drm/i915: Enable and Disable of HDCP2.2

Considering that HDCP2.2 is more secure than HDCP1.4, When a setup
supports HDCP2.2 and HDCP1.4, HDCP2.2 will be enabled.

When HDCP2.2 enabling fails and HDCP1.4 is supported, HDCP1.4 is
enabled.

This change implements a sequence of enabling and disabling of
HDCP2.2 authentication and HDCP2.2 port encryption.

v2:
  Included few optimization suggestions [Chris Wilson]
  Commit message is updated as per the rebased version.
  intel_wait_for_register is used instead of wait_for. [Chris Wilson]
v3:
  Extra comment added and Style issue fixed [Uma]
v4:
  Rebased as part of patch reordering.
  HDCP2 encryption status is tracked.
  HW state check is moved into WARN_ON [Daniel]
v5:
  Redefined the mei service functions as per comp redesign.
  Merged patches related to hdcp2.2 enabling and disabling [Sean Paul].
  Required shim functionality is defined [Sean Paul]
v6:
  Return values are handles [Uma]
  Realigned the code.
  Check for comp_master is removed.
v7:
  HDCP2.2 is attempted only if mei interface is up.
  Adjust to the new interface
  Avoid bool usage in struct [Tomas]
v8:
  mei_binded status check is removed.
  %s/hdcp2_in_use/hdcp2_encrypted
v9:
  bool is used in struct intel_hdcp. [Daniel]
v10:
  panel is replaced with sink [Uma]
  Mei interface decided the hdcp2_capability.
  WARN_ON if hdcp_enable is called when hdcp state is ENABLED.
  Reviewed-by Uma.

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1550338640-17470-7-git-send-email-ramalingam.c@intel.com

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index aaddde44b2702242752add7674b62ec248b67f18..7fcaa3ba538c5d54a61b9082df6aa6e14fa2c6db 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -399,6 +399,10 @@ struct intel_hdcp_shim {
 
        /* HDCP adaptation(DP/HDMI) required on the port */
        enum hdcp_wired_protocol protocol;
+
+       /* Detects whether sink is HDCP2.2 capable */
+       int (*hdcp_2_2_capable)(struct intel_digital_port *intel_dig_port,
+                               bool *capable);
 };
 
 struct intel_hdcp {
@@ -416,6 +420,9 @@ struct intel_hdcp {
        /* Flag indicates whether this connector supports HDCP2.2 or not. */
        bool hdcp2_supported;
 
+       /* HDCP2.2 Encryption status */
+       bool hdcp2_encrypted;
+
        /*
         * Content Stream Type defined by content owner. TYPE0(0x0) content can
         * flow in the link protected by HDCP2.2 or HDCP1.4, where as TYPE1(0x1)

diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index 66e3850a57a0f1d3e00774e2c4d6e6b824caf0ab..0b6ccb3d24fefd54b57f82d157886f8ce9576f05 100644 (file)
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -74,6 +74,32 @@ bool intel_hdcp_capable(struct intel_connector *connector)
        return capable;
 }
 
+/* Is HDCP2.2 capable on Platform and Sink */
+static bool intel_hdcp2_capable(struct intel_connector *connector)
+{
+       struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+       struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+       struct intel_hdcp *hdcp = &connector->hdcp;
+       bool capable = false;
+
+       /* I915 support for HDCP2.2 */
+       if (!hdcp->hdcp2_supported)
+               return false;
+
+       /* MEI interface is solid */
+       mutex_lock(&dev_priv->hdcp_comp_mutex);
+               if (!dev_priv->hdcp_comp_added ||  !dev_priv->hdcp_master) {
+                       mutex_unlock(&dev_priv->hdcp_comp_mutex);
+                       return false;
+               }
+       mutex_unlock(&dev_priv->hdcp_comp_mutex);
+
+       /* Sink's capability for HDCP2.2 */
+       hdcp->shim->hdcp_2_2_capable(intel_dig_port, &capable);
+
+       return capable;
+}
+
 static inline bool intel_hdcp_in_use(struct intel_connector *connector)
 {
        struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
@@ -1094,8 +1120,7 @@ int hdcp2_authenticate_port(struct intel_connector *connector)
        return ret;
 }
 
