What is share plane: Plane hardware only be used when the display scanout run into plane active scanout, that means we can reuse the plane hardware resources on plane non-active scanout.
-------------------------------------------------- | scanout | | ------------------ | | | parent plane | | | | active scanout | | | | | ----------------- | | ------------------ | share plane 1 | | | ----------------- |active scanout | | | | share plane 0 | | | | | |active scanout | ----------------- | | | | | | ----------------- | -------------------------------------------------- One plane hardware can be reuse for multi-planes, we assume the first plane is parent plane, other planes share the resource with first one. parent plane |---share plane 0 |---share plane 1 ...
Because resource share, There are some limit on share plane: one group of share planes need use same zpos, can not overlap, etc.
We assume share plane is a universal plane with some limit flags. people who use the share plane need know the limit, should call the ioctl DRM_CLIENT_CAP_SHARE_PLANES, and judge the planes limit before use it.
A group of share planes would has same shard id, so userspace can group them, judge share plane's limit.
Signed-off-by: Mark Yao mark.yao@rock-chips.com --- drivers/gpu/drm/drm_crtc.c | 110 ++++++++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_ioctl.c | 5 ++ include/drm/drmP.h | 5 ++ include/drm/drm_crtc.h | 14 ++++++ include/uapi/drm/drm.h | 7 +++ 5 files changed, 141 insertions(+)
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 9d3f80e..3a8257e 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1426,6 +1426,96 @@ int drm_plane_init(struct drm_device *dev, struct drm_plane *plane, EXPORT_SYMBOL(drm_plane_init);
/** + * drm_share_plane_init - Initialize a share plane + * @dev: DRM device + * @plane: plane object to init + * @parent: this plane share some resources with parent plane. + * @possible_crtcs: bitmask of possible CRTCs + * @funcs: callbacks for the new plane + * @formats: array of supported formats (%DRM_FORMAT_*) + * @format_count: number of elements in @formats + * @type: type of plane (overlay, primary, cursor) + * + * With this API, the plane can share hardware resources with other planes. + * + * -------------------------------------------------- + * | scanout | + * | ------------------ | + * | | parent plane | | + * | | active scanout | | + * | | | ----------------- | + * | ------------------ | share plane 1 | | + * | ----------------- |active scanout | | + * | | share plane 0 | | | | + * | |active scanout | ----------------- | + * | | | | + * | ----------------- | + * -------------------------------------------------- + * + * parent plane + * |---share plane 0 + * |---share plane 1 + * ... + * + * The plane hardware is used when the display scanout run into plane active + * scanout, that means we can reuse the plane hardware resources on plane + * non-active scanout. + * + * Because resource share, There are some limit on share plane: one group + * of share planes need use same zpos, can't not overlap, etc. + * + * Here assume share plane is a universal plane with some limit flags. + * people who use the share plane need know the limit, should call the ioctl + * DRM_CLIENT_CAP_SHARE_PLANES, and judge the planes limit before use it. + * + * Returns: + * Zero on success, error code on failure. + */ + +int drm_share_plane_init(struct drm_device *dev, struct drm_plane *plane, + struct drm_plane *parent, + unsigned long possible_crtcs, + const struct drm_plane_funcs *funcs, + const uint32_t *formats, unsigned int format_count, + enum drm_plane_type type) +{ + struct drm_mode_config *config = &dev->mode_config; + int ret; + int share_id; + + /* + * TODO: only verified on ATOMIC drm driver. + */ + if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) + return -EINVAL; + + ret = drm_universal_plane_init(dev, plane, possible_crtcs, funcs, + formats, format_count, type, NULL); + if (ret) + return ret; + + if (parent) { + /* + * Can't support more than two level plane share. + */ + WARN_ON(parent->parent); + share_id = parent->base.id; + plane->parent = parent; + + config->num_share_plane++; + if (plane->type == DRM_PLANE_TYPE_OVERLAY) + config->num_share_overlay_plane++; + } else { + share_id = plane->base.id; + } + + drm_object_attach_property(&plane->base, + config->prop_share_id, share_id); + return 0; +} +EXPORT_SYMBOL(drm_share_plane_init); + +/** * drm_plane_cleanup - Clean up the core plane usage * @plane: plane to cleanup * @@ -1452,6 +1542,11 @@ void drm_plane_cleanup(struct drm_plane *plane) dev->mode_config.num_total_plane--; if (plane->type == DRM_PLANE_TYPE_OVERLAY) dev->mode_config.num_overlay_plane--; + if (plane->parent) { + dev->mode_config.num_share_plane--; + if (plane->type == DRM_PLANE_TYPE_OVERLAY) + dev->mode_config.num_share_overlay_plane--; + } drm_modeset_unlock_all(dev);
