Now that all the pieces are in place we can add a description of how the feature works. Also modify the comments in struct intel_pxp into kerneldoc.
Signed-off-by: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Rodrigo Vivi rodrigo.vivi@intel.com --- Documentation/gpu/i915.rst | 8 ++++ drivers/gpu/drm/i915/pxp/intel_pxp.c | 28 +++++++++++++ drivers/gpu/drm/i915/pxp/intel_pxp_types.h | 47 ++++++++++++++++------ 3 files changed, 71 insertions(+), 12 deletions(-)
diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst index 101dde3eb1ea..78ecb9d5ec20 100644 --- a/Documentation/gpu/i915.rst +++ b/Documentation/gpu/i915.rst @@ -471,6 +471,14 @@ Object Tiling IOCTLs .. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_tiling.c :doc: buffer object tiling
+Protected Objects +----------------- + +.. kernel-doc:: drivers/gpu/drm/i915/pxp/intel_pxp.c + :doc: PXP + +.. kernel-doc:: drivers/gpu/drm/i915/pxp/intel_pxp_types.h + Microcontrollers ================
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c index d8815e91e091..4e095a9a9f07 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp.c +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c @@ -11,6 +11,34 @@ #include "gt/intel_context.h" #include "i915_drv.h"
+/** + * DOC: PXP + * + * PXP (Protected Xe Path) is a Gen12+ feature that allows execution and + * flip to display of protected (i.e. encrypted) objects. The SW support is + * enabled via the CONFIG_DRM_I915_PXP kconfig. + * + * Some of the PXP setup operations are performed by the Management Engine, + * which is handled by the mei driver; communication between i915 and mei is + * performed via the mei_pxp component module. + * + * Objects can opt-in to PXP encryption at creation time via the + * I915_GEM_CREATE_EXT_PROTECTED_CONTENT create_ext flag. For objects to be + * correctly protected they must be used in conjunction with a context created + * with the I915_CONTEXT_PARAM_PROTECTED_CONTENT flag. See the documentation + * of those two uapi flags for details and restrictions. + * + * Protected objects are tied to a pxp session; currently we only support one + * session, which i915 manages and whose index is available in the uapi + * (I915_PROTECTED_CONTENT_DEFAULT_SESSION) for use in instructions targeting + * protected objects. + * The session is invalidated by the HW when certain events occur (e.g. + * suspend/resume). When this happens, all the objects that were used with the + * session are marked as invalid and all contexts marked as using protected + * content are banned. Any further attempt at using them in an execbuf call is + * rejected, while flips are converted to black frames. + */ + /* KCR register definitions */ #define KCR_INIT _MMIO(0x320f0)
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h index ae24064bb57e..73ef7d1754e1 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h @@ -16,42 +16,65 @@ struct intel_context; struct i915_pxp_component;
+/** + * struct intel_pxp - pxp state + */ struct intel_pxp { + /** + * @pxp_component: i915_pxp_component struct of the bound mei_pxp + * module. Only set and cleared inside component bind/unbind functions, + * which are protected by &tee_mutex. + */ struct i915_pxp_component *pxp_component; + /** + * @pxp_component_added: track if the pxp component has been added. + * Set and cleared in tee init and fini functions respectively. + */ bool pxp_component_added;
+ /** @ce: kernel-owned context used for PXP operations */ struct intel_context *ce;
- /* + /** @arb_mutex: protects arb session start */ + struct mutex arb_mutex; + /** + * @arb_is_valid: tracks arb session status. * After a teardown, the arb session can still be in play on the HW * even if the keys are gone, so we can't rely on the HW state of the * session to know if it's valid and need to track the status in SW. */ - struct mutex arb_mutex; /* protects arb session start */ bool arb_is_valid;
- /* - * Keep track of which key instance we're on, so we can use it to - * determine if an object was created using the current key or a + /** + * @key_instance: tracks which key instance we're on, so we can use it + * to determine if an object was created using the current key or a * previous one. */ u32 key_instance;
- struct mutex tee_mutex; /* protects the tee channel binding */ + /** @tee_mutex: protects the tee channel binding and messaging. */ + struct mutex tee_mutex;
- /* - * If the HW perceives an attack on the integrity of the encryption it - * will invalidate the keys and expect SW to re-initialize the session. - * We keep track of this state to make sure we only re-start the arb - * session when required. + /** + * @hw_state_invalidated: if the HW perceives an attack on the integrity + * of the encryption it will invalidate the keys and expect SW to + * re-initialize the session. We keep track of this state to make sure + * we only re-start the arb session when required. */ bool hw_state_invalidated;
+ /** @irq_enabled: tracks the status of the kcr irqs */ bool irq_enabled; + /** + * @termination: tracks the status of a pending termination. Only + * re-initialized under gt->irq_lock and completed in &session_work. + */ struct completion termination;
+ /** @session_work: worker that manages session events. */ struct work_struct session_work; - u32 session_events; /* protected with gt->irq_lock */ + /** @session_events: pending session events, protected with gt->irq_lock. */ + u32 session_events; #define PXP_TERMINATION_REQUEST BIT(0) #define PXP_TERMINATION_COMPLETE BIT(1) #define PXP_INVAL_REQUIRED BIT(2)