drm/armada: avoid work allocation

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

drivers/gpu/drm/armada/armada_crtc.c

@@ -214,13 +214,15 @@ static void armada_drm_plane_work_call(struct armada_crtc *dcrtc,
 	void (*fn)(struct armada_crtc *, struct armada_plane_work *))
 {
 	struct armada_plane *dplane = drm_to_armada_plane(work->plane);
-	struct drm_pending_vblank_event *event = work->event;
-	struct drm_framebuffer *fb = work->old_fb;
+	struct drm_pending_vblank_event *event;
+	struct drm_framebuffer *fb;
 
 	if (fn)
 		fn(dcrtc, work);
 	drm_crtc_vblank_put(&dcrtc->crtc);
 
+	event = work->event;
+	fb = work->old_fb;
 	if (event || fb) {
 		struct drm_device *dev = dcrtc->crtc.dev;
 		unsigned long flags;
@@ -233,6 +235,9 @@ static void armada_drm_plane_work_call(struct armada_crtc *dcrtc,
 		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 
+	if (work->need_kfree)
+		kfree(work);
+
 	wake_up(&dplane->frame_wait);
 }
 
@@ -278,12 +283,6 @@ void armada_drm_plane_work_cancel(struct armada_crtc *dcrtc,
 		armada_drm_plane_work_call(dcrtc, work, work->cancel);
 }
 
-static void armada_drm_crtc_finish_frame_work(struct armada_crtc *dcrtc,
-	struct armada_plane_work *work)
-{
-	kfree(work);
-}
-
 static void armada_drm_crtc_complete_frame_work(struct armada_crtc *dcrtc,
 	struct armada_plane_work *work)
 {
@@ -292,8 +291,6 @@ static void armada_drm_crtc_complete_frame_work(struct armada_crtc *dcrtc,
 	spin_lock_irqsave(&dcrtc->irq_lock, flags);
 	armada_drm_crtc_update_regs(dcrtc, work->regs);
 	spin_unlock_irqrestore(&dcrtc->irq_lock, flags);
-
-	armada_drm_crtc_finish_frame_work(dcrtc, work);
 }
 
 static struct armada_plane_work *
@@ -308,7 +305,7 @@ armada_drm_crtc_alloc_plane_work(struct drm_plane *plane)
 
 	work->plane = plane;
 	work->fn = armada_drm_crtc_complete_frame_work;
-	work->cancel = armada_drm_crtc_finish_frame_work;
+	work->need_kfree = true;
 	armada_reg_queue_end(work->regs, i);
 
 	return work;
@@ -1173,6 +1170,11 @@ static const struct drm_plane_funcs armada_primary_plane_funcs = {
 
 int armada_drm_plane_init(struct armada_plane *plane)
 {
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(plane->works); i++)
+		plane->works[i].plane = &plane->base;
+
 	init_waitqueue_head(&plane->frame_wait);
 
 	return 0;

drivers/gpu/drm/armada/armada_crtc.h

@@ -38,6 +38,7 @@ struct armada_variant;
 struct armada_plane_work {
 	void (*fn)(struct armada_crtc *, struct armada_plane_work *);
 	void (*cancel)(struct armada_crtc *, struct armada_plane_work *);
+	bool need_kfree;
 	struct drm_plane *plane;
 	struct drm_framebuffer *old_fb;
 	struct drm_pending_vblank_event *event;
@@ -56,6 +57,8 @@ struct armada_plane_state {
 struct armada_plane {
 	struct drm_plane	base;
 	wait_queue_head_t	frame_wait;
+	bool			next_work;
+	struct armada_plane_work works[2];
 	struct armada_plane_work *work;
 	struct armada_plane_state state;
 };

drivers/gpu/drm/armada/armada_overlay.c

@@ -32,7 +32,6 @@ struct armada_ovl_plane_properties {
 
 struct armada_ovl_plane {
 	struct armada_plane base;
-	struct armada_plane_work work;
 	struct armada_ovl_plane_properties prop;
 };
 #define drm_to_armada_ovl_plane(p) \
@@ -85,7 +84,7 @@ armada_ovl_plane_update(struct drm_plane *plane, struct drm_crtc *crtc,
 {
 	struct armada_ovl_plane *dplane = drm_to_armada_ovl_plane(plane);
 	struct armada_crtc *dcrtc = drm_to_armada_crtc(crtc);
-	struct armada_plane_work *work = &dplane->work;
+	struct armada_plane_work *work;
 	const struct drm_format_info *format;
 	struct drm_plane_state state = {
 		.plane = plane,
@@ -119,6 +118,8 @@ armada_ovl_plane_update(struct drm_plane *plane, struct drm_crtc *crtc,
 	if (ret)
 		return ret;
 
+	work = &dplane->base.works[dplane->base.next_work];
+
 	ctrl0 = CFG_DMA_FMT(drm_fb_to_armada_fb(fb)->fmt) |
 		CFG_DMA_MOD(drm_fb_to_armada_fb(fb)->mod) |
 		CFG_CBSH_ENA;
@@ -248,6 +249,8 @@ armada_ovl_plane_update(struct drm_plane *plane, struct drm_crtc *crtc,
 		ret = armada_drm_plane_work_queue(dcrtc, work);
 		if (ret)
 			DRM_ERROR("failed to queue plane work: %d\n", ret);
+
+		dplane->base.next_work = !dplane->base.next_work;
 	}
 	return 0;
 }
@@ -434,8 +437,8 @@ int armada_overlay_plane_create(struct drm_device *dev, unsigned long crtcs)
 		return ret;
 	}
 
-	dplane->work.plane = &dplane->base.base;
-	dplane->work.fn = armada_ovl_plane_work;
+	dplane->base.works[0].fn = armada_ovl_plane_work;
+	dplane->base.works[1].fn = armada_ovl_plane_work;
 
 	ret = drm_universal_plane_init(dev, &dplane->base.base, crtcs,
 				       &armada_ovl_plane_funcs,