drivers/gpu/drm/nouveau/nouveau_dma.c - kernel/quantenna - Git at Google

 /*
  * 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 "nouveau_drv.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 = nvif_rd32(&chan->user, chan->user_get);
         if (chan->user_get_hi)
                 val |= (uint64_t)nvif_rd32(&chan->user, 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_cli *cli = (void *)chan->user.client;
 	struct nouveau_bo *pb = chan->push.buffer;
 	struct nvkm_vma *vma;
 	int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
 	u64 offset;

 	vma = nouveau_bo_vma_find(bo, 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;

 	mb();
 	/* Flush writes. */
 	nouveau_bo_rd32(pb, 0);

 	nvif_wr32(&chan->user, 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 = nvif_rd32(&chan->user, 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;
 }
	/*
	* 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 "nouveau_drv.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 = nvif_rd32(&chan->user, chan->user_get);
	if (chan->user_get_hi)
	val \|= (uint64_t)nvif_rd32(&chan->user, 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_cli cli = (void )chan->user.client;
	struct nouveau_bo *pb = chan->push.buffer;
	struct nvkm_vma *vma;
	int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
	u64 offset;

	vma = nouveau_bo_vma_find(bo, 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;

	mb();
	/* Flush writes. */
	nouveau_bo_rd32(pb, 0);

	nvif_wr32(&chan->user, 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 = nvif_rd32(&chan->user, 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;
	}