for tree@%s\n",
-				__func__, tree->full_name);
+		pr_err("sysfs_create_groups() failed for tree@%s\n",
+				tree->full_name);
 		goto err_remove_kobj;
 	}
 
@@ -871,9 +867,8 @@ static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn)
 		/* check against each subtree affected by this overlay */
 		list_for_each_entry(ce, &ovt->cset.entries, node) {
 			if (overlay_subtree_check(ce->np, dn)) {
-				pr_err("%s: #%d clashes #%d @%s\n",
-					__func__, ov->id, ovt->id,
-					dn->full_name);
+				pr_err("#%d clashes #%d @%s\n",
+					ov->id, ovt->id, dn->full_name);
 				return 0;
 			}
 		}
@@ -899,8 +894,7 @@ static int overlay_removal_is_ok(struct of_overlay *ov)
 
 	list_for_each_entry(ce, &ov->cset.entries, node) {
 		if (!overlay_is_topmost(ov, ce->np)) {
-			pr_err("%s: overlay #%d is not topmost\n",
-					__func__, ov->id);
+			pr_err("overlay #%d is not topmost\n", ov->id);
 			return 0;
 		}
 	}
@@ -926,16 +920,14 @@ int of_overlay_destroy(int id)
 	ov = idr_find(&ov_idr, id);
 	if (ov == NULL) {
 		err = -ENODEV;
-		pr_err("%s: Could not find overlay #%d\n",
-				__func__, id);
+		pr_err("Could not find overlay #%d\n", id);
 		goto out;
 	}
 
 	/* check whether the overlay is safe to remove */
 	if (!overlay_removal_is_ok(ov)) {
 		err = -EBUSY;
-		pr_err("%s: removal check failed for overlay #%d\n",
-				__func__, id);
+		pr_err("removal check failed for overlay #%d\n", id);
 		goto out;
 	}
 
-- 
1.7.12