[PATCH v2 2/2] drm/amdgpu: Add amdgpu_find_mm_node()

[Harish.Kasiviswanathan@xxxxxxx (Harish Kasiviswanathan)]

Change-Id: I12231e18bb60152843cd0e0213ddd0d0e04e7497
Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 36 +++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index dda4f08..e9bfe9d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -290,6 +290,23 @@ static uint64_t amdgpu_mm_node_addr(struct ttm_buffer_object *bo,
 }
 
 /**
+ * amdgpu_find_mm_node - Helper function finds the drm_mm_node
+ *  corresponding to @offset. It also modifies the offset to be
+ *  within the drm_mm_node returned
+ */
+static struct drm_mm_node *amdgpu_find_mm_node(struct ttm_mem_reg *mem,
+					       unsigned long *offset)
+{
+	struct drm_mm_node *mm_node = mem->mm_node;
+
+	while (*offset >= (mm_node->size << PAGE_SHIFT)) {
+		*offset -= (mm_node->size << PAGE_SHIFT);
+		++mm_node;
+	}
+	return mm_node;
+}
+
+/**
  * amdgpu_copy_ttm_mem_to_mem - Helper function for copy
  *
  * The function copies @size bytes from {src->mem + src->offset} to
@@ -319,21 +336,13 @@ int amdgpu_copy_ttm_mem_to_mem(struct amdgpu_device *adev,
 		return -EINVAL;
 	}
 
-	src_mm = src->mem->mm_node;
-	while (src->offset >= (src_mm->size << PAGE_SHIFT)) {
-		src->offset -= (src_mm->size << PAGE_SHIFT);
-		++src_mm;
-	}
+	src_mm = amdgpu_find_mm_node(src->mem, &src->offset);
 	src_node_start = amdgpu_mm_node_addr(src->bo, src_mm, src->mem) +
 					     src->offset;
 	src_node_size = (src_mm->size << PAGE_SHIFT) - src->offset;
 	src_page_offset = src_node_start & (PAGE_SIZE - 1);
 
-	dst_mm = dst->mem->mm_node;
-	while (dst->offset >= (dst_mm->size << PAGE_SHIFT)) {
-		dst->offset -= (dst_mm->size << PAGE_SHIFT);
-		++dst_mm;
-	}
+	dst_mm = amdgpu_find_mm_node(dst->mem, &dst->offset);
 	dst_node_start = amdgpu_mm_node_addr(dst->bo, dst_mm, dst->mem) +
 					     dst->offset;
 	dst_node_size = (dst_mm->size << PAGE_SHIFT) - dst->offset;
@@ -1216,7 +1225,7 @@ static int amdgpu_ttm_access_memory(struct ttm_buffer_object *bo,
 {
 	struct amdgpu_bo *abo = container_of(bo, struct amdgpu_bo, tbo);
 	struct amdgpu_device *adev = amdgpu_ttm_adev(abo->tbo.bdev);
-	struct drm_mm_node *nodes = abo->tbo.mem.mm_node;
+	struct drm_mm_node *nodes;
 	uint32_t value = 0;
 	int ret = 0;
 	uint64_t pos;
@@ -1225,10 +1234,7 @@ static int amdgpu_ttm_access_memory(struct ttm_buffer_object *bo,
 	if (bo->mem.mem_type != TTM_PL_VRAM)
 		return -EIO;
 
-	while (offset >= (nodes->size << PAGE_SHIFT)) {
-		offset -= nodes->size << PAGE_SHIFT;
-		++nodes;
-	}
+	nodes = amdgpu_find_mm_node(&abo->tbo.mem, &offset);
 	pos = (nodes->start << PAGE_SHIFT) + offset;
 
 	while (len && pos < adev->mc.mc_vram_size) {
-- 
1.9.1