[Intel-gfx] [RFC 05/14] drm/i915/pxp: set KCR reg init during the boot time

[Daniele Ceraolo Spurio]

Set the KCR init during the boot time, which is required by hardware,
to allow us doing further protection operation such as sending commands
to GPU or TEE.

Signed-off-by: Huang, Sean Z <sean.z.huang at intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 drivers/gpu/drm/i915/pxp/intel_pxp.c | 29 +++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index 4ddc8a71a3e7..950daee5b907 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -6,6 +6,24 @@
 #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)
 {
 	struct intel_gt *gt = pxp_to_gt(pxp);
@@ -43,19 +61,28 @@ void intel_pxp_init(struct intel_pxp *pxp)
 	if (!HAS_PXP(gt->i915))
 		return;
 
+	kcr_pxp_enable(gt);
+
 	ret = create_vcs_context(pxp);
 	if (ret)
-		return;
+		goto out_kcr;
 
 	drm_info(&gt->i915->drm, "Protected Xe Path (PXP) protected content support initialized\n");
 
 	return;
+
+out_kcr:
+	kcr_pxp_disable(gt);
 }
 
 void intel_pxp_fini(struct intel_pxp *pxp)
 {
+	struct intel_gt *gt = pxp_to_gt(pxp);
+
 	if (!intel_pxp_is_enabled(pxp))
 		return;
 
 	destroy_vcs_context(pxp);
+
+	kcr_pxp_disable(gt);
 }
-- 
2.29.2