[Intel-gfx] [PATCH v8 1/6] drm: Add Content protection type property
Pekka Paalanen
ppaalanen at gmail.com
Mon Jul 8 09:59:59 UTC 2019
On Mon, 8 Jul 2019 12:52:17 +0300
Pekka Paalanen <ppaalanen at gmail.com> wrote:
> On Fri, 5 Jul 2019 06:16:37 +0530
> Ramalingam C <ramalingam.c at intel.com> wrote:
>
> > This patch adds a DRM ENUM property to the selected connectors.
> > This property is used for mentioning the protected content's type
> > from userspace to kernel HDCP authentication.
> >
> > Type of the stream is decided by the protected content providers.
> > Type 0 content can be rendered on any HDCP protected display wires.
> > But Type 1 content can be rendered only on HDCP2.2 protected paths.
> >
> > So when a userspace sets this property to Type 1 and starts the HDCP
> > enable, kernel will honour it only if HDCP2.2 authentication is through
> > for type 1. Else HDCP enable will be failed.
> >
> > Need ACK for this new conenctor property from userspace consumer.
> >
> > v2:
> > cp_content_type is replaced with content_protection_type [daniel]
> > check at atomic_set_property is removed [Maarten]
> > v3:
> > %s/content_protection_type/hdcp_content_type [Pekka]
> > v4:
> > property is created for the first requested connector and then reused.
> > [Danvet]
> > v5:
> > kernel doc nits addressed [Daniel]
> > Rebased as part of patch reordering.
> > v6:
> > Kernel docs are modified [pekka]
> >
> > Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> > Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> > ---
> > drivers/gpu/drm/drm_atomic_uapi.c | 4 +++
> > drivers/gpu/drm/drm_connector.c | 22 ++++++++++++++
> > drivers/gpu/drm/drm_hdcp.c | 36 ++++++++++++++++++++++-
> > drivers/gpu/drm/i915/display/intel_hdcp.c | 4 ++-
> > include/drm/drm_connector.h | 7 +++++
> > include/drm/drm_hdcp.h | 2 +-
> > include/drm/drm_mode_config.h | 6 ++++
> > include/uapi/drm/drm_mode.h | 4 +++
> > 8 files changed, 82 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
> > index abe38bdf85ae..19ae119f1a5d 100644
> > --- a/drivers/gpu/drm/drm_atomic_uapi.c
> > +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> > @@ -747,6 +747,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
> > return -EINVAL;
> > }
> > state->content_protection = val;
> > + } else if (property == config->hdcp_content_type_property) {
> > + state->hdcp_content_type = val;
> > } else if (property == connector->colorspace_property) {
> > state->colorspace = val;
> > } else if (property == config->writeback_fb_id_property) {
> > @@ -831,6 +833,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
> > state->hdr_output_metadata->base.id : 0;
> > } else if (property == config->content_protection_property) {
> > *val = state->content_protection;
> > + } else if (property == config->hdcp_content_type_property) {
> > + *val = state->hdcp_content_type;
> > } 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 068d4b05f1be..17aef88c03a6 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -951,6 +951,28 @@ static const struct drm_prop_enum_list hdmi_colorspaces[] = {
> > * the value transitions from ENABLED to DESIRED. This signifies the link
> > * is no longer protected and userspace should take appropriate action
> > * (whatever that might be).
> > + * HDCP Content Type:
> > + * This property is used by the userspace to configure the kernel with
> > + * to be displayed stream's content type. Content Type of a stream is
> > + * decided by the owner of the stream, as "HDCP Type0" or "HDCP Type1".
> > + *
> > + * The value of the property can be one the below:
> > + * - "HDCP Type0": DRM_MODE_HDCP_CONTENT_TYPE0 = 0
> > + * HDCP Type0 streams can be transmitted on a link which is
> > + * encrypted with HDCP 1.4 or higher versions of HDCP(i.e HDCP2.2
> > + * and more).
