[Intel-gfx] [RFC v4 08/14] drm/i915/vm_bind: Abstract out common execbuf functions

Niranjana Vishwanathapura niranjana.vishwanathapura at intel.com
Wed Sep 21 07:09:39 UTC 2022


The new execbuf3 ioctl path and the legacy execbuf ioctl
paths have many common functionalities.
Share code between these two paths by abstracting out the
common functionalities into a separate file where possible.

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
---
 drivers/gpu/drm/i915/Makefile                 |   1 +
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 507 ++---------------
 .../drm/i915/gem/i915_gem_execbuffer_common.c | 530 ++++++++++++++++++
 .../drm/i915/gem/i915_gem_execbuffer_common.h |  47 ++
 4 files changed, 612 insertions(+), 473 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.c
 create mode 100644 drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.h

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 9bf939ef18ea..bf952f478555 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -148,6 +148,7 @@ gem-y += \
 	gem/i915_gem_create.o \
 	gem/i915_gem_dmabuf.o \
 	gem/i915_gem_domain.o \
+	gem/i915_gem_execbuffer_common.o \
 	gem/i915_gem_execbuffer.o \
 	gem/i915_gem_internal.o \
 	gem/i915_gem_object.o \
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 33d989a20227..363b2a788cdf 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -9,8 +9,6 @@
 #include <linux/sync_file.h>
 #include <linux/uaccess.h>
 
-#include <drm/drm_syncobj.h>
-
 #include "display/intel_frontbuffer.h"
 
 #include "gem/i915_gem_ioctls.h"
@@ -28,6 +26,7 @@
 #include "i915_file_private.h"
 #include "i915_gem_clflush.h"
 #include "i915_gem_context.h"
+#include "i915_gem_execbuffer_common.h"
 #include "i915_gem_evict.h"
 #include "i915_gem_ioctls.h"
 #include "i915_trace.h"
@@ -235,13 +234,6 @@ enum {
  * the batchbuffer in trusted mode, otherwise the ioctl is rejected.
  */
 
-struct eb_fence {
-	struct drm_syncobj *syncobj; /* Use with ptr_mask_bits() */
-	struct dma_fence *dma_fence;
-	u64 value;
-	struct dma_fence_chain *chain_fence;
-};
-
 struct i915_execbuffer {
 	struct drm_i915_private *i915; /** i915 backpointer */
 	struct drm_file *file; /** per-file lookup tables and limits */
@@ -2446,164 +2438,29 @@ static const enum intel_engine_id user_ring_map[] = {
 	[I915_EXEC_VEBOX]	= VECS0
 };
 
-static struct i915_request *eb_throttle(struct i915_execbuffer *eb, struct intel_context *ce)
-{
-	struct intel_ring *ring = ce->ring;
-	struct intel_timeline *tl = ce->timeline;
-	struct i915_request *rq;
-
-	/*
-	 * Completely unscientific finger-in-the-air estimates for suitable
-	 * maximum user request size (to avoid blocking) and then backoff.
-	 */
-	if (intel_ring_update_space(ring) >= PAGE_SIZE)
-		return NULL;
-
-	/*
-	 * Find a request that after waiting upon, there will be at least half
-	 * the ring available. The hysteresis allows us to compete for the
-	 * shared ring and should mean that we sleep less often prior to
-	 * claiming our resources, but not so long that the ring completely
-	 * drains before we can submit our next request.
-	 */
-	list_for_each_entry(rq, &tl->requests, link) {
-		if (rq->ring != ring)
-			continue;
-
-		if (__intel_ring_space(rq->postfix,
-				       ring->emit, ring->size) > ring->size / 2)
-			break;
-	}
-	if (&rq->link == &tl->requests)
-		return NULL; /* weird, we will check again later for real */
-
-	return i915_request_get(rq);
-}
-
-static int eb_pin_timeline(struct i915_execbuffer *eb, struct intel_context *ce,
-			   bool throttle)
-{
-	struct intel_timeline *tl;
-	struct i915_request *rq = NULL;
-
-	/*
-	 * Take a local wakeref for preparing to dispatch the execbuf as
-	 * we expect to access the hardware fairly frequently in the
-	 * process, and require the engine to be kept awake between accesses.
-	 * Upon dispatch, we acquire another prolonged wakeref that we hold
-	 * until the timeline is idle, which in turn releases the wakeref
-	 * taken on the engine, and the parent device.
-	 */
-	tl = intel_context_timeline_lock(ce);
-	if (IS_ERR(tl))
-		return PTR_ERR(tl);
-
-	intel_context_enter(ce);
-	if (throttle)
-		rq = eb_throttle(eb, ce);
-	intel_context_timeline_unlock(tl);
-
-	if (rq) {
-		bool nonblock = eb->file->filp->f_flags & O_NONBLOCK;
-		long timeout = nonblock ? 0 : MAX_SCHEDULE_TIMEOUT;
-
-		if (i915_request_wait(rq, I915_WAIT_INTERRUPTIBLE,
-				      timeout) < 0) {
-			i915_request_put(rq);
-
-			/*
-			 * Error path, cannot use intel_context_timeline_lock as
-			 * that is user interruptable and this clean up step
-			 * must be done.
-			 */
-			mutex_lock(&ce->timeline->mutex);
-			intel_context_exit(ce);
-			mutex_unlock(&ce->timeline->mutex);
-
-			if (nonblock)
-				return -EWOULDBLOCK;
-			else
-				return -EINTR;
-		}
-		i915_request_put(rq);
-	}
-
-	return 0;
-}
-
 static int eb_pin_engine(struct i915_execbuffer *eb, bool throttle)
 {
-	struct intel_context *ce = eb->context, *child;
 	int err;
-	int i = 0, j = 0;
 
