drm/nouveau: Add DRM driver for NVIDIA GPUs

This adds a drm/kms staging non-API stable driver for GPUs from NVIDIA.

This driver is a KMS-based driver and requires a compatible nouveau
userspace libdrm and nouveau X.org driver.

This driver requires firmware files not available in this kernel tree,
interested parties can find them via the nouveau project git archive.

This driver is reverse engineered, and is in no way supported by nVidia.

Support for nearly the complete range of nvidia hw from nv04->g80 (nv50)
is available, and the kms driver should support driving nearly all
output types (displayport is under development still) along with supporting
suspend/resume.

This work is all from the upstream nouveau project found at
nouveau.freedesktop.org.

The original authors list from nouveau git tree is:
Anssi Hannula <anssi.hannula@iki.fi>
Ben Skeggs <bskeggs@redhat.com>
Francisco Jerez <currojerez@riseup.net>
Maarten Maathuis <madman2003@gmail.com>
Marcin Kościelnicki <koriakin@0x04.net>
Matthew Garrett <mjg@redhat.com>
Matt Parnell <mparnell@gmail.com>
Patrice Mandin <patmandin@gmail.com>
Pekka Paalanen <pq@iki.fi>
Xavier Chantry <shiningxc@gmail.com>
along with project founder Stephane Marchesin <marchesin@icps.u-strasbg.fr>

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

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;
+}
+