Re: [PATCH 4/6] cxl/mem: Move character device region creation

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

On Thu, Jul 15, 2021 at 12:41 PM Ben Widawsky <ben.widawsky@intel.com> wrote:
>
> In order to merge the memdev specific functionality of cxl_pci into
> core, the character device creation currently handled by cxl_pci need to
> be moved. The rest of the changes are largely cut/paste, the actual
> functional change is done here in preparation.
>
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
> ---
>  drivers/cxl/core/bus.c | 12 ++++++++++++
>  drivers/cxl/mem.h      |  2 ++
>  drivers/cxl/pci.c      | 14 +-------------
>  3 files changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c
> index 33196813ebcb..8c2351c52d2b 100644
> --- a/drivers/cxl/core/bus.c
> +++ b/drivers/cxl/core/bus.c
> @@ -22,6 +22,8 @@
>   * instantiated by the core.
>   */
>
> +int cxl_mem_major;
> +EXPORT_SYMBOL_GPL(cxl_mem_major);

This symbol export is necessary here, but it's not needed by the end
of the series which leads me to question this fine grained split. I
think the shutdown patch is suitable to split, but this one and the
last can be squashed.

>  static DEFINE_IDA(cxl_port_ida);
>
>  static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
> @@ -632,12 +634,22 @@ EXPORT_SYMBOL_GPL(cxl_bus_type);
>
>  static __init int cxl_core_init(void)
>  {
> +       dev_t devt;
> +       int rc;
> +
> +       rc = alloc_chrdev_region(&devt, 0, CXL_MEM_MAX_DEVS, "cxl");
> +       if (rc)
> +               return rc;
> +
> +       cxl_mem_major = MAJOR(devt);

I'd rather have cxl_core_{init,exit}() call something like
cxl_memdev_{init,exit}() that way cxl_mem_major can become static
again.