 	GEM_BUG_ON(eb->args->flags & __EXEC_ENGINE_PINNED);
 
-	if (unlikely(intel_context_is_banned(ce)))
-		return -EIO;
-
-	/*
-	 * Pinning the contexts may generate requests in order to acquire
-	 * GGTT space, so do this first before we reserve a seqno for
-	 * ourselves.
-	 */
-	err = intel_context_pin_ww(ce, &eb->ww);
+	err = __eb_pin_engine(eb->context, &eb->ww, throttle,
+			      eb->file->filp->f_flags & O_NONBLOCK);
 	if (err)
 		return err;
-	for_each_child(ce, child) {
-		err = intel_context_pin_ww(child, &eb->ww);
-		GEM_BUG_ON(err);	/* perma-pinned should incr a counter */
-	}
-
-	for_each_child(ce, child) {
-		err = eb_pin_timeline(eb, child, throttle);
-		if (err)
-			goto unwind;
-		++i;
-	}
-	err = eb_pin_timeline(eb, ce, throttle);
-	if (err)
-		goto unwind;
 
 	eb->args->flags |= __EXEC_ENGINE_PINNED;
 	return 0;
-
-unwind:
-	for_each_child(ce, child) {
-		if (j++ < i) {
-			mutex_lock(&child->timeline->mutex);
-			intel_context_exit(child);
-			mutex_unlock(&child->timeline->mutex);
-		}
-	}
-	for_each_child(ce, child)
-		intel_context_unpin(child);
-	intel_context_unpin(ce);
-	return err;
 }
 
 static void eb_unpin_engine(struct i915_execbuffer *eb)
 {
-	struct intel_context *ce = eb->context, *child;
-
 	if (!(eb->args->flags & __EXEC_ENGINE_PINNED))
 		return;
 
 	eb->args->flags &= ~__EXEC_ENGINE_PINNED;
 
-	for_each_child(ce, child) {
-		mutex_lock(&child->timeline->mutex);
-		intel_context_exit(child);
-		mutex_unlock(&child->timeline->mutex);
-
-		intel_context_unpin(child);
-	}
-
-	mutex_lock(&ce->timeline->mutex);
-	intel_context_exit(ce);
-	mutex_unlock(&ce->timeline->mutex);
-
-	intel_context_unpin(ce);
+	__eb_unpin_engine(eb->context);
 }
 
 static unsigned int
@@ -2652,7 +2509,7 @@ eb_select_legacy_ring(struct i915_execbuffer *eb)
 static int
 eb_select_engine(struct i915_execbuffer *eb)
 {
-	struct intel_context *ce, *child;
+	struct intel_context *ce;
 	unsigned int idx;
 	int err;
 
@@ -2677,36 +2534,10 @@ eb_select_engine(struct i915_execbuffer *eb)
 	}
 	eb->num_batches = ce->parallel.number_children + 1;
 
-	for_each_child(ce, child)
-		intel_context_get(child);
-	intel_gt_pm_get(ce->engine->gt);
-
-	if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
-		err = intel_context_alloc_state(ce);
-		if (err)
-			goto err;
-	}
-	for_each_child(ce, child) {
-		if (!test_bit(CONTEXT_ALLOC_BIT, &child->flags)) {
-			err = intel_context_alloc_state(child);
-			if (err)
-				goto err;
-		}
-	}
-
-	/*
-	 * ABI: Before userspace accesses the GPU (e.g. execbuffer), report
-	 * EIO if the GPU is already wedged.
-	 */
-	err = intel_gt_terminally_wedged(ce->engine->gt);
+	err = __eb_select_engine(ce);
 	if (err)
 		goto err;
 
-	if (!i915_vm_tryget(ce->vm)) {
-		err = -ENOENT;
-		goto err;
-	}
-
 	eb->context = ce;
 	eb->gt = ce->engine->gt;
 
@@ -2715,12 +2546,9 @@ eb_select_engine(struct i915_execbuffer *eb)
 	 * during ww handling. The pool is destroyed when last pm reference
 	 * is dropped, which breaks our -EDEADLK handling.
 	 */
-	return err;
+	return 0;
 
 err:
-	intel_gt_pm_put(ce->engine->gt);
-	for_each_child(ce, child)
-		intel_context_put(child);
 	intel_context_put(ce);
 	return err;
 }
@@ -2728,24 +2556,7 @@ eb_select_engine(struct i915_execbuffer *eb)
 static void
 eb_put_engine(struct i915_execbuffer *eb)
 {
-	struct intel_context *child;
-
-	i915_vm_put(eb->context->vm);
-	intel_gt_pm_put(eb->gt);
-	for_each_child(eb->context, child)
-		intel_context_put(child);
-	intel_context_put(eb->context);
-}
-
-static void
-__free_fence_array(struct eb_fence *fences, unsigned int n)
-{
-	while (n--) {
-		drm_syncobj_put(ptr_mask_bits(fences[n].syncobj, 2));
-		dma_fence_put(fences[n].dma_fence);
-		dma_fence_chain_free(fences[n].chain_fence);
-	}
-	kvfree(fences);
+	__eb_put_engine(eb->context, eb->gt);
 }
 
