drm/amdgpu/gmc: add a way to force a particular placement for GART

We normally place GART based on the location of VRAM and the
available address space around that, but provide an option
to force a particular location for hardware that needs it.

v2: Switch to passing the placement via parameter
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -269,7 +269,8 @@ void amdgpu_gmc_sysvm_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc
  * If GART size is bigger than space left then we ajust GART size.
  * Thus function will never fails.
  */
-void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
+void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc,
+			      enum amdgpu_gart_placement gart_placement)
 {
 	const uint64_t four_gb = 0x100000000ULL;
 	u64 size_af, size_bf;
@@ -287,11 +288,22 @@ void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
 		mc->gart_size = max(size_bf, size_af);
 	}
 
-	if ((size_bf >= mc->gart_size && size_bf < size_af) ||
-	    (size_af < mc->gart_size))
-		mc->gart_start = 0;
-	else
+	switch (gart_placement) {
+	case AMDGPU_GART_PLACEMENT_HIGH:
 		mc->gart_start = max_mc_address - mc->gart_size + 1;
+		break;
+	case AMDGPU_GART_PLACEMENT_LOW:
+		mc->gart_start = 0;
+		break;
+	case AMDGPU_GART_PLACEMENT_BEST_FIT:
+	default:
+		if ((size_bf >= mc->gart_size && size_bf < size_af) ||
+		    (size_af < mc->gart_size))
+			mc->gart_start = 0;
+		else
+			mc->gart_start = max_mc_address - mc->gart_size + 1;
+		break;
+	}
 
 	mc->gart_start &= ~(four_gb - 1);
 	mc->gart_end = mc->gart_start + mc->gart_size - 1;

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

@@ -199,6 +199,12 @@ struct amdgpu_mem_partition_info {
 
 #define INVALID_PFN    -1
 
+enum amdgpu_gart_placement {
+	AMDGPU_GART_PLACEMENT_BEST_FIT = 0,
+	AMDGPU_GART_PLACEMENT_HIGH,
+	AMDGPU_GART_PLACEMENT_LOW,
+};
+
 struct amdgpu_gmc {
 	/* FB's physical address in MMIO space (for CPU to
 	 * map FB). This is different compared to the agp/
@@ -391,7 +397,8 @@ void amdgpu_gmc_sysvm_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc
 void amdgpu_gmc_vram_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc,
 			      u64 base);
 void amdgpu_gmc_gart_location(struct amdgpu_device *adev,
-			      struct amdgpu_gmc *mc);
+			      struct amdgpu_gmc *mc,
+			      enum amdgpu_gart_placement gart_placement);
 void amdgpu_gmc_agp_location(struct amdgpu_device *adev,
 			     struct amdgpu_gmc *mc);
 void amdgpu_gmc_set_agp_default(struct amdgpu_device *adev,

drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c

@@ -670,7 +670,7 @@ static void gmc_v10_0_vram_gtt_location(struct amdgpu_device *adev,
 	base += adev->gmc.xgmi.physical_node_id * adev->gmc.xgmi.node_segment_size;
 
 	amdgpu_gmc_vram_location(adev, &adev->gmc, base);
-	amdgpu_gmc_gart_location(adev, mc);
+	amdgpu_gmc_gart_location(adev, mc, AMDGPU_GART_PLACEMENT_BEST_FIT);
 	if (!amdgpu_sriov_vf(adev))
 		amdgpu_gmc_agp_location(adev, mc);
 

drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c

@@ -634,7 +634,7 @@ static void gmc_v11_0_vram_gtt_location(struct amdgpu_device *adev,
 	base = adev->mmhub.funcs->get_fb_location(adev);
 
 	amdgpu_gmc_vram_location(adev, &adev->gmc, base);
-	amdgpu_gmc_gart_location(adev, mc);
+	amdgpu_gmc_gart_location(adev, mc, AMDGPU_GART_PLACEMENT_BEST_FIT);
 	if (!amdgpu_sriov_vf(adev) ||
 	    (amdgpu_ip_version(adev, GC_HWIP, 0) < IP_VERSION(11, 5, 0)))
 		amdgpu_gmc_agp_location(adev, mc);

drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c

@@ -212,7 +212,7 @@ static void gmc_v6_0_vram_gtt_location(struct amdgpu_device *adev,
 	base <<= 24;
 
 	amdgpu_gmc_vram_location(adev, mc, base);
-	amdgpu_gmc_gart_location(adev, mc);
+	amdgpu_gmc_gart_location(adev, mc, AMDGPU_GART_PLACEMENT_BEST_FIT);
 }
 
 static void gmc_v6_0_mc_program(struct amdgpu_device *adev)

drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c

@@ -240,7 +240,7 @@ static void gmc_v7_0_vram_gtt_location(struct amdgpu_device *adev,
 	base <<= 24;
 
 	amdgpu_gmc_vram_location(adev, mc, base);
-	amdgpu_gmc_gart_location(adev, mc);
+	amdgpu_gmc_gart_location(adev, mc, AMDGPU_GART_PLACEMENT_BEST_FIT);
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c

@@ -414,7 +414,7 @@ static void gmc_v8_0_vram_gtt_location(struct amdgpu_device *adev,
 	base <<= 24;
 
 	amdgpu_gmc_vram_location(adev, mc, base);
-	amdgpu_gmc_gart_location(adev, mc);
+	amdgpu_gmc_gart_location(adev, mc, AMDGPU_GART_PLACEMENT_BEST_FIT);
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -1611,7 +1611,7 @@ static void gmc_v9_0_vram_gtt_location(struct amdgpu_device *adev,
 		amdgpu_gmc_sysvm_location(adev, mc);
 	} else {
 		amdgpu_gmc_vram_location(adev, mc, base);
-		amdgpu_gmc_gart_location(adev, mc);
+		amdgpu_gmc_gart_location(adev, mc, AMDGPU_GART_PLACEMENT_BEST_FIT);
 		if (!amdgpu_sriov_vf(adev))
 			amdgpu_gmc_agp_location(adev, mc);
 	}