[Intel-gfx] [PATCH 17/26] drm/i915/guc: Connect UAPI to GuC multi-lrc interface

Matthew Brost matthew.brost at intel.com
Mon Oct 11 22:59:49 UTC 2021


On Mon, Oct 11, 2021 at 03:09:43PM -0700, John Harrison wrote:
> On 10/4/2021 15:06, Matthew Brost wrote:
> > Introduce 'set parallel submit' extension to connect UAPI to GuC
> > multi-lrc interface. Kernel doc in new uAPI should explain it all.
> > 
> > IGT: https://patchwork.freedesktop.org/patch/447008/?series=93071&rev=1
> > media UMD: https://github.com/intel/media-driver/pull/1252
> > 
> > v2:
> >   (Daniel Vetter)
> >    - Add IGT link and placeholder for media UMD link
> > v3:
> >   (Kernel test robot)
> >    - Fix warning in unpin engines call
> >   (John Harrison)
> >    - Reword a bunch of the kernel doc
> > 
> > Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> > ---
> >   drivers/gpu/drm/i915/gem/i915_gem_context.c   | 221 +++++++++++++++++-
> >   .../gpu/drm/i915/gem/i915_gem_context_types.h |   6 +
> >   drivers/gpu/drm/i915/gt/intel_context_types.h |   9 +-
> >   drivers/gpu/drm/i915/gt/intel_engine.h        |  12 +-
> >   drivers/gpu/drm/i915/gt/intel_engine_cs.c     |   6 +-
> >   .../drm/i915/gt/intel_execlists_submission.c  |   6 +-
> >   drivers/gpu/drm/i915/gt/selftest_execlists.c  |  12 +-
> >   .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 114 ++++++++-
> >   include/uapi/drm/i915_drm.h                   | 131 +++++++++++
> >   9 files changed, 489 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > index 8c7ea6e56262..6290bc20ccb1 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > @@ -522,9 +522,150 @@ set_proto_ctx_engines_bond(struct i915_user_extension __user *base, void *data)
> >   	return 0;
> >   }
> > +static int
> > +set_proto_ctx_engines_parallel_submit(struct i915_user_extension __user *base,
> > +				      void *data)
> > +{
> > +	struct i915_context_engines_parallel_submit __user *ext =
> > +		container_of_user(base, typeof(*ext), base);
> > +	const struct set_proto_ctx_engines *set = data;
> > +	struct drm_i915_private *i915 = set->i915;
> > +	u64 flags;
> > +	int err = 0, n, i, j;
> > +	u16 slot, width, num_siblings;
> > +	struct intel_engine_cs **siblings = NULL;
> > +	intel_engine_mask_t prev_mask;
> > +
> > +	/* Disabling for now */
> > +	return -ENODEV;
> > +
> > +	/* FIXME: This is NIY for execlists */
> > +	if (!(intel_uc_uses_guc_submission(&i915->gt.uc)))
> > +		return -ENODEV;
> > +
> > +	if (get_user(slot, &ext->engine_index))
> > +		return -EFAULT;
> > +
> > +	if (get_user(width, &ext->width))
> > +		return -EFAULT;
> > +
> > +	if (get_user(num_siblings, &ext->num_siblings))
> > +		return -EFAULT;
> > +
> > +	if (slot >= set->num_engines) {
> > +		drm_dbg(&i915->drm, "Invalid placement value, %d >= %d\n",
> > +			slot, set->num_engines);
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (set->engines[slot].type != I915_GEM_ENGINE_TYPE_INVALID) {
> > +		drm_dbg(&i915->drm,
> > +			"Invalid placement[%d], already occupied\n", slot);
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (get_user(flags, &ext->flags))
> > +		return -EFAULT;
> > +
> > +	if (flags) {
> > +		drm_dbg(&i915->drm, "Unknown flags 0x%02llx", flags);
> > +		return -EINVAL;
> > +	}
> > +
> > +	for (n = 0; n < ARRAY_SIZE(ext->mbz64); n++) {
> > +		err = check_user_mbz(&ext->mbz64[n]);
> > +		if (err)
> > +			return err;
> > +	}
> > +
> > +	if (width < 2) {
> > +		drm_dbg(&i915->drm, "Width (%d) < 2\n", width);
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (num_siblings < 1) {
> > +		drm_dbg(&i915->drm, "Number siblings (%d) < 1\n",
> > +			num_siblings);
> > +		return -EINVAL;
> > +	}
