[FOR CI 4/5] drm/xe/display: Disable migration in the most critical section

[Maarten Lankhorst <dev@lankhorst.se>]

Lets see what happens if we only disable migration in the critical
section to ensure we do run as fast as possible without disabling
too much.

First attempt: Only disable migration.

Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
---
 drivers/gpu/drm/i915/display/intel_crtc.c   | 14 ++++++++++++++
 drivers/gpu/drm/i915/display/intel_cursor.c | 18 +++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_dmc.c    |  4 ++--
 drivers/gpu/drm/i915/display/intel_vblank.c | 13 ++++++++++---
 4 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index f34745b5ea497..6972850a1f7db 100644
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -569,6 +569,10 @@ void intel_pipe_update_start(struct intel_atomic_state *state,
 
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_disable();
+#ifndef I915
+	else
+		migrate_disable();
+#endif
 
 	crtc->debug.min_vbl = evade.min;
 	crtc->debug.max_vbl = evade.max;
@@ -588,6 +592,11 @@ void intel_pipe_update_start(struct intel_atomic_state *state,
 irq_disable:
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_disable();
+#ifndef I915
+	else
+		migrate_disable();
+#endif
+
 }
 
 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_VBLANK_EVADE)
@@ -733,8 +742,13 @@ void intel_pipe_update_end(struct intel_atomic_state *state,
 	if (!state->base.legacy_cursor_update)
 		intel_vrr_send_push(NULL, new_crtc_state);
 
+	/* Re-enable irqs here for !RT */
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_enable();
+#ifndef I915
+	else
+		migrate_enable();
+#endif
 
 	if (intel_vgpu_active(dev_priv))
 		goto out;
diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
index 780fcae77a984..08d56b9ea2526 100644
--- a/drivers/gpu/drm/i915/display/intel_cursor.c
+++ b/drivers/gpu/drm/i915/display/intel_cursor.c
@@ -912,6 +912,7 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 
 	intel_psr_lock(crtc_state);
 
+	bool vblanked = false;
 	if (!drm_WARN_ON(display->drm, drm_crtc_vblank_get(&crtc->base))) {
 		/*
 		 * TODO: maybe check if we're still in PSR
@@ -921,13 +922,21 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 
 		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 			local_irq_disable();
+#ifndef I915
+		else
+			migrate_disable();
+#endif
 
 		intel_vblank_evade(&evade);
 
-		drm_crtc_vblank_put(&crtc->base);
+		vblanked = true;
 	} else {
 		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 			local_irq_disable();
+#ifndef I915
+		else
+			migrate_disable();
+#endif
 	}
 
 	if (new_plane_state->uapi.visible) {
@@ -939,6 +948,10 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_enable();
+#ifndef I915
+	else
+		migrate_enable();
+#endif
 
 	intel_psr_unlock(crtc_state);
 
@@ -955,6 +968,9 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 		intel_plane_unpin_fb(old_plane_state);
 	}
 
+	if (vblanked)
+		drm_crtc_vblank_put(&crtc->base);
+
 out_free:
 	if (new_crtc_state)
 		intel_crtc_destroy_state(&crtc->base, &new_crtc_state->uapi);
diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
index be6d37ea1139a..239b6565105ea 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc.c
@@ -604,7 +604,7 @@ static void dmc_load_program(struct intel_display *display, enum intel_dmc_id dm
 
 	disable_all_event_handlers(display, dmc_id);
 
-	preempt_disable();
+	migrate_disable();
 
 	for (i = 0; i < dmc->dmc_info[dmc_id].dmc_fw_size; i++) {
 		intel_de_write_fw(display,
@@ -612,7 +612,7 @@ static void dmc_load_program(struct intel_display *display, enum intel_dmc_id dm
 				  dmc->dmc_info[dmc_id].payload[i]);
 	}
 
-	preempt_enable();
+	migrate_enable();
 
 	dmc_load_mmio(display, dmc_id);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c b/drivers/gpu/drm/i915/display/intel_vblank.c
index 7826f29619a14..6576088a6c6d8 100644
--- a/drivers/gpu/drm/i915/display/intel_vblank.c
+++ b/drivers/gpu/drm/i915/display/intel_vblank.c
@@ -387,7 +387,7 @@ static bool i915_get_crtc_scanoutpos(struct drm_crtc *_crtc,
 	intel_vblank_section_enter_irqf(display, &irqflags);
 
 	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+		migrate_disable();
 
 	/* Get optional system timestamp before query. */
 	if (stime)
@@ -452,7 +452,7 @@ static bool i915_get_crtc_scanoutpos(struct drm_crtc *_crtc,
 		*etime = ktime_get();
 
 	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+		migrate_enable();
 
 	intel_vblank_section_exit_irqf(display, irqflags);
 
@@ -763,11 +763,18 @@ int intel_vblank_evade(struct intel_vblank_evade_ctx *evade)
 
 		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 			local_irq_enable();
+#ifndef I915
+		else
+			migrate_enable();
+#endif
 
 		timeout = schedule_timeout(timeout);
-
 		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 			local_irq_disable();
+#ifndef I915
+		else
+			migrate_disable();
+#endif
 	}
 
 	finish_wait(wq, &wait);
-- 
2.51.0