drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c - kernel/msm-4.19 - Gitiles

 /**************************************************************************
  *
  * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
  * 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
  * THE COPYRIGHT HOLDERS, AUTHORS 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 "vmwgfx_drv.h"
 #include <drm/drmP.h>
 #include <drm/ttm/ttm_placement.h>

 bool vmw_fifo_have_3d(struct vmw_private *dev_priv)
 {
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
 	uint32_t fifo_min, hwversion;
 	const struct vmw_fifo_state *fifo = &dev_priv->fifo;

 	if (!(dev_priv->capabilities & SVGA_CAP_3D))
 		return false;

 	if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS) {
 		uint32_t result;

 		if (!dev_priv->has_mob)
 			return false;

 		mutex_lock(&dev_priv->hw_mutex);
 		vmw_write(dev_priv, SVGA_REG_DEV_CAP, SVGA3D_DEVCAP_3D);
 		result = vmw_read(dev_priv, SVGA_REG_DEV_CAP);
 		mutex_unlock(&dev_priv->hw_mutex);

 		return (result != 0);
 	}

 	if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
 		return false;

 	fifo_min = ioread32(fifo_mem  + SVGA_FIFO_MIN);
 	if (fifo_min <= SVGA_FIFO_3D_HWVERSION * sizeof(unsigned int))
 		return false;

 	hwversion = ioread32(fifo_mem +
 			     ((fifo->capabilities &
 			       SVGA_FIFO_CAP_3D_HWVERSION_REVISED) ?
 			      SVGA_FIFO_3D_HWVERSION_REVISED :
 			      SVGA_FIFO_3D_HWVERSION));

 	if (hwversion == 0)
 		return false;

 	if (hwversion < SVGA3D_HWVERSION_WS8_B1)
 		return false;

 	/* Non-Screen Object path does not support surfaces */
 	if (!dev_priv->sou_priv)
 		return false;

 	return true;
 }

 bool vmw_fifo_have_pitchlock(struct vmw_private *dev_priv)
 {
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
 	uint32_t caps;

 	if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
 		return false;

 	caps = ioread32(fifo_mem + SVGA_FIFO_CAPABILITIES);
 	if (caps & SVGA_FIFO_CAP_PITCHLOCK)
 		return true;

 	return false;
 }

 int vmw_fifo_init(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
 {
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
 	uint32_t max;
 	uint32_t min;
 	uint32_t dummy;

 	fifo->static_buffer_size = VMWGFX_FIFO_STATIC_SIZE;
 	fifo->static_buffer = vmalloc(fifo->static_buffer_size);
 	if (unlikely(fifo->static_buffer == NULL))
 		return -ENOMEM;

 	fifo->dynamic_buffer = NULL;
 	fifo->reserved_size = 0;
 	fifo->using_bounce_buffer = false;

 	mutex_init(&fifo->fifo_mutex);
 	init_rwsem(&fifo->rwsem);

 	/*
 	 * Allow mapping the first page read-only to user-space.
 	 */

 	DRM_INFO("width %d\n", vmw_read(dev_priv, SVGA_REG_WIDTH));
 	DRM_INFO("height %d\n", vmw_read(dev_priv, SVGA_REG_HEIGHT));
 	DRM_INFO("bpp %d\n", vmw_read(dev_priv, SVGA_REG_BITS_PER_PIXEL));

 	mutex_lock(&dev_priv->hw_mutex);
 	dev_priv->enable_state = vmw_read(dev_priv, SVGA_REG_ENABLE);
 	dev_priv->config_done_state = vmw_read(dev_priv, SVGA_REG_CONFIG_DONE);
 	dev_priv->traces_state = vmw_read(dev_priv, SVGA_REG_TRACES);
 	vmw_write(dev_priv, SVGA_REG_ENABLE, 1);

 	min = 4;
 	if (dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO)
 		min = vmw_read(dev_priv, SVGA_REG_MEM_REGS);
 	min <<= 2;

 	if (min < PAGE_SIZE)
 		min = PAGE_SIZE;

 	iowrite32(min, fifo_mem + SVGA_FIFO_MIN);
 	iowrite32(dev_priv->mmio_size, fifo_mem + SVGA_FIFO_MAX);
 	wmb();
 	iowrite32(min,  fifo_mem + SVGA_FIFO_NEXT_CMD);
 	iowrite32(min,  fifo_mem + SVGA_FIFO_STOP);
 	iowrite32(0, fifo_mem + SVGA_FIFO_BUSY);
 	mb();

 	vmw_write(dev_priv, SVGA_REG_CONFIG_DONE, 1);
 	mutex_unlock(&dev_priv->hw_mutex);

 	max = ioread32(fifo_mem + SVGA_FIFO_MAX);
 	min = ioread32(fifo_mem  + SVGA_FIFO_MIN);
 	fifo->capabilities = ioread32(fifo_mem + SVGA_FIFO_CAPABILITIES);

