[Intel-gfx] [PATCH] drm/i915: Check fb stride against plane max stride

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

commit 4e0b83a567e2 ("drm/i915: Extract per-platform plane->check()
functions") removed the plane max stride check for sprite planes.
I was going to add it back when introducing GTT remapping for the
display, but after further thought it seems better to re-introduce
it separately.

So let's add the max stride check back. And let's do it in a nicer
form than what we had before and do it for all plane types (easy
now that we have the ->max_stride() plane vfunc).

Only sprite planes really need this for now since primary planes
are capable of scanning out the current max fb size we allow, and
cursors have more stringent stride checks elsewhere.

Cc: José Roberto de Souza <jose.souza at intel.com>
Fixes: 4e0b83a567e2 ("drm/i915: Extract per-platform plane->check() functions")
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 14 ++++++++++++++
 drivers/gpu/drm/i915/intel_drv.h     |  1 +
 drivers/gpu/drm/i915/intel_sprite.c  | 22 ++++++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index eb25037d7b38..1eb99d5ec221 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3151,6 +3151,10 @@ int skl_check_plane_surface(struct intel_plane_state *plane_state)
 	plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0, rotation);
 	plane_state->color_plane[1].stride = intel_fb_pitch(fb, 1, rotation);
 
+	ret = intel_plane_check_stride(plane_state);
+	if (ret)
+		return ret;
+
 	if (!plane_state->base.visible)
 		return 0;
 
@@ -3286,10 +3290,15 @@ int i9xx_check_plane_surface(struct intel_plane_state *plane_state)
 	int src_x = plane_state->base.src.x1 >> 16;
 	int src_y = plane_state->base.src.y1 >> 16;
 	u32 offset;
+	int ret;
 
 	intel_fill_fb_ggtt_view(&plane_state->view, fb, rotation);
 	plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0, rotation);
 
+	ret = intel_plane_check_stride(plane_state);
+	if (ret)
+		return ret;
+
 	intel_add_fb_offsets(&src_x, &src_y, plane_state, 0);
 
 	if (INTEL_GEN(dev_priv) >= 4)
@@ -9685,10 +9694,15 @@ static int intel_cursor_check_surface(struct intel_plane_state *plane_state)
 	unsigned int rotation = plane_state->base.rotation;
 	int src_x, src_y;
 	u32 offset;
+	int ret;
 
 	intel_fill_fb_ggtt_view(&plane_state->view, fb, rotation);
 	plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0, rotation);
 
+	ret = intel_plane_check_stride(plane_state);
+	if (ret)
+		return ret;
+
 	src_x = plane_state->base.src_x >> 16;
 	src_y = plane_state->base.src_y >> 16;
 
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index bf1c38728a59..a34c2f1f9159 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -2140,6 +2140,7 @@ unsigned int skl_plane_max_stride(struct intel_plane *plane,
 				  unsigned int rotation);
 int skl_plane_check(struct intel_crtc_state *crtc_state,
 		    struct intel_plane_state *plane_state);
+int intel_plane_check_stride(const struct intel_plane_state *plane_state);
 int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state);
 int chv_plane_check_rotation(const struct intel_plane_state *plane_state);
 
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index d4c8e10fc90b..5fd2f7bf3927 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -230,6 +230,28 @@ void intel_pipe_update_end(struct intel_crtc_state *new_crtc_state)
 #endif
 }
 
+int intel_plane_check_stride(const struct intel_plane_state *plane_state)
+{
+	struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
+	const struct drm_framebuffer *fb = plane_state->base.fb;
+	unsigned int rotation = plane_state->base.rotation;
+	u32 stride, max_stride;
+
+	/* FIXME other color planes? */
+	stride = plane_state->color_plane[0].stride;
+	max_stride = plane->max_stride(plane, fb->format->format,
+				       fb->modifier, rotation);
+
+	if (stride > max_stride) {
+		DRM_DEBUG_KMS("[FB:%d] stride (%d) exceeds [PLANE:%d:%s] max stride (%d)\n",
+			      fb->base.id, stride,
+			      plane->base.base.id, plane->base.name, max_stride);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state)
 {
 	const struct drm_framebuffer *fb = plane_state->base.fb;
-- 
2.16.4