> > +
> > +	siblings = kmalloc_array(num_siblings * width,
> > +				 sizeof(*siblings),
> > +				 GFP_KERNEL);
> > +	if (!siblings)
> > +		return -ENOMEM;
> > +
> > +	/* Create contexts / engines */
> > +	for (i = 0; i < width; ++i) {
> > +		intel_engine_mask_t current_mask = 0;
> > +		struct i915_engine_class_instance prev_engine;
> > +
> > +		for (j = 0; j < num_siblings; ++j) {
> > +			struct i915_engine_class_instance ci;
> > +
> > +			n = i * num_siblings + j;
> > +			if (copy_from_user(&ci, &ext->engines[n], sizeof(ci))) {
> > +				err = -EFAULT;
> > +				goto out_err;
> > +			}
> > +
> > +			siblings[n] =
> > +				intel_engine_lookup_user(i915, ci.engine_class,
> > +							 ci.engine_instance);
> > +			if (!siblings[n]) {
> > +				drm_dbg(&i915->drm,
> > +					"Invalid sibling[%d]: { class:%d, inst:%d }\n",
> > +					n, ci.engine_class, ci.engine_instance);
> > +				err = -EINVAL;
> > +				goto out_err;
> > +			}
> > +
> > +			if (n) {
> > +				if (prev_engine.engine_class !=
> > +				    ci.engine_class) {
> > +					drm_dbg(&i915->drm,
> > +						"Mismatched class %d, %d\n",
> > +						prev_engine.engine_class,
> > +						ci.engine_class);
> > +					err = -EINVAL;
> > +					goto out_err;
> > +				}
> > +			}
> > +
> > +			prev_engine = ci;
> > +			current_mask |= siblings[n]->logical_mask;
> > +		}
> > +
> > +		if (i > 0) {
> > +			if (current_mask != prev_mask << 1) {
> > +				drm_dbg(&i915->drm,
> > +					"Non contiguous logical mask 0x%x, 0x%x\n",
> > +					prev_mask, current_mask);
> > +				err = -EINVAL;
> > +				goto out_err;
> > +			}
> > +		}
> > +		prev_mask = current_mask;
> > +	}
> > +
> > +	set->engines[slot].type = I915_GEM_ENGINE_TYPE_PARALLEL;
> > +	set->engines[slot].num_siblings = num_siblings;
> > +	set->engines[slot].width = width;
> > +	set->engines[slot].siblings = siblings;
> > +
> > +	return 0;
> > +
> > +out_err:
> > +	kfree(siblings);
> > +
> > +	return err;
> > +}
> > +
> >   static const i915_user_extension_fn set_proto_ctx_engines_extensions[] = {
> >   	[I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE] = set_proto_ctx_engines_balance,
> >   	[I915_CONTEXT_ENGINES_EXT_BOND] = set_proto_ctx_engines_bond,
> > +	[I915_CONTEXT_ENGINES_EXT_PARALLEL_SUBMIT] =
> > +		set_proto_ctx_engines_parallel_submit,
> >   };
> >   static int set_proto_ctx_engines(struct drm_i915_file_private *fpriv,
> > @@ -775,6 +916,25 @@ static int intel_context_set_gem(struct intel_context *ce,
> >   	return ret;
> >   }
> > +static void __unpin_engines(struct i915_gem_engines *e, unsigned int count)
> > +{
> > +	while (count--) {
> > +		struct intel_context *ce = e->engines[count], *child;
> > +
> > +		if (!ce || !test_bit(CONTEXT_PERMA_PIN, &ce->flags))
> > +			continue;
> > +
> > +		for_each_child(ce, child)
> > +			intel_context_unpin(child);
> > +		intel_context_unpin(ce);
> > +	}
> > +}
> > +
> > +static void unpin_engines(struct i915_gem_engines *e)
> > +{
> > +	__unpin_engines(e, e->num_engines);
> > +}
> > +
> >   static void __free_engines(struct i915_gem_engines *e, unsigned int count)
> >   {
> >   	while (count--) {
> > @@ -890,6 +1050,40 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx,
> >   	return err;
> >   }
> > +static int perma_pin_contexts(struct intel_context *ce)
> > +{
> > +	struct intel_context *child;
> > +	int i = 0, j = 0, ret;
> > +
> > +	GEM_BUG_ON(!intel_context_is_parent(ce));
> > +
> > +	ret = intel_context_pin(ce);
> > +	if (unlikely(ret))
> > +		return ret;
> > +
> > +	for_each_child(ce, child) {
> > +		ret = intel_context_pin(child);
> > +		if (unlikely(ret))
> > +			goto unwind;
> > +		++i;
> > +	}
> > +
> > +	set_bit(CONTEXT_PERMA_PIN, &ce->flags);
