[PATCH v1 0/2] Improve remote-endpoint parsing

[PATCH v1 0/2] Improve remote-endpoint parsing

[Saravana Kannan]

Some changes to do a more accurate parsing of remote-endpoints. Making
fw_devlink a tiny bit more efficient and the debug logs a bit cleaner when
trying to debug fw_devlink.

Saravana Kannan (2):
  of: property: Improve finding the consumer of a remote-endpoint
    property
  of: property: Improve finding the supplier of a remote-endpoint
    property

 drivers/of/property.c | 71 ++++++++++++++++++++-----------------------
 1 file changed, 33 insertions(+), 38 deletions(-)

-- 
2.43.0.594.gd9cf4e227d-goog

[PATCH v1 1/2] of: property: Improve finding the consumer of a remote-endpoint property

[Saravana Kannan]

We have a more accurate function to find the right consumer of a
remote-endpoint property instead of searching for a parent with
compatible string property. So, use that instead. While at it, make the
code to find the consumer a bit more flexible and based on the property
being parsed.

Fixes: f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/of/property.c | 52 +++++++++++++------------------------------
 1 file changed, 15 insertions(+), 37 deletions(-)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index 641a40cf5cf3..ba374a1f2072 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1063,36 +1063,6 @@ of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
 	return of_device_get_match_data(dev);
 }
 
-static struct device_node *of_get_compat_node(struct device_node *np)
-{
-	of_node_get(np);
-
-	while (np) {
-		if (!of_device_is_available(np)) {
-			of_node_put(np);
-			np = NULL;
-		}
-
-		if (of_property_present(np, "compatible"))
-			break;
-
-		np = of_get_next_parent(np);
-	}
-
-	return np;
-}
-
-static struct device_node *of_get_compat_node_parent(struct device_node *np)
-{
-	struct device_node *parent, *node;
-
-	parent = of_get_parent(np);
-	node = of_get_compat_node(parent);
-	of_node_put(parent);
-
-	return node;
-}
-
 static void of_link_to_phandle(struct device_node *con_np,
 			      struct device_node *sup_np)
 {
@@ -1222,10 +1192,10 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
  *  parse_prop.prop_name: Name of property holding a phandle value
  *  parse_prop.index: For properties holding a list of phandles, this is the
  *		      index into the list
+ * @get_con_dev: If the consumer node containing the property is never converted
+ *		 to a struct device, implement this ops so fw_devlink can use it
+ *		 to find the true consumer.
  * @optional: Describes whether a supplier is mandatory or not
- * @node_not_dev: The consumer node containing the property is never converted
- *		  to a struct device. Instead, parse ancestor nodes for the
- *		  compatible property to find a node corresponding to a device.
  *
  * Returns:
  * parse_prop() return values are
@@ -1236,8 +1206,8 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
 struct supplier_bindings {
 	struct device_node *(*parse_prop)(struct device_node *np,
 					  const char *prop_name, int index);
+	struct device_node *(*get_con_dev)(struct device_node *np);
 	bool optional;
-	bool node_not_dev;
 };
 
 DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
@@ -1328,6 +1298,11 @@ static struct device_node *parse_interrupts(struct device_node *np,
 	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
 }
 
+static struct device_node *get_remote_endpoint_dev(struct device_node *np)
+{
+	return to_of_node(fwnode_graph_get_port_parent(of_fwnode_handle(np)));
+}
+
 static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_clocks, },
 	{ .parse_prop = parse_interconnects, },
@@ -1352,7 +1327,10 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_pinctrl6, },
 	{ .parse_prop = parse_pinctrl7, },
 	{ .parse_prop = parse_pinctrl8, },
-	{ .parse_prop = parse_remote_endpoint, .node_not_dev = true, },
+	{
+		.parse_prop = parse_remote_endpoint,
+		.get_con_dev = get_remote_endpoint_dev,
+	},
 	{ .parse_prop = parse_pwms, },
 	{ .parse_prop = parse_resets, },
 	{ .parse_prop = parse_leds, },
@@ -1403,8 +1381,8 @@ static int of_link_property(struct device_node *con_np, const char *prop_name)
 		while ((phandle = s->parse_prop(con_np, prop_name, i))) {
 			struct device_node *con_dev_np;
 
-			con_dev_np = s->node_not_dev
-					? of_get_compat_node_parent(con_np)
+			con_dev_np = s->get_con_dev
+					? s->get_con_dev(con_np)
 					: of_node_get(con_np);
 			matched = true;
 			i++;
-- 
2.43.0.594.gd9cf4e227d-goog

