Re: [PATCH v2 1/4] drm/panfrost: Introduce uAPI for JM context creation

[Steven Price <steven.price@arm.com>]

On 04/09/2025 01:07, Adrián Larumbe wrote:
> From: Boris Brezillon <boris.brezillon@collabora.com>
> 
> The new uAPI lets user space query the KM driver for the available
> priorities a job can be given at submit time. These are managed through
> the notion of a context, for which we also provide new creation and
> destruction ioctls.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>

Reviewed-by: Steven Price <steven.price@arm.com>

> ---
>  include/uapi/drm/panfrost_drm.h | 50 +++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
> 
> diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
> index ed67510395bd..e8b47c9f6976 100644
> --- a/include/uapi/drm/panfrost_drm.h
> +++ b/include/uapi/drm/panfrost_drm.h
> @@ -22,6 +22,8 @@ extern "C" {
>  #define DRM_PANFROST_PERFCNT_DUMP		0x07
>  #define DRM_PANFROST_MADVISE			0x08
>  #define DRM_PANFROST_SET_LABEL_BO		0x09
> +#define DRM_PANFROST_JM_CTX_CREATE		0x0a
> +#define DRM_PANFROST_JM_CTX_DESTROY		0x0b
>  
>  #define DRM_IOCTL_PANFROST_SUBMIT		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_SUBMIT, struct drm_panfrost_submit)
>  #define DRM_IOCTL_PANFROST_WAIT_BO		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_WAIT_BO, struct drm_panfrost_wait_bo)
> @@ -31,6 +33,8 @@ extern "C" {
>  #define DRM_IOCTL_PANFROST_GET_BO_OFFSET	DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_BO_OFFSET, struct drm_panfrost_get_bo_offset)
>  #define DRM_IOCTL_PANFROST_MADVISE		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_MADVISE, struct drm_panfrost_madvise)
>  #define DRM_IOCTL_PANFROST_SET_LABEL_BO		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_SET_LABEL_BO, struct drm_panfrost_set_label_bo)
> +#define DRM_IOCTL_PANFROST_JM_CTX_CREATE	DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_JM_CTX_CREATE, struct drm_panfrost_jm_ctx_create)
> +#define DRM_IOCTL_PANFROST_JM_CTX_DESTROY	DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_JM_CTX_DESTROY, struct drm_panfrost_jm_ctx_destroy)
>  
>  /*
>   * Unstable ioctl(s): only exposed when the unsafe unstable_ioctls module
> @@ -71,6 +75,12 @@ struct drm_panfrost_submit {
>  
>  	/** A combination of PANFROST_JD_REQ_* */
>  	__u32 requirements;
> +
> +	/** JM context handle. Zero if you want to use the default context. */
> +	__u32 jm_ctx_handle;
> +
> +	/** Padding field. MBZ. */
> +	__u32 pad;
>  };
>  
>  /**
> @@ -177,6 +187,7 @@ enum drm_panfrost_param {
>  	DRM_PANFROST_PARAM_AFBC_FEATURES,
>  	DRM_PANFROST_PARAM_SYSTEM_TIMESTAMP,
>  	DRM_PANFROST_PARAM_SYSTEM_TIMESTAMP_FREQUENCY,
> +	DRM_PANFROST_PARAM_ALLOWED_JM_CTX_PRIORITIES,
>  };
>  
>  struct drm_panfrost_get_param {
> @@ -299,6 +310,45 @@ struct panfrost_dump_registers {
>  	__u32 value;
>  };
>  
> +enum drm_panfrost_jm_ctx_priority {
> +	/**
> +	 * @PANFROST_JM_CTX_PRIORITY_LOW: Low priority context.
> +	 */
> +	PANFROST_JM_CTX_PRIORITY_LOW = 0,
> +
> +	/**
> +	 * @PANFROST_JM_CTX_PRIORITY_MEDIUM: Medium priority context.
> +	 */
> +	PANFROST_JM_CTX_PRIORITY_MEDIUM,
> +
> +	/**
> +	 * @PANFROST_JM_CTX_PRIORITY_HIGH: High priority context.
> +	 *
> +	 * Requires CAP_SYS_NICE or DRM_MASTER.
> +	 */
> +	PANFROST_JM_CTX_PRIORITY_HIGH,
> +};
> +
> +struct drm_panfrost_jm_ctx_create {
> +	/** @handle: Handle of the created JM context */
> +	__u32 handle;
> +
> +	/** @priority: Context priority (see enum drm_panfrost_jm_ctx_priority). */
> +	__u32 priority;
> +};
> +
> +struct drm_panfrost_jm_ctx_destroy {
> +	/**
> +	 * @handle: Handle of the JM context to destroy.
> +	 *
> +	 * Must be a valid context handle returned by DRM_IOCTL_PANTHOR_JM_CTX_CREATE.
> +	 */
> +	__u32 handle;
> +
> +	/** @pad: Padding field, MBZ. */
> +	__u32 pad;
> +};
> +
>  #if defined(__cplusplus)
>  }
>  #endif