WARN_ON(plane->state && !plane->funcs->atomic_destroy_state); @@ -1600,6 +1695,13 @@ static int drm_mode_create_standard_properties(struct drm_device *dev) return -ENOMEM; dev->mode_config.plane_type_property = prop;
+ prop = drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, + "SHARE_ID", 0, UINT_MAX); + if (!prop) + return -ENOMEM; + + dev->mode_config.prop_share_id = prop; + prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC, "SRC_X", 0, UINT_MAX); if (!prop) @@ -2431,6 +2533,12 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data, num_planes = config->num_total_plane; else num_planes = config->num_overlay_plane; + if (!file_priv->share_planes) { + if (file_priv->universal_planes) + num_planes -= config->num_share_plane; + else + num_planes -= config->num_share_overlay_plane; + }
/* * This ioctl is called twice, once to determine how much space is @@ -2449,6 +2557,8 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data, if (plane->type != DRM_PLANE_TYPE_OVERLAY && !file_priv->universal_planes) continue; + if (plane->parent && !file_priv->share_planes) + continue;
if (put_user(plane->base.id, plane_ptr + copied)) return -EFAULT; diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 33af4a5..8b0120d 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -294,6 +294,11 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv) return -EINVAL; file_priv->universal_planes = req->value; break; + case DRM_CLIENT_CAP_SHARE_PLANES: + if (req->value > 1) + return -EINVAL; + file_priv->share_planes = req->value; + break; case DRM_CLIENT_CAP_ATOMIC: if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) return -EINVAL; diff --git a/include/drm/drmP.h b/include/drm/drmP.h index c2fe2cf..285d177 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -314,6 +314,11 @@ struct drm_file { /* true if client understands atomic properties */ unsigned atomic:1; /* + * true if client understands share planes and + * hardware support share planes. + */ + unsigned share_planes:1; + /* * This client is the creator of @master. * Protected by struct drm_device::master_mutex. */ diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 9e6ab4a..a3fe9b0 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -1660,6 +1660,7 @@ enum drm_plane_type { /** * struct drm_plane - central DRM plane control structure * @dev: DRM device this plane belongs to + * @parent: this plane share some resources with parent plane. * @head: for list management * @name: human readable name, can be overwritten by the driver * @base: base mode object @@ -1679,6 +1680,7 @@ enum drm_plane_type { */ struct drm_plane { struct drm_device *dev; + struct drm_plane *parent; struct list_head head;
char *name; @@ -2408,6 +2410,8 @@ struct drm_mode_config { */ int num_overlay_plane; int num_total_plane; + int num_share_plane; + int num_share_overlay_plane; struct list_head plane_list;
int num_crtc; @@ -2428,6 +2432,9 @@ struct drm_mode_config {
struct mutex blob_lock;
+ /* pointers to share properties */ + struct drm_property *prop_share_id; + /* pointers to standard properties */ struct list_head property_blob_list; struct drm_property *edid_property; @@ -2636,6 +2643,13 @@ extern int drm_plane_init(struct drm_device *dev, const struct drm_plane_funcs *funcs, const uint32_t *formats, unsigned int format_count, bool is_primary); +extern int drm_share_plane_init(struct drm_device *dev, struct drm_plane *plane, + struct drm_plane *parent, + unsigned long possible_crtcs, + const struct drm_plane_funcs *funcs, + const uint32_t *formats, + unsigned int format_count, + enum drm_plane_type type); extern void drm_plane_cleanup(struct drm_plane *plane);
/** diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 452675f..01979a4 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -677,6 +677,13 @@ struct drm_get_cap { */ #define DRM_CLIENT_CAP_ATOMIC 3
+/** + * DRM_CLIENT_CAP_SHARE_PLANES + * + * If set to 1, the DRM core will expose share planes to userspace. + */ +#define DRM_CLIENT_CAP_SHARE_PLANES 4 + /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */ struct drm_set_client_cap { __u64 capability;