On 05/09/2024 12:13, Mary Guillemard wrote:
> Expose allowed group priorities with a new device query.
>
> This new uAPI will be used in Mesa to properly report what priorities a
> user can use for EGL_IMG_context_priority.
>
> Since this extends the uAPI and because userland needs a way to
> advertise priorities accordingly, this also bumps the driver minor
> version.
>
> Signed-off-by: Mary Guillemard <mary.guillem...@collabora.com>
Minor nit below, but otherwise looks good.
> ---
> drivers/gpu/drm/panthor/panthor_drv.c | 61 ++++++++++++++++++---------
> include/uapi/drm/panthor_drm.h | 38 +++++++++++++++++
> 2 files changed, 80 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c
> b/drivers/gpu/drm/panthor/panthor_drv.c
> index 7b1db2adcb4c..f85aa2d99f09 100644
> --- a/drivers/gpu/drm/panthor/panthor_drv.c
> +++ b/drivers/gpu/drm/panthor/panthor_drv.c
> @@ -170,6 +170,7 @@ panthor_get_uobj_array(const struct drm_panthor_obj_array
> *in, u32 min_stride,
> PANTHOR_UOBJ_DECL(struct drm_panthor_gpu_info, tiler_present),
> \
> PANTHOR_UOBJ_DECL(struct drm_panthor_csif_info, pad), \
> PANTHOR_UOBJ_DECL(struct drm_panthor_timestamp_info,
> current_timestamp), \
> + PANTHOR_UOBJ_DECL(struct drm_panthor_group_priorities_info,
> pad), \
> PANTHOR_UOBJ_DECL(struct drm_panthor_sync_op, timeline_value),
> \
> PANTHOR_UOBJ_DECL(struct drm_panthor_queue_submit, syncs), \
> PANTHOR_UOBJ_DECL(struct drm_panthor_queue_create,
> ringbuf_size), \
> @@ -777,11 +778,41 @@ static int panthor_query_timestamp_info(struct
> panthor_device *ptdev,
> return 0;
> }
>
> +static int group_priority_permit(struct drm_file *file,
> + u8 priority)
> +{
> + /* Ensure that priority is valid */
> + if (priority > PANTHOR_GROUP_PRIORITY_REALTIME)
> + return -EINVAL;
> +
> + /* Medium priority and below are always allowed */
> + if (priority <= PANTHOR_GROUP_PRIORITY_MEDIUM)
> + return 0;
> +
> + /* Higher priorities require CAP_SYS_NICE or DRM_MASTER */
> + if (capable(CAP_SYS_NICE) || drm_is_current_master(file))
> + return 0;
> +
> + return -EACCES;
> +}
> +
> +static void panthor_query_group_priorities_info(struct drm_file *file,
> + struct
> drm_panthor_group_priorities_info *arg)
> +{
> + int prio;
> +
> + for (prio = PANTHOR_GROUP_PRIORITY_REALTIME; prio >= 0; prio--) {
> + if (!group_priority_permit(file, prio))
> + arg->allowed_mask |= 1 << prio;
> + }
> +}
> +
> static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data,
> struct drm_file *file)
> {
> struct panthor_device *ptdev = container_of(ddev, struct
> panthor_device, base);
> struct drm_panthor_dev_query *args = data;
> struct drm_panthor_timestamp_info timestamp_info;
> + struct drm_panthor_group_priorities_info priorities_info;
> int ret;
>
> if (!args->pointer) {
> @@ -798,6 +829,10 @@ static int panthor_ioctl_dev_query(struct drm_device
> *ddev, void *data, struct d
> args->size = sizeof(timestamp_info);
> return 0;
>
> + case DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO:
> + args->size = sizeof(priorities_info);
> + return 0;
> +
> default:
> return -EINVAL;
> }
> @@ -818,6 +853,10 @@ static int panthor_ioctl_dev_query(struct drm_device
> *ddev, void *data, struct d
>
> return PANTHOR_UOBJ_SET(args->pointer, args->size,
> timestamp_info);
>
> + case DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO:
> + panthor_query_group_priorities_info(file, &priorities_info);
> + return PANTHOR_UOBJ_SET(args->pointer, args->size,
> priorities_info);
> +
> default:
> return -EINVAL;
> }
> @@ -1037,24 +1076,6 @@ static int panthor_ioctl_group_destroy(struct
> drm_device *ddev, void *data,
> return panthor_group_destroy(pfile, args->group_handle);
> }
>
> -static int group_priority_permit(struct drm_file *file,
