drm/amdgpu: change gartsize default to 256MB

Limit the default GART size and save a lot of VRAM.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -75,7 +75,7 @@
  */
 extern int amdgpu_modeset;
 extern int amdgpu_vram_limit;
-extern int amdgpu_gart_size;
+extern unsigned amdgpu_gart_size;
 extern int amdgpu_gtt_size;
 extern int amdgpu_moverate;
 extern int amdgpu_benchmarking;

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -1132,13 +1132,11 @@ static void amdgpu_check_arguments(struct amdgpu_device *adev)
 		amdgpu_sched_jobs = roundup_pow_of_two(amdgpu_sched_jobs);
 	}
 
-	if (amdgpu_gart_size != -1) {
-		/* gtt size must be greater or equal to 32M */
-		if (amdgpu_gart_size < 32) {
-			dev_warn(adev->dev, "gart size (%d) too small\n",
-				 amdgpu_gart_size);
-			amdgpu_gart_size = -1;
-		}
+	if (amdgpu_gart_size < 32) {
+		/* gart size must be greater or equal to 32M */
+		dev_warn(adev->dev, "gart size (%d) too small\n",
+			 amdgpu_gart_size);
+		amdgpu_gart_size = 32;
 	}
 
 	if (amdgpu_gtt_size != -1 && amdgpu_gtt_size < 32) {

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -74,7 +74,7 @@
 #define KMS_DRIVER_PATCHLEVEL	0
 
 int amdgpu_vram_limit = 0;
-int amdgpu_gart_size = -1; /* auto */
+unsigned amdgpu_gart_size = 256;
 int amdgpu_gtt_size = -1; /* auto */
 int amdgpu_moverate = -1; /* auto */
 int amdgpu_benchmarking = 0;
@@ -121,8 +121,8 @@ int amdgpu_lbpw = -1;
 MODULE_PARM_DESC(vramlimit, "Restrict VRAM for testing, in megabytes");
 module_param_named(vramlimit, amdgpu_vram_limit, int, 0600);
 
-MODULE_PARM_DESC(gartsize, "Size of PCIE/IGP gart to setup in megabytes (32, 64, etc., -1 = auto)");
-module_param_named(gartsize, amdgpu_gart_size, int, 0600);
+MODULE_PARM_DESC(gartsize, "Size of PCIE/IGP gart to setup in megabytes (32, 64, etc.)");
+module_param_named(gartsize, amdgpu_gart_size, uint, 0600);
 
 MODULE_PARM_DESC(gttsize, "Size of the GTT domain in megabytes (-1 = auto)");
 module_param_named(gttsize, amdgpu_gtt_size, int, 0600);

drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c

@@ -65,14 +65,7 @@
  */
 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.gart_size = max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
-					adev->mc.mc_vram_size);
-	else
-		adev->mc.gart_size = (uint64_t)amdgpu_gart_size << 20;
+	adev->mc.gart_size = (uint64_t)amdgpu_gart_size << 20;
 }
 
 /**