[PATCH v3 3/4] fpga: add devm_fpga_region_create

From: Alan Tull
Date: Wed Sep 26 2018 - 12:12:47 EST

Add devm_fpga_region_create() which is the
managed version of fpga_region_create().

Change current region drivers to use
devm_fpga_region_create().

Signed-off-by: Alan Tull <atull@xxxxxxxxxx>
Suggested-by: Federico Vaga <federico.vaga@xxxxxxx>
---
v2: add suggested-by
v3: remove some unclear documentation about fpga_region_unregister
---
Documentation/driver-api/fpga/fpga-region.rst | 3 ++
drivers/fpga/dfl-fme-region.c | 6 +--
drivers/fpga/dfl.c | 6 +--
drivers/fpga/fpga-region.c | 65 +++++++++++++++++++++++----
drivers/fpga/of-fpga-region.c | 6 +--
include/linux/fpga/fpga-region.h | 4 ++
6 files changed, 70 insertions(+), 20 deletions(-)

diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
index f30333c..dc9f75c 100644
--- a/Documentation/driver-api/fpga/fpga-region.rst
+++ b/Documentation/driver-api/fpga/fpga-region.rst
@@ -90,6 +90,9 @@ API to add a new FPGA region
:functions: fpga_region

.. kernel-doc:: drivers/fpga/fpga-region.c
+ :functions: devm_fpga_region_create
+
+.. kernel-doc:: drivers/fpga/fpga-region.c
:functions: fpga_region_create

.. kernel-doc:: drivers/fpga/fpga-region.c
diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
index 3fa0de2..1eeb42a 100644
--- a/drivers/fpga/dfl-fme-region.c
+++ b/drivers/fpga/dfl-fme-region.c
@@ -39,7 +39,7 @@ static int fme_region_probe(struct platform_device *pdev)
if (IS_ERR(mgr))
return -EPROBE_DEFER;

- region = fpga_region_create(dev, mgr, fme_region_get_bridges);
+ region = devm_fpga_region_create(dev, mgr, fme_region_get_bridges);
if (!region) {
ret = -ENOMEM;
goto eprobe_mgr_put;
@@ -51,14 +51,12 @@ static int fme_region_probe(struct platform_device *pdev)

ret = fpga_region_register(region);
if (ret)
- goto region_free;
+ goto eprobe_mgr_put;

dev_dbg(dev, "DFL FME FPGA Region probed\n");

return 0;

-region_free:
- fpga_region_free(region);
eprobe_mgr_put:
fpga_mgr_put(mgr);
return ret;
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index a9b521b..2c09e50 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -899,7 +899,7 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
if (!cdev)
return ERR_PTR(-ENOMEM);

- cdev->region = fpga_region_create(info->dev, NULL, NULL);
+ cdev->region = devm_fpga_region_create(info->dev, NULL, NULL);
if (!cdev->region) {
ret = -ENOMEM;
goto free_cdev_exit;
@@ -911,7 +911,7 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)

ret = fpga_region_register(cdev->region);
if (ret)
- goto free_region_exit;
+ goto free_cdev_exit;

/* create and init build info for enumeration */
binfo = devm_kzalloc(info->dev, sizeof(*binfo), GFP_KERNEL);
@@ -942,8 +942,6 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)

unregister_region_exit:
fpga_region_unregister(cdev->region);
-free_region_exit:
- fpga_region_free(cdev->region);
free_cdev_exit:
devm_kfree(info->dev, cdev);
return ERR_PTR(ret);
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index 0d65220..bde5a9d 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -185,6 +185,10 @@ ATTRIBUTE_GROUPS(fpga_region);
* @mgr: manager that programs this region
* @get_bridges: optional function to get bridges to a list
*
+ * The caller of this function is responsible for freeing the resulting region
+ * struct with fpga_region_free(). Using devm_fpga_region_create() instead is
+ * recommended.
+ *
* Return: struct fpga_region or NULL
*/
struct fpga_region
@@ -230,8 +234,8 @@ struct fpga_region
EXPORT_SYMBOL_GPL(fpga_region_create);