 static int
@@ -2756,7 +2567,6 @@ add_timeline_fence_array(struct i915_execbuffer *eb,
 	u64 __user *user_values;
 	struct eb_fence *f;
 	u64 nfences;
-	int err = 0;
 
 	nfences = timeline_fences->fence_count;
 	if (!nfences)
@@ -2791,9 +2601,9 @@ add_timeline_fence_array(struct i915_execbuffer *eb,
 
 	while (nfences--) {
 		struct drm_i915_gem_exec_fence user_fence;
-		struct drm_syncobj *syncobj;
-		struct dma_fence *fence = NULL;
+		bool wait, signal;
 		u64 point;
+		int ret;
 
 		if (__copy_from_user(&user_fence,
 				     user_fences++,
@@ -2806,70 +2616,15 @@ add_timeline_fence_array(struct i915_execbuffer *eb,
 		if (__get_user(point, user_values++))
 			return -EFAULT;
 
-		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
-		if (!syncobj) {
-			DRM_DEBUG("Invalid syncobj handle provided\n");
-			return -ENOENT;
-		}
-
-		fence = drm_syncobj_fence_get(syncobj);
-
-		if (!fence && user_fence.flags &&
-		    !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
-			DRM_DEBUG("Syncobj handle has no fence\n");
-			drm_syncobj_put(syncobj);
-			return -EINVAL;
-		}
-
-		if (fence)
-			err = dma_fence_chain_find_seqno(&fence, point);
-
-		if (err && !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
-			DRM_DEBUG("Syncobj handle missing requested point %llu\n", point);
-			dma_fence_put(fence);
-			drm_syncobj_put(syncobj);
-			return err;
-		}
-
-		/*
-		 * A point might have been signaled already and
-		 * garbage collected from the timeline. In this case
-		 * just ignore the point and carry on.
-		 */
-		if (!fence && !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
-			drm_syncobj_put(syncobj);
+		wait = user_fence.flags & I915_EXEC_FENCE_WAIT;
+		signal = user_fence.flags & I915_EXEC_FENCE_SIGNAL;
+		ret = add_timeline_fence(eb->file, user_fence.handle, point,
+					 f, wait, signal);
+		if (ret < 0)
+			return ret;
+		else if (!ret)
 			continue;
-		}
 
-		/*
-		 * For timeline syncobjs we need to preallocate chains for
-		 * later signaling.
-		 */
-		if (point != 0 && user_fence.flags & I915_EXEC_FENCE_SIGNAL) {
-			/*
-			 * Waiting and signaling the same point (when point !=
-			 * 0) would break the timeline.
-			 */
-			if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
-				DRM_DEBUG("Trying to wait & signal the same timeline point.\n");
-				dma_fence_put(fence);
-				drm_syncobj_put(syncobj);
-				return -EINVAL;
-			}
-
-			f->chain_fence = dma_fence_chain_alloc();
-			if (!f->chain_fence) {
-				drm_syncobj_put(syncobj);
-				dma_fence_put(fence);
-				return -ENOMEM;
-			}
-		} else {
-			f->chain_fence = NULL;
-		}
-
-		f->syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
-		f->dma_fence = fence;
-		f->value = point;
 		f++;
 		eb->num_fences++;
 	}
@@ -2949,65 +2704,6 @@ static int add_fence_array(struct i915_execbuffer *eb)
 	return 0;
 }
 
-static void put_fence_array(struct eb_fence *fences, int num_fences)
-{
-	if (fences)
-		__free_fence_array(fences, num_fences);
-}
-
-static int
-await_fence_array(struct i915_execbuffer *eb,
-		  struct i915_request *rq)
-{
-	unsigned int n;
-	int err;
-
-	for (n = 0; n < eb->num_fences; n++) {
-		struct drm_syncobj *syncobj;
-		unsigned int flags;
-
-		syncobj = ptr_unpack_bits(eb->fences[n].syncobj, &flags, 2);
-
-		if (!eb->fences[n].dma_fence)
-			continue;
-
-		err = i915_request_await_dma_fence(rq, eb->fences[n].dma_fence);
-		if (err < 0)
-			return err;
-	}
-
-	return 0;
-}
-
-static void signal_fence_array(const struct i915_execbuffer *eb,
-			       struct dma_fence * const fence)
-{
-	unsigned int n;
-
-	for (n = 0; n < eb->num_fences; n++) {
-		struct drm_syncobj *syncobj;
-		unsigned int flags;
-
-		syncobj = ptr_unpack_bits(eb->fences[n].syncobj, &flags, 2);
-		if (!(flags & I915_EXEC_FENCE_SIGNAL))
-			continue;
-
-		if (eb->fences[n].chain_fence) {
-			drm_syncobj_add_point(syncobj,
-					      eb->fences[n].chain_fence,
-					      fence,
-					      eb->fences[n].value);
-			/*
-			 * The chain's ownership is transferred to the
-			 * timeline.
-			 */
-			eb->fences[n].chain_fence = NULL;
-		} else {
-			drm_syncobj_replace_fence(syncobj, fence);
-		}
-	}
-}
-
 static int
 parse_timeline_fences(struct i915_user_extension __user *ext, void *data)
 {
@@ -3020,80 +2716,6 @@ parse_timeline_fences(struct i915_user_extension __user *ext, void *data)
 	return add_timeline_fence_array(eb, &timeline_fences);
 }
 
