diff mbox series

[01/42] of: reserved_mem: Introduce devres-managed initialization functions

Message ID 20260703193855.110619-2-mukesh.ojha@oss.qualcomm.com (mailing list archive)
State New
Headers
Series of: reserved_mem: Introduce devres helpers and convert drivers |

Commit Message

Mukesh Ojha July 3, 2026, 7:38 p.m. UTC 
From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Introduce devres-based helpers for of_reserved_mem_device_init(_by_idx)
to help fight dangling references and ever so slightly reduce the
number of boilerplate deinitialization calls.

Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
---
 drivers/of/of_reserved_mem.c    | 41 +++++++++++++++++++++++++++++++++
 include/linux/of_reserved_mem.h | 25 ++++++++++++++++++++
 2 files changed, 66 insertions(+)

Comments

Rob Herring July 16, 2026, 8 p.m. UTC | #1 
On Sat, Jul 04, 2026 at 01:08:14AM +0530, Mukesh Ojha wrote:
> From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> 
> Introduce devres-based helpers for of_reserved_mem_device_init(_by_idx)
> to help fight dangling references and ever so slightly reduce the
> number of boilerplate deinitialization calls.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> ---
>  drivers/of/of_reserved_mem.c    | 41 +++++++++++++++++++++++++++++++++
>  include/linux/of_reserved_mem.h | 25 ++++++++++++++++++++
>  2 files changed, 66 insertions(+)
> 
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 82222bd45ac6..b35541e9fbe8 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -787,6 +787,47 @@ void of_reserved_mem_device_release(struct device *dev)
>  }
>  EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
>  
> +static void devm_of_reserved_mem_device_release(struct device *dev, void *res)
> +{
> +	of_reserved_mem_device_release(*(struct device **)res);
> +}
> +
> +/**
> + * devm_of_reserved_mem_device_init_by_idx() - Resource managed of_reserved_mem_device_init_by_idx()
> + * @dev: Pointer to the device to configure
> + * @np: Pointer to the device node with 'memory-region' property
> + * @idx: Index of selected region
> + *
> + * This is a resource managed version of of_reserved_mem_device_init_by_idx().
> + * The reserved memory region will be released automatically when the device
> + * is unbound.
> + *
> + * Returns: Negative errno on failure or zero on success.
> + */
> +int devm_of_reserved_mem_device_init_by_idx(struct device *dev,
> +					    struct device_node *np, int idx)

It looks to me like the only 2? users of this could be converted to 
devm_of_reserved_mem_device_init() instead. The mmc one obviously can. 
The imx one depends if np is dev->of_node. I'm not a fan of APIs with 
only a few users.

Rob
Mukesh Ojha July 17, 2026, 3:37 p.m. UTC | #2 
On Thu, Jul 16, 2026 at 03:00:48PM -0500, Rob Herring wrote:
> On Sat, Jul 04, 2026 at 01:08:14AM +0530, Mukesh Ojha wrote:
> > From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> > 
> > Introduce devres-based helpers for of_reserved_mem_device_init(_by_idx)
> > to help fight dangling references and ever so slightly reduce the
> > number of boilerplate deinitialization calls.
> > 
> > Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> > Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> > ---
> >  drivers/of/of_reserved_mem.c    | 41 +++++++++++++++++++++++++++++++++
> >  include/linux/of_reserved_mem.h | 25 ++++++++++++++++++++
> >  2 files changed, 66 insertions(+)
> > 
> > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> > index 82222bd45ac6..b35541e9fbe8 100644
> > --- a/drivers/of/of_reserved_mem.c
> > +++ b/drivers/of/of_reserved_mem.c
> > @@ -787,6 +787,47 @@ void of_reserved_mem_device_release(struct device *dev)
> >  }
> >  EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
> >  
> > +static void devm_of_reserved_mem_device_release(struct device *dev, void *res)
> > +{
> > +	of_reserved_mem_device_release(*(struct device **)res);
> > +}
> > +
> > +/**
> > + * devm_of_reserved_mem_device_init_by_idx() - Resource managed of_reserved_mem_device_init_by_idx()
> > + * @dev: Pointer to the device to configure
> > + * @np: Pointer to the device node with 'memory-region' property
> > + * @idx: Index of selected region
> > + *
> > + * This is a resource managed version of of_reserved_mem_device_init_by_idx().
> > + * The reserved memory region will be released automatically when the device
> > + * is unbound.
> > + *
> > + * Returns: Negative errno on failure or zero on success.
> > + */
> > +int devm_of_reserved_mem_device_init_by_idx(struct device *dev,
> > +					    struct device_node *np, int idx)
> 
> It looks to me like the only 2? users of this could be converted to 
> devm_of_reserved_mem_device_init() instead. The mmc one obviously can. 
> The imx one depends if np is dev->of_node. I'm not a fan of APIs with 
> only a few users.

