On Tue, Sep 14, 2021 at 02:43:27PM -0700, Russ Weight wrote:
> The FPGA region class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes the
> managed resource code and combines the create() and register()
> functions into a single register() or register_full() function.
>
> The register_full() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register() function
> supports the current parameter list for users that don't require the
> use of optional parameters.
>
> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> Reviewed-by: Xu Yilun <yilun.xu@xxxxxxxxx>
Acked-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> ---
> v12:
> - No change
> v11:
> - Rebased to latest linux-next (no conflicts)
> v10:
> - Fixed commit message to reference register_full() instead of
> register_simple().
> - Updated documentation to reference the fpga_region_info structure
> v9:
> - Cleaned up documentation for the FPGA Region register functions
> - Renamed fpga_region_register() to fpga_region_register_full()
> - Renamed fpga_region_register_simple() to fpga_region_register()
> v8:
> - Added reviewed-by tag.
> - Updated Documentation/driver-api/fpga/fpga-region.rst documentation.
> v7:
> - Update the commit message to describe the new parameters for the
> fpga_region_register() function and to mention the
> fpga_region_register_simple() function.
> - Fix function prototypes in header file to rename dev to parent.
> - Some cleanup of comments.
> - Update function definitions/prototypes to apply const to the new info
> parameter.
> - Verify a non-null info pointer in the register() functions.
> v6:
> - Moved FPGA manager optional parameters out of the ops structure and
> back into the FPGA Region structure.
> - Changed fpga_region_register() parameters to accept an info data
> structure to provide flexibility in passing optional parameters.
> - Added fpga_region_register_simple() functions to support current
> parameters for users that don't require the use of optional parameters.
> v5:
> - Rebased on top of recently accepted patches.
> - Created the fpga_region_ops data structure which is optionally passed
> to fpga_region_register(). compat_id, the get_bridges() pointer, and
> the priv pointer are included in the fpga_region_ops structure.
> v4:
> - Added the compat_id parameter to fpga_region_register() to ensure
> that the compat_id is set before the device_register() call.
> - Modified the dfl_fpga_feature_devs_enumerate() function to restore
> the fpga_region_register() call to the correct location.
> v3:
> - Cleaned up comment header for fpga_region_register()
> - Fix fpga_region_register() error return on ida_simple_get() failure
> v2:
> - No changes
> ---
> Documentation/driver-api/fpga/fpga-region.rst | 12 +-
> drivers/fpga/dfl-fme-region.c | 17 ++-
> drivers/fpga/dfl.c | 12 +-
> drivers/fpga/fpga-region.c | 119 +++++++-----------
> drivers/fpga/of-fpga-region.c | 10 +-
> include/linux/fpga/fpga-region.h | 36 ++++--
> 6 files changed, 95 insertions(+), 111 deletions(-)
>
> diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
> index 2636a27c11b2..dc55d60a0b4a 100644
> --- a/Documentation/driver-api/fpga/fpga-region.rst
> +++ b/Documentation/driver-api/fpga/fpga-region.rst
> @@ -46,8 +46,11 @@ API to add a new FPGA region
> ----------------------------
>
> * struct fpga_region - The FPGA region struct
> -* devm_fpga_region_create() - Allocate and init a region struct
> -* fpga_region_register() - Register an FPGA region
> +* struct fpga_region_info - Parameter structure for fpga_region_register_full()
> +* fpga_region_register_full() - Create and register an FPGA region using the
> + fpga_region_info structure to provide the full flexibility of options
> +* fpga_region_register() - Create and register an FPGA region using standard
> + arguments
> * fpga_region_unregister() - Unregister an FPGA region
>
> The FPGA region's probe function will need to get a reference to the FPGA
> @@ -75,8 +78,11 @@ following APIs to handle building or tearing down that list.