> > +
> > +	return 0;
> > +
> > +unwind:
> > +	intel_context_unpin(ce);
> > +	for_each_child(ce, child) {
> > +		if (j++ < i)
> > +			intel_context_unpin(child);
> > +		else
> > +			break;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> >   static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
> >   					     unsigned int num_engines,
> >   					     struct i915_gem_proto_engine *pe)
> > @@ -903,7 +1097,7 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
> >   	e->num_engines = num_engines;
> >   	for (n = 0; n < num_engines; n++) {
> > -		struct intel_context *ce;
> > +		struct intel_context *ce, *child;
> >   		int ret;
> >   		switch (pe[n].type) {
> > @@ -913,7 +1107,13 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
> >   		case I915_GEM_ENGINE_TYPE_BALANCED:
> >   			ce = intel_engine_create_virtual(pe[n].siblings,
> > -							 pe[n].num_siblings);
> > +							 pe[n].num_siblings, 0);
> > +			break;
> > +
> > +		case I915_GEM_ENGINE_TYPE_PARALLEL:
> > +			ce = intel_engine_create_parallel(pe[n].siblings,
> > +							  pe[n].num_siblings,
> > +							  pe[n].width);
> >   			break;
> >   		case I915_GEM_ENGINE_TYPE_INVALID:
> > @@ -934,6 +1134,22 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
> >   			err = ERR_PTR(ret);
> >   			goto free_engines;
> >   		}
> > +		for_each_child(ce, child) {
> > +			ret = intel_context_set_gem(child, ctx, pe->sseu);
> > +			if (ret) {
> > +				err = ERR_PTR(ret);
> > +				goto free_engines;
> > +			}
> > +		}
> > +
> > +		/* XXX: Must be done after setting gem context */
> There is still no explanation of this comment either here or in the commit
> message. It needs to say why it is a problem that the perma-pin must be done
> after the above set_gem call. And what must be done to fix this problem. And
> what issues could be expected because of this problem.
> 

I think the issue is intel_context_set_gem changes to the ring_size to
16k (default 4k) and the pin allocates the context state (including the
ring) so if alloc is done before calling intel_context_set_gem we have
mismatch between ring_size and what was allocated. I think this results
in hangs. Which some reordering we likely could push the perma-pinning
into the backend function intel_engine_create_parallel. It is fine as is
but at some point we may want to do this ordering so that's why I have
the XXX. Will add comment here explaining this.

> > +		if (pe[n].type == I915_GEM_ENGINE_TYPE_PARALLEL) {
> > +			ret = perma_pin_contexts(ce);
> > +			if (ret) {
> > +				err = ERR_PTR(ret);
> > +				goto free_engines;
> > +			}
> > +		}
> >   	}
> >   	return e;
> > @@ -1173,6 +1389,7 @@ static void context_close(struct i915_gem_context *ctx)
> >   	/* Flush any concurrent set_engines() */
> >   	mutex_lock(&ctx->engines_mutex);
> > +	unpin_engines(__context_engines_static(ctx));
> >   	engines_idle_release(ctx, rcu_replace_pointer(ctx->engines, NULL, 1));
> >   	i915_gem_context_set_closed(ctx);
> >   	mutex_unlock(&ctx->engines_mutex);
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> > index c4617e4d9fa9..eb5f9b4f2d19 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> > @@ -78,6 +78,9 @@ enum i915_gem_engine_type {
> >   	/** @I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set */
> >   	I915_GEM_ENGINE_TYPE_BALANCED,
> > +
> > +	/** @I915_GEM_ENGINE_TYPE_PARALLEL: A parallel engine set */
> > +	I915_GEM_ENGINE_TYPE_PARALLEL,
> >   };
> >   /**
> > @@ -108,6 +111,9 @@ struct i915_gem_proto_engine {
> >   	/** @num_siblings: Number of balanced siblings */
> Should this be updated to say 'number of balanced or parallel siblings'?
