Re: [PATCH] drm/panthor: Convert IOCTL defines to an enum

[Erik Faye-Lund]

On Tue, 2025-02-04 at 17:28 -0600, Rob Herring (Arm) wrote:
> Use an enum instead of #defines for panthor IOCTLs. This allows the
> header to be used with Rust code as bindgen can't handle complex
> defines.
> 


Unfortunately, this goes in the opposite direction than what I was
asked to do here:

https://lore.kernel.org/dri-devel/20241029140125.0607c26f@xxxxxxxxxxxxx/

...I still intend to get around to doing that, because we have problems
with C enum and large values. I don't know if we can solve that while
making Rust happy without requiring C23 (which allows to specify the
underlying type of an enum), unfortunately...

> Cc: Beata Michalska <beata.michalska@xxxxxxx>
> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
> ---
>  include/uapi/drm/panthor_drm.h | 86 +++++++++++++++++---------------
> --
>  1 file changed, 44 insertions(+), 42 deletions(-)
> 
> diff --git a/include/uapi/drm/panthor_drm.h
> b/include/uapi/drm/panthor_drm.h
> index b99763cbae48..97e2c4510e69 100644
> --- a/include/uapi/drm/panthor_drm.h
> +++ b/include/uapi/drm/panthor_drm.h
> @@ -129,48 +129,6 @@ enum drm_panthor_ioctl_id {
>  	DRM_PANTHOR_TILER_HEAP_DESTROY,
>  };
>  
> -/**
> - * DRM_IOCTL_PANTHOR() - Build a Panthor IOCTL number
> - * @__access: Access type. Must be R, W or RW.
> - * @__id: One of the DRM_PANTHOR_xxx id.
> - * @__type: Suffix of the type being passed to the IOCTL.
> - *
> - * Don't use this macro directly, use the DRM_IOCTL_PANTHOR_xxx
> - * values instead.
> - *
> - * Return: An IOCTL number to be passed to ioctl() from userspace.
> - */
> -#define DRM_IOCTL_PANTHOR(__access, __id, __type) \
> -	DRM_IO ## __access(DRM_COMMAND_BASE + DRM_PANTHOR_ ## __id,
> \
> -			   struct drm_panthor_ ## __type)
> -
> -#define DRM_IOCTL_PANTHOR_DEV_QUERY \
> -	DRM_IOCTL_PANTHOR(WR, DEV_QUERY, dev_query)
> -#define DRM_IOCTL_PANTHOR_VM_CREATE \
> -	DRM_IOCTL_PANTHOR(WR, VM_CREATE, vm_create)
> -#define DRM_IOCTL_PANTHOR_VM_DESTROY \
> -	DRM_IOCTL_PANTHOR(WR, VM_DESTROY, vm_destroy)
> -#define DRM_IOCTL_PANTHOR_VM_BIND \
> -	DRM_IOCTL_PANTHOR(WR, VM_BIND, vm_bind)
> -#define DRM_IOCTL_PANTHOR_VM_GET_STATE \
> -	DRM_IOCTL_PANTHOR(WR, VM_GET_STATE, vm_get_state)
> -#define DRM_IOCTL_PANTHOR_BO_CREATE \
> -	DRM_IOCTL_PANTHOR(WR, BO_CREATE, bo_create)
> -#define DRM_IOCTL_PANTHOR_BO_MMAP_OFFSET \
> -	DRM_IOCTL_PANTHOR(WR, BO_MMAP_OFFSET, bo_mmap_offset)
> -#define DRM_IOCTL_PANTHOR_GROUP_CREATE \
> -	DRM_IOCTL_PANTHOR(WR, GROUP_CREATE, group_create)