-static void retire_requests(struct intel_timeline *tl, struct i915_request *end)
-{
-	struct i915_request *rq, *rn;
-
-	list_for_each_entry_safe(rq, rn, &tl->requests, link)
-		if (rq == end || !i915_request_retire(rq))
-			break;
-}
-
-static int eb_request_add(struct i915_execbuffer *eb, struct i915_request *rq,
-			  int err, bool last_parallel)
-{
-	struct intel_timeline * const tl = i915_request_timeline(rq);
-	struct i915_sched_attr attr = {};
-	struct i915_request *prev;
-
-	lockdep_assert_held(&tl->mutex);
-	lockdep_unpin_lock(&tl->mutex, rq->cookie);
-
-	trace_i915_request_add(rq);
-
-	prev = __i915_request_commit(rq);
-
-	/* Check that the context wasn't destroyed before submission */
-	if (likely(!intel_context_is_closed(eb->context))) {
-		attr = eb->gem_context->sched;
-	} else {
-		/* Serialise with context_close via the add_to_timeline */
-		i915_request_set_error_once(rq, -ENOENT);
-		__i915_request_skip(rq);
-		err = -ENOENT; /* override any transient errors */
-	}
-
-	if (intel_context_is_parallel(eb->context)) {
-		if (err) {
-			__i915_request_skip(rq);
-			set_bit(I915_FENCE_FLAG_SKIP_PARALLEL,
-				&rq->fence.flags);
-		}
-		if (last_parallel)
-			set_bit(I915_FENCE_FLAG_SUBMIT_PARALLEL,
-				&rq->fence.flags);
-	}
-
-	__i915_request_queue(rq, &attr);
-
-	/* Try to clean up the client's timeline after submitting the request */
-	if (prev)
-		retire_requests(tl, prev);
-
-	mutex_unlock(&tl->mutex);
-
-	return err;
-}
-
-static int eb_requests_add(struct i915_execbuffer *eb, int err)
-{
-	int i;
-
-	/*
-	 * We iterate in reverse order of creation to release timeline mutexes in
-	 * same order.
-	 */
-	for_each_batch_add_order(eb, i) {
-		struct i915_request *rq = eb->requests[i];
-
-		if (!rq)
-			continue;
-		err |= eb_request_add(eb, rq, err, i == 0);
-	}
-
-	return err;
-}
-
 static const i915_user_extension_fn execbuf_extensions[] = {
 	[DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES] = parse_timeline_fences,
 };
@@ -3120,73 +2742,26 @@ parse_execbuf2_extensions(struct drm_i915_gem_execbuffer2 *args,
 				    eb);
 }
 
-static void eb_requests_get(struct i915_execbuffer *eb)
-{
-	unsigned int i;
-
-	for_each_batch_create_order(eb, i) {
-		if (!eb->requests[i])
-			break;
-
-		i915_request_get(eb->requests[i]);
-	}
-}
-
-static void eb_requests_put(struct i915_execbuffer *eb)
-{
-	unsigned int i;
-
-	for_each_batch_create_order(eb, i) {
-		if (!eb->requests[i])
-			break;
-
-		i915_request_put(eb->requests[i]);
-	}
-}
-
 static struct sync_file *
 eb_composite_fence_create(struct i915_execbuffer *eb, int out_fence_fd)
 {
 	struct sync_file *out_fence = NULL;
-	struct dma_fence_array *fence_array;
-	struct dma_fence **fences;
-	unsigned int i;
-
-	GEM_BUG_ON(!intel_context_is_parent(eb->context));
+	struct dma_fence *fence;
 
-	fences = kmalloc_array(eb->num_batches, sizeof(*fences), GFP_KERNEL);
-	if (!fences)
-		return ERR_PTR(-ENOMEM);
-
-	for_each_batch_create_order(eb, i) {
-		fences[i] = &eb->requests[i]->fence;
-		__set_bit(I915_FENCE_FLAG_COMPOSITE,
-			  &eb->requests[i]->fence.flags);
-	}
-
-	fence_array = dma_fence_array_create(eb->num_batches,
-					     fences,
-					     eb->context->parallel.fence_context,
-					     eb->context->parallel.seqno++,
-					     false);
-	if (!fence_array) {
-		kfree(fences);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	/* Move ownership to the dma_fence_array created above */
-	for_each_batch_create_order(eb, i)
-		dma_fence_get(fences[i]);
+	fence = __eb_composite_fence_create(eb->requests, eb->num_batches,
+					    eb->context);
+	if (IS_ERR(fence))
+		return ERR_CAST(fence);
 
 	if (out_fence_fd != -1) {
-		out_fence = sync_file_create(&fence_array->base);
+		out_fence = sync_file_create(fence);
 		/* sync_file now owns fence_arry, drop creation ref */
-		dma_fence_put(&fence_array->base);
+		dma_fence_put(fence);
 		if (!out_fence)
 			return ERR_PTR(-ENOMEM);
 	}
 