> > + * - "HDCP Type1": DRM_MODE_HDCP_CONTENT_TYPE1 = 1
> > + * HDCP Type1 streams can be transmitted on a link which is
> > + * encrypted only with HDCP 2.2. In future higher versions also
> > + * might support Type1 based on their spec.
> > + *
> > + * Note that the HDCP Content Type property is introduced at HDCP 2.2, and
> > + * defaults to type 0. It is only exposed by drivers supporting HDCP 2.2.
> > + * Based on how next versions of HDCP specs are defined content Type could
> > + * be used for higher versions too.
> > + * 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
>
> Hi,
>
> I think this doc covers all my previous comments on this patch now. One
> more thing, the wording here reads as:
> - userspace configures the content type
> - the kernel transmits the content if the link satisfies the type
> requirement
> - if the link does not satisfy the type requirement, the kernel will
> not transmit the content
>
> This is of course false, the kernel transmits anyway, but that is how
> the text reads from the "stream's content type" and "can be transmitted
> on". The problem is, that a userspace developer will think the stream
> is what he pushes into KMS, not what goes on the wire. The text also
> magnifies that misconception because it sounds like the stream is
> something different from the link. Actually, I don't understand what
> "the stream" is supposed to be here.
>
> Instead, I think you should explain how the content type property
> guides the kernel driver's attempts in negotiating the link encryption
> and how that then reflects in the content protection property (DESIRED
> vs. ENABLED). It might be best to not say anything about any "stream".
Btw. this UAPI has the following fundamental flaws:
- userspace cannot know which encryption is used on the link
- userspace cannot force Type0 if the driver succeeds enabling Type1
To me this seems like poor UAPI design. Why was this designed like this?
Thanks,
pq
> > *
> > * HDR_OUTPUT_METADATA:
> > * Connector property to enable userspace to send HDR Metadata to
> > diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c
> > index cd837bd409f7..ce235fd1c844 100644
> > --- a/drivers/gpu/drm/drm_hdcp.c
> > +++ b/drivers/gpu/drm/drm_hdcp.c
> > @@ -344,23 +344,41 @@ static struct drm_prop_enum_list drm_cp_enum_list[] = {
> > };
> > DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
> >
> > +static struct drm_prop_enum_list drm_hdcp_content_type_enum_list[] = {
> > + { DRM_MODE_HDCP_CONTENT_TYPE0, "HDCP Type0" },
> > + { DRM_MODE_HDCP_CONTENT_TYPE1, "HDCP Type1" },
> > +};
> > +DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name,
> > + drm_hdcp_content_type_enum_list)
> > +
> > /**
> > * drm_connector_attach_content_protection_property - attach content protection
> > * property
> > *
> > * @connector: connector to attach CP property on.
> > + * @hdcp_content_type: is HDCP Content Type property needed for connector
> > *
> > * This is used to add support for content protection on select connectors.
> > * Content Protection is intentionally vague to allow for different underlying
> > * technologies, however it is most implemented by HDCP.
> > *
> > + * When hdcp_content_type is true enum property called HDCP Content Type is
> > + * created (if it is not already) and attached to the connector.
> > + *
> > + * This property is used for sending the protected content's stream type
> > + * from userspace to kernel on selected connectors. Protected content provider
> > + * will decide their type of their content and declare the same to kernel.
> > + *
> > + * Content type will be used during the HDCP 2.2 authentication.
> > + * Content type will be set to &drm_connector_state.hdcp_content_type.
> > + *
> > * The content protection will be set to &drm_connector_state.content_protection
> > *
> > * Returns:
> > * Zero on success, negative errno on failure.