You are right, mmc can be but imx can't. I can make this static and drop
the API usage from imx but fix the leak by release function.
diff mbox series

Patch

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 82222bd45ac6..b35541e9fbe8 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -787,6 +787,47 @@  void of_reserved_mem_device_release(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 
+static void devm_of_reserved_mem_device_release(struct device *dev, void *res)
+{
+	of_reserved_mem_device_release(*(struct device **)res);
+}
+
+/**
+ * devm_of_reserved_mem_device_init_by_idx() - Resource managed of_reserved_mem_device_init_by_idx()
+ * @dev: Pointer to the device to configure
+ * @np: Pointer to the device node with 'memory-region' property
+ * @idx: Index of selected region
+ *
+ * This is a resource managed version of of_reserved_mem_device_init_by_idx().
+ * The reserved memory region will be released automatically when the device
+ * is unbound.
+ *
+ * Returns: Negative errno on failure or zero on success.
+ */
+int devm_of_reserved_mem_device_init_by_idx(struct device *dev,
+					    struct device_node *np, int idx)
+{
+	struct device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_of_reserved_mem_device_release, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = of_reserved_mem_device_init_by_idx(dev, np, idx);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	*ptr = dev;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_of_reserved_mem_device_init_by_idx);
+
 /**
  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
  * @np:		node pointer of the desired reserved-memory region
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index e8b20b29fa68..b9fd78123d77 100644
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -40,6 +40,9 @@  int of_reserved_mem_device_init_by_name(struct device *dev,
 					const char *name);
 void of_reserved_mem_device_release(struct device *dev);
 
+int devm_of_reserved_mem_device_init_by_idx(struct device *dev,
+					    struct device_node *np, int idx);
+
 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np);
 int of_reserved_mem_region_to_resource(const struct device_node *np,
 				       unsigned int idx, struct resource *res);
@@ -68,6 +71,13 @@  static inline int of_reserved_mem_device_init_by_name(struct device *dev,
 
 static inline void of_reserved_mem_device_release(struct device *pdev) { }
 
+static inline int devm_of_reserved_mem_device_init_by_idx(struct device *dev,
+							  struct device_node *np,
+							  int idx)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
 {
 	return NULL;
@@ -108,4 +118,19 @@  static inline int of_reserved_mem_device_init(struct device *dev)
 	return of_reserved_mem_device_init_by_idx(dev, dev->of_node, 0);
 }
 
+/**
+ * devm_of_reserved_mem_device_init() - Resource managed version of of_reserved_mem_device_init()
+ * @dev:	Pointer to the device to configure
+ *
+ * This is a resource managed version of of_reserved_mem_device_init().
+ * The reserved memory region will be released automatically when the device
+ * is unbound.
+ *
+ * Returns error code or zero on success.
+ */
+static inline int devm_of_reserved_mem_device_init(struct device *dev)
+{
+	return devm_of_reserved_mem_device_init_by_idx(dev, dev->of_node, 0);
+}
+
 #endif /* __OF_RESERVED_MEM_H */