1 files changed, 683 insertions, 0 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c b/drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c
new file mode 100644
index 000000000000..7400d617ae3c
--- /dev/null
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c
@@ -0,0 +1,683 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/**************************************************************************
+ *
+ * Copyright 2009-2020 VMware, Inc., Palo Alto, CA., USA
+ *
+ * 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 <linux/sched/signal.h>
+
+#include <drm/ttm/ttm_placement.h>
+
+#include "vmwgfx_drv.h"
+
+struct vmw_temp_set_context {
+	SVGA3dCmdHeader header;
+	SVGA3dCmdDXTempSetContext body;
+};
+
+bool vmw_supports_3d(struct vmw_private *dev_priv)
+{
+	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;
+
+		spin_lock(&dev_priv->cap_lock);
+		vmw_write(dev_priv, SVGA_REG_DEV_CAP, SVGA3D_DEVCAP_3D);
+		result = vmw_read(dev_priv, SVGA_REG_DEV_CAP);
+		spin_unlock(&dev_priv->cap_lock);
+
+		return (result != 0);
+	}
+
+	if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
+		return false;
+
+	fifo_min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
+	if (fifo_min <= SVGA_FIFO_3D_HWVERSION * sizeof(unsigned int))
+		return false;
+
+	hwversion = vmw_fifo_mem_read(dev_priv,
+				      ((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;
+
+	/* Legacy Display Unit does not support surfaces */
+	if (dev_priv->active_display_unit == vmw_du_legacy)
+		return false;
+
+	return true;
+}
+
+bool vmw_fifo_have_pitchlock(struct vmw_private *dev_priv)
+{
+	uint32_t caps;
+
+	if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
+		return false;
+
+	caps = vmw_fifo_mem_read(dev_priv, 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)
+{
+	uint32_t max;
+	uint32_t min;
+
+	fifo->dx = false;
+	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);
+
+	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));
+
+	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, SVGA_REG_ENABLE_ENABLE |
+		  SVGA_REG_ENABLE_HIDE);
+
+	vmw_write(dev_priv, SVGA_REG_TRACES, 0);
+
+	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;
+
+	vmw_fifo_mem_write(dev_priv, SVGA_FIFO_MIN, min);
+	vmw_fifo_mem_write(dev_priv, SVGA_FIFO_MAX, dev_priv->fifo_mem_size);
+	wmb();
+	vmw_fifo_mem_write(dev_priv, SVGA_FIFO_NEXT_CMD, min);
+	vmw_fifo_mem_write(dev_priv, SVGA_FIFO_STOP, min);
+	vmw_fifo_mem_write(dev_priv, SVGA_FIFO_BUSY, 0);
+	mb();
+
+	vmw_write(dev_priv, SVGA_REG_CONFIG_DONE, 1);
+
+	max = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
+	min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
+	fifo->capabilities = vmw_fifo_mem_read(dev_priv, 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);
+	vmw_fifo_mem_write(dev_priv, SVGA_FIFO_FENCE, dev_priv->last_read_seqno);
+
+	return 0;
+}
+
+void vmw_fifo_ping_host(struct vmw_private *dev_priv, uint32_t reason)
+{
+	u32 *fifo_mem = dev_priv->fifo_mem;
+
+	if (cmpxchg(fifo_mem + SVGA_FIFO_BUSY, 0, 1) == 0)
+		vmw_write(dev_priv, SVGA_REG_SYNC, reason);
+}
+
+void vmw_fifo_release(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
+{
+	vmw_write(dev_priv, SVGA_REG_SYNC, SVGA_SYNC_GENERIC);
+	while (vmw_read(dev_priv, SVGA_REG_BUSY) != 0)
+		;
+
+	dev_priv->last_read_seqno = vmw_fifo_mem_read(dev_priv, 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);
+
+	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)
+{
+	uint32_t max = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
+	uint32_t next_cmd = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_NEXT_CMD);
+	uint32_t min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
+	uint32_t stop = vmw_fifo_mem_read(dev_priv, 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;
+
+	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);
+
+	vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_FIFO_PROGRESS,
+			       &dev_priv->fifo_queue_waiters);
+
+	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;
+
+	vmw_generic_waiter_remove(dev_priv, SVGA_IRQFLAG_FIFO_PROGRESS,
+				  &dev_priv->fifo_queue_waiters);
+
+	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).
