[12/17,v2] drm/i915: Implementation of GuC client
diff mbox

Message ID 1435243213-22308-13-git-send-email-david.s.gordon@intel.com
State New
Headers show

Commit Message

Dave Gordon June 25, 2015, 2:40 p.m. UTC
A GuC client has its own doorbell and workqueue. It maintains the
doorbell cache line, process description object and work queue item.

A default guc_client is created for the i915 driver to use for
normal-priority in-order submission.

Note that the created client is not yet ready for use; doorbell
allocation will fail as we haven't yet linked the GuC's context
descriptor to the default contexts for each ring (see later patch).
However the driver will still be usable, automatically falling
back to execlist mode.

v2:
    Defer adding structure members until needed [Chris Wilson]
    Rationalise type declarations [Chris Wilson]

Issue: VIZ-4884
Signed-off-by: Alex Dai <yu.dai@intel.com>
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
---
 drivers/gpu/drm/i915/i915_guc_submission.c |  661 ++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_guc.h           |   43 ++
 drivers/gpu/drm/i915/intel_guc_loader.c    |   10 +
 3 files changed, 714 insertions(+)

Patch
diff mbox

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index e9d46d6..3c28c8b 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -27,6 +27,524 @@ 
 #include "intel_guc.h"
 
 /**
+ * DOC: GuC Client
+ *
+ * i915_guc_client:
+ * We use the term client to avoid confusion with contexts. A i915_guc_client is
+ * equivalent to GuC object guc_context_desc. This context descriptor is
+ * allocated from a pool of 1024 entries. Kernel driver will allocate doorbell
+ * and workqueue for it. Also the process descriptor (guc_process_desc), which
+ * is mapped to client space. So the client can write Work Item then ring the
+ * doorbell.
+ *
+ * To simplify the implementation, we allocate one gem object that contains all
+ * pages for doorbell, process descriptor and workqueue.
+ *
+ * The Scratch registers:
+ * There are 16 MMIO-based registers start from 0xC180. The kernel driver writes
+ * a value to the action register (SOFT_SCRATCH_0) along with any data. It then
+ * triggers an interrupt on the GuC via another register write (0xC4C8).
+ * Firmware writes a success/fail code back to the action register after
+ * processes the request. The kernel driver polls waiting for this update and
+ * then proceeds.
+ * See host2guc_action()
+ *
+ * Doorbells:
+ * Doorbells are interrupts to uKernel. A doorbell is a single cache line (QW)
+ * mapped into process space.
+ *
+ * Work Items:
+ * There are several types of work items that the host may place into a
+ * workqueue, each with its own requirements and limitations. Currently only
+ * WQ_TYPE_INORDER is needed to support legacy submission via GuC, which
+ * represents in-order queue. The kernel driver packs ring tail pointer and an
+ * ELSP context descriptor dword into Work Item.
+ * See guc_add_workqueue_item()
+ *
+ */
+
+/*
+ * Read GuC command/status register (SOFT_SCRATCH_0)
+ * Return true if it contains a response rather than a command
+ */
+static inline bool host2guc_action_response(struct drm_i915_private *dev_priv,
+					    u32 *status)
+{
+	u32 val = I915_READ(SOFT_SCRATCH(0));
+	*status = val;
