RE: [PATCH 01/10] fpga: fpga-mgr: Add devm_fpga_mgr_register() API

Wu, Hao
2020-10-05T05:18:55Z

> Subject: [PATCH 01/10] fpga: fpga-mgr: Add devm_fpga_mgr_register() API
>
> Add a devm_fpga_mgr_register() API that can be used to register a FPGA
> Manager that was created using devm_fpga_mgr_create().
>
> Introduce a struct fpga_mgr_devres that makes the devres
> allocation a little bit more readable and gets reused for
> devm_fpga_mgr_create() devm_fpga_mgr_register().
>
> Signed-off-by: Moritz Fischer <mdf@kernel.org>
> ---
> drivers/fpga/fpga-mgr.c | 76 ++++++++++++++++++++++++++++++-----
> include/linux/fpga/fpga-mgr.h | 2 +
> 2 files changed, 68 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index f38bab01432e..774ac98fb69c 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -21,6 +21,10 @@
> static DEFINE_IDA(fpga_mgr_ida);
> static struct class *fpga_mgr_class;
>
> +struct fpga_mgr_devres {
> + struct fpga_manager *mgr;
> +};
> +
> /**
> * fpga_image_info_alloc - Allocate a FPGA image info struct
> * @dev: owning device
> @@ -651,21 +655,21 @@ struct fpga_manager
> *devm_fpga_mgr_create(struct device *dev, const char *name,
> const struct fpga_manager_ops
> *mops,
> void *priv)
> {
> - struct fpga_manager **ptr, *mgr;
> + struct fpga_mgr_devres *dr;
>
> - ptr = devres_alloc(devm_fpga_mgr_release, sizeof(*ptr),
> GFP_KERNEL);
> - if (!ptr)
> + dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);

Should we update devm_fpga_mgr_release function to use fpga_mgr_devres as well?

> + if (!dr)
> return NULL;
>
> - mgr = fpga_mgr_create(dev, name, mops, priv);
> - if (!mgr) {
> - devres_free(ptr);
> - } else {
> - *ptr = mgr;
> - devres_add(dev, ptr);
> + dr->mgr = fpga_mgr_create(dev, name, mops, priv);
> + if (!dr->mgr) {
> + devres_free(dr);
> + return NULL;
> }
>
> - return mgr;
> + devres_add(dev, dr);
> +
> + return dr->mgr;
> }
> EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>
> @@ -722,6 +726,58 @@ void fpga_mgr_unregister(struct fpga_manager
> *mgr)
> }
> EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>
> +static int fpga_mgr_devres_match(struct device *dev, void *priv,

Maybe it's better to use "res" instead of "priv" which matches the
dr_match_t, and also devm_fpga_mgr_release function.

> + void *match_data)
> +{
> + struct fpga_mgr_devres *dr = priv;
> +
> + return match_data == dr->mgr;
> +}
> +
> +static void devm_fpga_mgr_unregister(struct device *dev, void *priv)
> +{

Same.

> + struct fpga_mgr_devres *dr = priv;
> +
> + fpga_mgr_unregister(dr->mgr);
> +}
> +
> +/**
> + * devm_fpga_mgr_register - resource managed variant of
> fpga_mgr_register()
> + * @dev: managing device for this FPGA manager
> + * @mgr: fpga manager struct
> + *
> + * This is the devres variant of fpga_mgr_register() for which the unregister
> + * function will be called automatically when the managing device is
> detached.
> + */
> +int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> +{
> + struct fpga_mgr_devres *dr;
> + int err;
> +
> + /* Make sure that the struct fpga_manager * that is passed in is
> + * managed itself.
> + */

Should we use the same style for code comments here,
I see other places in this file are using style like

/*
* ......
*/

Thanks
Hao