[PATCH v4 07/17] drm/i915/pxp: set KCR reg init

[Daniele Ceraolo Spurio]

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 at intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/pxp/intel_pxp.c     | 27 ++++++++++++++++++++++++
 drivers/gpu/drm/i915/pxp/intel_pxp.h     |  3 +++
 drivers/gpu/drm/i915/pxp/intel_pxp_tee.c |  5 +++++
 3 files changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index 5df2a09c9e4b..ab19d2a23ec2 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -7,6 +7,24 @@
 #include "gt/intel_context.h"
 #include "i915_drv.h"
 
+/* 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;
@@ -71,5 +89,14 @@ 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));
 }
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
index e87550fb9821..5427c3b28aa9 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
@@ -22,6 +22,9 @@ static inline bool intel_pxp_is_enabled(const struct intel_pxp *pxp)
 #ifdef CONFIG_DRM_I915_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)
 {
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
index 4ed234d8584f..dc0dcd040bf8 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
+++ b/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;
 }
 
-- 
2.29.2