[ Upstream commit 031f196d1b1b6d5dfcb0533b431e3ab1750e6189 ] [WHY] When PTEBufferSizeInRequests is zero, UBSAN reports the following warning because dml_log2 returns an unexpected negative value: shift exponent 4294966273 is too large for 32-bit type 'int' [HOW] In the case PTEBufferSizeInRequests is zero, skip the dml_log2() and assign the result directly. Reviewed-by: Jun Lei <Jun.Lei@amd.com> Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>