/**
- * fpga_region_free - free a struct fpga_region
- * @region: FPGA region created by fpga_region_create
+ * fpga_region_free - free a FPGA region created by fpga_region_create()
+ * @region: FPGA region
*/
void fpga_region_free(struct fpga_region *region)
{
@@ -240,21 +244,69 @@ void fpga_region_free(struct fpga_region *region)
}
EXPORT_SYMBOL_GPL(fpga_region_free);

+static void devm_fpga_region_release(struct device *dev, void *res)
+{
+ struct fpga_region *region = *(struct fpga_region **)res;
+
+ fpga_region_free(region);
+}
+
+/**
+ * devm_fpga_region_create - create and initialize a managed FPGA region struct
+ * @dev: device parent
+ * @mgr: manager that programs this region
+ * @get_bridges: optional function to get bridges to a list
+ *
+ * This function is intended for use in a FPGA region driver's probe function.
+ * After the region driver creates the region struct with
+ * devm_fpga_region_create(), it should register it with fpga_region_register().
+ * The region driver's remove function should call fpga_region_unregister().
+ * The region struct allocated with this function will be freed automatically on
+ * driver detach. This includes the case of a probe function returning error
+ * before calling fpga_region_register(), the struct will still get cleaned up.
+ *
+ * Return: struct fpga_region or NULL
+ */
+struct fpga_region
+*devm_fpga_region_create(struct device *dev,
+ struct fpga_manager *mgr,
+ int (*get_bridges)(struct fpga_region *))
+{
+ struct fpga_region **ptr, *region;
+
+ ptr = devres_alloc(devm_fpga_region_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ region = fpga_region_create(dev, mgr, get_bridges);
+ if (!region) {
+ devres_free(ptr);
+ } else {
+ *ptr = region;
+ devres_add(dev, ptr);
+ }
+
+ return region;
+}
+EXPORT_SYMBOL_GPL(devm_fpga_region_create);
+
/**
* fpga_region_register - register a FPGA region
- * @region: FPGA region created by fpga_region_create
+ * @region: FPGA region
+ *
* Return: 0 or -errno
*/
int fpga_region_register(struct fpga_region *region)
{
return device_add(&region->dev);
-
}
EXPORT_SYMBOL_GPL(fpga_region_register);

/**
- * fpga_region_unregister - unregister and free a FPGA region
+ * fpga_region_unregister - unregister a FPGA region
* @region: FPGA region
+ *
+ * This function is intended for use in a FPGA region driver's remove function.
*/
void fpga_region_unregister(struct fpga_region *region)
{
@@ -264,9 +316,6 @@ EXPORT_SYMBOL_GPL(fpga_region_unregister);

static void fpga_region_dev_release(struct device *dev)
{
- struct fpga_region *region = to_fpga_region(dev);
-
- fpga_region_free(region);
}

/**
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
index d6a70e4..75f64ab 100644
--- a/drivers/fpga/of-fpga-region.c
+++ b/drivers/fpga/of-fpga-region.c
@@ -410,7 +410,7 @@ static int of_fpga_region_probe(struct platform_device *pdev)
if (IS_ERR(mgr))
return -EPROBE_DEFER;

- region = fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
+ region = devm_fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
if (!region) {
ret = -ENOMEM;
goto eprobe_mgr_put;
@@ -418,7 +418,7 @@ static int of_fpga_region_probe(struct platform_device *pdev)

ret = fpga_region_register(region);
if (ret)
- goto eprobe_free;
+ goto eprobe_mgr_put;

of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
platform_set_drvdata(pdev, region);
@@ -427,8 +427,6 @@ static int of_fpga_region_probe(struct platform_device *pdev)

return 0;

-eprobe_free:
- fpga_region_free(region);
eprobe_mgr_put:
fpga_mgr_put(mgr);
return ret;
diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
index 0521b7f..27cb706 100644
--- a/include/linux/fpga/fpga-region.h
+++ b/include/linux/fpga/fpga-region.h
@@ -44,4 +44,8 @@ void fpga_region_free(struct fpga_region *region);
int fpga_region_register(struct fpga_region *region);
void fpga_region_unregister(struct fpga_region *region);

+struct fpga_region
+*devm_fpga_region_create(struct device *dev, struct fpga_manager *mgr,
+ int (*get_bridges)(struct fpga_region *));
+
#endif /* _FPGA_REGION_H */
--
2.7.4