drm/amdgpu: enable AGP aperture for GMC9 v2

Enable the old AGP aperture to avoid GART mappings.

v2: don't enable it for SRIOV
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c

@@ -65,16 +65,16 @@ static void gfxhub_v1_0_init_system_aperture_regs(struct amdgpu_device *adev)
 {
 	uint64_t value;
 
-	/* Disable AGP. */
+	/* Program the AGP BAR */
 	WREG32_SOC15(GC, 0, mmMC_VM_AGP_BASE, 0);
-	WREG32_SOC15(GC, 0, mmMC_VM_AGP_TOP, 0);
-	WREG32_SOC15(GC, 0, mmMC_VM_AGP_BOT, 0xFFFFFFFF);
+	WREG32_SOC15(GC, 0, mmMC_VM_AGP_BOT, adev->gmc.agp_start >> 24);
+	WREG32_SOC15(GC, 0, mmMC_VM_AGP_TOP, adev->gmc.agp_end >> 24);
 
 	/* Program the system aperture low logical page number. */
 	WREG32_SOC15(GC, 0, mmMC_VM_SYSTEM_APERTURE_LOW_ADDR,
-		     adev->gmc.vram_start >> 18);
+		     min(adev->gmc.vram_start, adev->gmc.agp_start) >> 18);
 	WREG32_SOC15(GC, 0, mmMC_VM_SYSTEM_APERTURE_HIGH_ADDR,
-		     adev->gmc.vram_end >> 18);
+		     max(adev->gmc.vram_end, adev->gmc.agp_end) >> 18);
 
 	/* Set default page address. */
 	value = adev->vram_scratch.gpu_addr - adev->gmc.vram_start

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

@@ -772,6 +772,8 @@ static void gmc_v9_0_vram_gtt_location(struct amdgpu_device *adev,
 		base = mmhub_v1_0_get_fb_location(adev);
 	amdgpu_gmc_vram_location(adev, &adev->gmc, base);
 	amdgpu_gmc_gart_location(adev, mc);
+	if (!amdgpu_sriov_vf(adev))
+		amdgpu_gmc_agp_location(adev, mc);
 	/* base offset of vram pages */
 	adev->vm_manager.vram_base_offset = gfxhub_v1_0_get_mc_fb_offset(adev);
 }

drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c

@@ -76,16 +76,16 @@ static void mmhub_v1_0_init_system_aperture_regs(struct amdgpu_device *adev)
 	uint64_t value;
 	uint32_t tmp;
 
-	/* Disable AGP. */
+	/* Program the AGP BAR */
 	WREG32_SOC15(MMHUB, 0, mmMC_VM_AGP_BASE, 0);
-	WREG32_SOC15(MMHUB, 0, mmMC_VM_AGP_TOP, 0);
-	WREG32_SOC15(MMHUB, 0, mmMC_VM_AGP_BOT, 0x00FFFFFF);
+	WREG32_SOC15(MMHUB, 0, mmMC_VM_AGP_BOT, adev->gmc.agp_start >> 24);
+	WREG32_SOC15(MMHUB, 0, mmMC_VM_AGP_TOP, adev->gmc.agp_end >> 24);
 
 	/* Program the system aperture low logical page number. */
 	WREG32_SOC15(MMHUB, 0, mmMC_VM_SYSTEM_APERTURE_LOW_ADDR,
-		     adev->gmc.vram_start >> 18);
+		     min(adev->gmc.vram_start, adev->gmc.agp_start) >> 18);
 	WREG32_SOC15(MMHUB, 0, mmMC_VM_SYSTEM_APERTURE_HIGH_ADDR,
-		     adev->gmc.vram_end >> 18);
+		     max(adev->gmc.vram_end, adev->gmc.agp_end) >> 18);
 
 	/* Set default page address. */
 	value = adev->vram_scratch.gpu_addr - adev->gmc.vram_start +