[RFC 04/10] drm/i915/vm_bind: Add out fence support

[Niranjana Vishwanathapura]

Add support for handling out fence of vm_bind call.

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h   |  2 +
 .../drm/i915/gem/i915_gem_vm_bind_object.c    | 74 +++++++++++++++++++
 drivers/gpu/drm/i915/i915_vma.c               |  6 +-
 drivers/gpu/drm/i915/i915_vma_types.h         |  7 ++
 4 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
index ee6e4c52e80e..849bf3c1061e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
@@ -45,5 +45,7 @@ int i915_gem_vm_bind_obj(struct i915_address_space *vm,
 			 struct drm_file *file);
 int i915_gem_vm_unbind_obj(struct i915_address_space *vm,
 			   struct drm_i915_gem_vm_unbind *va);
+void i915_vm_bind_signal_fence(struct i915_vma *vma,
+			       struct dma_fence * const fence);
 
 #endif /* __I915_GEM_VM_BIND_H */
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
index 3201204c8e74..96f139cc8060 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
@@ -5,6 +5,8 @@
 
 #include <linux/interval_tree_generic.h>
 
+#include <drm/drm_syncobj.h>
+
 #include "gem/i915_gem_vm_bind.h"
 #include "gt/gen8_engine_cs.h"
 
@@ -94,6 +96,68 @@ void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
 	}
 }
 
+static int i915_vm_bind_add_fence(struct drm_file *file, struct i915_vma *vma,
+				  u32 handle, u64 point)
+{
+	struct drm_syncobj *syncobj;
+
+	syncobj = drm_syncobj_find(file, handle);
+	if (!syncobj) {
+		DRM_DEBUG("Invalid syncobj handle provided\n");
+		return -ENOENT;
+	}
+
+	/*
+	 * For timeline syncobjs we need to preallocate chains for
+	 * later signaling.
+	 */
+	if (point) {
+		vma->vm_bind_fence.chain_fence = dma_fence_chain_alloc();
+		if (!vma->vm_bind_fence.chain_fence) {
+			drm_syncobj_put(syncobj);
+			return -ENOMEM;
+		}
+	} else {
+		vma->vm_bind_fence.chain_fence = NULL;
+	}
+
+	vma->vm_bind_fence.syncobj = syncobj;
+	vma->vm_bind_fence.value = point;
+
+	return 0;
+}
+
+static void i915_vm_bind_put_fence(struct i915_vma *vma)
+{
+	if (!vma->vm_bind_fence.syncobj)
+		return;
+
+	drm_syncobj_put(vma->vm_bind_fence.syncobj);
+	dma_fence_chain_free(vma->vm_bind_fence.chain_fence);
+}
+
+void i915_vm_bind_signal_fence(struct i915_vma *vma,
+			       struct dma_fence * const fence)
+{
+	struct drm_syncobj *syncobj = vma->vm_bind_fence.syncobj;
+
+	if (!syncobj)
+		return;
+
+	if (vma->vm_bind_fence.chain_fence) {
+		drm_syncobj_add_point(syncobj,
+				      vma->vm_bind_fence.chain_fence,
+				      fence, vma->vm_bind_fence.value);
+		/*
+		 * The chain's ownership is transferred to the
+		 * timeline.
+		 */
+		vma->vm_bind_fence.chain_fence = NULL;
+	} else {
+		drm_syncobj_replace_fence(syncobj, fence);
+	}
+}
+
 int i915_gem_vm_unbind_obj(struct i915_address_space *vm,
 			   struct drm_i915_gem_vm_unbind *va)
 {
@@ -202,6 +266,14 @@ int i915_gem_vm_bind_obj(struct i915_address_space *vm,
 	}
 
 	i915_gem_ww_ctx_init(&ww, true);
+
+	if (va->fence.flags & I915_TIMELINE_FENCE_SIGNAL) {
+		ret = i915_vm_bind_add_fence(file, vma, va->fence.handle,
+					     va->fence.value);
+		if (ret)
+			goto put_vma;
+	}
+
 	pin_flags = va->start | PIN_OFFSET_FIXED | PIN_USER;
 retry:
 	ret = i915_gem_object_lock(vma->obj, &ww);
@@ -230,6 +302,8 @@ int i915_gem_vm_bind_obj(struct i915_address_space *vm,
 			goto retry;
 	}
 
+	i915_vm_bind_put_fence(vma);
+put_vma:
 	if (ret)
 		i915_vma_destroy(vma);
 
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index f0226581d342..6737236b7884 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -1510,8 +1510,12 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
 err_vma_res:
 	i915_vma_resource_free(vma_res);
 err_fence:
-	if (work)
+	if (work) {
+		if (i915_vma_is_persistent(vma))
+			i915_vm_bind_signal_fence(vma, &work->base.dma);
+
 		dma_fence_work_commit_imm(&work->base);
+	}
 err_rpm:
 	if (wakeref)
 		intel_runtime_pm_put(&vma->vm->i915->runtime_pm, wakeref);
diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
index 2298b3d6b7c4..7d830a6a0b51 100644
--- a/drivers/gpu/drm/i915/i915_vma_types.h
+++ b/drivers/gpu/drm/i915/i915_vma_types.h
@@ -293,6 +293,13 @@ struct i915_vma {
 	/* Link in non-private persistent VMA list */
 	struct list_head non_priv_vm_bind_link;
 
+	/** Timeline fence for vm_bind completion notification */
+	struct {
+		struct drm_syncobj *syncobj;
+		u64 value;
+		struct dma_fence_chain *chain_fence;
+	} vm_bind_fence;
+
 	/** Interval tree structures for persistent vma */
 	struct rb_node rb;
 	u64 start;
-- 
2.21.0.rc0.32.g243a4c7e27