On 12/12/22 11:24, Rahul Singh wrote: > Hi Julien, > >> On 12 Dec 2022, at 4:07 pm, Julien Grall <jul...@xen.org> wrote: >> >> Hi Stewart, >> >> On 12/12/2022 16:00, Stewart Hildebrand wrote: >>> When building with clang 12 and CONFIG_ARM_SMMU_V3=y, we observe the >>> following build error: >>> drivers/passthrough/arm/smmu-v3.c:1408:20: error: unused function >>> 'arm_smmu_disable_pasid' [-Werror,-Wunused-function] >>> static inline void arm_smmu_disable_pasid(struct arm_smmu_master *master) { >>> } >>> ^ >>> Remove the function. >>> Signed-off-by: Stewart Hildebrand <stewart.hildebr...@amd.com> >>> --- >>> There is also a definition of arm_smmu_disable_pasid() just above, >>> guarded by #ifdef CONFIG_PCI_ATS. Should this one be removed too? It >>> might be nice to keep this definition for ease of backporting patches >>> from Linux, but if we ever plan on supporting PCI_ATS in Xen this may >>> need to be re-visited. >> >> Given the function is not called at all, I think this is a bit odd to remove >> the stub but leave the implementation when CONFIG_PCI_ATS is defined. >> >> Rahul, do you plan to use it in the PCI passthrough code? If yes, then I >> would consider to use __maybe_unused. > > No, this function will not be used in PCI passthrough code, but when we > merged the SMMUv3 code from Linux at that time we > decided to have this code and gate with CONFIG_PCI_ATS so that in the future > if someone wants to implement the PASID feature > will use these functions. > > I also agree with Julien we would consider using __maybe_unused.
OK, I will send a v2 with the __maybe_unused attribute (in both locations), in case PASID is to be implemented in the future.