-	eb->composite_fence = &fence_array->base;
+	eb->composite_fence = fence;
 
 	return out_fence;
 }
@@ -3218,7 +2793,7 @@ eb_fences_add(struct i915_execbuffer *eb, struct i915_request *rq,
 	}
 
 	if (eb->fences) {
-		err = await_fence_array(eb, rq);
+		err = await_fence_array(eb->fences, eb->num_fences, rq);
 		if (err)
 			return ERR_PTR(err);
 	}
@@ -3236,23 +2811,6 @@ eb_fences_add(struct i915_execbuffer *eb, struct i915_request *rq,
 	return out_fence;
 }
 
-static struct intel_context *
-eb_find_context(struct i915_execbuffer *eb, unsigned int context_number)
-{
-	struct intel_context *child;
-
-	if (likely(context_number == 0))
-		return eb->context;
-
-	for_each_child(eb->context, child)
-		if (!--context_number)
-			return child;
-
-	GEM_BUG_ON("Context not found");
-
-	return NULL;
-}
-
 static struct sync_file *
 eb_requests_create(struct i915_execbuffer *eb, struct dma_fence *in_fence,
 		   int out_fence_fd)
@@ -3262,7 +2820,8 @@ eb_requests_create(struct i915_execbuffer *eb, struct dma_fence *in_fence,
 
 	for_each_batch_create_order(eb, i) {
 		/* Allocate a request for this batch buffer nice and early. */
-		eb->requests[i] = i915_request_create(eb_find_context(eb, i));
+		eb->requests[i] =
+			i915_request_create(eb_find_context(eb->context, i));
 		if (IS_ERR(eb->requests[i])) {
 			out_fence = ERR_CAST(eb->requests[i]);
 			eb->requests[i] = NULL;
@@ -3442,11 +3001,13 @@ i915_gem_do_execbuffer(struct drm_device *dev,
 	err = eb_submit(&eb);
 
 err_request:
-	eb_requests_get(&eb);
-	err = eb_requests_add(&eb, err);
+	eb_requests_get(eb.requests, eb.num_batches);
+	err = eb_requests_add(eb.requests, eb.num_batches, eb.context,
+			      eb.gem_context->sched, err);
 
 	if (eb.fences)
-		signal_fence_array(&eb, eb.composite_fence ?
+		signal_fence_array(eb.fences, eb.num_fences,
+				   eb.composite_fence ?
 				   eb.composite_fence :
 				   &eb.requests[0]->fence);
 
@@ -3471,7 +3032,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
 	if (!out_fence && eb.composite_fence)
 		dma_fence_put(eb.composite_fence);
 
-	eb_requests_put(&eb);
+	eb_requests_put(eb.requests, eb.num_batches);
 