> 

Yes it should. Will fix.

Matt

> John.
> 
> >   	unsigned int num_siblings;
> > +	/** @width: Width of each sibling */
> > +	unsigned int width;
> > +
> >   	/** @siblings: Balanced siblings */
> >   	struct intel_engine_cs **siblings;
> > diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
> > index 8309d1141d0a..1d880303a7e4 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_context_types.h
> > +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
> > @@ -55,9 +55,13 @@ struct intel_context_ops {
> >   	void (*reset)(struct intel_context *ce);
> >   	void (*destroy)(struct kref *kref);
> > -	/* virtual engine/context interface */
> > +	/* virtual/parallel engine/context interface */
> >   	struct intel_context *(*create_virtual)(struct intel_engine_cs **engine,
> > -						unsigned int count);
> > +						unsigned int count,
> > +						unsigned long flags);
> > +	struct intel_context *(*create_parallel)(struct intel_engine_cs **engines,
> > +						 unsigned int num_siblings,
> > +						 unsigned int width);
> >   	struct intel_engine_cs *(*get_sibling)(struct intel_engine_cs *engine,
> >   					       unsigned int sibling);
> >   };
> > @@ -113,6 +117,7 @@ struct intel_context {
> >   #define CONTEXT_NOPREEMPT		8
> >   #define CONTEXT_LRCA_DIRTY		9
> >   #define CONTEXT_GUC_INIT		10
> > +#define CONTEXT_PERMA_PIN		11
> >   	struct {
> >   		u64 timeout_us;
> > diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
> > index 87579affb952..43f16a8347ee 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_engine.h
> > +++ b/drivers/gpu/drm/i915/gt/intel_engine.h
> > @@ -279,9 +279,19 @@ intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
> >   	return intel_engine_has_preemption(engine);
> >   }
> > +#define FORCE_VIRTUAL	BIT(0)
> >   struct intel_context *
> >   intel_engine_create_virtual(struct intel_engine_cs **siblings,
> > -			    unsigned int count);
> > +			    unsigned int count, unsigned long flags);
> > +
> > +static inline struct intel_context *
> > +intel_engine_create_parallel(struct intel_engine_cs **engines,
> > +			     unsigned int num_engines,
> > +			     unsigned int width)
> > +{
> > +	GEM_BUG_ON(!engines[0]->cops->create_parallel);
> > +	return engines[0]->cops->create_parallel(engines, num_engines, width);
> > +}
> >   static inline bool
> >   intel_virtual_engine_has_heartbeat(const struct intel_engine_cs *engine)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> > index 2eb798ad068b..ff6753ccb129 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> > @@ -1953,16 +1953,16 @@ ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine, ktime_t *now)
> >   struct intel_context *
> >   intel_engine_create_virtual(struct intel_engine_cs **siblings,
> > -			    unsigned int count)
> > +			    unsigned int count, unsigned long flags)
> >   {
> >   	if (count == 0)
> >   		return ERR_PTR(-EINVAL);
> > -	if (count == 1)
> > +	if (count == 1 && !(flags & FORCE_VIRTUAL))
> >   		return intel_context_create(siblings[0]);
> >   	GEM_BUG_ON(!siblings[0]->cops->create_virtual);
> > -	return siblings[0]->cops->create_virtual(siblings, count);
> > +	return siblings[0]->cops->create_virtual(siblings, count, flags);
> >   }
> >   struct i915_request *
> > diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > index 5ed1e222c308..8d7f571029df 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > @@ -201,7 +201,8 @@ static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine)
> >   }
> >   static struct intel_context *
> > -execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count);
> > +execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count,
> > +			 unsigned long flags);
> >   static struct i915_request *
> >   __active_request(const struct intel_timeline * const tl,
> > @@ -3784,7 +3785,8 @@ static void virtual_submit_request(struct i915_request *rq)
> >   }
> >   static struct intel_context *
> > -execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
> > +execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count,
> > +			 unsigned long flags)
> >   {
> >   	struct virtual_engine *ve;
> >   	unsigned int n;
> > diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c b/drivers/gpu/drm/i915/gt/selftest_execlists.c
> > index b3863abc51f5..74986b094b96 100644
> > --- a/drivers/gpu/drm/i915/gt/selftest_execlists.c
> > +++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c
> > @@ -3733,7 +3733,7 @@ static int nop_virtual_engine(struct intel_gt *gt,
> >   	GEM_BUG_ON(!nctx || nctx > ARRAY_SIZE(ve));
> >   	for (n = 0; n < nctx; n++) {
> > -		ve[n] = intel_engine_create_virtual(siblings, nsibling);
> > +		ve[n] = intel_engine_create_virtual(siblings, nsibling, 0);
> >   		if (IS_ERR(ve[n])) {
> >   			err = PTR_ERR(ve[n]);
> >   			nctx = n;
> > @@ -3929,7 +3929,7 @@ static int mask_virtual_engine(struct intel_gt *gt,
> >   	 * restrict it to our desired engine within the virtual engine.