Re: [PATCH v1 1/2] of: property: Improve finding the consumer of a remote-endpoint property

[Rob Herring]

On Fri, Feb 02, 2024 at 02:13:24AM -0800, Saravana Kannan wrote:
> We have a more accurate function to find the right consumer of a
> remote-endpoint property instead of searching for a parent with
> compatible string property. So, use that instead. While at it, make the
> code to find the consumer a bit more flexible and based on the property
> being parsed.
> 
> Fixes: f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>  drivers/of/property.c | 52 +++++++++++++------------------------------
>  1 file changed, 15 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 641a40cf5cf3..ba374a1f2072 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1063,36 +1063,6 @@ of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
>  	return of_device_get_match_data(dev);
>  }
>  
> -static struct device_node *of_get_compat_node(struct device_node *np)
> -{
> -	of_node_get(np);
> -
> -	while (np) {
> -		if (!of_device_is_available(np)) {
> -			of_node_put(np);
> -			np = NULL;
> -		}
> -
> -		if (of_property_present(np, "compatible"))
> -			break;
> -
> -		np = of_get_next_parent(np);
> -	}
> -
> -	return np;
> -}
> -
> -static struct device_node *of_get_compat_node_parent(struct device_node *np)
> -{
> -	struct device_node *parent, *node;
> -
> -	parent = of_get_parent(np);
> -	node = of_get_compat_node(parent);
> -	of_node_put(parent);
> -
> -	return node;
> -}
> -
>  static void of_link_to_phandle(struct device_node *con_np,
>  			      struct device_node *sup_np)
>  {
> @@ -1222,10 +1192,10 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
>   *  parse_prop.prop_name: Name of property holding a phandle value
>   *  parse_prop.index: For properties holding a list of phandles, this is the
>   *		      index into the list
> + * @get_con_dev: If the consumer node containing the property is never converted
> + *		 to a struct device, implement this ops so fw_devlink can use it
> + *		 to find the true consumer.
>   * @optional: Describes whether a supplier is mandatory or not
> - * @node_not_dev: The consumer node containing the property is never converted
> - *		  to a struct device. Instead, parse ancestor nodes for the
> - *		  compatible property to find a node corresponding to a device.
>   *
>   * Returns:
>   * parse_prop() return values are
> @@ -1236,8 +1206,8 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
>  struct supplier_bindings {
>  	struct device_node *(*parse_prop)(struct device_node *np,
>  					  const char *prop_name, int index);
> +	struct device_node *(*get_con_dev)(struct device_node *np);
>  	bool optional;
> -	bool node_not_dev;
>  };
>  
>  DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
> @@ -1328,6 +1298,11 @@ static struct device_node *parse_interrupts(struct device_node *np,
>  	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
>  }
>  
> +static struct device_node *get_remote_endpoint_dev(struct device_node *np)
> +{
> +	return to_of_node(fwnode_graph_get_port_parent(of_fwnode_handle(np)));

DT APIs shouldn't depend on fwnode APIs.

Otherwise, this series looks good.

Re: [PATCH v1 1/2] of: property: Improve finding the consumer of a remote-endpoint property

[Saravana Kannan]