 	DRM_INFO("Fifo max 0x%08x min 0x%08x cap 0x%08x\n",
 		 (unsigned int) max,
 		 (unsigned int) min,
 		 (unsigned int) fifo->capabilities);

 	atomic_set(&dev_priv->marker_seq, dev_priv->last_read_seqno);
 	iowrite32(dev_priv->last_read_seqno, fifo_mem + SVGA_FIFO_FENCE);
 	vmw_marker_queue_init(&fifo->marker_queue);
 	return vmw_fifo_send_fence(dev_priv, &dummy);
 }

 void vmw_fifo_ping_host(struct vmw_private *dev_priv, uint32_t reason)
 {
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;

 	mutex_lock(&dev_priv->hw_mutex);

 	if (unlikely(ioread32(fifo_mem + SVGA_FIFO_BUSY) == 0)) {
 		iowrite32(1, fifo_mem + SVGA_FIFO_BUSY);
 		vmw_write(dev_priv, SVGA_REG_SYNC, reason);
 	}

 	mutex_unlock(&dev_priv->hw_mutex);
 }

 void vmw_fifo_release(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
 {
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;

 	mutex_lock(&dev_priv->hw_mutex);

 	vmw_write(dev_priv, SVGA_REG_SYNC, SVGA_SYNC_GENERIC);
 	while (vmw_read(dev_priv, SVGA_REG_BUSY) != 0)
 		;

 	dev_priv->last_read_seqno = ioread32(fifo_mem + SVGA_FIFO_FENCE);

 	vmw_write(dev_priv, SVGA_REG_CONFIG_DONE,
 		  dev_priv->config_done_state);
 	vmw_write(dev_priv, SVGA_REG_ENABLE,
 		  dev_priv->enable_state);
 	vmw_write(dev_priv, SVGA_REG_TRACES,
 		  dev_priv->traces_state);

 	mutex_unlock(&dev_priv->hw_mutex);
 	vmw_marker_queue_takedown(&fifo->marker_queue);

 	if (likely(fifo->static_buffer != NULL)) {
 		vfree(fifo->static_buffer);
 		fifo->static_buffer = NULL;
 	}

 	if (likely(fifo->dynamic_buffer != NULL)) {
 		vfree(fifo->dynamic_buffer);
 		fifo->dynamic_buffer = NULL;
 	}
 }

 static bool vmw_fifo_is_full(struct vmw_private *dev_priv, uint32_t bytes)
 {
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
 	uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
 	uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
 	uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
 	uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);

 	return ((max - next_cmd) + (stop - min) <= bytes);
 }

 static int vmw_fifo_wait_noirq(struct vmw_private *dev_priv,
 			       uint32_t bytes, bool interruptible,
 			       unsigned long timeout)
 {
 	int ret = 0;
 	unsigned long end_jiffies = jiffies + timeout;
 	DEFINE_WAIT(__wait);

 	DRM_INFO("Fifo wait noirq.\n");

 	for (;;) {
 		prepare_to_wait(&dev_priv->fifo_queue, &__wait,
 				(interruptible) ?
 				TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
 		if (!vmw_fifo_is_full(dev_priv, bytes))
 			break;
 		if (time_after_eq(jiffies, end_jiffies)) {
 			ret = -EBUSY;
 			DRM_ERROR("SVGA device lockup.\n");
 			break;
 		}
 		schedule_timeout(1);
 		if (interruptible && signal_pending(current)) {
 			ret = -ERESTARTSYS;
 			break;
 		}
 	}
 	finish_wait(&dev_priv->fifo_queue, &__wait);
 	wake_up_all(&dev_priv->fifo_queue);
 	DRM_INFO("Fifo noirq exit.\n");
 	return ret;
 }

 static int vmw_fifo_wait(struct vmw_private *dev_priv,
 			 uint32_t bytes, bool interruptible,
 			 unsigned long timeout)
 {
 	long ret = 1L;
 	unsigned long irq_flags;

 	if (likely(!vmw_fifo_is_full(dev_priv, bytes)))
 		return 0;

 	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_FIFOFULL);
 	if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
 		return vmw_fifo_wait_noirq(dev_priv, bytes,
 					   interruptible, timeout);

 	mutex_lock(&dev_priv->hw_mutex);
 	if (atomic_add_return(1, &dev_priv->fifo_queue_waiters) > 0) {
 		spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
 		outl(SVGA_IRQFLAG_FIFO_PROGRESS,
 		     dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
 		dev_priv->irq_mask |= SVGA_IRQFLAG_FIFO_PROGRESS;
 		vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
 		spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
 	}
 	mutex_unlock(&dev_priv->hw_mutex);

 	if (interruptible)
 		ret = wait_event_interruptible_timeout
 		    (dev_priv->fifo_queue,
 		     !vmw_fifo_is_full(dev_priv, bytes), timeout);
 	else
 		ret = wait_event_timeout
 		    (dev_priv->fifo_queue,
 		     !vmw_fifo_is_full(dev_priv, bytes), timeout);

 	if (unlikely(ret == 0))
 		ret = -EBUSY;
 	else if (likely(ret > 0))
 		ret = 0;

 	mutex_lock(&dev_priv->hw_mutex);
 	if (atomic_dec_and_test(&dev_priv->fifo_queue_waiters)) {
 		spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
 		dev_priv->irq_mask &= ~SVGA_IRQFLAG_FIFO_PROGRESS;
 		vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
 		spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
 	}
 	mutex_unlock(&dev_priv->hw_mutex);

 	return ret;
 }

 /**
  * Reserve @bytes number of bytes in the fifo.
  *
  * This function will return NULL (error) on two conditions:
  *  If it timeouts waiting for fifo space, or if @bytes is larger than the
  *   available fifo space.
  *
  * Returns:
  *   Pointer to the fifo, or null on error (possible hardware hang).
  */
 void *vmw_fifo_reserve(struct vmw_private *dev_priv, uint32_t bytes)
 {
 	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
 	uint32_t max;
 	uint32_t min;
 	uint32_t next_cmd;
 	uint32_t reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
 	int ret;

 	mutex_lock(&fifo_state->fifo_mutex);
 	max = ioread32(fifo_mem + SVGA_FIFO_MAX);
 	min = ioread32(fifo_mem + SVGA_FIFO_MIN);
 	next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);

 	if (unlikely(bytes >= (max - min)))
 		goto out_err;