> >   	 */
> > -	ve = intel_engine_create_virtual(siblings, nsibling);
> > +	ve = intel_engine_create_virtual(siblings, nsibling, 0);
> >   	if (IS_ERR(ve)) {
> >   		err = PTR_ERR(ve);
> >   		goto out_close;
> > @@ -4060,7 +4060,7 @@ static int slicein_virtual_engine(struct intel_gt *gt,
> >   		i915_request_add(rq);
> >   	}
> > -	ce = intel_engine_create_virtual(siblings, nsibling);
> > +	ce = intel_engine_create_virtual(siblings, nsibling, 0);
> >   	if (IS_ERR(ce)) {
> >   		err = PTR_ERR(ce);
> >   		goto out;
> > @@ -4112,7 +4112,7 @@ static int sliceout_virtual_engine(struct intel_gt *gt,
> >   	/* XXX We do not handle oversubscription and fairness with normal rq */
> >   	for (n = 0; n < nsibling; n++) {
> > -		ce = intel_engine_create_virtual(siblings, nsibling);
> > +		ce = intel_engine_create_virtual(siblings, nsibling, 0);
> >   		if (IS_ERR(ce)) {
> >   			err = PTR_ERR(ce);
> >   			goto out;
> > @@ -4214,7 +4214,7 @@ static int preserved_virtual_engine(struct intel_gt *gt,
> >   	if (err)
> >   		goto out_scratch;
> > -	ve = intel_engine_create_virtual(siblings, nsibling);
> > +	ve = intel_engine_create_virtual(siblings, nsibling, 0);
> >   	if (IS_ERR(ve)) {
> >   		err = PTR_ERR(ve);
> >   		goto out_scratch;
> > @@ -4354,7 +4354,7 @@ static int reset_virtual_engine(struct intel_gt *gt,
> >   	if (igt_spinner_init(&spin, gt))
> >   		return -ENOMEM;
> > -	ve = intel_engine_create_virtual(siblings, nsibling);
> > +	ve = intel_engine_create_virtual(siblings, nsibling, 0);
> >   	if (IS_ERR(ve)) {
> >   		err = PTR_ERR(ve);
> >   		goto out_spin;
> > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> > index f69e984683aa..9b19e0d830a2 100644
> > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> > @@ -124,7 +124,13 @@ struct guc_virtual_engine {
> >   };
> >   static struct intel_context *
> > -guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count);
> > +guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count,
> > +		   unsigned long flags);
> > +
> > +static struct intel_context *
> > +guc_create_parallel(struct intel_engine_cs **engines,
> > +		    unsigned int num_siblings,
> > +		    unsigned int width);
> >   #define GUC_REQUEST_SIZE 64 /* bytes */
> > @@ -2611,6 +2617,7 @@ static const struct intel_context_ops guc_context_ops = {
> >   	.destroy = guc_context_destroy,
> >   	.create_virtual = guc_create_virtual,
> > +	.create_parallel = guc_create_parallel,
> >   };
> >   static void submit_work_cb(struct irq_work *wrk)
> > @@ -2860,8 +2867,6 @@ static const struct intel_context_ops virtual_guc_context_ops = {
> >   	.get_sibling = guc_virtual_get_sibling,
> >   };
> > -/* Future patches will use this function */
> > -__maybe_unused
> >   static int guc_parent_context_pin(struct intel_context *ce, void *vaddr)
> >   {
> >   	struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
> > @@ -2878,8 +2883,6 @@ static int guc_parent_context_pin(struct intel_context *ce, void *vaddr)
> >   	return __guc_context_pin(ce, engine, vaddr);
> >   }
> > -/* Future patches will use this function */
> > -__maybe_unused
> >   static int guc_child_context_pin(struct intel_context *ce, void *vaddr)
> >   {
> >   	struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
