[PATCH 2/2] drm/amdgpu: stop allocating dummy GTT nodes v2

[Chauhan, Madhav]

[AMD Public Use]

-----Original Message-----
From: Christian König <ckoenig.leichtzumerken at gmail.com> 
Sent: Thursday, July 9, 2020 8:40 PM
To: amd-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org
Cc: Chauhan, Madhav <Madhav.Chauhan at amd.com>
Subject: [PATCH 2/2] drm/amdgpu: stop allocating dummy GTT nodes v2

Now that TTM is fixed up we can finally stop that nonsense.

v2: Update the documentation as well.

LGTM, Reviewed-by: Madhav Chauhan <madhav.chauhan at amd.com>

Regards,
Madhav

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 106 ++++++--------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c     |  18 +++-
 2 files changed, 43 insertions(+), 81 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
index 2c20d23d62d1..0c44352ad5eb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
@@ -150,60 +150,7 @@ static int amdgpu_gtt_mgr_fini(struct ttm_mem_type_manager *man)
  */
 bool amdgpu_gtt_mgr_has_gart_addr(struct ttm_mem_reg *mem)  {
-	struct amdgpu_gtt_node *node = mem->mm_node;
-
-	return (node->node.start != AMDGPU_BO_INVALID_OFFSET);
-}
-
-/**
- * amdgpu_gtt_mgr_alloc - allocate new ranges
- *
- * @man: TTM memory type manager
- * @tbo: TTM BO we need this range for
- * @place: placement flags and restrictions
- * @mem: the resulting mem object
- *
- * Allocate the address space for a node.
- */
-static int amdgpu_gtt_mgr_alloc(struct ttm_mem_type_manager *man,
-				struct ttm_buffer_object *tbo,
-				const struct ttm_place *place,
-				struct ttm_mem_reg *mem)
-{
-	struct amdgpu_device *adev = amdgpu_ttm_adev(man->bdev);
-	struct amdgpu_gtt_mgr *mgr = man->priv;
-	struct amdgpu_gtt_node *node = mem->mm_node;
-	enum drm_mm_insert_mode mode;
-	unsigned long fpfn, lpfn;
-	int r;
-
-	if (amdgpu_gtt_mgr_has_gart_addr(mem))
-		return 0;
-
-	if (place)
-		fpfn = place->fpfn;
-	else
-		fpfn = 0;
-
-	if (place && place->lpfn)
-		lpfn = place->lpfn;
-	else
-		lpfn = adev->gart.num_cpu_pages;
-
-	mode = DRM_MM_INSERT_BEST;
-	if (place && place->flags & TTM_PL_FLAG_TOPDOWN)
-		mode = DRM_MM_INSERT_HIGH;
-
-	spin_lock(&mgr->lock);
-	r = drm_mm_insert_node_in_range(&mgr->mm, &node->node, mem->num_pages,
-					mem->page_alignment, 0, fpfn, lpfn,
-					mode);
-	spin_unlock(&mgr->lock);
-
-	if (!r)
-		mem->start = node->node.start;
-
-	return r;
+	return mem->mm_node != NULL;
 }
 
 /**
@@ -214,7 +161,7 @@ static int amdgpu_gtt_mgr_alloc(struct ttm_mem_type_manager *man,
  * @place: placement flags and restrictions
  * @mem: the resulting mem object
  *
- * Dummy, allocate the node but no space for it yet.
+ * GTT accounting and GART node allocation if necessary.
  */
 static int amdgpu_gtt_mgr_new(struct ttm_mem_type_manager *man,
 			      struct ttm_buffer_object *tbo, @@ -234,29 +181,37 @@ static int amdgpu_gtt_mgr_new(struct ttm_mem_type_manager *man,
 	atomic64_sub(mem->num_pages, &mgr->available);
 	spin_unlock(&mgr->lock);
 
+	if (!place->lpfn) {
+		mem->mm_node = NULL;
+		mem->start = AMDGPU_BO_INVALID_OFFSET;
+		return 0;
+	}
+
 	node = kzalloc(sizeof(*node), GFP_KERNEL);
 	if (!node) {
 		r = -ENOMEM;
 		goto err_out;
 	}
 
-	node->node.start = AMDGPU_BO_INVALID_OFFSET;
-	node->node.size = mem->num_pages;
 	node->tbo = tbo;
-	mem->mm_node = node;
 
-	if (place->fpfn || place->lpfn || place->flags & TTM_PL_FLAG_TOPDOWN) {
-		r = amdgpu_gtt_mgr_alloc(man, tbo, place, mem);
-		if (unlikely(r)) {
-			kfree(node);
-			mem->mm_node = NULL;
-			goto err_out;
-		}
-	} else {
-		mem->start = node->node.start;
-	}
+	spin_lock(&mgr->lock);
+	r = drm_mm_insert_node_in_range(&mgr->mm, &node->node, mem->num_pages,
+					mem->page_alignment, 0, place->fpfn,
+					place->lpfn, DRM_MM_INSERT_BEST);
+	spin_unlock(&mgr->lock);
+
+	if (unlikely(r))
+		goto err_free;
+
+	mem->mm_node = node;
+	mem->start = node->node.start;
 
 	return 0;
+
+err_free:
+	kfree(node);
+
 err_out:
 	atomic64_add(mem->num_pages, &mgr->available);
 
@@ -279,17 +234,14 @@ static void amdgpu_gtt_mgr_del(struct ttm_mem_type_manager *man,
 	struct amdgpu_gtt_mgr *mgr = man->priv;
 	struct amdgpu_gtt_node *node = mem->mm_node;
 
-	if (!node)
-		return;
-
-	spin_lock(&mgr->lock);
-	if (node->node.start != AMDGPU_BO_INVALID_OFFSET)
+	if (node) {
+		spin_lock(&mgr->lock);
 		drm_mm_remove_node(&node->node);
-	spin_unlock(&mgr->lock);
-	atomic64_add(mem->num_pages, &mgr->available);
+		spin_unlock(&mgr->lock);
+		kfree(node);
+	}
 
-	kfree(node);
-	mem->mm_node = NULL;
+	atomic64_add(mem->num_pages, &mgr->available);
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 38d2a7fb5698..50503f860fce 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -429,12 +429,22 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
 	}
 
 	src_offset = src->offset;
-	src_mm = amdgpu_find_mm_node(src->mem, &src_offset);
-	src_node_size = (src_mm->size << PAGE_SHIFT) - src_offset;
+	if (src->mem->mm_node) {
+		src_mm = amdgpu_find_mm_node(src->mem, &src_offset);
+		src_node_size = (src_mm->size << PAGE_SHIFT) - src_offset;
+	} else {
+		src_mm = NULL;
+		src_node_size = ULLONG_MAX;
+	}
 
 	dst_offset = dst->offset;
-	dst_mm = amdgpu_find_mm_node(dst->mem, &dst_offset);
-	dst_node_size = (dst_mm->size << PAGE_SHIFT) - dst_offset;
+	if (dst->mem->mm_node) {
+		dst_mm = amdgpu_find_mm_node(dst->mem, &dst_offset);
+		dst_node_size = (dst_mm->size << PAGE_SHIFT) - dst_offset;
+	} else {
+		dst_mm = NULL;
+		dst_node_size = ULLONG_MAX;
+	}
 
 	mutex_lock(&adev->mman.gtt_window_lock);
 
--
2.17.1