[PATCH v6 13/15] drm/i915/pxp: Add plane decryption support

[Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>]

From: Anshuman Gupta <anshuman.gupta@intel.com>

Add support to enable/disable PLANE_SURF Decryption Request bit.
It requires only to enable plane decryption support when following
condition met.
1. PXP session is enabled.
2. Buffer object is protected.

v2:
- Used gen fb obj user_flags instead gem_object_metadata. [Krishna]

v3:
- intel_pxp_gem_object_status() API changes.

v4: use intel_pxp_is_active (Daniele)

v5: rebase and use the new protected object status checker (Daniele)

v6: used plane state for plane_decryption to handle async flip
    as suggested by Ville.

v7: check pxp session while plane decrypt state computation. [Ville]
    removed pointless code. [Ville]

v8 (Daniele): update PXP check

Cc: Bommu Krishnaiah <krishnaiah.bommu@intel.com>
Cc: Huang Sean Z <sean.z.huang@intel.com>
Cc: Gaurav Kumar <kumar.gaurav@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
---
 .../gpu/drm/i915/display/intel_atomic_plane.c    | 16 ++++++++++++++++
 drivers/gpu/drm/i915/display/intel_display.c     |  4 ++++
 .../gpu/drm/i915/display/intel_display_types.h   |  3 +++
 .../gpu/drm/i915/display/skl_universal_plane.c   | 15 ++++++++++++---
 drivers/gpu/drm/i915/i915_reg.h                  |  1 +
 5 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
index 47234d898549..3f605a666ea8 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
@@ -41,6 +41,7 @@
 #include "intel_display_types.h"
 #include "intel_pm.h"
 #include "intel_sprite.h"
+#include "pxp/intel_pxp.h"
 
 static void intel_plane_state_reset(struct intel_plane_state *plane_state,
 				    struct intel_plane *plane)
@@ -383,6 +384,14 @@ intel_crtc_get_plane(struct intel_crtc *crtc, enum plane_id plane_id)
 	return NULL;
 }
 
+static int bo_has_valid_encryption(const struct drm_i915_gem_object *obj)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+
+	return i915_gem_object_has_valid_protection(obj) &&
+	       intel_pxp_is_active(&i915->gt.pxp);
+}
+
 int intel_plane_atomic_check(struct intel_atomic_state *state,
 			     struct intel_plane *plane)
 {
@@ -397,6 +406,7 @@ int intel_plane_atomic_check(struct intel_atomic_state *state,
 		intel_atomic_get_old_crtc_state(state, crtc);
 	struct intel_crtc_state *new_crtc_state =
 		intel_atomic_get_new_crtc_state(state, crtc);
+	const struct drm_framebuffer *fb;
 
 	if (new_crtc_state && new_crtc_state->bigjoiner_slave) {
 		struct intel_plane *master_plane =
@@ -413,6 +423,12 @@ int intel_plane_atomic_check(struct intel_atomic_state *state,
 					  new_master_plane_state,
 					  crtc);
 
+	fb = new_plane_state->hw.fb;
+	if (fb)
+		new_plane_state->decrypt = bo_has_valid_encryption(intel_fb_obj(fb));
+	else
+		new_plane_state->decrypt = old_plane_state->decrypt;
+
 	new_plane_state->uapi.visible = false;
 	if (!new_crtc_state)
 		return 0;
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 97a216edf600..eca645900770 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -9891,6 +9891,10 @@ static int intel_atomic_check_async(struct intel_atomic_state *state)
 			drm_dbg_kms(&i915->drm, "Color range cannot be changed in async flip\n");
 			return -EINVAL;
 		}
+
+		/* plane decryption is allow to change only in synchronous flips */
+		if (old_plane_state->decrypt != new_plane_state->decrypt)
+			return -EINVAL;
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 34ec83fc7167..24f06cdf3340 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -629,6 +629,9 @@ struct intel_plane_state {
 
 	struct intel_fb_view view;
 
+	/* Plane pxp decryption state */
+	bool decrypt;
+
 	/* plane control register */
 	u32 ctl;
 
diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
index 3ad04bf2a0fd..06df634c216f 100644
--- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
+++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
@@ -18,6 +18,7 @@
 #include "intel_sprite.h"
 #include "skl_scaler.h"
 #include "skl_universal_plane.h"
+#include "pxp/intel_pxp.h"
 
 static const u32 skl_plane_formats[] = {
 	DRM_FORMAT_C8,
@@ -1024,7 +1025,7 @@ skl_program_plane(struct intel_plane *plane,
 	u8 alpha = plane_state->hw.alpha >> 8;
 	u32 plane_color_ctl = 0, aux_dist = 0;
 	unsigned long irqflags;
-	u32 keymsk, keymax;
+	u32 keymsk, keymax, plane_surf;
 	u32 plane_ctl = plane_state->ctl;
 
 	plane_ctl |= skl_plane_ctl_crtc(crtc_state);
@@ -1113,8 +1114,16 @@ skl_program_plane(struct intel_plane *plane,
 	 * the control register just before the surface register.
 	 */
 	intel_de_write_fw(dev_priv, PLANE_CTL(pipe, plane_id), plane_ctl);
-	intel_de_write_fw(dev_priv, PLANE_SURF(pipe, plane_id),
-			  intel_plane_ggtt_offset(plane_state) + surf_addr);
+	plane_surf = intel_plane_ggtt_offset(plane_state) + surf_addr;
+
+	/*
+	 * FIXME: pxp session invalidation can hit any time even at time of commit
+	 * or after the commit, display content will be garbage.
+	 */
+	if (plane_state->decrypt)
+		plane_surf |= PLANE_SURF_DECRYPT;
+
+	intel_de_write_fw(dev_priv, PLANE_SURF(pipe, plane_id), plane_surf);
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 1a2a71916dfc..4f4fdd59ecfc 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7345,6 +7345,7 @@ enum {
 #define _PLANE_SURF_3(pipe)	_PIPE(pipe, _PLANE_SURF_3_A, _PLANE_SURF_3_B)
 #define PLANE_SURF(pipe, plane)	\
 	_MMIO_PLANE(plane, _PLANE_SURF_1(pipe), _PLANE_SURF_2(pipe))
+#define   PLANE_SURF_DECRYPT			REG_BIT(2)
 
 #define _PLANE_OFFSET_1_B			0x711a4
 #define _PLANE_OFFSET_2_B			0x712a4
-- 
2.32.0