> > @@ -2891,8 +2894,6 @@ static int guc_child_context_pin(struct intel_context *ce, void *vaddr)
> >   	return __guc_context_pin(ce, engine, vaddr);
> >   }
> > -/* Future patches will use this function */
> > -__maybe_unused
> >   static void guc_parent_context_unpin(struct intel_context *ce)
> >   {
> >   	struct intel_guc *guc = ce_to_guc(ce);
> > @@ -2908,8 +2909,6 @@ static void guc_parent_context_unpin(struct intel_context *ce)
> >   	lrc_unpin(ce);
> >   }
> > -/* Future patches will use this function */
> > -__maybe_unused
> >   static void guc_child_context_unpin(struct intel_context *ce)
> >   {
> >   	GEM_BUG_ON(context_enabled(ce));
> > @@ -2920,8 +2919,6 @@ static void guc_child_context_unpin(struct intel_context *ce)
> >   	lrc_unpin(ce);
> >   }
> > -/* Future patches will use this function */
> > -__maybe_unused
> >   static void guc_child_context_post_unpin(struct intel_context *ce)
> >   {
> >   	GEM_BUG_ON(!intel_context_is_child(ce));
> > @@ -2932,6 +2929,98 @@ static void guc_child_context_post_unpin(struct intel_context *ce)
> >   	intel_context_unpin(ce->parallel.parent);
> >   }
> > +static void guc_child_context_destroy(struct kref *kref)
> > +{
> > +	struct intel_context *ce = container_of(kref, typeof(*ce), ref);
> > +
> > +	__guc_context_destroy(ce);
> > +}
> > +
> > +static const struct intel_context_ops virtual_parent_context_ops = {
> > +	.alloc = guc_virtual_context_alloc,
> > +
> > +	.pre_pin = guc_context_pre_pin,
> > +	.pin = guc_parent_context_pin,
> > +	.unpin = guc_parent_context_unpin,
> > +	.post_unpin = guc_context_post_unpin,
> > +
> > +	.ban = guc_context_ban,
> > +
> > +	.cancel_request = guc_context_cancel_request,
> > +
> > +	.enter = guc_virtual_context_enter,
> > +	.exit = guc_virtual_context_exit,
> > +
> > +	.sched_disable = guc_context_sched_disable,
> > +
> > +	.destroy = guc_context_destroy,
> > +
> > +	.get_sibling = guc_virtual_get_sibling,
> > +};
> > +
> > +static const struct intel_context_ops virtual_child_context_ops = {
> > +	.alloc = guc_virtual_context_alloc,
> > +
> > +	.pre_pin = guc_context_pre_pin,
> > +	.pin = guc_child_context_pin,
> > +	.unpin = guc_child_context_unpin,
> > +	.post_unpin = guc_child_context_post_unpin,
> > +
> > +	.cancel_request = guc_context_cancel_request,
> > +
> > +	.enter = guc_virtual_context_enter,
> > +	.exit = guc_virtual_context_exit,
> > +
> > +	.destroy = guc_child_context_destroy,
> > +
> > +	.get_sibling = guc_virtual_get_sibling,
> > +};
> > +
> > +static struct intel_context *
> > +guc_create_parallel(struct intel_engine_cs **engines,
> > +		    unsigned int num_siblings,
> > +		    unsigned int width)
> > +{
> > +	struct intel_engine_cs **siblings = NULL;
> > +	struct intel_context *parent = NULL, *ce, *err;
> > +	int i, j;
> > +
> > +	siblings = kmalloc_array(num_siblings,
> > +				 sizeof(*siblings),
> > +				 GFP_KERNEL);
> > +	if (!siblings)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	for (i = 0; i < width; ++i) {
> > +		for (j = 0; j < num_siblings; ++j)
> > +			siblings[j] = engines[i * num_siblings + j];
> > +
> > +		ce = intel_engine_create_virtual(siblings, num_siblings,
> > +						 FORCE_VIRTUAL);
> > +		if (!ce) {
> > +			err = ERR_PTR(-ENOMEM);
> > +			goto unwind;
> > +		}
> > +
> > +		if (i == 0) {