 err_vma:
 	eb_release_vmas(&eb, true);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.c
new file mode 100644
index 000000000000..167268dfd930
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.c
@@ -0,0 +1,530 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include <linux/dma-fence-array.h>
+#include "gt/intel_gt.h"
+#include "gt/intel_gt_pm.h"
+#include "gt/intel_ring.h"
+
+#include "i915_gem_execbuffer_common.h"
+
+#define __EXEC_COMMON_FENCE_WAIT	BIT(0)
+#define __EXEC_COMMON_FENCE_SIGNAL	BIT(1)
+
+static struct i915_request *eb_throttle(struct intel_context *ce)
+{
+	struct intel_ring *ring = ce->ring;
+	struct intel_timeline *tl = ce->timeline;
+	struct i915_request *rq;
+
+	/*
+	 * Completely unscientific finger-in-the-air estimates for suitable
+	 * maximum user request size (to avoid blocking) and then backoff.
+	 */
+	if (intel_ring_update_space(ring) >= PAGE_SIZE)
+		return NULL;
+
+	/*
+	 * Find a request that after waiting upon, there will be at least half
+	 * the ring available. The hysteresis allows us to compete for the
+	 * shared ring and should mean that we sleep less often prior to
+	 * claiming our resources, but not so long that the ring completely
+	 * drains before we can submit our next request.
+	 */
+	list_for_each_entry(rq, &tl->requests, link) {
+		if (rq->ring != ring)
+			continue;
+
+		if (__intel_ring_space(rq->postfix,
+				       ring->emit, ring->size) > ring->size / 2)
+			break;
+	}
+	if (&rq->link == &tl->requests)
+		return NULL; /* weird, we will check again later for real */
+
+	return i915_request_get(rq);
+}
+
+static int eb_pin_timeline(struct intel_context *ce, bool throttle,
+			   bool nonblock)
+{
+	struct intel_timeline *tl;
+	struct i915_request *rq = NULL;
+
+	/*
+	 * Take a local wakeref for preparing to dispatch the execbuf as
+	 * we expect to access the hardware fairly frequently in the
+	 * process, and require the engine to be kept awake between accesses.
+	 * Upon dispatch, we acquire another prolonged wakeref that we hold
+	 * until the timeline is idle, which in turn releases the wakeref
+	 * taken on the engine, and the parent device.
+	 */
+	tl = intel_context_timeline_lock(ce);
+	if (IS_ERR(tl))
+		return PTR_ERR(tl);
+
+	intel_context_enter(ce);
+	if (throttle)
+		rq = eb_throttle(ce);
+	intel_context_timeline_unlock(tl);
+
+	if (rq) {
+		long timeout = nonblock ? 0 : MAX_SCHEDULE_TIMEOUT;
+
+		if (i915_request_wait(rq, I915_WAIT_INTERRUPTIBLE,
+				      timeout) < 0) {
+			i915_request_put(rq);
+
+			/*
+			 * Error path, cannot use intel_context_timeline_lock as
+			 * that is user interruptable and this clean up step
+			 * must be done.
+			 */
+			mutex_lock(&ce->timeline->mutex);
+			intel_context_exit(ce);
+			mutex_unlock(&ce->timeline->mutex);
+
+			if (nonblock)
+				return -EWOULDBLOCK;
+			else
+				return -EINTR;
+		}
+		i915_request_put(rq);
+	}
+
+	return 0;
+}
+
+int __eb_pin_engine(struct intel_context *ce, struct i915_gem_ww_ctx *ww,
+		    bool throttle, bool nonblock)
+{
+	struct intel_context *child;
+	int err;
+	int i = 0, j = 0;
+
+	if (unlikely(intel_context_is_banned(ce)))
+		return -EIO;
+
+	/*
+	 * Pinning the contexts may generate requests in order to acquire
+	 * GGTT space, so do this first before we reserve a seqno for
+	 * ourselves.
+	 */
+	err = intel_context_pin_ww(ce, ww);
+	if (err)
+		return err;
+
+	for_each_child(ce, child) {
+		err = intel_context_pin_ww(child, ww);
+		GEM_BUG_ON(err);	/* perma-pinned should incr a counter */
+	}
+
+	for_each_child(ce, child) {
+		err = eb_pin_timeline(child, throttle, nonblock);
+		if (err)
+			goto unwind;
+		++i;
+	}
+	err = eb_pin_timeline(ce, throttle, nonblock);
+	if (err)
+		goto unwind;
+
+	return 0;
+
+unwind:
+	for_each_child(ce, child) {
+		if (j++ < i) {
+			mutex_lock(&child->timeline->mutex);
+			intel_context_exit(child);
+			mutex_unlock(&child->timeline->mutex);
+		}
+	}
+	for_each_child(ce, child)
+		intel_context_unpin(child);
+	intel_context_unpin(ce);
+	return err;
+}
+
+void __eb_unpin_engine(struct intel_context *ce)
+{
+	struct intel_context *child;
+
+	for_each_child(ce, child) {
+		mutex_lock(&child->timeline->mutex);
+		intel_context_exit(child);
+		mutex_unlock(&child->timeline->mutex);
+
+		intel_context_unpin(child);
+	}
+
+	mutex_lock(&ce->timeline->mutex);
+	intel_context_exit(ce);
+	mutex_unlock(&ce->timeline->mutex);
+
+	intel_context_unpin(ce);
+}
+
+struct intel_context *
+eb_find_context(struct intel_context *context, unsigned int context_number)
+{
+	struct intel_context *child;
+
+	if (likely(context_number == 0))
+		return context;
+
+	for_each_child(context, child)
+		if (!--context_number)
+			return child;
+
+	GEM_BUG_ON("Context not found");
+
+	return NULL;
+}
+
+static void __free_fence_array(struct eb_fence *fences, u64 n)
+{
+	while (n--) {
+		drm_syncobj_put(ptr_mask_bits(fences[n].syncobj, 2));
+		dma_fence_put(fences[n].dma_fence);
+		dma_fence_chain_free(fences[n].chain_fence);
+	}
+	kvfree(fences);
+}
+
+void put_fence_array(struct eb_fence *fences, u64 num_fences)