+	return GUC2HOST_IS_RESPONSE(val);
+}
+
+static int host2guc_action(struct intel_guc *guc, u32 *data, u32 len)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+	u32 status;
+	int i;
+	int ret;
+
+	if (WARN_ON(len < 1 || len > 15))
+		return -EINVAL;
+
+	spin_lock(&dev_priv->guc.host2guc_lock);
+
+	dev_priv->guc.action_count += 1;
+	dev_priv->guc.action_cmd = data[0];
+
+	for (i = 0; i < len; i++)
+		I915_WRITE(SOFT_SCRATCH(i), data[i]);
+
+	POSTING_READ(SOFT_SCRATCH(i - 1));
+
+	I915_WRITE(HOST2GUC_INTERRUPT, HOST2GUC_TRIGGER);
+
+	ret = wait_for_atomic(host2guc_action_response(dev_priv, &status), 10);
+	if (status != GUC2HOST_STATUS_SUCCESS) {
+		/* either GuC doesn't respond, which is a TIMEOUT,
+		 * or a failure code is returned. */
+		if (ret != -ETIMEDOUT)
+			ret = -EIO;
+
+		DRM_ERROR("GUC: host2guc action 0x%X failed. ret=%d "
+				"status=0x%08X response=0x%08X\n",
+				data[0], ret, status,
+				I915_READ(SOFT_SCRATCH(15)));
+
+		dev_priv->guc.action_fail += 1;
+		dev_priv->guc.action_err = ret;
+	}
+	dev_priv->guc.action_status = status;
+
+	spin_unlock(&dev_priv->guc.host2guc_lock);
+
+	return ret;
+}
+
+/*
+ * Tell the GuC to allocate or deallocate a specific doorbell
+ */
+
+static int host2guc_allocate_doorbell(struct intel_guc *guc,
+				      struct i915_guc_client *client)
+{
+	u32 data[2];
+
+	data[0] = HOST2GUC_ACTION_ALLOCATE_DOORBELL;
+	data[1] = client->ctx_index;
+
+	return host2guc_action(guc, data, 2);
+}
+
+static int host2guc_release_doorbell(struct intel_guc *guc,
+				     struct i915_guc_client *client)
+{
+	u32 data[2];
+
+	data[0] = HOST2GUC_ACTION_DEALLOCATE_DOORBELL;
+	data[1] = client->ctx_index;
+
+	return host2guc_action(guc, data, 2);
+}
+
+/*
+ * Initialise, update, or clear doorbell data shared with the GuC
+ *
+ * These functions modify shared data and so need access to the mapped
+ * client object which contains the page being used for the doorbell
+ */
+
+static void guc_init_doorbell(struct intel_guc *guc,
+			      struct i915_guc_client *client)
+{
+	struct guc_doorbell_info *doorbell;
+	void *base;
+
+	base = kmap_atomic(i915_gem_object_get_page(client->client_obj, 0));
+	doorbell = base + client->doorbell_offset;
+
+	doorbell->db_status = 1;
+	doorbell->cookie = 0;
+
+	kunmap_atomic(base);
+}
+
+static int guc_ring_doorbell(struct i915_guc_client *gc)
+{
+	struct guc_process_desc *desc;
+	union guc_doorbell_qw db_cmp, db_exc, db_ret;
+	union guc_doorbell_qw *db;
+	void *base;
+	int attempt = 2, ret = -EAGAIN;
+
+	base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, 0));
+	desc = base + gc->proc_desc_offset;
+
+	/* Update the tail so it is visible to GuC */
+	desc->tail = gc->wq_tail;
+
+	/* current cookie */
+	db_cmp.db_status = GUC_DOORBELL_ENABLED;
+	db_cmp.cookie = gc->cookie;
+
+	/* cookie to be updated */
+	db_exc.db_status = GUC_DOORBELL_ENABLED;
+	db_exc.cookie = gc->cookie + 1;
+	if (db_exc.cookie == 0)
+		db_exc.cookie = 1;
+
+	/* pointer of current doorbell cacheline */
+	db = base + gc->doorbell_offset;
+
+	while (attempt--) {
+		/* lets ring the doorbell */
+		db_ret.value_qw = atomic64_cmpxchg((atomic64_t *)db,
+			db_cmp.value_qw, db_exc.value_qw);
+
+		/* if the exchange was successfully executed */
+		if (db_ret.value_qw == db_cmp.value_qw) {
+			/* db was successfully rung */