 	BUG_ON(fifo_state->reserved_size != 0);
 	BUG_ON(fifo_state->dynamic_buffer != NULL);

 	fifo_state->reserved_size = bytes;

 	while (1) {
 		uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);
 		bool need_bounce = false;
 		bool reserve_in_place = false;

 		if (next_cmd >= stop) {
 			if (likely((next_cmd + bytes < max ||
 				    (next_cmd + bytes == max && stop > min))))
 				reserve_in_place = true;

 			else if (vmw_fifo_is_full(dev_priv, bytes)) {
 				ret = vmw_fifo_wait(dev_priv, bytes,
 						    false, 3 * HZ);
 				if (unlikely(ret != 0))
 					goto out_err;
 			} else
 				need_bounce = true;

 		} else {

 			if (likely((next_cmd + bytes < stop)))
 				reserve_in_place = true;
 			else {
 				ret = vmw_fifo_wait(dev_priv, bytes,
 						    false, 3 * HZ);
 				if (unlikely(ret != 0))
 					goto out_err;
 			}
 		}

 		if (reserve_in_place) {
 			if (reserveable || bytes <= sizeof(uint32_t)) {
 				fifo_state->using_bounce_buffer = false;

 				if (reserveable)
 					iowrite32(bytes, fifo_mem +
 						  SVGA_FIFO_RESERVED);
 				return fifo_mem + (next_cmd >> 2);
 			} else {
 				need_bounce = true;
 			}
 		}

 		if (need_bounce) {
 			fifo_state->using_bounce_buffer = true;
 			if (bytes < fifo_state->static_buffer_size)
 				return fifo_state->static_buffer;
 			else {
 				fifo_state->dynamic_buffer = vmalloc(bytes);
 				return fifo_state->dynamic_buffer;
 			}
 		}
 	}
 out_err:
 	fifo_state->reserved_size = 0;
 	mutex_unlock(&fifo_state->fifo_mutex);
 	return NULL;
 }

 static void vmw_fifo_res_copy(struct vmw_fifo_state *fifo_state,
 			      __le32 __iomem *fifo_mem,
 			      uint32_t next_cmd,
 			      uint32_t max, uint32_t min, uint32_t bytes)
 {
 	uint32_t chunk_size = max - next_cmd;
 	uint32_t rest;
 	uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
 	    fifo_state->dynamic_buffer : fifo_state->static_buffer;

 	if (bytes < chunk_size)
 		chunk_size = bytes;

 	iowrite32(bytes, fifo_mem + SVGA_FIFO_RESERVED);
 	mb();
 	memcpy_toio(fifo_mem + (next_cmd >> 2), buffer, chunk_size);
 	rest = bytes - chunk_size;
 	if (rest)
 		memcpy_toio(fifo_mem + (min >> 2), buffer + (chunk_size >> 2),
 			    rest);
 }

 static void vmw_fifo_slow_copy(struct vmw_fifo_state *fifo_state,
 			       __le32 __iomem *fifo_mem,
 			       uint32_t next_cmd,
 			       uint32_t max, uint32_t min, uint32_t bytes)
 {
 	uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
 	    fifo_state->dynamic_buffer : fifo_state->static_buffer;

 	while (bytes > 0) {
 		iowrite32(*buffer++, fifo_mem + (next_cmd >> 2));
 		next_cmd += sizeof(uint32_t);
 		if (unlikely(next_cmd == max))
 			next_cmd = min;
 		mb();
 		iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
 		mb();
 		bytes -= sizeof(uint32_t);
 	}
 }

 void vmw_fifo_commit(struct vmw_private *dev_priv, uint32_t bytes)
 {
 	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
 	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
 	uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
 	uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
 	uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
 	bool reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;

 	BUG_ON((bytes & 3) != 0);
 	BUG_ON(bytes > fifo_state->reserved_size);

 	fifo_state->reserved_size = 0;

 	if (fifo_state->using_bounce_buffer) {
 		if (reserveable)
 			vmw_fifo_res_copy(fifo_state, fifo_mem,
 					  next_cmd, max, min, bytes);
 		else
 			vmw_fifo_slow_copy(fifo_state, fifo_mem,
 					   next_cmd, max, min, bytes);

 		if (fifo_state->dynamic_buffer) {
 			vfree(fifo_state->dynamic_buffer);
 			fifo_state->dynamic_buffer = NULL;
 		}