> .. kernel-doc:: include/linux/fpga/fpga-region.h
> :functions: fpga_region
>
> +.. kernel-doc:: include/linux/fpga/fpga-region.h
> + :functions: fpga_region_info
> +
> .. kernel-doc:: drivers/fpga/fpga-region.c
> - :functions: devm_fpga_region_create
> + :functions: fpga_region_register_full
>
> .. kernel-doc:: drivers/fpga/fpga-region.c
> :functions: fpga_region_register
> diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
> index 1eeb42af1012..4aebde0a7f1c 100644
> --- a/drivers/fpga/dfl-fme-region.c
> +++ b/drivers/fpga/dfl-fme-region.c
> @@ -30,6 +30,7 @@ static int fme_region_get_bridges(struct fpga_region *region)
> static int fme_region_probe(struct platform_device *pdev)
> {
> struct dfl_fme_region_pdata *pdata = dev_get_platdata(&pdev->dev);
> + struct fpga_region_info info = { 0 };
> struct device *dev = &pdev->dev;
> struct fpga_region *region;
> struct fpga_manager *mgr;
> @@ -39,20 +40,18 @@ static int fme_region_probe(struct platform_device *pdev)
> if (IS_ERR(mgr))
> return -EPROBE_DEFER;
>
> - region = devm_fpga_region_create(dev, mgr, fme_region_get_bridges);
> - if (!region) {
> - ret = -ENOMEM;
> + info.mgr = mgr;
> + info.compat_id = mgr->compat_id;
> + info.get_bridges = fme_region_get_bridges;
> + info.priv = pdata;
> + region = fpga_region_register_full(dev, &info);
> + if (IS_ERR(region)) {
> + ret = PTR_ERR(region);
> goto eprobe_mgr_put;
> }
>
> - region->priv = pdata;
> - region->compat_id = mgr->compat_id;
> platform_set_drvdata(pdev, region);
>
> - ret = fpga_region_register(region);
> - if (ret)
> - goto eprobe_mgr_put;
> -
> dev_dbg(dev, "DFL FME FPGA Region probed\n");
>
> return 0;
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index c99b78ee008a..1f2ad1c309f7 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -1405,19 +1405,15 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
> if (!cdev)
> return ERR_PTR(-ENOMEM);
>
> - cdev->region = devm_fpga_region_create(info->dev, NULL, NULL);
> - if (!cdev->region) {
> - ret = -ENOMEM;
> - goto free_cdev_exit;
> - }
> -
> cdev->parent = info->dev;
> mutex_init(&cdev->lock);
> INIT_LIST_HEAD(&cdev->port_dev_list);
>
> - ret = fpga_region_register(cdev->region);
> - if (ret)
> + cdev->region = fpga_region_register(info->dev, NULL, NULL);
> + if (IS_ERR(cdev->region)) {
> + ret = PTR_ERR(cdev->region);
> goto free_cdev_exit;
> + }
>
> /* create and init build info for enumeration */
> binfo = devm_kzalloc(info->dev, sizeof(*binfo), GFP_KERNEL);
> diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
> index a4838715221f..b0ac18de4885 100644
> --- a/drivers/fpga/fpga-region.c
> +++ b/drivers/fpga/fpga-region.c
> @@ -180,39 +180,42 @@ static struct attribute *fpga_region_attrs[] = {
> ATTRIBUTE_GROUPS(fpga_region);
>
> /**
> - * fpga_region_create - alloc and init a struct fpga_region
> + * fpga_region_register_full - create and register an FPGA Region device
> * @parent: device parent
> - * @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.
> + * @info: parameters for FPGA Region
> *
> - * Return: struct fpga_region or NULL
> + * Return: struct fpga_region or ERR_PTR()
> */
> -struct fpga_region
> -*fpga_region_create(struct device *parent,
> - struct fpga_manager *mgr,
> - int (*get_bridges)(struct fpga_region *))
> +struct fpga_region *
> +fpga_region_register_full(struct device *parent, const struct fpga_region_info *info)
> {
> struct fpga_region *region;
> int id, ret = 0;
>
> + if (!info) {
> + dev_err(parent,
> + "Attempt to register without required info structure\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> region = kzalloc(sizeof(*region), GFP_KERNEL);
> if (!region)
> - return NULL;
> + return ERR_PTR(-ENOMEM);
>
> id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
> - if (id < 0)
> + if (id < 0) {
> + ret = id;
> goto err_free;
> + }
> +
> + region->mgr = info->mgr;
> + region->compat_id = info->compat_id;
> + region->priv = info->priv;
> + region->get_bridges = info->get_bridges;
>
> - region->mgr = mgr;
> - region->get_bridges = get_bridges;
> mutex_init(®ion->mutex);
> INIT_LIST_HEAD(®ion->bridge_list);
>
> - device_initialize(®ion->dev);
> region->dev.class = fpga_region_class;
> region->dev.parent = parent;
> region->dev.of_node = parent->of_node;
> @@ -222,6 +225,12 @@ struct fpga_region
> if (ret)
> goto err_remove;
>
> + ret = device_register(®ion->dev);
> + if (ret) {
> + put_device(®ion->dev);
> + return ERR_PTR(ret);
> + }
> +
> return region;
>
> err_remove:
> @@ -229,76 +238,32 @@ struct fpga_region
> err_free:
> kfree(region);
>
> - return NULL;
> -}
> -EXPORT_SYMBOL_GPL(fpga_region_create);
> -
> -/**
> - * fpga_region_free - free an FPGA region created by fpga_region_create()
> - * @region: FPGA region
> - */
> -void fpga_region_free(struct fpga_region *region)
> -{
> - ida_simple_remove(&fpga_region_ida, region->dev.id);
> - kfree(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);
> + return ERR_PTR(ret);
> }
> +EXPORT_SYMBOL_GPL(fpga_region_register_full);
>
> /**
> - * devm_fpga_region_create - create and initialize a managed FPGA region struct
> + * fpga_region_register - create and register an FPGA Region device
> * @parent: 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 an 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.
