[PATCH v5 11/12] drm: Add CP downstream_info property
Daniel Vetter
daniel at ffwll.ch
Mon Apr 29 07:38:32 UTC 2019
On Thu, Apr 18, 2019 at 02:28:04PM +0530, Ramalingam C wrote:
> This patch adds a optional CP downstream info blob property to the
> connectors. This enables the Userspace to read the information of HDCP
> authenticated downstream topology.
>
> Driver will update this blob with all downstream information at the
> end of the authentication.
>
> In case userspace configures this platform as repeater, then this
> information is needed for the authentication with upstream HDCP
> transmitter.
>
> v2:
> s/cp_downstream/content_protection_downstream [daniel]
> v3:
> s/content_protection_downstream/hdcp_topology [daniel]
> v4:
> hdcp_topology_info struct is added with explicit padding [Daniel]
> v5:
> Rebased.
>
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> ---
> drivers/gpu/drm/drm_atomic_uapi.c | 3 ++
> drivers/gpu/drm/drm_connector.c | 20 ++++++++++
> drivers/gpu/drm/drm_hdcp.c | 65 +++++++++++++++++++++++++++++++
> include/drm/drm_connector.h | 6 +++
> include/drm/drm_hdcp.h | 6 +++
> include/drm/drm_mode_config.h | 6 +++
> include/uapi/drm/drm_mode.h | 37 ++++++++++++++++++
> 7 files changed, 143 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
> index 0b0747869963..1c9e1ab0d536 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -813,6 +813,9 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
> *val = state->content_protection;
> } else if (property == config->hdcp_content_type_property) {
> *val = state->hdcp_content_type;
> + } else if (property == config->hdcp_topology_property) {
> + *val = connector->hdcp_topology_blob_ptr ?
> + connector->hdcp_topology_blob_ptr->base.id : 0;
> } else if (property == config->writeback_fb_id_property) {
> /* Writeback framebuffer is one-shot, write and forget */
> *val = 0;
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 436cf8e764cc..033ced774d37 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -246,6 +246,7 @@ int drm_connector_init(struct drm_device *dev,
> mutex_init(&connector->mutex);
> connector->edid_blob_ptr = NULL;
> connector->tile_blob_ptr = NULL;
> + connector->hdcp_topology_blob_ptr = NULL;
> connector->status = connector_status_unknown;
> connector->display_info.panel_orientation =
> DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
> @@ -972,6 +973,25 @@ static const struct drm_prop_enum_list hdmi_colorspaces[] = {
> * authentication process. If content type is changed when
> * content_protection is not UNDESIRED, then kernel will disable the HDCP
> * and re-enable with new type in the same atomic commit
> + * HDCP Topology:
> + * This blob property is used to pass the HDCP downstream topology details
> + * of a HDCP encrypted connector, from kernel to userspace.
> + * This provides all required information to userspace, so that userspace
> + * can implement the HDCP repeater using the kernel as downstream ports of
> + * the repeater. as illustrated below:
> + *
> + * HDCP Repeaters
> + * +--------------------------------------------------------------+
> + * | |
> + * | | |
> + * | Userspace HDCP Receiver +-----> KMD HDCP transmitters |
> + * | (Upstream Port) <------+ (Downstream Ports) |
> + * | | |
> + * | |
> + * +--------------------------------------------------------------+
Hm I think this misrenders, since the table isn't indented or marked as
fixed with. Did you check the output of $make htmldocs?
> + *
> + * Kernel will populate this blob only when the HDCP authentication is
> + * successful.
> *
> * max bpc:
> * This range property is used by userspace to limit the bit depth. When
> diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c
> index 5640c4e744fe..c0d3fc93fc50 100644
> --- a/drivers/gpu/drm/drm_hdcp.c
> +++ b/drivers/gpu/drm/drm_hdcp.c
> @@ -431,3 +431,68 @@ void drm_hdcp_update_content_protection(struct drm_connector *connector,
> dev->mode_config.content_protection_property);
> }
> EXPORT_SYMBOL(drm_hdcp_update_content_protection);
> +
> +/**
> + * drm_connector_attach_hdcp_topology_property - attach hdcp topology property
> + *
> + * @connector: connector to attach hdcp topology property with.
> + *
> + * This is used to add support for hdcp topology support on select connectors.
> + * When Intel platform is configured as repeater, this downstream info is used
> + * by userspace, to complete the repeater authentication of HDCP specification
> + * with upstream HDCP transmitter.
> + *
> + * The blob_id of the hdcp topology info will be set to
> + * &drm_connector_state.hdcp_topology
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int drm_connector_attach_hdcp_topology_property(struct drm_connector *connector)
> +{
> + struct drm_device *dev = connector->dev;
> + struct drm_property *prop = dev->mode_config.hdcp_topology_property;
> +
> + if (!prop)
> + prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
> + DRM_MODE_PROP_IMMUTABLE,
> + "HDCP Topology", 0);
> + if (!prop)
> + return -ENOMEM;
> +
> + drm_object_attach_property(&connector->base, prop, 0);
> + dev->mode_config.hdcp_topology_property = prop;
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_connector_attach_hdcp_topology_property);
> +
> +/**
> + * drm_connector_update_hdcp_topology_property - update the hdcp topology
> + * property of a connector
> + * @connector: drm connector, the topology is associated to
> + * @hdcp_topology_info: new content for the blob of hdcp_topology_property
> + *
> + * This function creates a new blob modeset object and assigns its id to the
> + * connector's hdcp_topology_property.