 	}

 	down_write(&fifo_state->rwsem);
 	if (fifo_state->using_bounce_buffer || reserveable) {
 		next_cmd += bytes;
 		if (next_cmd >= max)
 			next_cmd -= max - min;
 		mb();
 		iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
 	}

 	if (reserveable)
 		iowrite32(0, fifo_mem + SVGA_FIFO_RESERVED);
 	mb();
 	up_write(&fifo_state->rwsem);
 	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
 	mutex_unlock(&fifo_state->fifo_mutex);
 }

 int vmw_fifo_send_fence(struct vmw_private *dev_priv, uint32_t *seqno)
 {
 	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
 	struct svga_fifo_cmd_fence *cmd_fence;
 	void *fm;
 	int ret = 0;
 	uint32_t bytes = sizeof(__le32) + sizeof(*cmd_fence);

 	fm = vmw_fifo_reserve(dev_priv, bytes);
 	if (unlikely(fm == NULL)) {
 		*seqno = atomic_read(&dev_priv->marker_seq);
 		ret = -ENOMEM;
 		(void)vmw_fallback_wait(dev_priv, false, true, *seqno,
 					false, 3*HZ);
 		goto out_err;
 	}

 	do {
 		*seqno = atomic_add_return(1, &dev_priv->marker_seq);
 	} while (*seqno == 0);

 	if (!(fifo_state->capabilities & SVGA_FIFO_CAP_FENCE)) {

 		/*
 		 * Don't request hardware to send a fence. The
 		 * waiting code in vmwgfx_irq.c will emulate this.
 		 */

 		vmw_fifo_commit(dev_priv, 0);
 		return 0;
 	}

 	*(__le32 *) fm = cpu_to_le32(SVGA_CMD_FENCE);
 	cmd_fence = (struct svga_fifo_cmd_fence *)
 	    ((unsigned long)fm + sizeof(__le32));

 	iowrite32(*seqno, &cmd_fence->fence);
 	vmw_fifo_commit(dev_priv, bytes);
 	(void) vmw_marker_push(&fifo_state->marker_queue, *seqno);
 	vmw_update_seqno(dev_priv, fifo_state);

 out_err:
 	return ret;
 }

 /**
  * vmw_fifo_emit_dummy_legacy_query - emits a dummy query to the fifo using
  * legacy query commands.
  *
  * @dev_priv: The device private structure.
  * @cid: The hardware context id used for the query.
  *
  * See the vmw_fifo_emit_dummy_query documentation.
  */
 static int vmw_fifo_emit_dummy_legacy_query(struct vmw_private *dev_priv,
 					    uint32_t cid)
 {
 	/*
 	 * A query wait without a preceding query end will
 	 * actually finish all queries for this cid
 	 * without writing to the query result structure.
 	 */

 	struct ttm_buffer_object *bo = dev_priv->dummy_query_bo;
 	struct {
 		SVGA3dCmdHeader header;
 		SVGA3dCmdWaitForQuery body;
 	} *cmd;

 	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

 	if (unlikely(cmd == NULL)) {
 		DRM_ERROR("Out of fifo space for dummy query.\n");
 		return -ENOMEM;
 	}

 	cmd->header.id = SVGA_3D_CMD_WAIT_FOR_QUERY;
 	cmd->header.size = sizeof(cmd->body);
 	cmd->body.cid = cid;
 	cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;

 	if (bo->mem.mem_type == TTM_PL_VRAM) {
 		cmd->body.guestResult.gmrId = SVGA_GMR_FRAMEBUFFER;
 		cmd->body.guestResult.offset = bo->offset;
 	} else {
 		cmd->body.guestResult.gmrId = bo->mem.start;
 		cmd->body.guestResult.offset = 0;
 	}

 	vmw_fifo_commit(dev_priv, sizeof(*cmd));

 	return 0;
 }

 /**
  * vmw_fifo_emit_dummy_gb_query - emits a dummy query to the fifo using
  * guest-backed resource query commands.
  *
  * @dev_priv: The device private structure.
  * @cid: The hardware context id used for the query.
  *
  * See the vmw_fifo_emit_dummy_query documentation.
  */
 static int vmw_fifo_emit_dummy_gb_query(struct vmw_private *dev_priv,
 					uint32_t cid)
 {
 	/*
 	 * A query wait without a preceding query end will
 	 * actually finish all queries for this cid
 	 * without writing to the query result structure.
 	 */

 	struct ttm_buffer_object *bo = dev_priv->dummy_query_bo;
 	struct {
 		SVGA3dCmdHeader header;
 		SVGA3dCmdWaitForGBQuery body;
 	} *cmd;

 	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

 	if (unlikely(cmd == NULL)) {
 		DRM_ERROR("Out of fifo space for dummy query.\n");
 		return -ENOMEM;
 	}

 	cmd->header.id = SVGA_3D_CMD_WAIT_FOR_GB_QUERY;
 	cmd->header.size = sizeof(cmd->body);
 	cmd->body.cid = cid;
 	cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;
 	BUG_ON(bo->mem.mem_type != VMW_PL_MOB);
 	cmd->body.mobid = bo->mem.start;
 	cmd->body.offset = 0;

 	vmw_fifo_commit(dev_priv, sizeof(*cmd));

 	return 0;
 }


 /**
  * vmw_fifo_emit_dummy_gb_query - emits a dummy query to the fifo using
  * appropriate resource query commands.
  *
  * @dev_priv: The device private structure.
  * @cid: The hardware context id used for the query.
  *
  * This function is used to emit a dummy occlusion query with
  * no primitives rendered between query begin and query end.
  * It's used to provide a query barrier, in order to know that when
  * this query is finished, all preceding queries are also finished.
  *
  * A Query results structure should have been initialized at the start
  * of the dev_priv->dummy_query_bo buffer object. And that buffer object
  * must also be either reserved or pinned when this function is called.
  *
  * Returns -ENOMEM on failure to reserve fifo space.
  */
 int vmw_fifo_emit_dummy_query(struct vmw_private *dev_priv,
 			      uint32_t cid)
 {
 	if (dev_priv->has_mob)
 		return vmw_fifo_emit_dummy_gb_query(dev_priv, cid);