+			gc->cookie = db_exc.cookie;
+			ret = 0;
+			break;
+		}
+
+		/* XXX: doorbell was lost and need to acquire it again */
+		if (db_ret.db_status == GUC_DOORBELL_DISABLED)
+			break;
+
+		DRM_ERROR("Cookie mismatch. Expected %d, returned %d\n",
+			  db_cmp.cookie, db_ret.cookie);
+
+		/* update the cookie to newly read cookie from GuC */
+		db_cmp.cookie = db_ret.cookie;
+		db_exc.cookie = db_ret.cookie + 1;
+		if (db_exc.cookie == 0)
+			db_exc.cookie = 1;
+	}
+
+	kunmap_atomic(base);
+	return ret;
+}
+
+static void guc_disable_doorbell(struct intel_guc *guc,
+				 struct i915_guc_client *client)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+	struct guc_doorbell_info *doorbell;
+	void *base;
+	int drbreg = GEN8_DRBREGL(client->doorbell_id);
+	int value;
+
+	base = kmap_atomic(i915_gem_object_get_page(client->client_obj, 0));
+	doorbell = base + client->doorbell_offset;
+
+	doorbell->db_status = 0;
+
+	kunmap_atomic(base);
+
+	I915_WRITE(drbreg, I915_READ(drbreg) & ~GEN8_DRB_VALID);
+
+	value = I915_READ(drbreg);
+	WARN_ON((value & GEN8_DRB_VALID) != 0);
+
+	I915_WRITE(GEN8_DRBREGU(client->doorbell_id), 0);
+	I915_WRITE(drbreg, 0);
+
+	/* XXX: wait for any interrupts */
+	/* XXX: wait for workqueue to drain */
+}
+
+/*
+ * Select, assign and relase doorbell cachelines
+ *
+ * These functions track which doorbell cachelines are in use.
+ * The data they manipulate is protected by the host2guc lock.
+ */
+
+static uint32_t select_doorbell_cacheline(struct intel_guc *guc)
+{
+	const uint32_t cacheline_size = boot_cpu_data.x86_clflush_size;
+	uint32_t offset;
+
+	spin_lock(&guc->host2guc_lock);
+
+	/* Doorbell uses a single cache line within a page */
+	offset = guc->db_cacheline & PAGE_MASK;
+
+	/* Moving to next cache line to reduce contention */
+	guc->db_cacheline += cacheline_size;
+
+	spin_unlock(&guc->host2guc_lock);
+
+	return offset;
+}
+
+static uint16_t assign_doorbell(struct intel_guc *guc, uint32_t priority)
+{
+	/* The bitmap is split into two halves - high and normal priority. */
+	const uint16_t half = GUC_MAX_DOORBELLS / 2;
+	const uint16_t start = (priority <= GUC_CTX_PRIORITY_HIGH) ? half : 0;
+	const uint16_t end = start + half;
+	uint16_t id;
+
+	spin_lock(&guc->host2guc_lock);
+	id = find_next_zero_bit(guc->doorbell_bitmap, end, start);
+	if (id == end)
+		id = GUC_INVALID_DOORBELL_ID;
+	else
+		bitmap_set(guc->doorbell_bitmap, id, 1);
+	spin_unlock(&guc->host2guc_lock);
+
+	return id;
+}
+
+static void release_doorbell(struct intel_guc *guc, uint16_t id)
+{
+	spin_lock(&guc->host2guc_lock);
+	bitmap_clear(guc->doorbell_bitmap, id, 1);
+	spin_unlock(&guc->host2guc_lock);
+}
+
+/*
+ * Initialise the process descriptor shared with the GuC firmware.
+ */
+static void guc_init_proc_desc(struct intel_guc *guc,
+			       struct i915_guc_client *client)
+{
+	struct guc_process_desc *desc;
+	void *base;
+
+	base = kmap_atomic(i915_gem_object_get_page(client->client_obj, 0));
+	desc = base + client->proc_desc_offset;
+
+	memset(desc, 0, sizeof(*desc));
+
+	/*
+	 * XXX: pDoorbell and WQVBaseAddress are pointers in process address
+	 * space for ring3 clients (set them as in mmap_ioctl) or kernel
+	 * space for kernel clients (map on demand instead? May make debug
+	 * easier to have it mapped).
+	 */
+	desc->wq_base_addr = 0;