> + * This simple version of the register function should be sufficient for most users.
> + * The fpga_region_register_full() function is available for users that need to
> + * pass additional, optional parameters.
> *
> - * Return: struct fpga_region or NULL
> + * Return: struct fpga_region or ERR_PTR()
> */
> -struct fpga_region
> -*devm_fpga_region_create(struct device *parent,
> - struct fpga_manager *mgr,
> - int (*get_bridges)(struct fpga_region *))
> +struct fpga_region *
> +fpga_region_register(struct device *parent, 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;
> + struct fpga_region_info info = { 0 };
>
> - region = fpga_region_create(parent, mgr, get_bridges);
> - if (!region) {
> - devres_free(ptr);
> - } else {
> - *ptr = region;
> - devres_add(parent, ptr);
> - }
> + info.mgr = mgr;
> + info.get_bridges = get_bridges;
>
> - return region;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_region_create);
> -
> -/**
> - * fpga_region_register - register an FPGA region
> - * @region: FPGA region
> - *
> - * Return: 0 or -errno
> - */
> -int fpga_region_register(struct fpga_region *region)
> -{
> - return device_add(®ion->dev);
> + return fpga_region_register_full(parent, &info);
> }
> EXPORT_SYMBOL_GPL(fpga_region_register);
>
> @@ -316,6 +281,10 @@ EXPORT_SYMBOL_GPL(fpga_region_unregister);
>
> static void fpga_region_dev_release(struct device *dev)
> {
> + struct fpga_region *region = to_fpga_region(dev);
> +
> + ida_simple_remove(&fpga_region_ida, region->dev.id);
> + kfree(region);
> }
>
> /**
> diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
> index e3c25576b6b9..9c662db1c508 100644
> --- a/drivers/fpga/of-fpga-region.c
> +++ b/drivers/fpga/of-fpga-region.c
> @@ -405,16 +405,12 @@ static int of_fpga_region_probe(struct platform_device *pdev)
> if (IS_ERR(mgr))
> return -EPROBE_DEFER;
>
> - region = devm_fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
> - if (!region) {
> - ret = -ENOMEM;
> + region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges);
> + if (IS_ERR(region)) {
> + ret = PTR_ERR(region);
> goto eprobe_mgr_put;
> }
>
> - ret = fpga_region_register(region);
> - if (ret)
> - goto eprobe_mgr_put;
> -
> of_platform_populate(np, fpga_region_of_match, NULL, ®ion->dev);
> platform_set_drvdata(pdev, region);
>
> diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
> index 27cb706275db..3b87f232425c 100644
> --- a/include/linux/fpga/fpga-region.h
> +++ b/include/linux/fpga/fpga-region.h
> @@ -7,6 +7,27 @@
> #include <linux/fpga/fpga-mgr.h>
> #include <linux/fpga/fpga-bridge.h>
>
> +struct fpga_region;
> +
> +/**
> + * struct fpga_region_info - collection of parameters an FPGA Region
> + * @mgr: fpga region manager
> + * @compat_id: FPGA region id for compatibility check.
> + * @priv: fpga region private data
> + * @get_bridges: optional function to get bridges to a list
> + *
> + * fpga_region_info contains parameters for the register_full function.
> + * These are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_region_info {
> + struct fpga_manager *mgr;
> + struct fpga_compat_id *compat_id;
> + void *priv;
> + int (*get_bridges)(struct fpga_region *region);
> +};
> +
> /**
> * struct fpga_region - FPGA Region structure
> * @dev: FPGA Region device
> @@ -37,15 +58,12 @@ struct fpga_region *fpga_region_class_find(
>
> int fpga_region_program_fpga(struct fpga_region *region);
>
> -struct fpga_region
> -*fpga_region_create(struct device *dev, struct fpga_manager *mgr,
> - int (*get_bridges)(struct fpga_region *));
> -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 *
> +fpga_region_register_full(struct device *parent, const struct fpga_region_info *info);
>
> -struct fpga_region
> -*devm_fpga_region_create(struct device *dev, struct fpga_manager *mgr,
> - int (*get_bridges)(struct fpga_region *));
> +struct fpga_region *
> +fpga_region_register(struct device *parent, struct fpga_manager *mgr,
> + int (*get_bridges)(struct fpga_region *));
> +void fpga_region_unregister(struct fpga_region *region);
>
> #endif /* _FPGA_REGION_H */
> --
> 2.25.1