 	return vmw_fifo_emit_dummy_legacy_query(dev_priv, cid);
 }
	/**************************************************************************
	*
	* Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
	* 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
	* THE COPYRIGHT HOLDERS, AUTHORS 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 "vmwgfx_drv.h"
	#include <drm/drmP.h>
	#include <drm/ttm/ttm_placement.h>

	bool vmw_fifo_have_3d(struct vmw_private *dev_priv)
	{
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
	uint32_t fifo_min, hwversion;
	const struct vmw_fifo_state *fifo = &dev_priv->fifo;

	if (!(dev_priv->capabilities & SVGA_CAP_3D))
	return false;

	if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS) {
	uint32_t result;

	if (!dev_priv->has_mob)
	return false;

	mutex_lock(&dev_priv->hw_mutex);
	vmw_write(dev_priv, SVGA_REG_DEV_CAP, SVGA3D_DEVCAP_3D);
	result = vmw_read(dev_priv, SVGA_REG_DEV_CAP);
	mutex_unlock(&dev_priv->hw_mutex);

	return (result != 0);
	}

	if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
	return false;

	fifo_min = ioread32(fifo_mem + SVGA_FIFO_MIN);
	if (fifo_min <= SVGA_FIFO_3D_HWVERSION * sizeof(unsigned int))
	return false;

	hwversion = ioread32(fifo_mem +
	((fifo->capabilities &
	SVGA_FIFO_CAP_3D_HWVERSION_REVISED) ?
	SVGA_FIFO_3D_HWVERSION_REVISED :
	SVGA_FIFO_3D_HWVERSION));

	if (hwversion == 0)
	return false;

	if (hwversion < SVGA3D_HWVERSION_WS8_B1)
	return false;

	/* Non-Screen Object path does not support surfaces */
	if (!dev_priv->sou_priv)
	return false;

	return true;
	}

	bool vmw_fifo_have_pitchlock(struct vmw_private *dev_priv)
	{
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
	uint32_t caps;

	if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
	return false;

	caps = ioread32(fifo_mem + SVGA_FIFO_CAPABILITIES);
	if (caps & SVGA_FIFO_CAP_PITCHLOCK)
	return true;

	return false;
	}

	int vmw_fifo_init(struct vmw_private dev_priv, struct vmw_fifo_state fifo)
	{
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
	uint32_t max;
	uint32_t min;
	uint32_t dummy;

	fifo->static_buffer_size = VMWGFX_FIFO_STATIC_SIZE;
	fifo->static_buffer = vmalloc(fifo->static_buffer_size);
	if (unlikely(fifo->static_buffer == NULL))
	return -ENOMEM;

	fifo->dynamic_buffer = NULL;
	fifo->reserved_size = 0;
	fifo->using_bounce_buffer = false;

	mutex_init(&fifo->fifo_mutex);
	init_rwsem(&fifo->rwsem);

	/*
	* Allow mapping the first page read-only to user-space.
	*/

	DRM_INFO("width %d\n", vmw_read(dev_priv, SVGA_REG_WIDTH));
	DRM_INFO("height %d\n", vmw_read(dev_priv, SVGA_REG_HEIGHT));
	DRM_INFO("bpp %d\n", vmw_read(dev_priv, SVGA_REG_BITS_PER_PIXEL));

	mutex_lock(&dev_priv->hw_mutex);
	dev_priv->enable_state = vmw_read(dev_priv, SVGA_REG_ENABLE);
	dev_priv->config_done_state = vmw_read(dev_priv, SVGA_REG_CONFIG_DONE);
	dev_priv->traces_state = vmw_read(dev_priv, SVGA_REG_TRACES);
	vmw_write(dev_priv, SVGA_REG_ENABLE, 1);

	min = 4;
	if (dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO)
	min = vmw_read(dev_priv, SVGA_REG_MEM_REGS);
	min <<= 2;

	if (min < PAGE_SIZE)
	min = PAGE_SIZE;

	iowrite32(min, fifo_mem + SVGA_FIFO_MIN);
	iowrite32(dev_priv->mmio_size, fifo_mem + SVGA_FIFO_MAX);
	wmb();
	iowrite32(min, fifo_mem + SVGA_FIFO_NEXT_CMD);
	iowrite32(min, fifo_mem + SVGA_FIFO_STOP);
	iowrite32(0, fifo_mem + SVGA_FIFO_BUSY);
	mb();

	vmw_write(dev_priv, SVGA_REG_CONFIG_DONE, 1);
	mutex_unlock(&dev_priv->hw_mutex);

	max = ioread32(fifo_mem + SVGA_FIFO_MAX);
	min = ioread32(fifo_mem + SVGA_FIFO_MIN);
	fifo->capabilities = ioread32(fifo_mem + SVGA_FIFO_CAPABILITIES);

