1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_dma.c b/drivers/gpu/drm/nouveau/nouveau_dma.c
new file mode 100644
index 00000000000..703553687b2
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nouveau_dma.c
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2007 Ben Skeggs.
+ * All Rights Reserved.
+ *
+ * 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 (including the
+ * next paragraph) 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 OWNER(S) AND/OR ITS SUPPLIERS 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.
+ *
+ */
+
+#include "drmP.h"
+#include "drm.h"
+#include "nouveau_drv.h"
+#include "nouveau_dma.h"
+
+int
+nouveau_dma_init(struct nouveau_channel *chan)
+{
+	struct drm_device *dev = chan->dev;
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	struct nouveau_gpuobj *m2mf = NULL;
+	int ret, i;
+
+	/* Create NV_MEMORY_TO_MEMORY_FORMAT for buffer moves */
+	ret = nouveau_gpuobj_gr_new(chan, dev_priv->card_type < NV_50 ?
+				    0x0039 : 0x5039, &m2mf);
+	if (ret)
+		return ret;
+
+	ret = nouveau_gpuobj_ref_add(dev, chan, NvM2MF, m2mf, NULL);
+	if (ret)
+		return ret;
+
+	/* NV_MEMORY_TO_MEMORY_FORMAT requires a notifier object */
+	ret = nouveau_notifier_alloc(chan, NvNotify0, 32, &chan->m2mf_ntfy);
+	if (ret)
+		return ret;
+
+	/* Map push buffer */
+	ret = nouveau_bo_map(chan->pushbuf_bo);
+	if (ret)
+		return ret;
+
+	/* Map M2MF notifier object - fbcon. */
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		ret = nouveau_bo_map(chan->notifier_bo);
+		if (ret)
+			return ret;
+	}
+
+	/* Initialise DMA vars */
+	chan->dma.max  = (chan->pushbuf_bo->bo.mem.size >> 2) - 2;
+	chan->dma.put  = 0;
+	chan->dma.cur  = chan->dma.put;
+	chan->dma.free = chan->dma.max - chan->dma.cur;
+
+	/* Insert NOPS for NOUVEAU_DMA_SKIPS */
+	ret = RING_SPACE(chan, NOUVEAU_DMA_SKIPS);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < NOUVEAU_DMA_SKIPS; i++)
+		OUT_RING(chan, 0);
+
+	/* Initialise NV_MEMORY_TO_MEMORY_FORMAT */
+	ret = RING_SPACE(chan, 4);
+	if (ret)
+		return ret;
+	BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_NAME, 1);
+	OUT_RING(chan, NvM2MF);
+	BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_DMA_NOTIFY, 1);
+	OUT_RING(chan, NvNotify0);
+
+	/* Sit back and pray the channel works.. */
+	FIRE_RING(chan);
+
+	return 0;
+}
+
+void
+OUT_RINGp(struct nouveau_channel *chan, const void *data, unsigned nr_dwords)
+{
+	bool is_iomem;
+	u32 *mem = ttm_kmap_obj_virtual(&chan->pushbuf_bo->kmap, &is_iomem);
+	mem = &mem[chan->dma.cur];
+	if (is_iomem)
+		memcpy_toio((void __force __iomem *)mem, data, nr_dwords * 4);
+	else
+		memcpy(mem, data, nr_dwords * 4);
+	chan->dma.cur += nr_dwords;
+}
+
+static inline bool
+READ_GET(struct nouveau_channel *chan, uint32_t *get)
+{
+	uint32_t val;
+
+	val = nvchan_rd32(chan, chan->user_get);
+	if (val < chan->pushbuf_base ||
+	    val >= chan->pushbuf_base + chan->pushbuf_bo->bo.mem.size) {
+		/* meaningless to dma_wait() except to know whether the
+		 * GPU has stalled or not
+		 */
+		*get = val;
+		return false;
+	}
+
+	*get = (val - chan->pushbuf_base) >> 2;
+	return true;
+}
+
+int
+nouveau_dma_wait(struct nouveau_channel *chan, int size)
+{
+	uint32_t get, prev_get = 0, cnt = 0;
+	bool get_valid;
+
+	while (chan->dma.free < size) {
+		/* reset counter as long as GET is still advancing, this is
+		 * to avoid misdetecting a GPU lockup if the GPU happens to
+		 * just be processing an operation that takes a long time
+		 */
+		get_valid = READ_GET(chan, &get);
+		if (get != prev_get) {
+			prev_get = get;
+			cnt = 0;
+		}
+
+		if ((++cnt & 0xff) == 0) {
+			DRM_UDELAY(1);
+			if (cnt > 100000)
+				return -EBUSY;
+		}
+
+		/* loop until we have a usable GET pointer.  the value
+		 * we read from the GPU may be outside the main ring if
+		 * PFIFO is processing a buffer called from the main ring,
+		 * discard these values until something sensible is seen.
+		 *
+		 * the other case we discard GET is while the GPU is fetching
+		 * from the SKIPS area, so the code below doesn't have to deal
+		 * with some fun corner cases.
+		 */
+		if (!get_valid || get < NOUVEAU_DMA_SKIPS)
+			continue;
+
+		if (get <= chan->dma.cur) {
+			/* engine is fetching behind us, or is completely
+			 * idle (GET == PUT) so we have free space up until
+			 * the end of the push buffer
+			 *
+			 * we can only hit that path once per call due to
+			 * looping back to the beginning of the push buffer,
+			 * we'll hit the fetching-ahead-of-us path from that
+			 * point on.
+			 *
+			 * the *one* exception to that rule is if we read
+			 * GET==PUT, in which case the below conditional will
+			 * always succeed and break us out of the wait loop.
+			 */
+			chan->dma.free = chan->dma.max - chan->dma.cur;
+			if (chan->dma.free >= size)
+				break;
+
+			/* not enough space left at the end of the push buffer,
+			 * instruct the GPU to jump back to the start right
+			 * after processing the currently pending commands.
+			 */
+			OUT_RING(chan, chan->pushbuf_base | 0x20000000);
+			WRITE_PUT(NOUVEAU_DMA_SKIPS);
+
+			/* we're now submitting commands at the start of
+			 * the push buffer.
+			 */
+			chan->dma.cur  =
+			chan->dma.put  = NOUVEAU_DMA_SKIPS;
+		}
+
+		/* engine fetching ahead of us, we have space up until the
+		 * current GET pointer.  the "- 1" is to ensure there's
+		 * space left to emit a jump back to the beginning of the
+		 * push buffer if we require it.  we can never get GET == PUT
+		 * here, so this is safe.
+		 */
+		chan->dma.free = get - chan->dma.cur - 1;
+	}
+
+	return 0;
+}
+