drm/nouveau: create real execution engine for software object class

Just a cleanup more or less, and to remove the need for special handling of
software objects.

This removes a heap of documentation on dma/graph object formats.  The info
is very out of date with our current understanding, and is far better
documented in rnndb in envytools git.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_software.h b/drivers/gpu/drm/nouveau/nouveau_software.h
new file mode 100644
index 0000000..fe30a8f
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nouveau_software.h
@@ -0,0 +1,68 @@
+#ifndef __NOUVEAU_SOFTWARE_H__
+#define __NOUVEAU_SOFTWARE_H__
+
+struct nouveau_software_priv {
+	struct nouveau_exec_engine base;
+	struct list_head vblank;
+};
+
+struct nouveau_software_chan {
+	struct list_head flip;
+	struct {
+		struct list_head list;
+		struct nouveau_bo *bo;
+		u32 offset;
+		u32 value;
+		u32 head;
+	} vblank;
+};
+
+static inline void
+nouveau_software_vblank(struct drm_device *dev, int crtc)
+{
+	struct nouveau_software_priv *psw = nv_engine(dev, NVOBJ_ENGINE_SW);
+	struct nouveau_software_chan *pch, *tmp;
+
+	list_for_each_entry_safe(pch, tmp, &psw->vblank, vblank.list) {
+		if (pch->vblank.head != crtc)
+			continue;
+
+		nouveau_bo_wr32(pch->vblank.bo, pch->vblank.offset,
+						pch->vblank.value);
+		list_del(&pch->vblank.list);
+		drm_vblank_put(dev, crtc);
+	}
+}
+
+static inline void
+nouveau_software_context_new(struct nouveau_software_chan *pch)
+{
+	INIT_LIST_HEAD(&pch->flip);
+}
+
+static inline void
+nouveau_software_create(struct nouveau_software_priv *psw)
+{
+	INIT_LIST_HEAD(&psw->vblank);
+}
+
+static inline u16
+nouveau_software_class(struct drm_device *dev)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	if (dev_priv->card_type <= NV_04)
+		return 0x006e;
+	if (dev_priv->card_type <= NV_40)
+		return 0x016e;
+	if (dev_priv->card_type <= NV_50)
+		return 0x506e;
+	if (dev_priv->card_type <= NV_E0)
+		return 0x906e;
+	return 0x0000;
+}
+
+int nv04_software_create(struct drm_device *);
+int nv50_software_create(struct drm_device *);
+int nvc0_software_create(struct drm_device *);
+
+#endif