> - u8 priority)
> -{
> - /* Ensure that priority is valid */
> - if (priority > PANTHOR_GROUP_PRIORITY_REALTIME)
> - return -EINVAL;
> -
> - /* Medium priority and below are always allowed */
> - if (priority <= PANTHOR_GROUP_PRIORITY_MEDIUM)
> - return 0;
> -
> - /* Higher priorities require CAP_SYS_NICE or DRM_MASTER */
> - if (capable(CAP_SYS_NICE) || drm_is_current_master(file))
> - return 0;
> -
> - return -EACCES;
> -}
> -
> static int panthor_ioctl_group_create(struct drm_device *ddev, void *data,
> struct drm_file *file)
> {
> @@ -1436,6 +1457,8 @@ static void panthor_debugfs_init(struct drm_minor
> *minor)
> * PanCSF driver version:
> * - 1.0 - initial interface
> * - 1.1 - adds DEV_QUERY_TIMESTAMP_INFO query
> + * - 1.2 - adds DEV_QUERY_GROUP_PRIORITIES_INFO query
> + * - adds PANTHOR_GROUP_PRIORITY_REALTIME priority
> */
> static const struct drm_driver panthor_drm_driver = {
> .driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ |
> @@ -1449,7 +1472,7 @@ static const struct drm_driver panthor_drm_driver = {
> .desc = "Panthor DRM driver",
> .date = "20230801",
> .major = 1,
> - .minor = 1,
> + .minor = 2,
>
> .gem_create_object = panthor_gem_create_object,
> .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table,
> diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
> index 011a555e4674..520c467f946d 100644
> --- a/include/uapi/drm/panthor_drm.h
> +++ b/include/uapi/drm/panthor_drm.h
> @@ -263,6 +263,11 @@ enum drm_panthor_dev_query_type {
>
> /** @DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO: Query timestamp information.
> */
> DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO,
> +
> + /**
> + * @DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO: Query allowed group
> priorities information.
> + */
> + DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO,
> };
>
> /**
> @@ -399,6 +404,39 @@ struct drm_panthor_timestamp_info {
> __u64 timestamp_offset;
> };
>
> +/**
> + * enum drm_panthor_allowed_group_priority - Allowed group priority flags
> + */
> +enum drm_panthor_group_allow_priority_flags {
> + /** @PANTHOR_GROUP_ALLOW_PRIORITY_LOW: Allow low priority group. */
> + PANTHOR_GROUP_ALLOW_PRIORITY_LOW = 1 << 0,
> +
> + /** @PANTHOR_GROUP_ALLOW_PRIORITY_MEDIUM: Allow medium priority group.
> */
> + PANTHOR_GROUP_ALLOW_PRIORITY_MEDIUM = 1 << 1,
> +
> + /** @PANTHOR_GROUP_ALLOW_PRIORITY_HIGH: Allow high priority group. */
> + PANTHOR_GROUP_ALLOW_PRIORITY_HIGH = 1 << 2,
> +
> + /** @PANTHOR_GROUP_ALLOW_PRIORITY_REALTIME: Allow realtime priority
> group. */
> + PANTHOR_GROUP_ALLOW_PRIORITY_REALTIME = 1 << 3,
> +};
It would be good to reference the existing priority enums rather than
adding magic numbers. So:
PANTHOR_GROUP_ALLOW_PRIORITY_LOW = (1 << PANTHOR_GROUP_PRIORITY_LOW)
etc
Although I'd also be very tempted not to include this enum at all and
just add a explanation below that the bits in allowed_mask refer to the
corresponding bits from drm_panthor_group_priority. Personally if I was
writing code to check this I'd want to write something like:
if (allowed_mask & BIT(PANTHOR_GROUP_PRIORITY_HIGH))
Steve
> +
> +/**
> + * struct drm_panthor_group_priorities_info - Group priorities information
> + *
> + * Structure grouping all queryable information relating to the allowed
> group priorities.
> + */
> +struct drm_panthor_group_priorities_info {
> + /**
> + * @allowed_mask: A mask of drm_panthor_group_allow_priority_flags
> flags containing the
> + * allowed group priorities.
> + */
> + __u8 allowed_mask;
> +
> + /** @pad: Padding fields, MBZ. */
> + __u8 pad[3];
> +};
> +
> /**
> * struct drm_panthor_dev_query - Arguments passed to
> DRM_PANTHOR_IOCTL_DEV_QUERY
> */
