drm/i915: Use the same vblank worker for atomic unpin

In case of legacy cursor update, the cursor VMA needs to be unpinned
only after vblank. This exceeds the lifetime of the whole atomic commit.

Any trick I attempted to keep the atomic commit alive didn't work, as
drm_atomic_helper_setup_commit() force throttles on any old commit that
wasn't cleaned up.

The only option remaining is to remove the plane from the atomic commit,
and use the same path as the legacy cursor update to clean the state
after vblank.

Changes since previous version:
- Call the memset for plane state immediately when scheduling vblank,
  this prevents a use-after-free in cursor cleanup.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522053341.137592-4-maarten.lankhorst@linux.intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
index 79244ea06b9af64805296bbc8ba047166b09d3a3..e979786aa5cf3db543a2fb234ae5361b982a956b 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
@@ -43,6 +43,7 @@
 #include "i9xx_plane_regs.h"
 #include "intel_atomic_plane.h"
 #include "intel_cdclk.h"
+#include "intel_cursor.h"
 #include "intel_display_rps.h"
 #include "intel_display_trace.h"
 #include "intel_display_types.h"
@@ -1201,7 +1202,6 @@ intel_cleanup_plane_fb(struct drm_plane *plane,
 
        intel_display_rps_mark_interactive(dev_priv, state, false);
 
-       /* Should only be called after a successful intel_prepare_plane_fb()! */
        intel_plane_unpin_fb(old_plane_state);
 }
 
@@ -1214,3 +1214,14 @@ void intel_plane_helper_add(struct intel_plane *plane)
 {
        drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
 }
+
+void intel_plane_init_cursor_vblank_work(struct intel_plane_state *old_plane_state,
+                                        struct intel_plane_state *new_plane_state)
+{
+       if (!old_plane_state->ggtt_vma ||
+           old_plane_state->ggtt_vma == new_plane_state->ggtt_vma)
+               return;
+
+       drm_vblank_work_init(&old_plane_state->unpin_work, old_plane_state->uapi.crtc,
+                            intel_cursor_unpin_work);
+}

diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.h b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
index 84541d97c67befabdd3b3cfcd11f93a14deec035..6c4fe359646504b1f47dd0433212dfb9be84588d 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.h
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.h
@@ -71,5 +71,7 @@ void intel_plane_set_invisible(struct intel_crtc_state *crtc_state,
                               struct intel_plane_state *plane_state);
 void intel_plane_helper_add(struct intel_plane *plane);
 bool intel_plane_needs_physical(struct intel_plane *plane);
+void intel_plane_init_cursor_vblank_work(struct intel_plane_state *old_plane_state,
+                                        struct intel_plane_state *new_plane_state);
 
 #endif /* __INTEL_ATOMIC_PLANE_H__ */

diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index a2b8953d728351606387270992faa05b49ed65a9..1b578cad2813468cf9b7d61d936974c2304e118c 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -496,6 +496,19 @@ void intel_pipe_update_start(struct intel_atomic_state *state,
        if (intel_crtc_needs_vblank_work(new_crtc_state))
                intel_crtc_vblank_work_init(new_crtc_state);
 
+       if (state->base.legacy_cursor_update) {
+               struct intel_plane *plane;
+               struct intel_plane_state *old_plane_state, *new_plane_state;
+               int i;
+
+               for_each_oldnew_intel_plane_in_state(state, plane, old_plane_state,
+                                                    new_plane_state, i) {
+                       if (old_plane_state->uapi.crtc == &crtc->base)
+                               intel_plane_init_cursor_vblank_work(old_plane_state,
+                                                                   new_plane_state);
+               }
+       }
+
        intel_vblank_evade_init(old_crtc_state, new_crtc_state, &evade);
 
        if (drm_WARN_ON(&dev_priv->drm, drm_crtc_vblank_get(&crtc->base)))
@@ -621,6 +634,24 @@ void intel_pipe_update_end(struct intel_atomic_state *state,
                intel_crtc_arm_vblank_event(new_crtc_state);
        }
 
+       if (state->base.legacy_cursor_update) {
+               struct intel_plane *plane;
+               struct intel_plane_state *old_plane_state;
+               int i;
+
+               for_each_old_intel_plane_in_state(state, plane, old_plane_state, i) {
+                       if (old_plane_state->uapi.crtc == &crtc->base &&
+                           old_plane_state->unpin_work.vblank) {
+                               drm_vblank_work_schedule(&old_plane_state->unpin_work,
+                                                        drm_crtc_accurate_vblank_count(&crtc->base) + 1,
+                                                        false);
+
+                               /* Remove plane from atomic state, cleanup/free is done from vblank worker. */
+                               memset(&state->base.planes[i], 0, sizeof(state->base.planes[i]));
+                       }
+               }
+       }
+
        /*
         * Send VRR Push to terminate Vblank. If we are already in vblank
         * this has to be done _after_ sampling the frame counter, as

diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
index 1c5bc3cf4a6883ee51722574f139155d49e849ef..9ad53e1cbbd063e117446d042fea78f37a540ee4 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_cursor.c
+++ b/drivers/gpu/drm/i915/display/intel_cursor.c
@@ -761,7 +761,7 @@ static bool intel_cursor_format_mod_supported(struct drm_plane *_plane,
        return format == DRM_FORMAT_ARGB8888;
 }
 
-static void intel_cursor_unpin_work(struct kthread_work *base)
+void intel_cursor_unpin_work(struct kthread_work *base)
 {
        struct drm_vblank_work *work = to_drm_vblank_work(base);
        struct intel_plane_state *plane_state =

diff --git a/drivers/gpu/drm/i915/display/intel_cursor.h b/drivers/gpu/drm/i915/display/intel_cursor.h
index ce333bf4c2d5596742f11dd2623693b23050a790..e2d9ec710a864961324ce6a164aeb168e4c82a1d 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_cursor.h
+++ b/drivers/gpu/drm/i915/display/intel_cursor.h
@@ -9,9 +9,12 @@
 enum pipe;
 struct drm_i915_private;
 struct intel_plane;
+struct kthread_work;
 
 struct intel_plane *
 intel_cursor_plane_create(struct drm_i915_private *dev_priv,
                          enum pipe pipe);
 
+void intel_cursor_unpin_work(struct kthread_work *base);
+
 #endif