[PATCH 1/3] drm/amdgpu: track if a PD needs an update

[Christian König]

From: Christian König <christian.koenig at amd.com>

That should reduce our command submission overhead quite a bit.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 7 ++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 55d1c7f..3f5863e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -173,6 +173,7 @@ static int amdgpu_vm_validate_level(struct amdgpu_vm_pt *parent,
 	if (!parent->entries)
 		return 0;
 
+	parent->needs_update = true;
 	for (i = 0; i <= parent->last_entry_used; ++i) {
 		struct amdgpu_vm_pt *entry = &parent->entries[i];
 
@@ -351,6 +352,7 @@ static int amdgpu_vm_alloc_levels(struct amdgpu_device *adev,
 
 			entry->bo = pt;
 			entry->addr = 0;
+			parent->needs_update = true;
 		}
 
 		if (level < adev->vm_manager.num_level) {
@@ -361,6 +363,8 @@ static int amdgpu_vm_alloc_levels(struct amdgpu_device *adev,
 						   sub_eaddr, level);
 			if (r)
 				return r;
+
+			parent->needs_update |= entry->needs_update;
 		}
 	}
 
@@ -1050,7 +1054,7 @@ static int amdgpu_vm_update_level(struct amdgpu_device *adev,
 
 	int r;
 
-	if (!parent->entries)
+	if (!parent->entries || !parent->needs_update)
 		return 0;
 
 	memset(&params, 0, sizeof(params));
@@ -1196,6 +1200,7 @@ static int amdgpu_vm_update_level(struct amdgpu_device *adev,
 			return r;
 	}
 
+	parent->needs_update = false;
 	return 0;
 
 error_free:
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 3441ec5..c3dfd3e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -102,6 +102,7 @@ struct amdgpu_vm_pt {
 	/* array of page tables, one for each directory entry */
 	struct amdgpu_vm_pt	*entries;
 	unsigned		last_entry_used;
+	bool			needs_update;
 };
 
 struct amdgpu_vm {
-- 
2.7.4