1 files changed, 262 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 0000000..40f91e1
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nouveau_dma.c
@@ -0,0 +1,262 @@
+/*
+ * 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 <core/client.h>
+
+#include "nouveau_drm.h"
+#include "nouveau_dma.h"
+
+void
+OUT_RINGp(struct nouveau_channel *chan, const void *data, unsigned nr_dwords)
+{
+	bool is_iomem;
+	u32 *mem = ttm_kmap_obj_virtual(&chan->push.buffer->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;
+}
+
+/* Fetch and adjust GPU GET pointer
+ *
+ * Returns:
+ *  value >= 0, the adjusted GET pointer
+ *  -EINVAL if GET pointer currently outside main push buffer
+ *  -EBUSY if timeout exceeded
+ */
+static inline int
+READ_GET(struct nouveau_channel *chan, uint64_t *prev_get, int *timeout)
+{
+	uint64_t val;
+
+	val = nv_ro32(chan->object, chan->user_get);
+        if (chan->user_get_hi)
+                val |= (uint64_t)nv_ro32(chan->object, chan->user_get_hi) << 32;
+
+	/* 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
+	 */
+	if (val != *prev_get) {
+		*prev_get = val;
+		*timeout = 0;
+	}
+
+	if ((++*timeout & 0xff) == 0) {
+		udelay(1);
+		if (*timeout > 100000)
+			return -EBUSY;
+	}
+
+	if (val < chan->push.vma.offset ||
+	    val > chan->push.vma.offset + (chan->dma.max << 2))
+		return -EINVAL;
+
+	return (val - chan->push.vma.offset) >> 2;
+}
+
+void
+nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
+	      int delta, int length)
+{
+	struct nouveau_bo *pb = chan->push.buffer;
+	struct nouveau_vma *vma;
+	int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
+	u64 offset;
+
+	vma = nouveau_bo_vma_find(bo, nv_client(chan->cli)->vm);
+	BUG_ON(!vma);
+	offset = vma->offset + delta;
+
+	BUG_ON(chan->dma.ib_free < 1);
+
+	nouveau_bo_wr32(pb, ip++, lower_32_bits(offset));
+	nouveau_bo_wr32(pb, ip++, upper_32_bits(offset) | length << 8);
+
+	chan->dma.ib_put = (chan->dma.ib_put + 1) & chan->dma.ib_max;
+
+	DRM_MEMORYBARRIER();
+	/* Flush writes. */
+	nouveau_bo_rd32(pb, 0);
+
+	nv_wo32(chan->object, 0x8c, chan->dma.ib_put);
+	chan->dma.ib_free--;
+}
+
+static int
+nv50_dma_push_wait(struct nouveau_channel *chan, int count)
+{
+	uint32_t cnt = 0, prev_get = 0;
+
+	while (chan->dma.ib_free < count) {
+		uint32_t get = nv_ro32(chan->object, 0x88);
+		if (get != prev_get) {
+			prev_get = get;
+			cnt = 0;
+		}
+
+		if ((++cnt & 0xff) == 0) {
+			DRM_UDELAY(1);
+			if (cnt > 100000)
+				return -EBUSY;
+		}
+
+		chan->dma.ib_free = get - chan->dma.ib_put;
+		if (chan->dma.ib_free <= 0)
+			chan->dma.ib_free += chan->dma.ib_max;
+	}
+
+	return 0;
+}
+
+static int
+nv50_dma_wait(struct nouveau_channel *chan, int slots, int count)
+{
+	uint64_t prev_get = 0;
+	int ret, cnt = 0;
+
+	ret = nv50_dma_push_wait(chan, slots + 1);
+	if (unlikely(ret))
+		return ret;
+
+	while (chan->dma.free < count) {
+		int get = READ_GET(chan, &prev_get, &cnt);
+		if (unlikely(get < 0)) {
+			if (get == -EINVAL)
+				continue;
+
+			return get;
+		}
+
+		if (get <= chan->dma.cur) {
+			chan->dma.free = chan->dma.max - chan->dma.cur;
+			if (chan->dma.free >= count)
+				break;
+
+			FIRE_RING(chan);
+			do {
+				get = READ_GET(chan, &prev_get, &cnt);
+				if (unlikely(get < 0)) {
+					if (get == -EINVAL)
+						continue;
+					return get;
+				}
+			} while (get == 0);
+			chan->dma.cur = 0;
+			chan->dma.put = 0;
+		}
+
+		chan->dma.free = get - chan->dma.cur - 1;
+	}
+
+	return 0;
+}
+
+int
+nouveau_dma_wait(struct nouveau_channel *chan, int slots, int size)
+{
+	uint64_t prev_get = 0;
+	int cnt = 0, get;
+
+	if (chan->dma.ib_max)
+		return nv50_dma_wait(chan, slots, size);
+
+	while (chan->dma.free < size) {
+		get = READ_GET(chan, &prev_get, &cnt);
+		if (unlikely(get == -EBUSY))
+			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 (unlikely(get == -EINVAL) || 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->push.vma.offset | 0x20000000);
+
+			/* wait for GET to depart from the skips area.
+			 * prevents writing GET==PUT and causing a race
+			 * condition that causes us to think the GPU is
+			 * idle when it's not.
+			 */
+			do {
+				get = READ_GET(chan, &prev_get, &cnt);
+				if (unlikely(get == -EBUSY))
+					return -EBUSY;
+				if (unlikely(get == -EINVAL))
+					continue;
+			} while (get <= NOUVEAU_DMA_SKIPS);
+			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;
+}
+