> > */
> > int drm_connector_attach_content_protection_property(
> > - struct drm_connector *connector)
> > + struct drm_connector *connector, bool hdcp_content_type)
> > {
> > struct drm_device *dev = connector->dev;
> > struct drm_property *prop =
> > @@ -377,6 +395,22 @@ int drm_connector_attach_content_protection_property(
> > DRM_MODE_CONTENT_PROTECTION_UNDESIRED);
> > dev->mode_config.content_protection_property = prop;
> >
> > + if (!hdcp_content_type)
> > + return 0;
> > +
> > + prop = dev->mode_config.hdcp_content_type_property;
> > + if (!prop)
> > + prop = drm_property_create_enum(dev, 0, "HDCP Content Type",
> > + drm_hdcp_content_type_enum_list,
> > + ARRAY_SIZE(
> > + drm_hdcp_content_type_enum_list));
> > + if (!prop)
> > + return -ENOMEM;
> > +
> > + drm_object_attach_property(&connector->base, prop,
> > + DRM_MODE_HDCP_CONTENT_TYPE0);
> > + dev->mode_config.hdcp_content_type_property = prop;
> > +
> > return 0;
> > }
> > EXPORT_SYMBOL(drm_connector_attach_content_protection_property);
> > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > index bc3a94d491c4..2a4d10952b74 100644
> > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > @@ -1829,7 +1829,9 @@ int intel_hdcp_init(struct intel_connector *connector,
> > if (!shim)
> > return -EINVAL;
> >
> > - ret = drm_connector_attach_content_protection_property(&connector->base);
> > + ret =
> > + drm_connector_attach_content_protection_property(&connector->base,
> > + false);
> > if (ret)
> > return ret;
> >
> > diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> > index 4c30d751487a..d6432967a2a9 100644
> > --- a/include/drm/drm_connector.h
> > +++ b/include/drm/drm_connector.h
> > @@ -601,6 +601,12 @@ struct drm_connector_state {
> > */
> > unsigned int content_type;
> >
> > + /**
> > + * @hdcp_content_type: Connector property to pass the type of
> > + * protected content. This is most commonly used for HDCP.
> > + */
> > + unsigned int hdcp_content_type;
> > +
> > /**
> > * @scaling_mode: Connector property to control the
> > * upscaling, mostly used for built-in panels.
> > @@ -1484,6 +1490,7 @@ const char *drm_get_dvi_i_select_name(int val);
> > const char *drm_get_tv_subconnector_name(int val);
> > const char *drm_get_tv_select_name(int val);
> > const char *drm_get_content_protection_name(int val);
> > +const char *drm_get_hdcp_content_type_name(int val);
> >
> > int drm_mode_create_dvi_i_properties(struct drm_device *dev);
> > int drm_mode_create_tv_margin_properties(struct drm_device *dev);
> > diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h
> > index 13771a496e2b..2970abdfaf12 100644
> > --- a/include/drm/drm_hdcp.h
> > +++ b/include/drm/drm_hdcp.h
> > @@ -291,5 +291,5 @@ struct drm_connector;
> > bool drm_hdcp_check_ksvs_revoked(struct drm_device *dev,
> > u8 *ksvs, u32 ksv_count);
> > int drm_connector_attach_content_protection_property(
> > - struct drm_connector *connector);
> > + struct drm_connector *connector, bool hdcp_content_type);
> > #endif
> > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> > index 759d462d028b..6c4b5bc85951 100644
> > --- a/include/drm/drm_mode_config.h
> > +++ b/include/drm/drm_mode_config.h
> > @@ -849,6 +849,12 @@ struct drm_mode_config {
> > */
> > struct drm_property *content_protection_property;
> >
> > + /**
> > + * @hdcp_content_type_property: DRM ENUM property for type of
> > + * Protected Content.
> > + */
> > + struct drm_property *hdcp_content_type_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 5ab331e5dc23..5c954394093f 100644
> > --- a/include/uapi/drm/drm_mode.h
> > +++ b/include/uapi/drm/drm_mode.h
> > @@ -218,6 +218,10 @@ extern "C" {
> > #define DRM_MODE_CONTENT_PROTECTION_DESIRED 1
> > #define DRM_MODE_CONTENT_PROTECTION_ENABLED 2
> >
> > +/* Content Type classification for HDCP2.2 vs others */
> > +#define DRM_MODE_HDCP_CONTENT_TYPE0 0
> > +#define DRM_MODE_HDCP_CONTENT_TYPE1 1
> > +
> > struct drm_mode_modeinfo {
> > __u32 clock;
> > __u16 hdisplay;
>
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