On Mon, Feb 5, 2024 at 9:36 AM Rob Herring <robh@kernel.org> wrote:
>
> On Fri, Feb 02, 2024 at 02:13:24AM -0800, Saravana Kannan wrote:
> > We have a more accurate function to find the right consumer of a
> > remote-endpoint property instead of searching for a parent with
> > compatible string property. So, use that instead. While at it, make the
> > code to find the consumer a bit more flexible and based on the property
> > being parsed.
> >
> > Fixes: f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > ---
> >  drivers/of/property.c | 52 +++++++++++++------------------------------
> >  1 file changed, 15 insertions(+), 37 deletions(-)
> >
> > diff --git a/drivers/of/property.c b/drivers/of/property.c
> > index 641a40cf5cf3..ba374a1f2072 100644
> > --- a/drivers/of/property.c
> > +++ b/drivers/of/property.c
> > @@ -1063,36 +1063,6 @@ of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
> >       return of_device_get_match_data(dev);
> >  }
> >
> > -static struct device_node *of_get_compat_node(struct device_node *np)
> > -{
> > -     of_node_get(np);
> > -
> > -     while (np) {
> > -             if (!of_device_is_available(np)) {
> > -                     of_node_put(np);
> > -                     np = NULL;
> > -             }
> > -
> > -             if (of_property_present(np, "compatible"))
> > -                     break;
> > -
> > -             np = of_get_next_parent(np);
> > -     }
> > -
> > -     return np;
> > -}
> > -
> > -static struct device_node *of_get_compat_node_parent(struct device_node *np)
> > -{
> > -     struct device_node *parent, *node;
> > -
> > -     parent = of_get_parent(np);
> > -     node = of_get_compat_node(parent);
> > -     of_node_put(parent);
> > -
> > -     return node;
> > -}
> > -
> >  static void of_link_to_phandle(struct device_node *con_np,
> >                             struct device_node *sup_np)
> >  {
> > @@ -1222,10 +1192,10 @@ static struct device_node *parse_##fname(struct device_node *np,           \
> >   *  parse_prop.prop_name: Name of property holding a phandle value
> >   *  parse_prop.index: For properties holding a list of phandles, this is the
> >   *                 index into the list
> > + * @get_con_dev: If the consumer node containing the property is never converted
> > + *            to a struct device, implement this ops so fw_devlink can use it
> > + *            to find the true consumer.
> >   * @optional: Describes whether a supplier is mandatory or not
> > - * @node_not_dev: The consumer node containing the property is never converted
> > - *             to a struct device. Instead, parse ancestor nodes for the
> > - *             compatible property to find a node corresponding to a device.
> >   *
> >   * Returns:
> >   * parse_prop() return values are
> > @@ -1236,8 +1206,8 @@ static struct device_node *parse_##fname(struct device_node *np,             \
> >  struct supplier_bindings {
> >       struct device_node *(*parse_prop)(struct device_node *np,
> >                                         const char *prop_name, int index);
> > +     struct device_node *(*get_con_dev)(struct device_node *np);
> >       bool optional;
> > -     bool node_not_dev;
> >  };
> >
> >  DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
> > @@ -1328,6 +1298,11 @@ static struct device_node *parse_interrupts(struct device_node *np,
> >       return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
> >  }
> >
> > +static struct device_node *get_remote_endpoint_dev(struct device_node *np)
> > +{
> > +     return to_of_node(fwnode_graph_get_port_parent(of_fwnode_handle(np)));
>
> DT APIs shouldn't depend on fwnode APIs.

I get what you are saying, but is it an API though? It's a static
internal function that's eventually used by .add_link to add fwnode
links. Would it be better if I rolled this into two separate inline
code where this function is getting called from? I'm trying to avoid
duplicating the function that's already present in
fwnode_graph_get_port_parent(), but it also feels too specific an op
to introduce into drivers/of/property.c

How would you like me to handle this? I don't see a good option.

> Otherwise, this series looks good.

Thanks,
Saravana

Re: [PATCH v1 1/2] of: property: Improve finding the consumer of a remote-endpoint property

[Saravana Kannan]