	DRM_INFO("Fifo max 0x%08x min 0x%08x cap 0x%08x\n",
	(unsigned int) max,
	(unsigned int) min,
	(unsigned int) fifo->capabilities);

	atomic_set(&dev_priv->marker_seq, dev_priv->last_read_seqno);
	iowrite32(dev_priv->last_read_seqno, fifo_mem + SVGA_FIFO_FENCE);
	vmw_marker_queue_init(&fifo->marker_queue);
	return vmw_fifo_send_fence(dev_priv, &dummy);
	}

	void vmw_fifo_ping_host(struct vmw_private *dev_priv, uint32_t reason)
	{
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;

	mutex_lock(&dev_priv->hw_mutex);

	if (unlikely(ioread32(fifo_mem + SVGA_FIFO_BUSY) == 0)) {
	iowrite32(1, fifo_mem + SVGA_FIFO_BUSY);
	vmw_write(dev_priv, SVGA_REG_SYNC, reason);
	}

	mutex_unlock(&dev_priv->hw_mutex);
	}

	void vmw_fifo_release(struct vmw_private dev_priv, struct vmw_fifo_state fifo)
	{
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;

	mutex_lock(&dev_priv->hw_mutex);

	vmw_write(dev_priv, SVGA_REG_SYNC, SVGA_SYNC_GENERIC);
	while (vmw_read(dev_priv, SVGA_REG_BUSY) != 0)
	;

	dev_priv->last_read_seqno = ioread32(fifo_mem + SVGA_FIFO_FENCE);

	vmw_write(dev_priv, SVGA_REG_CONFIG_DONE,
	dev_priv->config_done_state);
	vmw_write(dev_priv, SVGA_REG_ENABLE,
	dev_priv->enable_state);
	vmw_write(dev_priv, SVGA_REG_TRACES,
	dev_priv->traces_state);

	mutex_unlock(&dev_priv->hw_mutex);
	vmw_marker_queue_takedown(&fifo->marker_queue);

	if (likely(fifo->static_buffer != NULL)) {
	vfree(fifo->static_buffer);
	fifo->static_buffer = NULL;
	}

	if (likely(fifo->dynamic_buffer != NULL)) {
	vfree(fifo->dynamic_buffer);
	fifo->dynamic_buffer = NULL;
	}
	}

	static bool vmw_fifo_is_full(struct vmw_private *dev_priv, uint32_t bytes)
	{
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
	uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
	uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
	uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
	uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);

	return ((max - next_cmd) + (stop - min) <= bytes);
	}

	static int vmw_fifo_wait_noirq(struct vmw_private *dev_priv,
	uint32_t bytes, bool interruptible,
	unsigned long timeout)
	{
	int ret = 0;
	unsigned long end_jiffies = jiffies + timeout;
	DEFINE_WAIT(__wait);

	DRM_INFO("Fifo wait noirq.\n");

	for (;;) {
	prepare_to_wait(&dev_priv->fifo_queue, &__wait,
	(interruptible) ?
	TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
	if (!vmw_fifo_is_full(dev_priv, bytes))
	break;
	if (time_after_eq(jiffies, end_jiffies)) {
	ret = -EBUSY;
	DRM_ERROR("SVGA device lockup.\n");
	break;
	}
	schedule_timeout(1);
	if (interruptible && signal_pending(current)) {
	ret = -ERESTARTSYS;
	break;
	}
	}
	finish_wait(&dev_priv->fifo_queue, &__wait);
	wake_up_all(&dev_priv->fifo_queue);
	DRM_INFO("Fifo noirq exit.\n");
	return ret;
	}

	static int vmw_fifo_wait(struct vmw_private *dev_priv,
	uint32_t bytes, bool interruptible,
	unsigned long timeout)
	{
	long ret = 1L;
	unsigned long irq_flags;

	if (likely(!vmw_fifo_is_full(dev_priv, bytes)))
	return 0;

	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_FIFOFULL);
	if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
	return vmw_fifo_wait_noirq(dev_priv, bytes,
	interruptible, timeout);

	mutex_lock(&dev_priv->hw_mutex);
	if (atomic_add_return(1, &dev_priv->fifo_queue_waiters) > 0) {
	spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
	outl(SVGA_IRQFLAG_FIFO_PROGRESS,
	dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
	dev_priv->irq_mask \|= SVGA_IRQFLAG_FIFO_PROGRESS;
	vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
	spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
	}
	mutex_unlock(&dev_priv->hw_mutex);

	if (interruptible)
	ret = wait_event_interruptible_timeout
	(dev_priv->fifo_queue,
	!vmw_fifo_is_full(dev_priv, bytes), timeout);
	else
	ret = wait_event_timeout
	(dev_priv->fifo_queue,
	!vmw_fifo_is_full(dev_priv, bytes), timeout);

	if (unlikely(ret == 0))
	ret = -EBUSY;
	else if (likely(ret > 0))
	ret = 0;

	mutex_lock(&dev_priv->hw_mutex);
	if (atomic_dec_and_test(&dev_priv->fifo_queue_waiters)) {
	spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
	dev_priv->irq_mask &= ~SVGA_IRQFLAG_FIFO_PROGRESS;
	vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
	spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
	}
	mutex_unlock(&dev_priv->hw_mutex);

	return ret;
	}

	/**
	* Reserve @bytes number of bytes in the fifo.
	*
	* This function will return NULL (error) on two conditions:
	* If it timeouts waiting for fifo space, or if @bytes is larger than the
	* available fifo space.
	*
	* Returns:
	* Pointer to the fifo, or null on error (possible hardware hang).
	*/
	void vmw_fifo_reserve(struct vmw_private dev_priv, uint32_t bytes)
	{
	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
	uint32_t max;
	uint32_t min;
	uint32_t next_cmd;
	uint32_t reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
	int ret;

	mutex_lock(&fifo_state->fifo_mutex);
	max = ioread32(fifo_mem + SVGA_FIFO_MAX);
	min = ioread32(fifo_mem + SVGA_FIFO_MIN);
	next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);

	if (unlikely(bytes >= (max - min)))
	goto out_err;