-static __attribute__((unused))
-int hdcp2_close_mei_session(struct intel_connector *connector)
+static int hdcp2_close_mei_session(struct intel_connector *connector)
 {
        struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
        struct i915_hdcp_comp_master *comp;
@@ -1116,12 +1141,157 @@ int hdcp2_close_mei_session(struct intel_connector *connector)
        return ret;
 }
 
-static __attribute__((unused))
-int hdcp2_deauthenticate_port(struct intel_connector *connector)
+static int hdcp2_deauthenticate_port(struct intel_connector *connector)
 {
        return hdcp2_close_mei_session(connector);
 }
 
+static int hdcp2_authenticate_sink(struct intel_connector *connector)
+{
+       DRM_ERROR("Sink authentication is done in subsequent patches\n");
+
+       return -EINVAL;
+}
+
+static int hdcp2_enable_encryption(struct intel_connector *connector)
+{
+       struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+       struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+       struct intel_hdcp *hdcp = &connector->hdcp;
+       enum port port = connector->encoder->port;
+       int ret;
+
+       WARN_ON(I915_READ(HDCP2_STATUS_DDI(port)) & LINK_ENCRYPTION_STATUS);
+
+       if (hdcp->shim->toggle_signalling) {
+               ret = hdcp->shim->toggle_signalling(intel_dig_port, true);
+               if (ret) {
+                       DRM_ERROR("Failed to enable HDCP signalling. %d\n",
+                                 ret);
+                       return ret;
+               }
+       }
+
+       if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_AUTH_STATUS) {
+               /* Link is Authenticated. Now set for Encryption */
+               I915_WRITE(HDCP2_CTL_DDI(port),
+                          I915_READ(HDCP2_CTL_DDI(port)) |
+                          CTL_LINK_ENCRYPTION_REQ);
+       }
+
+       ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
+                                     LINK_ENCRYPTION_STATUS,
+                                     LINK_ENCRYPTION_STATUS,
+                                     ENCRYPT_STATUS_CHANGE_TIMEOUT_MS);
+
+       return ret;
+}
+
+static int hdcp2_disable_encryption(struct intel_connector *connector)
+{
+       struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+       struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+       struct intel_hdcp *hdcp = &connector->hdcp;
+       enum port port = connector->encoder->port;
+       int ret;
+
+       WARN_ON(!(I915_READ(HDCP2_STATUS_DDI(port)) & LINK_ENCRYPTION_STATUS));
+
+       I915_WRITE(HDCP2_CTL_DDI(port),
+                  I915_READ(HDCP2_CTL_DDI(port)) & ~CTL_LINK_ENCRYPTION_REQ);
+
+       ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
+                                     LINK_ENCRYPTION_STATUS, 0x0,
+                                     ENCRYPT_STATUS_CHANGE_TIMEOUT_MS);
+       if (ret == -ETIMEDOUT)
+               DRM_DEBUG_KMS("Disable Encryption Timedout");
+
+       if (hdcp->shim->toggle_signalling) {
+               ret = hdcp->shim->toggle_signalling(intel_dig_port, false);
+               if (ret) {
+                       DRM_ERROR("Failed to disable HDCP signalling. %d\n",
+                                 ret);
+                       return ret;
+               }
+       }
+
+       return ret;
+}
+
+static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
+{
+       int ret, i, tries = 3;
+
+       for (i = 0; i < tries; i++) {
+               ret = hdcp2_authenticate_sink(connector);
+               if (!ret)
+                       break;
+
+               /* Clearing the mei hdcp session */
+               DRM_DEBUG_KMS("HDCP2.2 Auth %d of %d Failed.(%d)\n",
+                             i + 1, tries, ret);
+               if (hdcp2_deauthenticate_port(connector) < 0)
+                       DRM_DEBUG_KMS("Port deauth failed.\n");
+       }
+
+       if (i != tries) {
+               /*
+                * Ensuring the required 200mSec min time interval between
+                * Session Key Exchange and encryption.
+                */
+               msleep(HDCP_2_2_DELAY_BEFORE_ENCRYPTION_EN);
+               ret = hdcp2_enable_encryption(connector);
+               if (ret < 0) {
+                       DRM_DEBUG_KMS("Encryption Enable Failed.(%d)\n", ret);
+                       if (hdcp2_deauthenticate_port(connector) < 0)
+                               DRM_DEBUG_KMS("Port deauth failed.\n");
+               }
+       }
+
+       return ret;
+}
+
+static int _intel_hdcp2_enable(struct intel_connector *connector)
+{
+       struct intel_hdcp *hdcp = &connector->hdcp;
+       int ret;
+
+       DRM_DEBUG_KMS("[%s:%d] HDCP2.2 is being enabled. Type: %d\n",
+                     connector->base.name, connector->base.base.id,
+                     hdcp->content_type);
+
+       ret = hdcp2_authenticate_and_encrypt(connector);
+       if (ret) {
+               DRM_DEBUG_KMS("HDCP2 Type%d  Enabling Failed. (%d)\n",
+                             hdcp->content_type, ret);
+               return ret;
+       }
+
+       DRM_DEBUG_KMS("[%s:%d] HDCP2.2 is enabled. Type %d\n",
+                     connector->base.name, connector->base.base.id,
+                     hdcp->content_type);
+
+       hdcp->hdcp2_encrypted = true;
+       return 0;
+}
+
+static int _intel_hdcp2_disable(struct intel_connector *connector)
+{
+       int ret;
+
+       DRM_DEBUG_KMS("[%s:%d] HDCP2.2 is being Disabled\n",
+                     connector->base.name, connector->base.base.id);
+
+       ret = hdcp2_disable_encryption(connector);
+
+       if (hdcp2_deauthenticate_port(connector) < 0)
+               DRM_DEBUG_KMS("Port deauth failed.\n");
+
+       connector->hdcp.hdcp2_encrypted = false;
+
+       return ret;
+}
+
 static void intel_hdcp_check_work(struct work_struct *work)
 {
        struct intel_hdcp *hdcp = container_of(to_delayed_work(work),
@@ -1263,22 +1433,34 @@ int intel_hdcp_init(struct intel_connector *connector,
 int intel_hdcp_enable(struct intel_connector *connector)
 {
        struct intel_hdcp *hdcp = &connector->hdcp;
-       int ret;
+       int ret = -EINVAL;
 