+	desc->db_base_addr = 0;
+
+	desc->context_id = client->ctx_index;
+	desc->wq_size_bytes = client->wq_size;
+	desc->wq_status = WQ_STATUS_ACTIVE;
+	desc->priority = client->priority;
+
+	kunmap_atomic(base);
+}
+
+/*
+ * Initialise/clear the context descriptor shared with the GuC firmware.
+ *
+ * This descriptor tells the GuC where (in GGTT space) to find the important
+ * data structures relating to this client (doorbell, process descriptor,
+ * write queue, etc).
+ */
+
+static void guc_init_ctx_desc(struct intel_guc *guc,
+			      struct i915_guc_client *client)
+{
+	struct guc_context_desc desc;
+	struct sg_table *sg;
+
+	memset(&desc, 0, sizeof(desc));
+
+	desc.attribute = GUC_CTX_DESC_ATTR_ACTIVE | GUC_CTX_DESC_ATTR_KERNEL;
+	desc.context_id = client->ctx_index;
+	desc.priority = client->priority;
+	desc.engines_used = (1 << RCS) | (1 << VCS) | (1 << BCS) |
+			    (1 << VECS) | (1 << VCS2); /* all engines */
+	desc.db_id = client->doorbell_id;
+
+	/*
+	 * The CPU address is only needed at certain points, so kmap_atomic on
+	 * demand instead of storing it in the ctx descriptor.
+	 * XXX: May make debug easier to have it mapped
+	 */
+	desc.db_trigger_cpu = 0;
+	desc.db_trigger_uk = client->doorbell_offset +
+		i915_gem_obj_ggtt_offset(client->client_obj);
+	desc.db_trigger_phy = client->doorbell_offset +
+		sg_dma_address(client->client_obj->pages->sgl);
+
+	desc.process_desc = client->proc_desc_offset +
+		i915_gem_obj_ggtt_offset(client->client_obj);
+
+	desc.wq_addr = client->wq_offset +
+		i915_gem_obj_ggtt_offset(client->client_obj);
+
+	desc.wq_size = client->wq_size;
+
+	/*
+	 * XXX: Take LRCs from an existing intel_context if this is not an
+	 * IsKMDCreatedContext client
+	 */
+	desc.desc_private = (uintptr_t)client;
+
+	/* Pool context is pinned already */
+	sg = guc->ctx_pool_obj->pages;
+	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
+			     sizeof(desc) * client->ctx_index);
+}
+
+static void guc_fini_ctx_desc(struct intel_guc *guc,
+			      struct i915_guc_client *client)
+{
+	struct guc_context_desc desc;
+	struct sg_table *sg;
+
+	memset(&desc, 0, sizeof(desc));
+
+	sg = guc->ctx_pool_obj->pages;
+	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
+			     sizeof(desc) * client->ctx_index);
+}
+
+/* Get valid workqueue item and return it back to offset */
+static int guc_get_workqueue_space(struct i915_guc_client *gc, u32 *offset)
+{
+	struct guc_process_desc *desc;
+	void *base;
+	u32 size = sizeof(struct guc_wq_item);
+	int ret = 0, timeout_counter = 200;
+	unsigned long flags;
+
+	base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, 0));
+	desc = base + gc->proc_desc_offset;
+
+	while (timeout_counter-- > 0) {
+		spin_lock_irqsave(&gc->wq_lock, flags);
+
+		ret = wait_for_atomic(CIRC_SPACE(gc->wq_tail, desc->head,
+				gc->wq_size) >= size, 1);
+
+		if (!ret) {
+			*offset = gc->wq_tail;
+
+			/* advance the tail for next workqueue item */
+			gc->wq_tail += size;
+			gc->wq_tail &= gc->wq_size - 1;
+
+			/* this will break the loop */
+			timeout_counter = 0;
+		}
+
+		spin_unlock_irqrestore(&gc->wq_lock, flags);
+	};
+
+	kunmap_atomic(base);
+
+	return ret;
+}
+
+static int guc_add_workqueue_item(struct i915_guc_client *gc,
+				  struct intel_context *ctx,
+				  struct intel_engine_cs *ring)