+{
+	if (fences)
+		__free_fence_array(fences, num_fences);
+}
+
+int add_timeline_fence(struct drm_file *file, u32 handle, u64 point,
+		       struct eb_fence *f, bool wait, bool signal)
+{
+	struct drm_syncobj *syncobj;
+	struct dma_fence *fence = NULL;
+	u32 flags = 0;
+	int err = 0;
+
+	syncobj = drm_syncobj_find(file, handle);
+	if (!syncobj) {
+		DRM_DEBUG("Invalid syncobj handle provided\n");
+		return -ENOENT;
+	}
+
+	fence = drm_syncobj_fence_get(syncobj);
+
+	if (!fence && wait && !signal) {
+		DRM_DEBUG("Syncobj handle has no fence\n");
+		drm_syncobj_put(syncobj);
+		return -EINVAL;
+	}
+
+	if (fence)
+		err = dma_fence_chain_find_seqno(&fence, point);
+
+	if (err && !signal) {
+		DRM_DEBUG("Syncobj handle missing requested point %llu\n", point);
+		dma_fence_put(fence);
+		drm_syncobj_put(syncobj);
+		return err;
+	}
+
+	/*
+	 * A point might have been signaled already and
+	 * garbage collected from the timeline. In this case
+	 * just ignore the point and carry on.
+	 */
+	if (!fence && !signal) {
+		drm_syncobj_put(syncobj);
+		return 0;
+	}
+
+	/*
+	 * For timeline syncobjs we need to preallocate chains for
+	 * later signaling.
+	 */
+	if (point != 0 && signal) {
+		/*
+		 * Waiting and signaling the same point (when point !=
+		 * 0) would break the timeline.
+		 */
+		if (wait) {
+			DRM_DEBUG("Trying to wait & signal the same timeline point.\n");
+			dma_fence_put(fence);
+			drm_syncobj_put(syncobj);
+			return -EINVAL;
+		}
+
+		f->chain_fence = dma_fence_chain_alloc();
+		if (!f->chain_fence) {
+			drm_syncobj_put(syncobj);
+			dma_fence_put(fence);
+			return -ENOMEM;
+		}
+	} else {
+		f->chain_fence = NULL;
+	}
+
+	flags |= wait ? __EXEC_COMMON_FENCE_WAIT : 0;
+	flags |= signal ? __EXEC_COMMON_FENCE_SIGNAL : 0;
+
+	f->syncobj = ptr_pack_bits(syncobj, flags, 2);
+	f->dma_fence = fence;
+	f->value = point;
+	return 1;
+}
+
+int await_fence_array(struct eb_fence *fences, u64 num_fences,
+		      struct i915_request *rq)
+{
+	unsigned int n;
+
+	for (n = 0; n < num_fences; n++) {
+		struct drm_syncobj *syncobj;
+		unsigned int flags;
+		int err;
+
+		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
+
+		if (!fences[n].dma_fence)
+			continue;
+
+		err = i915_request_await_dma_fence(rq, fences[n].dma_fence);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+void signal_fence_array(struct eb_fence *fences, u64 num_fences,
+			struct dma_fence * const fence)
+{
+	unsigned int n;
+
+	for (n = 0; n < num_fences; n++) {
+		struct drm_syncobj *syncobj;
+		unsigned int flags;
+
+		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
+		if (!(flags & __EXEC_COMMON_FENCE_SIGNAL))
+			continue;
+
+		if (fences[n].chain_fence) {
+			drm_syncobj_add_point(syncobj,
+					      fences[n].chain_fence,
+					      fence,
+					      fences[n].value);
+			/*
+			 * The chain's ownership is transferred to the
+			 * timeline.
+			 */
+			fences[n].chain_fence = NULL;
+		} else {
+			drm_syncobj_replace_fence(syncobj, fence);
+		}
+	}
+}
+
+/*
+ * Using two helper loops for the order of which requests / batches are created
+ * and added the to backend. Requests are created in order from the parent to
+ * the last child. Requests are added in the reverse order, from the last child
+ * to parent. This is done for locking reasons as the timeline lock is acquired
+ * during request creation and released when the request is added to the
+ * backend. To make lockdep happy (see intel_context_timeline_lock) this must be
+ * the ordering.
+ */
+#define for_each_batch_create_order(_num_batches) \
+	for (unsigned int i = 0; i < (_num_batches); ++i)
+#define for_each_batch_add_order(_num_batches) \
+	for (int i = (_num_batches) - 1; i >= 0; --i)
+
+static void retire_requests(struct intel_timeline *tl, struct i915_request *end)
+{
+	struct i915_request *rq, *rn;
+
+	list_for_each_entry_safe(rq, rn, &tl->requests, link)
+		if (rq == end || !i915_request_retire(rq))
+			break;
+}
+
+static int eb_request_add(struct intel_context *context,
+			  struct i915_request *rq,
+			  struct i915_sched_attr sched,
+			  int err, bool last_parallel)
+{
+	struct intel_timeline * const tl = i915_request_timeline(rq);
+	struct i915_sched_attr attr = {};
+	struct i915_request *prev;
+
+	lockdep_assert_held(&tl->mutex);
+	lockdep_unpin_lock(&tl->mutex, rq->cookie);
+
+	trace_i915_request_add(rq);
+
+	prev = __i915_request_commit(rq);
+
+	/* Check that the context wasn't destroyed before submission */
+	if (likely(!intel_context_is_closed(context))) {
+		attr = sched;
+	} else {
+		/* Serialise with context_close via the add_to_timeline */
+		i915_request_set_error_once(rq, -ENOENT);
+		__i915_request_skip(rq);
+		err = -ENOENT; /* override any transient errors */
+	}
+
+	if (intel_context_is_parallel(context)) {
+		if (err) {
+			__i915_request_skip(rq);
+			set_bit(I915_FENCE_FLAG_SKIP_PARALLEL,
+				&rq->fence.flags);
+		}
+		if (last_parallel)
+			set_bit(I915_FENCE_FLAG_SUBMIT_PARALLEL,
+				&rq->fence.flags);
+	}
+
+	__i915_request_queue(rq, &attr);
+