	BUG_ON(fifo_state->reserved_size != 0);
	BUG_ON(fifo_state->dynamic_buffer != NULL);

	fifo_state->reserved_size = bytes;

	while (1) {
	uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);
	bool need_bounce = false;
	bool reserve_in_place = false;

	if (next_cmd >= stop) {
	if (likely((next_cmd + bytes < max \|\|
	(next_cmd + bytes == max && stop > min))))
	reserve_in_place = true;

	else if (vmw_fifo_is_full(dev_priv, bytes)) {
	ret = vmw_fifo_wait(dev_priv, bytes,
	false, 3 * HZ);
	if (unlikely(ret != 0))
	goto out_err;
	} else
	need_bounce = true;

	} else {

	if (likely((next_cmd + bytes < stop)))
	reserve_in_place = true;
	else {
	ret = vmw_fifo_wait(dev_priv, bytes,
	false, 3 * HZ);
	if (unlikely(ret != 0))
	goto out_err;
	}
	}

	if (reserve_in_place) {
	if (reserveable \|\| bytes <= sizeof(uint32_t)) {
	fifo_state->using_bounce_buffer = false;

	if (reserveable)
	iowrite32(bytes, fifo_mem +
	SVGA_FIFO_RESERVED);
	return fifo_mem + (next_cmd >> 2);
	} else {
	need_bounce = true;
	}
	}

	if (need_bounce) {
	fifo_state->using_bounce_buffer = true;
	if (bytes < fifo_state->static_buffer_size)
	return fifo_state->static_buffer;
	else {
	fifo_state->dynamic_buffer = vmalloc(bytes);
	return fifo_state->dynamic_buffer;
	}
	}
	}
	out_err:
	fifo_state->reserved_size = 0;
	mutex_unlock(&fifo_state->fifo_mutex);
	return NULL;
	}

	static void vmw_fifo_res_copy(struct vmw_fifo_state *fifo_state,
	__le32 __iomem *fifo_mem,
	uint32_t next_cmd,
	uint32_t max, uint32_t min, uint32_t bytes)
	{
	uint32_t chunk_size = max - next_cmd;
	uint32_t rest;
	uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
	fifo_state->dynamic_buffer : fifo_state->static_buffer;

	if (bytes < chunk_size)
	chunk_size = bytes;

	iowrite32(bytes, fifo_mem + SVGA_FIFO_RESERVED);
	mb();
	memcpy_toio(fifo_mem + (next_cmd >> 2), buffer, chunk_size);
	rest = bytes - chunk_size;
	if (rest)
	memcpy_toio(fifo_mem + (min >> 2), buffer + (chunk_size >> 2),
	rest);
	}

	static void vmw_fifo_slow_copy(struct vmw_fifo_state *fifo_state,
	__le32 __iomem *fifo_mem,
	uint32_t next_cmd,
	uint32_t max, uint32_t min, uint32_t bytes)
	{
	uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
	fifo_state->dynamic_buffer : fifo_state->static_buffer;

	while (bytes > 0) {
	iowrite32(*buffer++, fifo_mem + (next_cmd >> 2));
	next_cmd += sizeof(uint32_t);
	if (unlikely(next_cmd == max))
	next_cmd = min;
	mb();
	iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
	mb();
	bytes -= sizeof(uint32_t);
	}
	}

	void vmw_fifo_commit(struct vmw_private *dev_priv, uint32_t bytes)
	{
	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
	uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
	uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
	uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
	bool reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;

	BUG_ON((bytes & 3) != 0);
	BUG_ON(bytes > fifo_state->reserved_size);

	fifo_state->reserved_size = 0;

	if (fifo_state->using_bounce_buffer) {
	if (reserveable)
	vmw_fifo_res_copy(fifo_state, fifo_mem,
	next_cmd, max, min, bytes);
	else
	vmw_fifo_slow_copy(fifo_state, fifo_mem,
	next_cmd, max, min, bytes);

	if (fifo_state->dynamic_buffer) {
	vfree(fifo_state->dynamic_buffer);
	fifo_state->dynamic_buffer = NULL;
	}