+{
+	struct drm_i915_gem_object *ctx_obj = ctx->engine[ring->id].state;
+	struct intel_ringbuffer *ringbuf = ctx->engine[ring->id].ringbuf;
+	struct guc_wq_item *wqi;
+	void *base;
+	u32 tail, wq_len, wq_off = 0;
+	int ret;
+
+	ret = guc_get_workqueue_space(gc, &wq_off);
+	if (ret)
+		return ret;
+
+	/* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we
+	 * should not have the case where structure wqi is across page, neither
+	 * wrapped to the beginning. This simplifies the implementation below.
+	 *
+	 * XXX: if not the case, we need save data to a temp wqi and copy it to
+	 * workqueue buffer dw by dw.
+	 */
+	WARN_ON(sizeof(struct guc_wq_item) != 16);
+	WARN_ON(wq_off & 3);
+
+	/* wq starts from the page after doorbell / process_desc */
+	base = kmap_atomic(i915_gem_object_get_page(gc->client_obj,
+			(wq_off + GUC_DB_SIZE) >> PAGE_SHIFT));
+	wq_off &= PAGE_SIZE - 1;
+	wqi = (struct guc_wq_item *)((char *)base + wq_off);
+
+	/* len does not include the header */
+	wq_len = sizeof(struct guc_wq_item) / sizeof(u32) - 1;
+	wqi->header = WQ_TYPE_INORDER |
+			(wq_len << WQ_LEN_SHIFT) |
+			(ring->id << WQ_TARGET_SHIFT) |
+			WQ_NO_WCFLUSH_WAIT;
+
+	/* The GuC wants only the low-order word of the context descriptor */
+	wqi->context_desc = (u32)intel_lr_context_descriptor(ring, ctx_obj);
+
+	/* The GuC firmware wants the tail index in QWords, not bytes */
+	tail = ringbuf->tail >> 3;
+	wqi->ring_tail = tail << WQ_RING_TAIL_SHIFT;
+	wqi->fence_id = 0; /*XXX: what fence to be here */
+
+	kunmap_atomic(base);
+
+	return 0;
+}
+
+static void update_context_image(struct intel_context *ctx,
+				 struct intel_engine_cs *ring)
+{
+	struct drm_i915_gem_object *ctx_obj = ctx->engine[ring->id].state;
+	struct intel_ringbuffer *ringbuf = ctx->engine[ring->id].ringbuf;
+
+	intel_lr_context_update(ctx_obj, ringbuf->obj, ~0u);
+}
+
+/**
+ * i915_guc_submit() - Submit commands through GuC
+ * @client:	the guc client where commands will go through
+ * @ctx:	LRC where commands come from
+ * @ring:	HW engine that will excute the commands
+ *
+ * Return:	0 if succeed
+ */
+int i915_guc_submit(struct i915_guc_client *client,
+		    struct intel_context *ctx,
+		    struct intel_engine_cs *ring)
+{
+	int q_ret, b_ret;
+	unsigned long flags;
+
+	/* Need this because of the deferred pin ctx and ring */
+	/* Shall we move this right after ring is pinned? */
+	update_context_image(ctx, ring);
+
+	q_ret = guc_add_workqueue_item(client, ctx, ring);
+	if (q_ret == 0)
+		b_ret = guc_ring_doorbell(client);
+
+	spin_lock_irqsave(&client->wq_lock, flags);
+	client->submissions += 1;
+	if (q_ret) {
+		client->q_fail += 1;
+		client->retcode = q_ret;
+	} else if (b_ret) {
+		client->b_fail += 1;
+		client->retcode = q_ret = b_ret;
+	} else {
+		client->retcode = 0;
+	}
+	spin_unlock_irqrestore(&client->wq_lock, flags);
+
+	return q_ret;
+}
+
+/*
+ * Everything below here is concerned with setup & teardown, and is
+ * therefore not part of the somewhat time-critical batch-submission
+ * path of i915_guc_submit() above.
+ */
+
+/**
  * gem_allocate_guc_obj() - Allocate gem object for GuC usage
  * @dev:	drm device
  * @size:	size of object
@@ -75,6 +593,121 @@  static void gem_release_guc_obj(struct drm_i915_gem_object *obj)
 	drm_gem_object_unreference(&obj->base);
 }
 
