[RFC PATCH v3 1/3] drivers/accel: define kconfig and register a new major

[Stanislaw Gruszka]

On Sun, Nov 06, 2022 at 11:02:23PM +0200, Oded Gabbay wrote:
> Add a new Kconfig for the accel subsystem. The Kconfig currently
> contains only the basic CONFIG_DRM_ACCEL option that will be used to
> decide whether to compile the accel registration code. Therefore, the
> kconfig option is defined as bool.
> 
> The accel code will be compiled as part of drm.ko and will be called
> directly from the DRM core code. The reason we compile it as part of
> drm.ko and not as a separate module is because of cyclic dependency
> between drm.ko and the separate module (if it would have existed).
> This is due to the fact that DRM core code calls accel functions and
> vice-versa.
> 
> The accelerator devices will be exposed to the user space with a new,
> dedicated major number - 261.
> 
> The accel init function registers the new major number as a char device
> and create corresponding sysfs and debugfs root entries, similar to
> what is done in DRM init function.
> 
> I added a new header called drm_accel.h to include/drm/, that will hold
> the prototypes of the drm_accel.c functions. In case CONFIG_DRM_ACCEL
> is set to 'N', that header will contain empty inline implementations of
> those functions, to allow DRM core code to compile successfully
> without dependency on CONFIG_DRM_ACCEL.
> 
> I Updated the MAINTAINERS file accordingly with the newly added folder
> and I have taken the liberty to appropriate the dri-devel mailing list
> and the dri-devel IRC channel for the accel subsystem.
> 
> Signed-off-by: Oded Gabbay <ogabbay at kernel.org>

Tested-by: Stanislaw Gruszka <stanislaw.gruszka at linux.intel.com>

I tested those patches with intel_vpu driver. After initial troubles,
I got things worked with our driver and user mode components.

Regards
Stanislaw