drm/i915/pxp: set KCR reg init

The setting is required by hardware to allow us doing further protection
operation such as sending commands to GPU or TEE. The register needs to
be re-programmed on resume, so for simplicitly we bundle the programming
with the component binding, which is automatically called on resume.

Further HW set-up operations will be added in the same location in
follow-up patches, so get ready for them by using a couple of
init/fini_hw wrappers instead of calling the KCR funcs directly.

v3: move programming to component binding function, rework commit msg

Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924191452.1539378-7-alan.previn.teres.alexis@intel.com

drivers/gpu/drm/i915/pxp/intel_pxp.c

@@ -12,6 +12,23 @@ struct intel_gt *pxp_to_gt(const struct intel_pxp *pxp)
 	return container_of(pxp, struct intel_gt, pxp);
 }
 
+/* KCR register definitions */
+#define KCR_INIT _MMIO(0x320f0)
+/* Setting KCR Init bit is required after system boot */
+#define KCR_INIT_ALLOW_DISPLAY_ME_WRITES REG_BIT(14)
+
+static void kcr_pxp_enable(struct intel_gt *gt)
+{
+	intel_uncore_write(gt->uncore, KCR_INIT,
+			   _MASKED_BIT_ENABLE(KCR_INIT_ALLOW_DISPLAY_ME_WRITES));
+}
+
+static void kcr_pxp_disable(struct intel_gt *gt)
+{
+	intel_uncore_write(gt->uncore, KCR_INIT,
+			   _MASKED_BIT_DISABLE(KCR_INIT_ALLOW_DISPLAY_ME_WRITES));
+}
+
 static int create_vcs_context(struct intel_pxp *pxp)
 {
 	static struct lock_class_key pxp_lock;
@@ -79,5 +96,14 @@ void intel_pxp_fini(struct intel_pxp *pxp)
 	intel_pxp_tee_component_fini(pxp);
 
 	destroy_vcs_context(pxp);
-
+}
+
+void intel_pxp_init_hw(struct intel_pxp *pxp)
+{
+	kcr_pxp_enable(pxp_to_gt(pxp));
+}
+
+void intel_pxp_fini_hw(struct intel_pxp *pxp)
+{
+	kcr_pxp_disable(pxp_to_gt(pxp));
 }

drivers/gpu/drm/i915/pxp/intel_pxp.h

@@ -17,6 +17,9 @@ static inline bool intel_pxp_is_enabled(const struct intel_pxp *pxp)
 struct intel_gt *pxp_to_gt(const struct intel_pxp *pxp);
 void intel_pxp_init(struct intel_pxp *pxp);
 void intel_pxp_fini(struct intel_pxp *pxp);
+
+void intel_pxp_init_hw(struct intel_pxp *pxp);
+void intel_pxp_fini_hw(struct intel_pxp *pxp);
 #else
 static inline void intel_pxp_init(struct intel_pxp *pxp)
 {

drivers/gpu/drm/i915/pxp/intel_pxp_tee.c

@@ -33,6 +33,9 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev,
 	pxp->pxp_component = data;
 	pxp->pxp_component->tee_dev = tee_kdev;
 
+	/* the component is required to fully start the PXP HW */
+	intel_pxp_init_hw(pxp);
+
 	return 0;
 }
 
@@ -41,6 +44,8 @@ static void i915_pxp_tee_component_unbind(struct device *i915_kdev,
 {
 	struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
 
+	intel_pxp_fini_hw(pxp);
+
 	pxp->pxp_component = NULL;
 }