[PATCH 4/8] drm/amdgpu: allow direct submission in the VM backends

[Christian König]

This allows us to update page tables directly while in a page fault.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h      |  5 ++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c  |  4 +++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 29 +++++++++++++--------
 3 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 91baf95212a6..66e27b941a55 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -191,6 +191,11 @@ struct amdgpu_vm_update_params {
 	 */
 	struct amdgpu_vm *vm;
 
+	/**
+	 * @direct: if changes should be made directly
+	 */
+	bool direct;
+
 	/**
 	 * @pages_addr:
 	 *
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c
index 5222d165abfc..f94e4896079c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c
@@ -49,6 +49,10 @@ static int amdgpu_vm_cpu_prepare(struct amdgpu_vm_update_params *p, void *owner,
 {
 	int r;
 
+	/* Don't wait for anything during page fault */
+	if (p->direct)
+		return 0;
+
 	/* Wait for PT BOs to be idle. PTs share the same resv. object
 	 * as the root PD BO
 	 */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
index ddd181f5ed37..891d597063cb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
@@ -68,17 +68,17 @@ static int amdgpu_vm_sdma_prepare(struct amdgpu_vm_update_params *p,
 	if (r)
 		return r;
 
-	r = amdgpu_sync_fence(p->adev, &p->job->sync, exclusive, false);
-	if (r)
-		return r;
+	p->num_dw_left = ndw;
+
+	if (p->direct)
+		return 0;
 
-	r = amdgpu_sync_resv(p->adev, &p->job->sync, root->tbo.resv,
-			     owner, false);
+	r = amdgpu_sync_fence(p->adev, &p->job->sync, exclusive, false);
 	if (r)
 		return r;
 
-	p->num_dw_left = ndw;
-	return 0;
+	return amdgpu_sync_resv(p->adev, &p->job->sync, root->tbo.resv,
+				owner, false);
 }
 
 /**
@@ -99,13 +99,21 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
 	struct dma_fence *f;
 	int r;
 
-	ring = container_of(p->vm->entity.rq->sched, struct amdgpu_ring, sched);
+	if (p->direct)
+		ring = p->adev->vm_manager.page_fault;
+	else
+		ring = container_of(p->vm->entity.rq->sched,
+				    struct amdgpu_ring, sched);
 
 	WARN_ON(ib->length_dw == 0);
 	amdgpu_ring_pad_ib(ring, ib);
 	WARN_ON(ib->length_dw > p->num_dw_left);
-	r = amdgpu_job_submit(p->job, &p->vm->entity,
-			      AMDGPU_FENCE_OWNER_VM, &f);
+
+	if (p->direct)
+		r = amdgpu_job_submit_direct(p->job, ring, &f);
+	else
+		r = amdgpu_job_submit(p->job, &p->vm->entity,
+				      AMDGPU_FENCE_OWNER_VM, &f);
 	if (r)
 		goto error;
 
@@ -120,7 +128,6 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
 	return r;
 }
 
-
 /**
  * amdgpu_vm_sdma_copy_ptes - copy the PTEs from mapping
  *
-- 
2.17.1