+ */
+static void *vmw_local_fifo_reserve(struct vmw_private *dev_priv,
+				    uint32_t bytes)
+{
+	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
+	u32  *fifo_mem = dev_priv->fifo_mem;
+	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 = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
+	min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
+	next_cmd = vmw_fifo_mem_read(dev_priv, 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 = vmw_fifo_mem_read(dev_priv, 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)
+					vmw_fifo_mem_write(dev_priv,
+							   SVGA_FIFO_RESERVED,
+							   bytes);
+				return (void __force *) (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);
+				if (!fifo_state->dynamic_buffer)
+					goto out_err;
+				return fifo_state->dynamic_buffer;
+			}
+		}
+	}
+out_err:
+	fifo_state->reserved_size = 0;
+	mutex_unlock(&fifo_state->fifo_mutex);
+
+	return NULL;
+}
+
+void *vmw_cmd_ctx_reserve(struct vmw_private *dev_priv, uint32_t bytes,
+			  int ctx_id)
+{
+	void *ret;
+
+	if (dev_priv->cman)
+		ret = vmw_cmdbuf_reserve(dev_priv->cman, bytes,
+					 ctx_id, false, NULL);
+	else if (ctx_id == SVGA3D_INVALID_ID)
+		ret = vmw_local_fifo_reserve(dev_priv, bytes);
+	else {
+		WARN(1, "Command buffer has not been allocated.\n");
+		ret = NULL;
+	}
+	if (IS_ERR_OR_NULL(ret))
+		return NULL;
+
+	return ret;
+}
+
+static void vmw_fifo_res_copy(struct vmw_fifo_state *fifo_state,
+			      struct vmw_private *vmw,
+			      uint32_t next_cmd,
+			      uint32_t max, uint32_t min, uint32_t bytes)
+{
+	u32 *fifo_mem = vmw->fifo_mem;
+	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;
+
+	vmw_fifo_mem_write(vmw, SVGA_FIFO_RESERVED, bytes);
+	mb();
+	memcpy(fifo_mem + (next_cmd >> 2), buffer, chunk_size);
+	rest = bytes - chunk_size;
+	if (rest)
+		memcpy(fifo_mem + (min >> 2), buffer + (chunk_size >> 2), rest);
+}
+
+static void vmw_fifo_slow_copy(struct vmw_fifo_state *fifo_state,
+			       struct vmw_private *vmw,
+			       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) {
+		vmw_fifo_mem_write(vmw, (next_cmd >> 2), *buffer++);
+		next_cmd += sizeof(uint32_t);
+		if (unlikely(next_cmd == max))
+			next_cmd = min;
+		mb();
+		vmw_fifo_mem_write(vmw, SVGA_FIFO_NEXT_CMD, next_cmd);
+		mb();
+		bytes -= sizeof(uint32_t);
+	}
+}
+
+static void vmw_local_fifo_commit(struct vmw_private *dev_priv, uint32_t bytes)
+{
+	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
+	uint32_t next_cmd = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_NEXT_CMD);
+	uint32_t max = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
+	uint32_t min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
+	bool reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
+
+	if (fifo_state->dx)
+		bytes += sizeof(struct vmw_temp_set_context);
+
+	fifo_state->dx = false;
+	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, dev_priv,
+					  next_cmd, max, min, bytes);
+		else
+			vmw_fifo_slow_copy(fifo_state, dev_priv,
+					   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();
+		vmw_fifo_mem_write(dev_priv, SVGA_FIFO_NEXT_CMD, next_cmd);
+	}
+
+	if (reserveable)
+		vmw_fifo_mem_write(dev_priv, SVGA_FIFO_RESERVED, 0);
+	mb();
+	up_write(&fifo_state->rwsem);
+	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
+	mutex_unlock(&fifo_state->fifo_mutex);
+}
+
+void vmw_cmd_commit(struct vmw_private *dev_priv, uint32_t bytes)
+{
+	if (dev_priv->cman)
+		vmw_cmdbuf_commit(dev_priv->cman, bytes, NULL, false);
+	else
+		vmw_local_fifo_commit(dev_priv, bytes);
+}
+
+
+/**
+ * vmw_fifo_commit_flush - Commit fifo space and flush any buffered commands.
+ *
+ * @dev_priv: Pointer to device private structure.
+ * @bytes: Number of bytes to commit.
+ */
+void vmw_cmd_commit_flush(struct vmw_private *dev_priv, uint32_t bytes)
+{
+	if (dev_priv->cman)
+		vmw_cmdbuf_commit(dev_priv->cman, bytes, NULL, true);
+	else
+		vmw_local_fifo_commit(dev_priv, bytes);
+}
+
+/**
+ * vmw_fifo_flush - Flush any buffered commands and make sure command processing
+ * starts.
+ *
+ * @dev_priv: Pointer to device private structure.
+ * @interruptible: Whether to wait interruptible if function needs to sleep.
+ */
+int vmw_cmd_flush(struct vmw_private *dev_priv, bool interruptible)
+{
+	might_sleep();
+
+	if (dev_priv->cman)
+		return vmw_cmdbuf_cur_flush(dev_priv->cman, interruptible);
+	else
+		return 0;
+}
+
+int vmw_cmd_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;
+	u32 *fm;
+	int ret = 0;
+	uint32_t bytes = sizeof(u32) + sizeof(*cmd_fence);
+
+	fm = VMW_CMD_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_cmd_commit(dev_priv, 0);
+		return 0;
+	}
+
+	*fm++ = SVGA_CMD_FENCE;
+	cmd_fence = (struct svga_fifo_cmd_fence *) fm;
+	cmd_fence->fence = *seqno;
+	vmw_cmd_commit_flush(dev_priv, bytes);
+	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->base;
+	struct {
+		SVGA3dCmdHeader header;
+		SVGA3dCmdWaitForQuery body;
+	} *cmd;
+
+	cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
+	if (unlikely(cmd == NULL))
+		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->mem.start << PAGE_SHIFT;
+	} else {
+		cmd->body.guestResult.gmrId = bo->mem.start;
+		cmd->body.guestResult.offset = 0;
+	}
+
+	vmw_cmd_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->base;
+	struct {
+		SVGA3dCmdHeader header;
+		SVGA3dCmdWaitForGBQuery body;
+	} *cmd;
+
+	cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
+	if (unlikely(cmd == NULL))
+		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_cmd_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_cmd_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);
+}