[Intel-gfx] [RFC 13/14] drm/i915/pxp: Add plane decryption support

[Daniele Ceraolo Spurio]

From: Anshuman Gupta <anshuman.gupta at 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)

Cc: Bommu Krishnaiah <krishnaiah.bommu at intel.com>
Cc: Huang Sean Z <sean.z.huang at intel.com>
Cc: Gaurav Kumar <kumar.gaurav at intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 drivers/gpu/drm/i915/display/intel_sprite.c | 21 ++++++++++++++++++---
 drivers/gpu/drm/i915/i915_reg.h             |  1 +
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
index 402030251c64..77156d38c7e3 100644
--- a/drivers/gpu/drm/i915/display/intel_sprite.c
+++ b/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -39,6 +39,8 @@
 #include <drm/drm_plane_helper.h>
 #include <drm/drm_rect.h>
 
+#include "pxp/intel_pxp.h"
+
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include "i915_vgpu.h"
@@ -738,6 +740,11 @@ icl_program_input_csc(struct intel_plane *plane,
 			  PLANE_INPUT_CSC_POSTOFF(pipe, plane_id, 2), 0x0);
 }
 
+static bool intel_fb_obj_protected(const struct drm_i915_gem_object *obj)
+{
+	return obj->user_flags & I915_BO_PROTECTED ? true : false;
+}
+
 static void
 skl_plane_async_flip(struct intel_plane *plane,
 		     const struct intel_crtc_state *crtc_state,
@@ -778,6 +785,7 @@ skl_program_plane(struct intel_plane *plane,
 	u32 surf_addr = plane_state->color_plane[color_plane].offset;
 	u32 stride = skl_plane_stride(plane_state, color_plane);
 	const struct drm_framebuffer *fb = plane_state->hw.fb;
+	const struct drm_i915_gem_object *obj = intel_fb_obj(fb);
 	int aux_plane = intel_main_to_aux_plane(fb, color_plane);
 	int crtc_x = plane_state->uapi.dst.x1;
 	int crtc_y = plane_state->uapi.dst.y1;
@@ -788,7 +796,7 @@ 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);
@@ -868,8 +876,15 @@ 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;
+
+	if (intel_pxp_is_active(&dev_priv->gt.pxp) &&
+	    intel_fb_obj_protected(obj))
+		plane_surf |= PLANE_SURF_DECRYPTION_ENABLED;
+	else
+		plane_surf &= ~PLANE_SURF_DECRYPTION_ENABLED;
+
+	intel_de_write_fw(dev_priv, PLANE_SURF(pipe, plane_id), plane_surf);
 
 	if (plane_state->scaler_id >= 0)
 		skl_program_scaler(plane, crtc_state, plane_state);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0dcc04c7d2d8..6cb1283b4eed 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7223,6 +7223,7 @@ 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_DECRYPTION_ENABLED		REG_BIT(2)
 
 #define _PLANE_OFFSET_1_B			0x711a4
 #define _PLANE_OFFSET_2_B			0x712a4
-- 
2.29.2