diff mbox

[v2,3/4] resource: Add device-managed insert/remove_resource()

Message ID 1456959056-12316-4-git-send-email-toshi.kani@hpe.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Kani, Toshi March 2, 2016, 10:50 p.m. UTC
insert_resource() and remove_resouce() are called by producers
of resources, such as FW modules and bus drivers.  These modules
may be implemented as loadable modules.

Add device-managed implementaions of insert_resource() and
remove_resouce() functions.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
---
 include/linux/ioport.h |    5 +++
 kernel/resource.c      |   69 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

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Comments

Dan Williams March 3, 2016, 10:45 p.m. UTC | #1
On Wed, Mar 2, 2016 at 2:50 PM, Toshi Kani <toshi.kani@hpe.com> wrote:
> insert_resource() and remove_resouce() are called by producers
> of resources, such as FW modules and bus drivers.  These modules
> may be implemented as loadable modules.
>
> Add device-managed implementaions of insert_resource() and
> remove_resouce() functions.
>
> Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Dan Williams <dan.j.williams@intel.com>
> ---
>  include/linux/ioport.h |    5 +++
>  kernel/resource.c      |   69 ++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 74 insertions(+)
>
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index 8017b8b..3580038 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -259,6 +259,11 @@ extern struct resource * __devm_request_region(struct device *dev,
>
>  extern void __devm_release_region(struct device *dev, struct resource *parent,
>                                   resource_size_t start, resource_size_t n);
> +
> +extern int devm_insert_resource(struct device *dev, struct resource *root,
> +                                struct resource *new);
> +extern void devm_remove_resource(struct device *dev, struct resource *old);
> +
>  extern int iomem_map_sanity_check(resource_size_t addr, unsigned long size);
>  extern int iomem_is_exclusive(u64 addr);
>
> diff --git a/kernel/resource.c b/kernel/resource.c
> index effb6ee..b1a3394 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -1449,6 +1449,75 @@ void __devm_release_region(struct device *dev, struct resource *parent,
>  EXPORT_SYMBOL(__devm_release_region);
>
>  /*
> + * Remove function for devm_insert_resource() and devm_remove_resource().
> + */
> +static void devm_resource_remove(struct device *dev, void *ptr)
> +{
> +       struct resource **r = ptr;
> +
> +       remove_resource(*r);
> +}
> +

Maybe call this __devm_remove_resource?  I think this makes it clearer
that it is a private helper function.  I was initially confused about
the difference between devm_resource_remove and devm_remove_resource.
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Kani, Toshi March 3, 2016, 11:48 p.m. UTC | #2
On Thu, 2016-03-03 at 14:45 -0800, Dan Williams wrote:
> On Wed, Mar 2, 2016 at 2:50 PM, Toshi Kani <toshi.kani@hpe.com> wrote:
 :
> > 
> > diff --git a/kernel/resource.c b/kernel/resource.c
> > index effb6ee..b1a3394 100644
> > --- a/kernel/resource.c
> > +++ b/kernel/resource.c
> > @@ -1449,6 +1449,75 @@ void __devm_release_region(struct device *dev,
> > struct resource *parent,
> >  EXPORT_SYMBOL(__devm_release_region);
> > 
> >  /*
> > + * Remove function for devm_insert_resource() and
> > devm_remove_resource().
> > + */
> > +static void devm_resource_remove(struct device *dev, void *ptr)
> > +{
> > +       struct resource **r = ptr;
> > +
> > +       remove_resource(*r);
> > +}
> > +
> 
> Maybe call this __devm_remove_resource?  I think this makes it clearer
> that it is a private helper function.  I was initially confused about
> the difference between devm_resource_remove and devm_remove_resource.

Will do.  I followed the naming convention of devm_resource_release() in
the same file, but I agree that this is confusing.

Thanks,
-Toshi
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diff mbox

Patch

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 8017b8b..3580038 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -259,6 +259,11 @@  extern struct resource * __devm_request_region(struct device *dev,
 
 extern void __devm_release_region(struct device *dev, struct resource *parent,
 				  resource_size_t start, resource_size_t n);
+
+extern int devm_insert_resource(struct device *dev, struct resource *root,
+				 struct resource *new);
+extern void devm_remove_resource(struct device *dev, struct resource *old);
+
 extern int iomem_map_sanity_check(resource_size_t addr, unsigned long size);
 extern int iomem_is_exclusive(u64 addr);
 
diff --git a/kernel/resource.c b/kernel/resource.c
index effb6ee..b1a3394 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1449,6 +1449,75 @@  void __devm_release_region(struct device *dev, struct resource *parent,
 EXPORT_SYMBOL(__devm_release_region);
 
 /*
+ * Remove function for devm_insert_resource() and devm_remove_resource().
+ */
+static void devm_resource_remove(struct device *dev, void *ptr)
+{
+	struct resource **r = ptr;
+
+	remove_resource(*r);
+}
+
+/**
+ * devm_insert_resource() - insert an I/O or memory resource
+ * @dev: device for which to produce the resource
+ * @root: root of the resource tree
+ * @new: descriptor of the new resource
+ *
+ * This is a device-managed version of insert_resource(). There is usually
+ * no need to release resources requested by this function explicitly since
+ * that will be taken care of when the device is unbound from its bus driver.
+ * If for some reason the resource needs to be released explicitly, because
+ * of ordering issues for example, bus drivers must call devm_remove_resource()
+ * rather than the regular remove_resource().
+ *
+ * devm_insert_resource() is intended for producers of resources, such as
+ * FW modules and bus drivers.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int devm_insert_resource(struct device *dev, struct resource *root,
+			  struct resource *new)
+{
+	struct resource **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_resource_remove, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	*ptr = new;
+
+	ret = insert_resource(root, new);
+	if (ret) {
+		dev_err(dev, "unable to insert resource: %pR (%d)\n", new, ret);
+		devres_free(ptr);
+		return -EBUSY;
+	}
+
+	devres_add(dev, ptr);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_insert_resource);
+
+/**
+ * devm_remove_resource() - remove a previously inserted resource
+ * @dev: device for which to remove the resource
+ * @old: descriptor of the resource
+ *
+ * Remove a resource previously inserted using devm_insert_resource().
+ *
+ * devm_remove_resource() is intended for producers of resources, such as
+ * FW modules and bus drivers.
+ */
+void devm_remove_resource(struct device *dev, struct resource *old)
+{
+	WARN_ON(devres_release(dev, devm_resource_remove, devm_resource_match,
+			       old));
+}
+EXPORT_SYMBOL_GPL(devm_remove_resource);
+
+/*
  * Called from init/main.c to reserve IO ports.
  */
 #define MAXRESERVE 4