+static void guc_client_free(struct drm_device *dev,
+			    struct i915_guc_client *client)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_guc *guc = &dev_priv->guc;
+
+	if (!client)
+		return;
+
+	if (client->doorbell_id != GUC_INVALID_DOORBELL_ID) {
+		/*
+		 * First disable the doorbell, then tell the GuC we've
+		 * finished with it, finally deallocate it in our bitmap
+		 */
+		guc_disable_doorbell(guc, client);
+		host2guc_release_doorbell(guc, client);
+		release_doorbell(guc, client->doorbell_id);
+	}
+
+	/*
+	 * XXX: wait for any outstanding submissions before freeing memory.
+	 * Be sure to drop any locks
+	 */
+
+	gem_release_guc_obj(client->client_obj);
+
+	if (client->ctx_index != GUC_INVALID_CTX_ID) {
+		guc_fini_ctx_desc(guc, client);
+		ida_simple_remove(&guc->ctx_ids, client->ctx_index);
+	}
+
+	kfree(client);
+}
+
+/**
+ * guc_client_alloc() - Allocate an i915_guc_client
+ * @dev:	drm device
+ * @priority:	four levels priority _CRITICAL, _HIGH, _NORMAL and _LOW
+ * 		The kernel client to replace ExecList submission is created with
+ * 		NORMAL priority. Priority of a client for scheduler can be HIGH,
+ * 		while a preemption context can use CRITICAL.
+ *
+ * Return:	An i915_guc_client object if success.
+ */
+static struct i915_guc_client *guc_client_alloc(struct drm_device *dev,
+						uint32_t priority)
+{
+	struct i915_guc_client *client;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_guc *guc = &dev_priv->guc;
+	struct drm_i915_gem_object *obj;
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return NULL;
+
+	client->doorbell_id = GUC_INVALID_DOORBELL_ID;
+	client->priority = priority;
+
+	client->ctx_index = (uint32_t)ida_simple_get(&guc->ctx_ids, 0,
+			GUC_MAX_GPU_CONTEXTS, GFP_KERNEL);
+	if (client->ctx_index >= GUC_MAX_GPU_CONTEXTS) {
+		client->ctx_index = GUC_INVALID_CTX_ID;
+		goto err;
+	}
+
+	/* The first page is doorbell/proc_desc. Two followed pages are wq. */
+	obj = gem_allocate_guc_obj(dev, GUC_DB_SIZE + GUC_WQ_SIZE);
+	if (!obj)
+		goto err;
+
+	client->client_obj = obj;
+	client->wq_offset = GUC_DB_SIZE;
+	client->wq_size = GUC_WQ_SIZE;
+	spin_lock_init(&client->wq_lock);
+
+	client->doorbell_offset = select_doorbell_cacheline(guc);
+
+	/*
+	 * Since the doorbell only requires a single cacheline, we can save
+	 * space by putting the application process descriptor in the same
+	 * page. Use the half of the page that doesn't include the doorbell.
+	 */
+	if (client->doorbell_offset >= (GUC_DB_SIZE / 2))
+		client->proc_desc_offset = 0;
+	else
+		client->proc_desc_offset = (GUC_DB_SIZE / 2);
+
+	client->doorbell_id = assign_doorbell(guc, client->priority);
+	if (client->doorbell_id == GUC_INVALID_DOORBELL_ID)
+		/* XXX: evict a doorbell instead */
+		goto err;
+
+	guc_init_proc_desc(guc, client);
+	guc_init_ctx_desc(guc, client);
+	guc_init_doorbell(guc, client);
+
+	/* Invalidate GuC TLB to let GuC take the latest updates to GTT. */
+	I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);
+
+	/* XXX: Any cache flushes needed? General domain mgmt calls? */
+
+	if (host2guc_allocate_doorbell(guc, client))
+		goto err;
+
+	DRM_DEBUG_DRIVER("new priority %u client %p: ctx_index %u db_id %u\n",
+		priority, client, client->ctx_index, client->doorbell_id);
+
+	return client;
+
+err:
+	guc_client_free(dev, client);
+	return NULL;
+}
+
 static void guc_create_log(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
@@ -138,6 +771,8 @@  int i915_guc_submission_init(struct drm_device *dev)
 	if (!guc->ctx_pool_obj)
 		return -ENOMEM;
 
