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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>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.