diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 20e0ed96efbbae74001c10f428be4f30b5b35a7b..df63823ad4dbc3c96e28d919d98a63af139d51a9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -559,6 +559,7 @@ struct amdgpu_gart {
 	const struct amdgpu_gart_funcs *gart_funcs;
 };
 
+void amdgpu_gart_set_defaults(struct amdgpu_device *adev);
 int amdgpu_gart_table_ram_alloc(struct amdgpu_device *adev);
 void amdgpu_gart_table_ram_free(struct amdgpu_device *adev);
 int amdgpu_gart_table_vram_alloc(struct amdgpu_device *adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
index a57abc1a25fb5fbe6da96410316cc85342363b44..982b1cc11dac65aa9836bfad71dda76da0016cbe 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
@@ -55,6 +55,26 @@
 /*
  * Common GART table functions.
  */
+
+/**
+ * amdgpu_gart_set_defaults - set the default gtt_size
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Set the default gtt_size based on parameters and available VRAM.
+ */
+void amdgpu_gart_set_defaults(struct amdgpu_device *adev)
+{
+	/* unless the user had overridden it, set the gart
+	 * size equal to the 1024 or vram, whichever is larger.
+	 */
+	if (amdgpu_gart_size == -1)
+		adev->mc.gtt_size = max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
+					adev->mc.mc_vram_size);
+	else
+		adev->mc.gtt_size = (uint64_t)amdgpu_gart_size << 20;
+}
+
 /**
  * amdgpu_gart_table_ram_alloc - allocate system ram for gart page table
  *
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
index c1a124a867754108f0003372792448f4a23ebacd..5f7750c6497e1401e61ca4b5f50e08538bd6513c 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
@@ -321,15 +321,7 @@ static int gmc_v6_0_mc_init(struct amdgpu_device *adev)
 	adev->mc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL * 1024ULL;
 	adev->mc.visible_vram_size = adev->mc.aper_size;
 
-	/* unless the user had overridden it, set the gart
-	 * size equal to the 1024 or vram, whichever is larger.
-	 */
-	if (amdgpu_gart_size == -1)
-		adev->mc.gtt_size = max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
-					adev->mc.mc_vram_size);
-	else
-		adev->mc.gtt_size = (uint64_t)amdgpu_gart_size << 20;
-
+	amdgpu_gart_set_defaults(adev);
 	gmc_v6_0_vram_gtt_location(adev, &adev->mc);
 
 	return 0;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
index 575d7258374670a9c1fdc8472e55a865183e876f..388b52febc8b676d964b6e99e2ddbe648a6cce1b 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
@@ -373,15 +373,7 @@ static int gmc_v7_0_mc_init(struct amdgpu_device *adev)
 	if (adev->mc.visible_vram_size > adev->mc.real_vram_size)
 		adev->mc.visible_vram_size = adev->mc.real_vram_size;
 
-	/* unless the user had overridden it, set the gart
-	 * size equal to the 1024 or vram, whichever is larger.
-	 */
-	if (amdgpu_gart_size == -1)
-		adev->mc.gtt_size = max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
-					adev->mc.mc_vram_size);
-	else
-		adev->mc.gtt_size = (uint64_t)amdgpu_gart_size << 20;
-
+	amdgpu_gart_set_defaults(adev);
 	gmc_v7_0_vram_gtt_location(adev, &adev->mc);
 
 	return 0;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index 6379177b9fcb7c75644c2db632be937425283475..d148d1c585b3b7c0c32a4fb24d32d8fcd335ce01 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -535,15 +535,7 @@ static int gmc_v8_0_mc_init(struct amdgpu_device *adev)
 	if (adev->mc.visible_vram_size > adev->mc.real_vram_size)
 		adev->mc.visible_vram_size = adev->mc.real_vram_size;
 
-	/* unless the user had overridden it, set the gart
-	 * size equal to the 1024 or vram, whichever is larger.
-	 */
-	if (amdgpu_gart_size == -1)
-		adev->mc.gtt_size = max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
-					adev->mc.mc_vram_size);
-	else
-		adev->mc.gtt_size = (uint64_t)amdgpu_gart_size << 20;
-
+	amdgpu_gart_set_defaults(adev);
 	gmc_v8_0_vram_gtt_location(adev, &adev->mc);
 
 	return 0;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index c6394ea69f96e1eda54f85234daa0fd67adcd979..dbb43d99e02e6b53f09dd7e21dfa8eddd6e45ec5 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -494,15 +494,7 @@ static int gmc_v9_0_mc_init(struct amdgpu_device *adev)
 	if (adev->mc.visible_vram_size > adev->mc.real_vram_size)
 		adev->mc.visible_vram_size = adev->mc.real_vram_size;
 
-	/* unless the user had overridden it, set the gart
-	 * size equal to the 1024 or vram, whichever is larger.
-	 */
-	if (amdgpu_gart_size == -1)
-		adev->mc.gtt_size = max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
-					adev->mc.mc_vram_size);
-	else
-		adev->mc.gtt_size = (uint64_t)amdgpu_gart_size << 20;
-
+	amdgpu_gart_set_defaults(adev);
 	gmc_v9_0_vram_gtt_location(adev, &adev->mc);
 
 	return 0;