drm/msm: subclass drm_atomic_state

This will give the kms backends a slot to stash their own hw specific
global state.
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_atomic.c

@@ -241,6 +241,10 @@ int msm_atomic_commit(struct drm_device *dev,
 
 	drm_atomic_helper_swap_state(state, true);
 
+	/* swap driver private state while still holding state_lock */
+	if (to_kms_state(state)->state)
+		priv->kms->funcs->swap_state(priv->kms, state);
+
 	/*
 	 * Everything below can be run asynchronously without the need to grab
 	 * any modeset locks at all under one conditions: It must be guaranteed
@@ -271,3 +275,30 @@ int msm_atomic_commit(struct drm_device *dev,
 	drm_atomic_helper_cleanup_planes(dev, state);
 	return ret;
 }
+
+struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev)
+{
+	struct msm_kms_state *state = kzalloc(sizeof(*state), GFP_KERNEL);
+
+	if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
+		kfree(state);
+		return NULL;
+	}
+
+	return &state->base;
+}
+
+void msm_atomic_state_clear(struct drm_atomic_state *s)
+{
+	struct msm_kms_state *state = to_kms_state(s);
+	drm_atomic_state_default_clear(&state->base);
+	kfree(state->state);
+	state->state = NULL;
+}
+
+void msm_atomic_state_free(struct drm_atomic_state *state)
+{
+	kfree(to_kms_state(state)->state);
+	drm_atomic_state_default_release(state);
+	kfree(state);
+}

drivers/gpu/drm/msm/msm_drv.c

@@ -46,6 +46,9 @@ static const struct drm_mode_config_funcs mode_config_funcs = {
 	.output_poll_changed = msm_fb_output_poll_changed,
 	.atomic_check = msm_atomic_check,
 	.atomic_commit = msm_atomic_commit,
+	.atomic_state_alloc = msm_atomic_state_alloc,
+	.atomic_state_clear = msm_atomic_state_clear,
+	.atomic_state_free = msm_atomic_state_free,
 };
 
 int msm_register_address_space(struct drm_device *dev,

drivers/gpu/drm/msm/msm_drv.h

@@ -179,6 +179,9 @@ int msm_atomic_check(struct drm_device *dev,
 		     struct drm_atomic_state *state);
 int msm_atomic_commit(struct drm_device *dev,
 		struct drm_atomic_state *state, bool nonblock);
+struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev);
+void msm_atomic_state_clear(struct drm_atomic_state *state);
+void msm_atomic_state_free(struct drm_atomic_state *state);
 
 int msm_register_address_space(struct drm_device *dev,
 		struct msm_gem_address_space *aspace);

drivers/gpu/drm/msm/msm_kms.h

@@ -40,6 +40,8 @@ struct msm_kms_funcs {
 	irqreturn_t (*irq)(struct msm_kms *kms);
 	int (*enable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
 	void (*disable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
+	/* swap global atomic state: */
+	void (*swap_state)(struct msm_kms *kms, struct drm_atomic_state *state);
 	/* modeset, bracketing atomic_commit(): */
 	void (*prepare_commit)(struct msm_kms *kms, struct drm_atomic_state *state);
 	void (*complete_commit)(struct msm_kms *kms, struct drm_atomic_state *state);
@@ -65,6 +67,18 @@ struct msm_kms {
 	int irq;
 };
 
+/**
+ * Subclass of drm_atomic_state, to allow kms backend to have driver
+ * private global state.  The kms backend can do whatever it wants
+ * with the ->state ptr.  On ->atomic_state_clear() the ->state ptr
+ * is kfree'd and set back to NULL.
+ */
+struct msm_kms_state {
+	struct drm_atomic_state base;
+	void *state;
+};
+#define to_kms_state(x) container_of(x, struct msm_kms_state, base)
+
 static inline void msm_kms_init(struct msm_kms *kms,
 		const struct msm_kms_funcs *funcs)
 {