drm/amdgpu: add set_reg_remap callback for NBIO 2.3

This will be used to consolidate the register remap offset
configuration and fix  HDP flushes on systems non-4K pages.
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/nbio_v2_3.c

@@ -553,6 +553,20 @@ static void nbio_v2_3_clear_doorbell_interrupt(struct amdgpu_device *adev)
 	}
 }
 
+#define MMIO_REG_HOLE_OFFSET (0x80000 - PAGE_SIZE)
+
+static void nbio_v2_3_set_reg_remap(struct amdgpu_device *adev)
+{
+	if (!amdgpu_sriov_vf(adev) && (PAGE_SIZE <= 4096)) {
+		adev->rmmio_remap.reg_offset = MMIO_REG_HOLE_OFFSET;
+		adev->rmmio_remap.bus_addr = adev->rmmio_base + MMIO_REG_HOLE_OFFSET;
+	} else {
+		adev->rmmio_remap.reg_offset = SOC15_REG_OFFSET(NBIO, 0,
+			mmBIF_BX_DEV0_EPF0_VF0_HDP_MEM_COHERENCY_FLUSH_CNTL) << 2;
+		adev->rmmio_remap.bus_addr = 0;
+	}
+}
+
 const struct amdgpu_nbio_funcs nbio_v2_3_funcs = {
 	.get_hdp_flush_req_offset = nbio_v2_3_get_hdp_flush_req_offset,
 	.get_hdp_flush_done_offset = nbio_v2_3_get_hdp_flush_done_offset,
@@ -577,4 +591,5 @@ const struct amdgpu_nbio_funcs nbio_v2_3_funcs = {
 	.apply_lc_spc_mode_wa = nbio_v2_3_apply_lc_spc_mode_wa,
 	.apply_l1_link_width_reconfig_wa = nbio_v2_3_apply_l1_link_width_reconfig_wa,
 	.clear_doorbell_interrupt = nbio_v2_3_clear_doorbell_interrupt,
+	.set_reg_remap = nbio_v2_3_set_reg_remap,
 };