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int
> +drm_connector_update_hdcp_topology_property(struct drm_connector *connector,
> + const struct hdcp_topology_info *info)
> +{
> + struct drm_device *dev = connector->dev;
> + int ret;
> +
> + if (!info)
> + return -EINVAL;
> +
> + ret = drm_property_replace_global_blob(dev,
> + &connector->hdcp_topology_blob_ptr,
> + sizeof(struct hdcp_topology_info),
> + info, &connector->base,
> + dev->mode_config.hdcp_topology_property);
> + return ret;
> +}
Hm, I'd put this into the previous function that also sends out the
uevent. That way we can guarantee that we update everyting _before_ we
send out the uevent to signal to userspace that it should take some
action.
> +EXPORT_SYMBOL(drm_connector_update_hdcp_topology_property);
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 9e2f1a9de2a0..180f8f4d4526 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1050,6 +1050,12 @@ struct drm_connector {
> /** @properties: property tracking for this connector */
> struct drm_object_properties properties;
>
> + /**
> + * @hdcp_topology_blob_ptr: DRM BLOB pointer for hdcp downstream
> + * topology information.
> + */
> + struct drm_property_blob *hdcp_topology_blob_ptr;
> +
> /**
> * @scaling_mode_property: Optional atomic property to control the
> * upscaling. See drm_connector_attach_content_protection_property().
> diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h
> index 9457c7ec0d37..011f35e121a5 100644
> --- a/include/drm/drm_hdcp.h
> +++ b/include/drm/drm_hdcp.h
> @@ -300,10 +300,16 @@ struct hdcp2_srm_header {
>
> struct drm_device;
> struct drm_connector;
> +struct hdcp_topology_info;
>
> bool drm_hdcp_ksvs_revocated(struct drm_device *dev, u8 *ksvs, u32 ksv_count);
> int drm_connector_attach_content_protection_property(
> struct drm_connector *connector, bool hdcp_content_type);
> void drm_hdcp_update_content_protection(struct drm_connector *connector,
> u64 val);
> +int drm_connector_attach_hdcp_topology_property(
> + struct drm_connector *connector);
> +int drm_connector_update_hdcp_topology_property(
> + struct drm_connector *connector,
> + const struct hdcp_topology_info *info);
> #endif
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index b359b5b71eb9..4349b614fa15 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -848,6 +848,12 @@ struct drm_mode_config {
> */
> struct drm_property *hdcp_content_type_property;
>
> + /**
> + * @hdcp_topology_property: DRM BLOB property for hdcp downstream
> + * topology information.
> + */
> + struct drm_property *hdcp_topology_property;
> +
> /* dumb ioctl parameters */
> uint32_t preferred_depth, prefer_shadow;
>
> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
> index 8ac03351fdee..9d7cdfab4962 100644
> --- a/include/uapi/drm/drm_mode.h
> +++ b/include/uapi/drm/drm_mode.h
> @@ -213,6 +213,43 @@ extern "C" {
> #define DRM_MODE_HDCP_CONTENT_TYPE0 0
> #define DRM_MODE_HDCP_CONTENT_TYPE1 1
>
> +#define DRM_MODE_HDCP_KSV_LEN 5
> +#define DRM_MODE_HDCP_MAX_DEVICE_CNT 127
> +#define DRM_MODE_HDCP14_IN_FORCE (1 << 0)
> +#define DRM_MODE_HDCP22_IN_FORCE (1 << 1)
> +
> +struct hdcp_topology_info {
> + /* Version of HDCP authenticated (1.4/2.2) */
> + __u32 ver_in_force;
> +
> + /* Applicable only for HDCP2.2 */
> + __u32 content_type;
> +
> + /* KSV of immediate HDCP Sink. In Little-Endian Format. */
> + __u8 bksv[DRM_MODE_HDCP_KSV_LEN];
> +
> + /* Whether Immediate HDCP sink is a repeater? */
> + __u8 is_repeater;
> +
> + /* Depth received from immediate downstream repeater */
> + __u8 depth;
> + __u8 pad1;
> +
> + /* Device count received from immediate downstream repeater */
> + __u32 device_count;
> +
> + /*
> + * Max buffer required to hold ksv list received from immediate
> + * repeater. In this array first device_count * DRM_MODE_HDCP_KSV_LEN
> + * will hold the valid ksv bytes.
> + * If authentication specification is
> + * HDCP1.4 - each KSV's Bytes will be in Little-Endian format.
> + * HDCP2.2 - each KSV's Bytes will be in Big-Endian format.
> + */
> + __u8 ksv_list[DRM_MODE_HDCP_KSV_LEN * DRM_MODE_HDCP_MAX_DEVICE_CNT];
> + __u8 pad2[5];
> +} __packed;
So I think we need userspace for this, but not sure where the discussions
on that are right now. Is this feasible, or this and follow-up i915 patch
more fyi and not for upstream?
-Daniel
> +
> struct drm_mode_modeinfo {
> __u32 clock;
> __u16 hdisplay;
> --
> 2.19.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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