	}

	down_write(&fifo_state->rwsem);
	if (fifo_state->using_bounce_buffer \|\| reserveable) {
	next_cmd += bytes;
	if (next_cmd >= max)
	next_cmd -= max - min;
	mb();
	iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
	}

	if (reserveable)
	iowrite32(0, fifo_mem + SVGA_FIFO_RESERVED);
	mb();
	up_write(&fifo_state->rwsem);
	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
	mutex_unlock(&fifo_state->fifo_mutex);
	}

	int vmw_fifo_send_fence(struct vmw_private dev_priv, uint32_t seqno)
	{
	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
	struct svga_fifo_cmd_fence *cmd_fence;
	void *fm;
	int ret = 0;
	uint32_t bytes = sizeof(__le32) + sizeof(*cmd_fence);

	fm = vmw_fifo_reserve(dev_priv, bytes);
	if (unlikely(fm == NULL)) {
	*seqno = atomic_read(&dev_priv->marker_seq);
	ret = -ENOMEM;
	(void)vmw_fallback_wait(dev_priv, false, true, *seqno,
	false, 3*HZ);
	goto out_err;
	}

	do {
	*seqno = atomic_add_return(1, &dev_priv->marker_seq);
	} while (*seqno == 0);

	if (!(fifo_state->capabilities & SVGA_FIFO_CAP_FENCE)) {

	/*
	* Don't request hardware to send a fence. The
	* waiting code in vmwgfx_irq.c will emulate this.
	*/

	vmw_fifo_commit(dev_priv, 0);
	return 0;
	}

	(__le32 ) fm = cpu_to_le32(SVGA_CMD_FENCE);
	cmd_fence = (struct svga_fifo_cmd_fence *)
	((unsigned long)fm + sizeof(__le32));

	iowrite32(*seqno, &cmd_fence->fence);
	vmw_fifo_commit(dev_priv, bytes);
	(void) vmw_marker_push(&fifo_state->marker_queue, *seqno);
	vmw_update_seqno(dev_priv, fifo_state);

	out_err:
	return ret;
	}

	/**
	* vmw_fifo_emit_dummy_legacy_query - emits a dummy query to the fifo using
	* legacy query commands.
	*
	* @dev_priv: The device private structure.
	* @cid: The hardware context id used for the query.
	*
	* See the vmw_fifo_emit_dummy_query documentation.
	*/
	static int vmw_fifo_emit_dummy_legacy_query(struct vmw_private *dev_priv,
	uint32_t cid)
	{
	/*
	* A query wait without a preceding query end will
	* actually finish all queries for this cid
	* without writing to the query result structure.
	*/

	struct ttm_buffer_object *bo = dev_priv->dummy_query_bo;
	struct {
	SVGA3dCmdHeader header;
	SVGA3dCmdWaitForQuery body;
	} *cmd;

	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

	if (unlikely(cmd == NULL)) {
	DRM_ERROR("Out of fifo space for dummy query.\n");
	return -ENOMEM;
	}

	cmd->header.id = SVGA_3D_CMD_WAIT_FOR_QUERY;
	cmd->header.size = sizeof(cmd->body);
	cmd->body.cid = cid;
	cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;

	if (bo->mem.mem_type == TTM_PL_VRAM) {
	cmd->body.guestResult.gmrId = SVGA_GMR_FRAMEBUFFER;
	cmd->body.guestResult.offset = bo->offset;
	} else {
	cmd->body.guestResult.gmrId = bo->mem.start;
	cmd->body.guestResult.offset = 0;
	}

	vmw_fifo_commit(dev_priv, sizeof(*cmd));

	return 0;
	}

	/**
	* vmw_fifo_emit_dummy_gb_query - emits a dummy query to the fifo using
	* guest-backed resource query commands.
	*
	* @dev_priv: The device private structure.
	* @cid: The hardware context id used for the query.
	*
	* See the vmw_fifo_emit_dummy_query documentation.
	*/
	static int vmw_fifo_emit_dummy_gb_query(struct vmw_private *dev_priv,
	uint32_t cid)
	{
	/*
	* A query wait without a preceding query end will
	* actually finish all queries for this cid
	* without writing to the query result structure.
	*/

	struct ttm_buffer_object *bo = dev_priv->dummy_query_bo;
	struct {
	SVGA3dCmdHeader header;
	SVGA3dCmdWaitForGBQuery body;
	} *cmd;

	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

	if (unlikely(cmd == NULL)) {
	DRM_ERROR("Out of fifo space for dummy query.\n");
	return -ENOMEM;
	}

	cmd->header.id = SVGA_3D_CMD_WAIT_FOR_GB_QUERY;
	cmd->header.size = sizeof(cmd->body);
	cmd->body.cid = cid;
	cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;
	BUG_ON(bo->mem.mem_type != VMW_PL_MOB);
	cmd->body.mobid = bo->mem.start;
	cmd->body.offset = 0;

	vmw_fifo_commit(dev_priv, sizeof(*cmd));

	return 0;
	}


	/**
	* vmw_fifo_emit_dummy_gb_query - emits a dummy query to the fifo using
	* appropriate resource query commands.
	*
	* @dev_priv: The device private structure.
	* @cid: The hardware context id used for the query.
	*
	* This function is used to emit a dummy occlusion query with
	* no primitives rendered between query begin and query end.
	* It's used to provide a query barrier, in order to know that when
	* this query is finished, all preceding queries are also finished.
	*
	* A Query results structure should have been initialized at the start
	* of the dev_priv->dummy_query_bo buffer object. And that buffer object
	* must also be either reserved or pinned when this function is called.
	*
	* Returns -ENOMEM on failure to reserve fifo space.
	*/
	int vmw_fifo_emit_dummy_query(struct vmw_private *dev_priv,
	uint32_t cid)
	{
	if (dev_priv->has_mob)
	return vmw_fifo_emit_dummy_gb_query(dev_priv, cid);

	return vmw_fifo_emit_dummy_legacy_query(dev_priv, cid);
	}