> -#define DRM_IOCTL_PANTHOR_GROUP_DESTROY \
> -	DRM_IOCTL_PANTHOR(WR, GROUP_DESTROY, group_destroy)
> -#define DRM_IOCTL_PANTHOR_GROUP_SUBMIT \
> -	DRM_IOCTL_PANTHOR(WR, GROUP_SUBMIT, group_submit)
> -#define DRM_IOCTL_PANTHOR_GROUP_GET_STATE \
> -	DRM_IOCTL_PANTHOR(WR, GROUP_GET_STATE, group_get_state)
> -#define DRM_IOCTL_PANTHOR_TILER_HEAP_CREATE \
> -	DRM_IOCTL_PANTHOR(WR, TILER_HEAP_CREATE, tiler_heap_create)
> -#define DRM_IOCTL_PANTHOR_TILER_HEAP_DESTROY \
> -	DRM_IOCTL_PANTHOR(WR, TILER_HEAP_DESTROY,
> tiler_heap_destroy)
> -
>  /**
>   * DOC: IOCTL arguments
>   */
> @@ -1019,6 +977,50 @@ struct drm_panthor_tiler_heap_destroy {
>  	__u32 pad;
>  };
>  
> +/**
> + * DRM_IOCTL_PANTHOR() - Build a Panthor IOCTL number
> + * @__access: Access type. Must be R, W or RW.
> + * @__id: One of the DRM_PANTHOR_xxx id.
> + * @__type: Suffix of the type being passed to the IOCTL.
> + *
> + * Don't use this macro directly, use the DRM_IOCTL_PANTHOR_xxx
> + * values instead.
> + *
> + * Return: An IOCTL number to be passed to ioctl() from userspace.
> + */
> +#define DRM_IOCTL_PANTHOR(__access, __id, __type) \
> +	DRM_IO ## __access(DRM_COMMAND_BASE + DRM_PANTHOR_ ## __id,
> \
> +			   struct drm_panthor_ ## __type)
> +
> +enum {
> +	DRM_IOCTL_PANTHOR_DEV_QUERY =
> +		DRM_IOCTL_PANTHOR(WR, DEV_QUERY, dev_query),
> +	DRM_IOCTL_PANTHOR_VM_CREATE =
> +		DRM_IOCTL_PANTHOR(WR, VM_CREATE, vm_create),
> +	DRM_IOCTL_PANTHOR_VM_DESTROY =
> +		DRM_IOCTL_PANTHOR(WR, VM_DESTROY, vm_destroy),
> +	DRM_IOCTL_PANTHOR_VM_BIND =
> +		DRM_IOCTL_PANTHOR(WR, VM_BIND, vm_bind),
> +	DRM_IOCTL_PANTHOR_VM_GET_STATE =
> +		DRM_IOCTL_PANTHOR(WR, VM_GET_STATE, vm_get_state),
> +	DRM_IOCTL_PANTHOR_BO_CREATE =
> +		DRM_IOCTL_PANTHOR(WR, BO_CREATE, bo_create),
> +	DRM_IOCTL_PANTHOR_BO_MMAP_OFFSET =
> +		DRM_IOCTL_PANTHOR(WR, BO_MMAP_OFFSET,
> bo_mmap_offset),
> +	DRM_IOCTL_PANTHOR_GROUP_CREATE =
> +		DRM_IOCTL_PANTHOR(WR, GROUP_CREATE, group_create),
> +	DRM_IOCTL_PANTHOR_GROUP_DESTROY =
> +		DRM_IOCTL_PANTHOR(WR, GROUP_DESTROY, group_destroy),
> +	DRM_IOCTL_PANTHOR_GROUP_SUBMIT =
> +		DRM_IOCTL_PANTHOR(WR, GROUP_SUBMIT, group_submit),
> +	DRM_IOCTL_PANTHOR_GROUP_GET_STATE =
> +		DRM_IOCTL_PANTHOR(WR, GROUP_GET_STATE,
> group_get_state),
> +	DRM_IOCTL_PANTHOR_TILER_HEAP_CREATE =
> +		DRM_IOCTL_PANTHOR(WR, TILER_HEAP_CREATE,
> tiler_heap_create),
> +	DRM_IOCTL_PANTHOR_TILER_HEAP_DESTROY =
> +		DRM_IOCTL_PANTHOR(WR, TILER_HEAP_DESTROY,
> tiler_heap_destroy),
> +};
> +
>  #if defined(__cplusplus)
>  }
>  #endif