Re: [PATCH v4 13/18] fpga: region: add register/unregister functions

From: Wu Hao
Date: Thu Sep 14 2017 - 06:04:09 EST

On Thu, Sep 14, 2017 at 04:48:36AM +0800, Alan Tull wrote:
> Another step in separating common code from device tree specific
> code for FPGA regions.
>
> * add FPGA region register/unregister functions.
> * add the register/unregister functions to the header
> * use devm_kzalloc to alloc the region.
> * add a method for getting bridges to the region struct
> * add priv to the region struct
> * use region->info in of_fpga_region_get_bridges
>
> Signed-off-by: Alan Tull <atull@xxxxxxxxxx>
> ---
> v2: split out from another patch
> v3: use region->info, remove info param where applicable
> v4: no change to this patch in this version of patchset
> ---
> drivers/fpga/fpga-region.c | 106 ++++++++++++++++++++++++---------------
> include/linux/fpga/fpga-region.h | 7 +++
> 2 files changed, 72 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
> index 92ab216..ce57383 100644
> --- a/drivers/fpga/fpga-region.c
> +++ b/drivers/fpga/fpga-region.c
> @@ -143,7 +143,6 @@ static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np)
> /**
> * of_fpga_region_get_bridges - create a list of bridges
> * @region: FPGA region
> - * @info: FPGA image info
> *
> * Create a list of bridges including the parent bridge and the bridges
> * specified by "fpga-bridges" property. Note that the
> @@ -156,11 +155,11 @@ static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np)
> * Return 0 for success (even if there are no bridges specified)
> * or -EBUSY if any of the bridges are in use.
> */
> -static int of_fpga_region_get_bridges(struct fpga_region *region,
> - struct fpga_image_info *info)
> +static int of_fpga_region_get_bridges(struct fpga_region *region)
> {
> struct device *dev = &region->dev;
> struct device_node *region_np = dev->of_node;
> + struct fpga_image_info *info = region->info;
> struct device_node *br, *np, *parent_br = NULL;
> int i, ret;
>
> @@ -192,7 +191,7 @@ static int of_fpga_region_get_bridges(struct fpga_region *region,
> continue;
>
> /* If node is a bridge, get it and add to list */
> - ret = of_fpga_bridge_get_to_list(br, region->info,
> + ret = of_fpga_bridge_get_to_list(br, info,
> &region->bridge_list);
>
> /* If any of the bridges are in use, give up */
> @@ -229,10 +228,16 @@ int fpga_region_program_fpga(struct fpga_region *region)
> goto err_put_region;
> }
>
> - ret = of_fpga_region_get_bridges(region, info);
> - if (ret) {
> - dev_err(dev, "failed to get FPGA bridges\n");
> - goto err_unlock_mgr;
> + /*
> + * In some cases, we already have a list of bridges in the
> + * fpga region struct. Or we don't have any bridges.
> + */
> + if (region->get_bridges) {
> + ret = region->get_bridges(region);
> + if (ret) {
> + dev_err(dev, "failed to get fpga region bridges\n");
> + goto err_unlock_mgr;
> + }
> }
>
> ret = fpga_bridges_disable(&region->bridge_list);
> @@ -259,7 +264,8 @@ int fpga_region_program_fpga(struct fpga_region *region)
> return 0;
>
> err_put_br:
> - fpga_bridges_put(&region->bridge_list);
> + if (region->get_bridges)
> + fpga_bridges_put(&region->bridge_list);
> err_unlock_mgr:
> fpga_mgr_unlock(region->mgr);
> err_put_region:
> @@ -522,39 +528,20 @@ static struct notifier_block fpga_region_of_nb = {
> .notifier_call = of_fpga_region_notify,
> };
>
> -static int of_fpga_region_probe(struct platform_device *pdev)
> +int fpga_region_register(struct device *dev, struct fpga_region *region)
> {
> - struct device *dev = &pdev->dev;
> - struct device_node *np = dev->of_node;
> - struct fpga_region *region;
> - struct fpga_manager *mgr;
> int id, ret = 0;
>
> - mgr = of_fpga_region_get_mgr(np);
> - if (IS_ERR(mgr))
> - return -EPROBE_DEFER;
> -
> - region = kzalloc(sizeof(*region), GFP_KERNEL);
> - if (!region) {
> - ret = -ENOMEM;
> - goto err_put_mgr;
> - }
> -
> - region->mgr = mgr;
> -
> id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
> - if (id < 0) {
> - ret = id;
> - goto err_kfree;
> - }
> + if (id < 0)
> + return id;
>
> mutex_init(&region->mutex);
> INIT_LIST_HEAD(&region->bridge_list);
> -
> device_initialize(&region->dev);
> region->dev.class = fpga_region_class;
> region->dev.parent = dev;
> - region->dev.of_node = np;
> + region->dev.of_node = dev->of_node;
> region->dev.id = id;
> dev_set_drvdata(dev, region);
>
> @@ -566,19 +553,58 @@ static int of_fpga_region_probe(struct platform_device *pdev)
> if (ret)
> goto err_remove;
>
> + return 0;
> +
> +err_remove:
> + ida_simple_remove(&fpga_region_ida, id);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(fpga_region_register);
> +
> +int fpga_region_unregister(struct fpga_region *region)
> +{
> + device_unregister(&region->dev);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(fpga_region_unregister);
> +
> +static int of_fpga_region_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev->of_node;
> + struct fpga_region *region;
> + struct fpga_manager *mgr;
> + int ret;
> +
> + /* Find the FPGA mgr specified by region or parent region. */
> + mgr = of_fpga_region_get_mgr(np);
> + if (IS_ERR(mgr))
> + return -EPROBE_DEFER;
> +
> + region = devm_kzalloc(dev, sizeof(*region), GFP_KERNEL);
> + if (!region) {
> + ret = -ENOMEM;
> + goto eprobe_mgr_put;
> + }
> +
> + region->mgr = mgr;
> +
> + /* Specify how to get bridges for this type of region. */
> + region->get_bridges = of_fpga_region_get_bridges;
> +
> + ret = fpga_region_register(dev, region);
> + if (ret)
> + goto eprobe_mgr_put;
> +
> of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
>
> dev_info(dev, "FPGA Region probed\n");
>
> return 0;
>
> -err_remove:
> - ida_simple_remove(&fpga_region_ida, id);
> -err_kfree:
> - kfree(region);
> -err_put_mgr:
> +eprobe_mgr_put:
> fpga_mgr_put(mgr);
> -
> return ret;
> }
>
> @@ -586,8 +612,7 @@ static int of_fpga_region_remove(struct platform_device *pdev)
> {
> struct fpga_region *region = platform_get_drvdata(pdev);
>
> - device_unregister(&region->dev);
> - fpga_mgr_put(region->mgr);
> + fpga_region_unregister(region);