        if (!hdcp->shim)
                return -ENOENT;
 
        mutex_lock(&hdcp->mutex);
+       WARN_ON(hdcp->value == DRM_MODE_CONTENT_PROTECTION_ENABLED);
 
-       ret = _intel_hdcp_enable(connector);
-       if (ret)
-               goto out;
+       /*
+        * Considering that HDCP2.2 is more secure than HDCP1.4, If the setup
+        * is capable of HDCP2.2, it is preferred to use HDCP2.2.
+        */
+       if (intel_hdcp2_capable(connector))
+               ret = _intel_hdcp2_enable(connector);
+
+       /* When HDCP2.2 fails, HDCP1.4 will be attempted */
+       if (ret && intel_hdcp_capable(connector)) {
+               ret = _intel_hdcp_enable(connector);
+               if (!ret)
+                       schedule_delayed_work(&hdcp->check_work,
+                                             DRM_HDCP_CHECK_PERIOD_MS);
+       }
+
+       if (!ret) {
+               hdcp->value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+               schedule_work(&hdcp->prop_work);
+       }
 
-       hdcp->value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
-       schedule_work(&hdcp->prop_work);
-       schedule_delayed_work(&hdcp->check_work,
-                             DRM_HDCP_CHECK_PERIOD_MS);
-out:
        mutex_unlock(&hdcp->mutex);
        return ret;
 }
@@ -1295,7 +1477,9 @@ int intel_hdcp_disable(struct intel_connector *connector)
 
        if (hdcp->value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
                hdcp->value = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
-               if (hdcp->hdcp_encrypted)
+               if (hdcp->hdcp2_encrypted)
+                       ret = _intel_hdcp2_disable(connector);
+               else if (hdcp->hdcp_encrypted)
                        ret = _intel_hdcp_disable(connector);
        }