Revert "Revert "drm/amdgpu/gmc11: enable AGP aperture""

This reverts commit 1a65327a.

This should be resolved so we can re-enable this. Also,
the AGP apeture was bring programmed to 0 on MMHUB 3.0.1
since agp_start and end were not being set.
Acked-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Yifan Zhang <yifan1.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfxhub_v3_0.c

@@ -151,10 +151,11 @@ static void gfxhub_v3_0_init_system_aperture_regs(struct amdgpu_device *adev)
 {
 	uint64_t value;
 
-	/* Disable AGP. */
+	/* Program the AGP BAR */
 	WREG32_SOC15(GC, 0, regGCMC_VM_AGP_BASE, 0);
-	WREG32_SOC15(GC, 0, regGCMC_VM_AGP_TOP, 0);
-	WREG32_SOC15(GC, 0, regGCMC_VM_AGP_BOT, 0x00FFFFFF);
+	WREG32_SOC15(GC, 0, regGCMC_VM_AGP_BOT, adev->gmc.agp_start >> 24);
+	WREG32_SOC15(GC, 0, regGCMC_VM_AGP_TOP, adev->gmc.agp_end >> 24);
+
 
 	/* Program the system aperture low logical page number. */
 	WREG32_SOC15(GC, 0, regGCMC_VM_SYSTEM_APERTURE_LOW_ADDR,

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

@@ -673,6 +673,7 @@ static void gmc_v11_0_vram_gtt_location(struct amdgpu_device *adev,
 
 	amdgpu_gmc_vram_location(adev, &adev->gmc, base);
 	amdgpu_gmc_gart_location(adev, mc);
+	amdgpu_gmc_agp_location(adev, mc);
 
 	/* base offset of vram pages */
 	if (amdgpu_sriov_vf(adev))

drivers/gpu/drm/amd/amdgpu/mmhub_v3_0.c

@@ -177,10 +177,11 @@ static void mmhub_v3_0_init_system_aperture_regs(struct amdgpu_device *adev)
 	 * these regs, and they will be programed at host.
 	 * so skip programing these regs.
 	 */
-	/* Disable AGP. */
+	/* Program the AGP BAR */
 	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_BASE, 0);
-	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_TOP, 0);
-	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_BOT, 0x00FFFFFF);
+	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_BOT, adev->gmc.agp_start >> 24);
+	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_TOP, adev->gmc.agp_end >> 24);
+
 	/* Program the system aperture low logical page number. */
 	WREG32_SOC15(MMHUB, 0, regMMMC_VM_SYSTEM_APERTURE_LOW_ADDR,
 		     adev->gmc.vram_start >> 18);

drivers/gpu/drm/amd/amdgpu/mmhub_v3_0_2.c

@@ -162,10 +162,10 @@ static void mmhub_v3_0_2_init_system_aperture_regs(struct amdgpu_device *adev)
 	uint64_t value;
 	uint32_t tmp;
 
-	/* Disable AGP. */
+	/* Program the AGP BAR */
 	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_BASE, 0);
-	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_TOP, 0);
-	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_BOT, 0x00FFFFFF);
+	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_BOT, adev->gmc.agp_start >> 24);
+	WREG32_SOC15(MMHUB, 0, regMMMC_VM_AGP_TOP, adev->gmc.agp_end >> 24);
 
 	if (!amdgpu_sriov_vf(adev)) {
 		/*