According to Spec, it is ILLEGAL to set STE.S1STALLD if STALL_MODEL
is not 0b00, which means we should not disable stall mode if stall
or terminate mode is not configuable.
Meanwhile, it is also ILLEGAL when STALL_MODEL==0b10 && CD.S==0 which
means if stall mode is force we should always set CD.S.
As Jean-Philippe's suggestion, this patch introduce a feature bit
ARM_SMMU_FEAT_STALL_FORCE, which means smmu only supports stall force.
Therefore, we can avoid the ILLEGAL setting of STE.S1STALLD.by checking
ARM_SMMU_FEAT_STALL_FORCE.
This patch keeps the ARM_SMMU_FEAT_STALLS as the meaning of stall supported
(force or configuable) to easy to expand the future function, i.e. we can
only use ARM_SMMU_FEAT_STALLS to check whether we should register fault
handle or enable master can_stall, etc to supporte platform SVM.
The feature bit, STE.S1STALLD and CD.S setting will be like:
STALL_MODEL FEATURE S1STALLD CD.S
0b00 ARM_SMMU_FEAT_STALLS 0b1 0b0
0b01 !ARM_SMMU_FEAT_STALLS && !ARM_SMMU_FEAT_STALL_FORCE 0b0 0b0
0b10 ARM_SMMU_FEAT_STALLS && ARM_SMMU_FEAT_STALL_FORCE 0b0 0b1
after apply this patch.
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
9cff86fd2b