drm/nouveau/fence: convert to exec engine, and improve channel sync

Now have a somewhat simpler semaphore sync implementation for nv17:nv84,
and a switched to using semaphores as fences on nv84+ and making use of
the hardware's >= acquire operation.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nvc0_fence.c b/drivers/gpu/drm/nouveau/nvc0_fence.c
new file mode 100644
index 0000000..41545f1
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvc0_fence.c
@@ -0,0 +1,182 @@
+/*
+ * Copyright 2012 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+
+#include "drmP.h"
+#include "nouveau_drv.h"
+#include "nouveau_dma.h"
+#include "nouveau_ramht.h"
+#include "nouveau_fence.h"
+
+struct nvc0_fence_priv {
+	struct nouveau_fence_priv base;
+	struct nouveau_bo *bo;
+};
+
+struct nvc0_fence_chan {
+	struct nouveau_fence_chan base;
+	struct nouveau_vma vma;
+};
+
+static int
+nvc0_fence_emit(struct nouveau_fence *fence)
+{
+	struct nouveau_channel *chan = fence->channel;
+	struct nvc0_fence_chan *fctx = chan->engctx[NVOBJ_ENGINE_FENCE];
+	u64 addr = fctx->vma.offset + chan->id * 16;
+	int ret;
+
+	ret = RING_SPACE(chan, 5);
+	if (ret == 0) {
+		BEGIN_NVC0(chan, 0, NV84_SUBCHAN_SEMAPHORE_ADDRESS_HIGH, 4);
+		OUT_RING  (chan, upper_32_bits(addr));
+		OUT_RING  (chan, lower_32_bits(addr));
+		OUT_RING  (chan, fence->sequence);
+		OUT_RING  (chan, NV84_SUBCHAN_SEMAPHORE_TRIGGER_WRITE_LONG);
+		FIRE_RING (chan);
+	}
+
+	return ret;
+}
+
+static int
+nvc0_fence_sync(struct nouveau_fence *fence, struct nouveau_channel *chan)
+{
+	struct nvc0_fence_chan *fctx = chan->engctx[NVOBJ_ENGINE_FENCE];
+	u64 addr = fctx->vma.offset + fence->channel->id * 16;
+	int ret;
+
+	ret = RING_SPACE(chan, 5);
+	if (ret == 0) {
+		BEGIN_NVC0(chan, 0, NV84_SUBCHAN_SEMAPHORE_ADDRESS_HIGH, 4);
+		OUT_RING  (chan, upper_32_bits(addr));
+		OUT_RING  (chan, lower_32_bits(addr));
+		OUT_RING  (chan, fence->sequence);
+		OUT_RING  (chan, NV84_SUBCHAN_SEMAPHORE_TRIGGER_ACQUIRE_GEQUAL |
+				 NVC0_SUBCHAN_SEMAPHORE_TRIGGER_YIELD);
+		FIRE_RING (chan);
+	}
+
+	return ret;
+}
+
+static u32
+nvc0_fence_read(struct nouveau_channel *chan)
+{
+	struct nvc0_fence_priv *priv = nv_engine(chan->dev, NVOBJ_ENGINE_FENCE);
+	return nouveau_bo_rd32(priv->bo, chan->id * 16/4);
+}
+
+static void
+nvc0_fence_context_del(struct nouveau_channel *chan, int engine)
+{
+	struct nvc0_fence_priv *priv = nv_engine(chan->dev, engine);
+	struct nvc0_fence_chan *fctx = chan->engctx[engine];
+
+	nouveau_bo_vma_del(priv->bo, &fctx->vma);
+	nouveau_fence_context_del(&fctx->base);
+	chan->engctx[engine] = NULL;
+	kfree(fctx);
+}
+
+static int
+nvc0_fence_context_new(struct nouveau_channel *chan, int engine)
+{
+	struct nvc0_fence_priv *priv = nv_engine(chan->dev, engine);
+	struct nvc0_fence_chan *fctx;
+	int ret;
+
+	fctx = chan->engctx[engine] = kzalloc(sizeof(*fctx), GFP_KERNEL);
+	if (!fctx)
+		return -ENOMEM;
+
+	nouveau_fence_context_new(&fctx->base);
+
+	ret = nouveau_bo_vma_add(priv->bo, chan->vm, &fctx->vma);
+	if (ret)
+		nvc0_fence_context_del(chan, engine);
+
+	nouveau_bo_wr32(priv->bo, chan->id * 16/4, 0x00000000);
+	return ret;
+}
+
+static int
+nvc0_fence_fini(struct drm_device *dev, int engine, bool suspend)
+{
+	return 0;
+}
+
+static int
+nvc0_fence_init(struct drm_device *dev, int engine)
+{
+	return 0;
+}
+
+static void
+nvc0_fence_destroy(struct drm_device *dev, int engine)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	struct nvc0_fence_priv *priv = nv_engine(dev, engine);
+
+	nouveau_bo_unmap(priv->bo);
+	nouveau_bo_ref(NULL, &priv->bo);
+	dev_priv->eng[engine] = NULL;
+	kfree(priv);
+}
+
+int
+nvc0_fence_create(struct drm_device *dev)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	struct nouveau_fifo_engine *pfifo = &dev_priv->engine.fifo;
+	struct nvc0_fence_priv *priv;
+	int ret;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base.engine.destroy = nvc0_fence_destroy;
+	priv->base.engine.init = nvc0_fence_init;
+	priv->base.engine.fini = nvc0_fence_fini;
+	priv->base.engine.context_new = nvc0_fence_context_new;
+	priv->base.engine.context_del = nvc0_fence_context_del;
+	priv->base.emit = nvc0_fence_emit;
+	priv->base.sync = nvc0_fence_sync;
+	priv->base.read = nvc0_fence_read;
+	dev_priv->eng[NVOBJ_ENGINE_FENCE] = &priv->base.engine;
+
+	ret = nouveau_bo_new(dev, 16 * pfifo->channels, 0, TTM_PL_FLAG_VRAM,
+			     0, 0, NULL, &priv->bo);
+	if (ret == 0) {
+		ret = nouveau_bo_pin(priv->bo, TTM_PL_FLAG_VRAM);
+		if (ret == 0)
+			ret = nouveau_bo_map(priv->bo);
+		if (ret)
+			nouveau_bo_ref(NULL, &priv->bo);
+	}
+
+	if (ret)
+		nvc0_fence_destroy(dev, NVOBJ_ENGINE_FENCE);
+	return ret;
+}