+	/* Try to clean up the client's timeline after submitting the request */
+	if (prev)
+		retire_requests(tl, prev);
+
+	mutex_unlock(&tl->mutex);
+
+	return err;
+}
+
+int eb_requests_add(struct i915_request **requests, unsigned int num_batches,
+		    struct intel_context *context, struct i915_sched_attr sched,
+		    int err)
+{
+	/*
+	 * We iterate in reverse order of creation to release timeline mutexes
+	 * in same order.
+	 */
+	for_each_batch_add_order(num_batches) {
+		struct i915_request *rq = requests[i];
+
+		if (!rq)
+			continue;
+
+		err = eb_request_add(context, rq, sched, err, i == 0);
+	}
+
+	return err;
+}
+
+void eb_requests_get(struct i915_request **requests, unsigned int num_batches)
+{
+	for_each_batch_create_order(num_batches) {
+		if (!requests[i])
+			break;
+
+		i915_request_get(requests[i]);
+	}
+}
+
+void eb_requests_put(struct i915_request **requests, unsigned int num_batches)
+{
+	for_each_batch_create_order(num_batches) {
+		if (!requests[i])
+			break;
+
+		i915_request_put(requests[i]);
+	}
+}
+
+struct dma_fence *__eb_composite_fence_create(struct i915_request **requests,
+					      unsigned int num_batches,
+					      struct intel_context *context)
+{
+	struct dma_fence_array *fence_array;
+	struct dma_fence **fences;
+
+	GEM_BUG_ON(!intel_context_is_parent(context));
+
+	fences = kmalloc_array(num_batches, sizeof(*fences), GFP_KERNEL);
+	if (!fences)
+		return ERR_PTR(-ENOMEM);
+
+	for_each_batch_create_order(num_batches) {
+		fences[i] = &requests[i]->fence;
+		__set_bit(I915_FENCE_FLAG_COMPOSITE,
+			  &requests[i]->fence.flags);
+	}
+
+	fence_array = dma_fence_array_create(num_batches,
+					     fences,
+					     context->parallel.fence_context,
+					     context->parallel.seqno++,
+					     false);
+	if (!fence_array) {
+		kfree(fences);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* Move ownership to the dma_fence_array created above */
+	for_each_batch_create_order(num_batches)
+		dma_fence_get(fences[i]);
+
+	return &fence_array->base;
+}
+
+int __eb_select_engine(struct intel_context *ce)
+{
+	struct intel_context *child;
+	int err;
+
+	for_each_child(ce, child)
+		intel_context_get(child);
+	intel_gt_pm_get(ce->engine->gt);
+
+	if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
+		err = intel_context_alloc_state(ce);
+		if (err)
+			goto err;
+	}
+	for_each_child(ce, child) {
+		if (!test_bit(CONTEXT_ALLOC_BIT, &child->flags)) {
+			err = intel_context_alloc_state(child);
+			if (err)
+				goto err;
+		}
+	}
+
+	/*
+	 * ABI: Before userspace accesses the GPU (e.g. execbuffer), report
+	 * EIO if the GPU is already wedged.
+	 */
+	err = intel_gt_terminally_wedged(ce->engine->gt);
+	if (err)
+		goto err;
+
+	if (!i915_vm_tryget(ce->vm)) {
+		err = -ENOENT;
+		goto err;
+	}
+
+	return 0;
+err:
+	intel_gt_pm_put(ce->engine->gt);
+	for_each_child(ce, child)
+		intel_context_put(child);
+	return err;
+}
+
+void __eb_put_engine(struct intel_context *context, struct intel_gt *gt)
+{
+	struct intel_context *child;
+
+	i915_vm_put(context->vm);
+	intel_gt_pm_put(gt);
+	for_each_child(context, child)
+		intel_context_put(child);
+	intel_context_put(context);
+}
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.h b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.h
new file mode 100644
index 000000000000..725febfd6a53
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef __I915_GEM_EXECBUFFER_COMMON_H
+#define __I915_GEM_EXECBUFFER_COMMON_H
+
+#include <drm/drm_syncobj.h>
+
+#include "gt/intel_context.h"
+
+struct eb_fence {
+	struct drm_syncobj *syncobj;
+	struct dma_fence *dma_fence;
+	u64 value;
+	struct dma_fence_chain *chain_fence;
+};
+
+int __eb_pin_engine(struct intel_context *ce, struct i915_gem_ww_ctx *ww,
+		    bool throttle, bool nonblock);
+void __eb_unpin_engine(struct intel_context *ce);
+int __eb_select_engine(struct intel_context *ce);
+void __eb_put_engine(struct intel_context *context, struct intel_gt *gt);
+
+struct intel_context *
+eb_find_context(struct intel_context *context, unsigned int context_number);
+
+int add_timeline_fence(struct drm_file *file, u32 handle, u64 point,
+		       struct eb_fence *f, bool wait, bool signal);
+void put_fence_array(struct eb_fence *fences, u64 num_fences);
+int await_fence_array(struct eb_fence *fences, u64 num_fences,
+		      struct i915_request *rq);
+void signal_fence_array(struct eb_fence *fences, u64 num_fences,
+			struct dma_fence * const fence);
+
+int eb_requests_add(struct i915_request **requests, unsigned int num_batches,
+		    struct intel_context *context, struct i915_sched_attr sched,
+		    int err);
+void eb_requests_get(struct i915_request **requests, unsigned int num_batches);
+void eb_requests_put(struct i915_request **requests, unsigned int num_batches);
+
+struct dma_fence *__eb_composite_fence_create(struct i915_request **requests,
+					      unsigned int num_batches,
+					      struct intel_context *context);
+
+#endif /* __I915_GEM_EXECBUFFER_COMMON_H */
-- 
2.21.0.rc0.32.g243a4c7e27



More information about the Intel-gfx mailing list