Bug 212619

Just built 5.12.1 and got:

+ ld -m elf_x86_64 --emit-relocs --discard-none -z max-page-size=0x200000 --build-id=sha1 --orphan-handling=warn --strip-debug -o .tmp_vmlinux.kallsyms1 -T ./arch/x86/kernel/vmlinux.lds --whole-archive arch/x86/kernel/head_64.o arch/x86/kernel/head64.o arch/x86/kernel/ebda.o arch/x86/kernel/platform-quirks.o init/built-in.a usr/built-in.a arch/x86/built-in.a kernel/built-in.a certs/built-in.a mm/built-in.a fs/built-in.a ipc/built-in.a security/built-in.a crypto/built-in.a block/built-in.a lib/built-in.a arch/x86/lib/built-in.a lib/lib.a arch/x86/lib/lib.a drivers/built-in.a sound/built-in.a net/built-in.a virt/built-in.a arch/x86/pci/built-in.a arch/x86/power/built-in.a arch/x86/video/built-in.a --no-whole-archive --start-group --end-group
ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_bind_process_to_device':
kfd_iommu.c:(.text+0x27d): undefined reference to `amd_iommu_bind_pasid'
ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_unbind_process':
kfd_iommu.c:(.text+0x2de): undefined reference to `amd_iommu_unbind_pasid'
ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_suspend':
kfd_iommu.c:(.text+0x3a3): undefined reference to `amd_iommu_set_invalidate_ctx_cb'
ld: kfd_iommu.c:(.text+0x3ae): undefined reference to `amd_iommu_set_invalid_ppr_cb'
ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_resume':
kfd_iommu.c:(.text+0x40b): undefined reference to `amd_iommu_init_device'
ld: kfd_iommu.c:(.text+0x429): undefined reference to `amd_iommu_set_invalidate_ctx_cb'
ld: kfd_iommu.c:(.text+0x439): undefined reference to `amd_iommu_set_invalid_ppr_cb'
ld: kfd_iommu.c:(.text+0x4aa): undefined reference to `amd_iommu_bind_pasid'
ld: kfd_iommu.c:(.text+0x50c): undefined reference to `amd_iommu_set_invalidate_ctx_cb'
ld: kfd_iommu.c:(.text+0x517): undefined reference to `amd_iommu_set_invalid_ppr_cb'
ld: kfd_iommu.c:(.text+0x520): undefined reference to `amd_iommu_free_device'
ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_suspend':
kfd_iommu.c:(.text+0x3bf): undefined reference to `amd_iommu_free_device'

This look like the same issue.

found this patch which seems to fix things:

---
  drivers/gpu/drm/amd/amdkfd/Kconfig | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

 diff --git a/drivers/gpu/drm/amd/amdkfd/Kconfig b/drivers/gpu/drm/amd/amdkfd/Kconfig
 index f02c938f75da..91f85dfb7ba6 100644
 --- a/drivers/gpu/drm/amd/amdkfd/Kconfig
 +++ b/drivers/gpu/drm/amd/amdkfd/Kconfig
 @@ -5,8 +5,9 @@
  
  config HSA_AMD
  	bool "HSA kernel driver for AMD GPU devices"
 -	depends on DRM_AMDGPU && (X86_64 || ARM64 || PPC64)
 -	imply AMD_IOMMU_V2 if X86_64
 +	depends on DRM_AMDGPU && ((X86_64 && IOMMU_SUPPORT && ACPI) || ARM64 || PPC64)
 +	select AMD_IOMMU if X86_64
 +	select AMD_IOMMU_V2 if X86_64
  	select HMM_MIRROR
  	select MMU_NOTIFIER
  	select DRM_AMDGPU_USERPTR

Originally, a bit of code just like the above was used. It was later removed. Therefore, the question still remains as to whether or not the kernel should be able to build with the HSA driver enabled with the IOMMMU_V2 as a module.