> > +			parent = ce;
> > +			parent->ops = &virtual_parent_context_ops;
> > +		} else {
> > +			ce->ops = &virtual_child_context_ops;
> > +			intel_context_bind_parent_child(parent, ce);
> > +		}
> > +	}
> > +
> > +	kfree(siblings);
> > +	return parent;
> > +
> > +unwind:
> > +	if (parent)
> > +		intel_context_put(parent);
> > +	kfree(siblings);
> > +	return err;
> > +}
> > +
> >   static bool
> >   guc_irq_enable_breadcrumbs(struct intel_breadcrumbs *b)
> >   {
> > @@ -3759,7 +3848,8 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc,
> >   }
> >   static struct intel_context *
> > -guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
> > +guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count,
> > +		   unsigned long flags)
> >   {
> >   	struct guc_virtual_engine *ve;
> >   	struct intel_guc *guc;
> > diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> > index b1248a67b4f8..f7c19e5464ae 100644
> > --- a/include/uapi/drm/i915_drm.h
> > +++ b/include/uapi/drm/i915_drm.h
> > @@ -1824,6 +1824,7 @@ struct drm_i915_gem_context_param {
> >    * Extensions:
> >    *   i915_context_engines_load_balance (I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE)
> >    *   i915_context_engines_bond (I915_CONTEXT_ENGINES_EXT_BOND)
> > + *   i915_context_engines_parallel_submit (I915_CONTEXT_ENGINES_EXT_PARALLEL_SUBMIT)
> >    */
> >   #define I915_CONTEXT_PARAM_ENGINES	0xa
> > @@ -2049,6 +2050,135 @@ struct i915_context_engines_bond {
> >   	struct i915_engine_class_instance engines[N__]; \
> >   } __attribute__((packed)) name__
> > +/**
> > + * struct i915_context_engines_parallel_submit - Configure engine for
> > + * parallel submission.
> > + *
> > + * Setup a slot in the context engine map to allow multiple BBs to be submitted
> > + * in a single execbuf IOCTL. Those BBs will then be scheduled to run on the GPU
> > + * in parallel. Multiple hardware contexts are created internally in the i915 to
> > + * run these BBs. Once a slot is configured for N BBs only N BBs can be
> > + * submitted in each execbuf IOCTL and this is implicit behavior e.g. The user
> > + * doesn't tell the execbuf IOCTL there are N BBs, the execbuf IOCTL knows how
> > + * many BBs there are based on the slot's configuration. The N BBs are the last
> > + * N buffer objects or first N if I915_EXEC_BATCH_FIRST is set.
> > + *
> > + * The default placement behavior is to create implicit bonds between each
> > + * context if each context maps to more than 1 physical engine (e.g. context is
> > + * a virtual engine). Also we only allow contexts of same engine class and these
> > + * contexts must be in logically contiguous order. Examples of the placement
> > + * behavior are described below. Lastly, the default is to not allow BBs to be
> > + * preempted mid-batch. Rather insert coordinated preemption points on all
> > + * hardware contexts between each set of BBs. Flags could be added in the future
> > + * to change both of these default behaviors.
> > + *
> > + * Returns -EINVAL if hardware context placement configuration is invalid or if
> > + * the placement configuration isn't supported on the platform / submission
> > + * interface.
> > + * Returns -ENODEV if extension isn't supported on the platform / submission
> > + * interface.
