On Mon, Mar 8, 2021 at 8:11 PM Felix Kuehling felix.kuehling@amd.com wrote:
Am 2021-03-08 um 2:05 p.m. schrieb Arnd Bergmann:
On Mon, Mar 8, 2021 at 5:24 PM Felix Kuehling felix.kuehling@amd.com wrote:
The driver build should work without IOMMUv2. In amdkfd/Makefile, we have this condition:
ifneq ($(CONFIG_AMD_IOMMU_V2),) AMDKFD_FILES += $(AMDKFD_PATH)/kfd_iommu.o endif
In amdkfd/kfd_iommu.h we define inline stubs of the functions that are causing your link-failures if IOMMU_V2 is not enabled:
#if defined(CONFIG_AMD_IOMMU_V2_MODULE) || defined(CONFIG_AMD_IOMMU_V2) ... function declarations ... #else ... stubs ... #endif
Right, that is the problem I tried to explain in my patch description.
Should we just drop the 'imply' then and add a proper dependency like this?
depends on DRM_AMDGPU && (X86_64 || ARM64 || PPC64) depends on AMD_IOMMU_V2=y || DRM_AMDGPU=mI can send a v2 after some testing if you prefer this version.
No. My point is, there should not be a hard dependency. The build should work without CONFIG_AMD_IOMMU_V2. I don't understand why it's not working for you. It looks like you're building kfd_iommu.o, which should not be happening when AMD_IOMMU_V2 is not enabled. The condition in amdkfd/Makefile should make sure that kfd_iommu.o doesn't get built with your kernel config.
Again, as I explained in the changelog text, AMD_IOMMU_V2 configured as a loadable module, while AMDGPU is configured as built-in.
The causes a link failure for the vmlinux file, because the linker cannot resolve addresses of loadable modules at compile time -- they have not been loaded yet.
Arnd