On Mon, Feb 5, 2024 at 11:47 AM Saravana Kannan <saravanak@google.com> wrote:
>
> On Mon, Feb 5, 2024 at 9:36 AM Rob Herring <robh@kernel.org> wrote:
> >
> > On Fri, Feb 02, 2024 at 02:13:24AM -0800, Saravana Kannan wrote:
> > > We have a more accurate function to find the right consumer of a
> > > remote-endpoint property instead of searching for a parent with
> > > compatible string property. So, use that instead. While at it, make the
> > > code to find the consumer a bit more flexible and based on the property
> > > being parsed.
> > >
> > > Fixes: f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
> > > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > > ---
> > >  drivers/of/property.c | 52 +++++++++++++------------------------------
> > >  1 file changed, 15 insertions(+), 37 deletions(-)
> > >
> > > diff --git a/drivers/of/property.c b/drivers/of/property.c
> > > index 641a40cf5cf3..ba374a1f2072 100644
> > > --- a/drivers/of/property.c
> > > +++ b/drivers/of/property.c
> > > @@ -1063,36 +1063,6 @@ of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
> > >       return of_device_get_match_data(dev);
> > >  }
> > >
> > > -static struct device_node *of_get_compat_node(struct device_node *np)
> > > -{
> > > -     of_node_get(np);
> > > -
> > > -     while (np) {
> > > -             if (!of_device_is_available(np)) {
> > > -                     of_node_put(np);
> > > -                     np = NULL;
> > > -             }
> > > -
> > > -             if (of_property_present(np, "compatible"))
> > > -                     break;
> > > -
> > > -             np = of_get_next_parent(np);
> > > -     }
> > > -
> > > -     return np;
> > > -}
> > > -
> > > -static struct device_node *of_get_compat_node_parent(struct device_node *np)
> > > -{
> > > -     struct device_node *parent, *node;
> > > -
> > > -     parent = of_get_parent(np);
> > > -     node = of_get_compat_node(parent);
> > > -     of_node_put(parent);
> > > -
> > > -     return node;
> > > -}
> > > -
> > >  static void of_link_to_phandle(struct device_node *con_np,
> > >                             struct device_node *sup_np)
> > >  {
> > > @@ -1222,10 +1192,10 @@ static struct device_node *parse_##fname(struct device_node *np,           \
> > >   *  parse_prop.prop_name: Name of property holding a phandle value
> > >   *  parse_prop.index: For properties holding a list of phandles, this is the
> > >   *                 index into the list
> > > + * @get_con_dev: If the consumer node containing the property is never converted
> > > + *            to a struct device, implement this ops so fw_devlink can use it
> > > + *            to find the true consumer.
> > >   * @optional: Describes whether a supplier is mandatory or not
> > > - * @node_not_dev: The consumer node containing the property is never converted
> > > - *             to a struct device. Instead, parse ancestor nodes for the
> > > - *             compatible property to find a node corresponding to a device.
> > >   *
> > >   * Returns:
> > >   * parse_prop() return values are
> > > @@ -1236,8 +1206,8 @@ static struct device_node *parse_##fname(struct device_node *np,             \
> > >  struct supplier_bindings {
> > >       struct device_node *(*parse_prop)(struct device_node *np,
> > >                                         const char *prop_name, int index);
> > > +     struct device_node *(*get_con_dev)(struct device_node *np);
> > >       bool optional;
> > > -     bool node_not_dev;
> > >  };
> > >
> > >  DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
> > > @@ -1328,6 +1298,11 @@ static struct device_node *parse_interrupts(struct device_node *np,
> > >       return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
> > >  }
> > >
> > > +static struct device_node *get_remote_endpoint_dev(struct device_node *np)
> > > +{
> > > +     return to_of_node(fwnode_graph_get_port_parent(of_fwnode_handle(np)));
> >
> > DT APIs shouldn't depend on fwnode APIs.
>
> I get what you are saying, but is it an API though? It's a static
> internal function that's eventually used by .add_link to add fwnode
> links. Would it be better if I rolled this into two separate inline
> code where this function is getting called from? I'm trying to avoid
> duplicating the function that's already present in
> fwnode_graph_get_port_parent(), but it also feels too specific an op
> to introduce into drivers/of/property.c
>
> How would you like me to handle this? I don't see a good option.

Nevermind, there's already of_graph_get_port_parent() that does
exactly the same as fwnode_graph_get_port_parent(). I'll just use
that.

-Saravana

[PATCH v1 2/2] of: property: Improve finding the supplier of a remote-endpoint property

[Saravana Kannan]

After commit 4a032827daa8 ("of: property: Simplify of_link_to_phandle()"),
remote-endpoint properties created a fwnode link from the consumer device
to the supplier endpoint. This is a tiny bit inefficient (not buggy) when
trying to create device links or detecting cycles. So, improve this the
same way we improved finding the consumer of a remote-endpoint property.

Fixes: 4a032827daa8 ("of: property: Simplify of_link_to_phandle()")
Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/of/property.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index ba374a1f2072..6c168446b647 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1232,7 +1232,6 @@ DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL)
 DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL)
 DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL)
 DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL)
-DEFINE_SIMPLE_PROP(remote_endpoint, "remote-endpoint", NULL)
 DEFINE_SIMPLE_PROP(pwms, "pwms", "#pwm-cells")
 DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
 DEFINE_SIMPLE_PROP(leds, "leds", NULL)
@@ -1303,6 +1302,24 @@ static struct device_node *get_remote_endpoint_dev(struct device_node *np)
 	return to_of_node(fwnode_graph_get_port_parent(of_fwnode_handle(np)));
 }
 
+static struct device_node *parse_remote_endpoint(struct device_node *np,
+						 const char *prop_name,
+						 int index)
+{
+	struct device_node *endpoint, *sup;
+
+	if (strcmp(prop_name, "remote-endpoint"))
+		return NULL;
+
+	endpoint = of_parse_phandle(np, prop_name, index);
+	if (!endpoint)
+		return NULL;
+
+	sup = get_remote_endpoint_dev(endpoint);
+	of_node_put(endpoint);
+	return sup;
+}
+
 static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_clocks, },
 	{ .parse_prop = parse_interconnects, },
-- 
2.43.0.594.gd9cf4e227d-goog