+	spin_lock_init(&dev_priv->guc.host2guc_lock);
+
 	ida_init(&guc->ctx_ids);
 
 	guc_create_log(guc);
@@ -145,6 +780,32 @@  int i915_guc_submission_init(struct drm_device *dev)
 	return 0;
 }
 
+int i915_guc_submission_enable(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_guc *guc = &dev_priv->guc;
+	struct i915_guc_client *client;
+
+	/* client for execbuf submission */
+	client = guc_client_alloc(dev, GUC_CTX_PRIORITY_NORMAL);
+	if (!client) {
+		DRM_ERROR("Failed to create execbuf guc_client\n");
+		return -ENOMEM;
+	}
+
+	guc->execbuf_client = client;
+	return 0;
+}
+
+void i915_guc_submission_disable(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_guc *guc = &dev_priv->guc;
+
+	guc_client_free(dev, guc->execbuf_client);
+	guc->execbuf_client = NULL;
+}
+
 void i915_guc_submission_fini(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index 394e106..d7ffb0f 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -28,6 +28,30 @@ 
 #include "intel_guc_fwif.h"
 #include "i915_guc_reg.h"
 
+struct i915_guc_client {
+	struct drm_i915_gem_object *client_obj;
+	uint32_t priority;
+	uint32_t ctx_index;
+
+	uint32_t proc_desc_offset;
+	uint32_t doorbell_offset;
+	uint32_t cookie;
+	uint16_t doorbell_id;
+	uint16_t padding;		/* Maintain alignment		*/
+
+	uint32_t wq_offset;
+	uint32_t wq_size;
+
+	spinlock_t wq_lock;		/* Protects all data below	*/
+	uint32_t wq_tail;
+
+	/* GuC submission statistics & status */
+	uint64_t submissions;
+	uint32_t q_fail;
+	uint32_t b_fail;
+	int retcode;
+};
+
 struct intel_guc {
 	/* Generic uC firmware management */
 	struct intel_uc_fw guc_fw;
@@ -43,6 +67,20 @@  struct intel_guc {
 
 	struct drm_i915_gem_object *ctx_pool_obj;
 	struct ida ctx_ids;
+
+	struct i915_guc_client *execbuf_client;
+
+	spinlock_t host2guc_lock;	/* Protects all data below	*/
+
+	DECLARE_BITMAP(doorbell_bitmap, GUC_MAX_DOORBELLS);
+	int db_cacheline;
+
+	/* Action status & statistics */
+	uint64_t action_count;		/* Total commands issued	*/
+	uint32_t action_cmd;		/* Last command word		*/
+	uint32_t action_status;		/* Last return status		*/
+	uint32_t action_fail;		/* Total number of failures	*/
+	int32_t action_err;		/* Last error code		*/
 };
 
 /* intel_guc_loader.c */
@@ -52,6 +90,11 @@  extern void intel_guc_ucode_fini(struct drm_device *dev);
 
 /* i915_guc_submission.c */
 int i915_guc_submission_init(struct drm_device *dev);
+int i915_guc_submission_enable(struct drm_device *dev);
+int i915_guc_submit(struct i915_guc_client *client,
+		    struct intel_context *ctx,
+		    struct intel_engine_cs *ring);
+void i915_guc_submission_disable(struct drm_device *dev);
 void i915_guc_submission_fini(struct drm_device *dev);
 
 #endif
diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
index 50f16ad..bd85063 100644
--- a/drivers/gpu/drm/i915/intel_guc_loader.c
+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
@@ -409,6 +409,8 @@  int intel_guc_ucode_load(struct drm_device *dev, bool wait)
 	if (guc_fw->uc_fw_fetch_status == INTEL_UC_FIRMWARE_PENDING && !wait)
 		return -EAGAIN;
 
+	i915_guc_submission_disable(dev);
+
 	if (guc_fw->uc_fw_fetch_status == INTEL_UC_FIRMWARE_NONE)
 		return 0;
 
@@ -436,12 +438,20 @@  int intel_guc_ucode_load(struct drm_device *dev, bool wait)
 		intel_uc_fw_status_repr(guc_fw->uc_fw_fetch_status),
 		intel_uc_fw_status_repr(guc_fw->uc_fw_load_status));
 
+	if (i915.enable_guc_submission) {
+		err = i915_guc_submission_enable(dev);
+		if (err)
+			goto fail;
+	}
+
 	return 0;
 
 fail:
 	if (guc_fw->uc_fw_load_status == INTEL_UC_FIRMWARE_PENDING)
 		guc_fw->uc_fw_load_status = INTEL_UC_FIRMWARE_FAIL;
 
+	i915_guc_submission_disable(dev);
+
 	DRM_ERROR("Failed to initialize GuC, error %d\n", err);
 
 	return err;