Hi Alan

Do you think if we need to keep fpga_mgr_put(region->mgr) in this remove
function? :)

Thanks
Hao

>
> return 0;
> }
> @@ -606,7 +631,6 @@ 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/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
> index f84a2e1..76dda68 100644
> --- a/include/linux/fpga/fpga-region.h
> +++ b/include/linux/fpga/fpga-region.h
> @@ -12,6 +12,8 @@
> * @bridge_list: list of FPGA bridges specified in region
> * @mgr: FPGA manager
> * @info: FPGA image info
> + * @priv: private data
> + * @get_bridges: optional function to get bridges to a list
> */
> struct fpga_region {
> struct device dev;
> @@ -19,10 +21,15 @@ struct fpga_region {
> struct list_head bridge_list;
> struct fpga_manager *mgr;
> struct fpga_image_info *info;
> + void *priv;
> + int (*get_bridges)(struct fpga_region *region);
> };
>
> #define to_fpga_region(d) container_of(d, struct fpga_region, dev)
>
> int fpga_region_program_fpga(struct fpga_region *region);
>
> +int fpga_region_register(struct device *dev, struct fpga_region *region);
> +int fpga_region_unregister(struct fpga_region *region);
> +
> #endif /* _FPGA_REGION_H */
> --
> 2.7.4
>
> --
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