Re: [PATCH] cxl: Convert driver id to an enum

[Dan Williams <dan.j.williams@intel.com>]

On Tue, Jul 6, 2021 at 9:59 AM Ben Widawsky <ben.widawsky@intel.com> wrote:
>
> CXL drivers can be of only one type. As such, an enum is the most
> logical way to represent that singleton nature. By converting to an
> enum, it's easy and obvious how to add new driver types.
>
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
> ---
>  drivers/cxl/cxl.h | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index ec90b32d4bd8..dd005a5e296b 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -328,12 +328,17 @@ devm_cxl_add_passthrough_decoder(struct device *host, struct cxl_port *port)
>
>  extern struct bus_type cxl_bus_type;
>
> +enum cxl_driver_id {
> +       CXL_DEVICE_NVDIMM_BRIDGE,
> +       CXL_DEVICE_NVDIMM,
> +};
> +
>  struct cxl_driver {
>         const char *name;
>         int (*probe)(struct device *dev);
>         void (*remove)(struct device *dev);
>         struct device_driver drv;
> -       int id;
> +       enum cxl_driver_id id;
>  };
>
>  static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv)
> @@ -346,9 +351,6 @@ int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner,
>  #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME)
>  void cxl_driver_unregister(struct cxl_driver *cxl_drv);
>
> -#define CXL_DEVICE_NVDIMM_BRIDGE       1
> -#define CXL_DEVICE_NVDIMM              2
> -
>  #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*")
>  #define CXL_MODALIAS_FMT "cxl:t%d"

Doesn't this break module aliasing? I.e. __stringfy(CXL_DEVICE_NVDIMM)
changes from:

"2" to "CXL_DEVICE_NVDIMM"

?