> > + *
> > + * .. code-block:: none
> > + *
> > + *	Examples syntax:
> > + *	CS[X] = generic engine of same class, logical instance X
> > + *	INVALID = I915_ENGINE_CLASS_INVALID, I915_ENGINE_CLASS_INVALID_NONE
> > + *
> > + *	Example 1 pseudo code:
> > + *	set_engines(INVALID)
> > + *	set_parallel(engine_index=0, width=2, num_siblings=1,
> > + *		     engines=CS[0],CS[1])
> > + *
> > + *	Results in the following valid placement:
> > + *	CS[0], CS[1]
> > + *
> > + *	Example 2 pseudo code:
> > + *	set_engines(INVALID)
> > + *	set_parallel(engine_index=0, width=2, num_siblings=2,
> > + *		     engines=CS[0],CS[2],CS[1],CS[3])
> > + *
> > + *	Results in the following valid placements:
> > + *	CS[0], CS[1]
> > + *	CS[2], CS[3]
> > + *
> > + *	This can be thought of as two virtual engines, each containing two
> > + *	engines thereby making a 2D array. However, there are bonds tying the
> > + *	entries together and placing restrictions on how they can be scheduled.
> > + *	Specifically, the scheduler can choose only vertical columns from the 2D
> > + *	array. That is, CS[0] is bonded to CS[1] and CS[2] to CS[3]. So if the
> > + *	scheduler wants to submit to CS[0], it must also choose CS[1] and vice
> > + *	versa. Same for CS[2] requires also using CS[3].
> > + *	VE[0] = CS[0], CS[2]
> > + *	VE[1] = CS[1], CS[3]
> > + *
> > + *	Example 3 pseudo code:
> > + *	set_engines(INVALID)
> > + *	set_parallel(engine_index=0, width=2, num_siblings=2,
> > + *		     engines=CS[0],CS[1],CS[1],CS[3])
> > + *
> > + *	Results in the following valid and invalid placements:
> > + *	CS[0], CS[1]
> > + *	CS[1], CS[3] - Not logically contiguous, return -EINVAL
> > + */
> > +struct i915_context_engines_parallel_submit {
> > +	/**
> > +	 * @base: base user extension.
> > +	 */
> > +	struct i915_user_extension base;
> > +
> > +	/**
> > +	 * @engine_index: slot for parallel engine
> > +	 */
> > +	__u16 engine_index;
> > +
> > +	/**
> > +	 * @width: number of contexts per parallel engine or in other words the
> > +	 * number of batches in each submission
> > +	 */
> > +	__u16 width;
> > +
> > +	/**
> > +	 * @num_siblings: number of siblings per context or in other words the
> > +	 * number of possible placements for each submission
> > +	 */
> > +	__u16 num_siblings;
> > +
> > +	/**
> > +	 * @mbz16: reserved for future use; must be zero
> > +	 */
> > +	__u16 mbz16;
> > +
> > +	/**
> > +	 * @flags: all undefined flags must be zero, currently not defined flags
> > +	 */
> > +	__u64 flags;
> > +
> > +	/**
> > +	 * @mbz64: reserved for future use; must be zero
> > +	 */
> > +	__u64 mbz64[3];
> > +
> > +	/**
> > +	 * @engines: 2-d array of engine instances to configure parallel engine
> > +	 *
> > +	 * length = width (i) * num_siblings (j)
> > +	 * index = j + i * num_siblings
> > +	 */
> > +	struct i915_engine_class_instance engines[0];
> > +
> > +} __packed;
> > +
> > +#define I915_DEFINE_CONTEXT_ENGINES_PARALLEL_SUBMIT(name__, N__) struct { \
> > +	struct i915_user_extension base; \
> > +	__u16 engine_index; \
> > +	__u16 width; \
> > +	__u16 num_siblings; \
> > +	__u16 mbz16; \
> > +	__u64 flags; \
> > +	__u64 mbz64[3]; \
> > +	struct i915_engine_class_instance engines[N__]; \
> > +} __attribute__((packed)) name__
> > +
> >   /**
> >    * DOC: Context Engine Map uAPI
> >    *
> > @@ -2108,6 +2238,7 @@ struct i915_context_param_engines {
> >   	__u64 extensions; /* linked chain of extension blocks, 0 terminates */
> >   #define I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE 0 /* see i915_context_engines_load_balance */
> >   #define I915_CONTEXT_ENGINES_EXT_BOND 1 /* see i915_context_engines_bond */
> > +#define I915_CONTEXT_ENGINES_EXT_PARALLEL_SUBMIT 2 /* see i915_context_engines_parallel_submit */
> >   	struct i915_engine_class_instance engines[0];
> >   } __attribute__((packed));
> 


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