[PATCH] drm/amdkfd: fix build error with missing AMD_IOMMU_V2

[Felix Kuehling]

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

Regards,
  Felix

Am 2021-03-08 um 10:33 a.m. schrieb Arnd Bergmann:
> From: Arnd Bergmann <arnd at arndb.de>
>
> Using 'imply AMD_IOMMU_V2' does not guarantee that the driver can link
> against the exported functions. If the GPU driver is built-in but the
> IOMMU driver is a loadable module, the kfd_iommu.c file is indeed
> built but does not work:
>
> x86_64-linux-ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_bind_process_to_device':
> kfd_iommu.c:(.text+0x516): undefined reference to `amd_iommu_bind_pasid'
> x86_64-linux-ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_unbind_process':
> kfd_iommu.c:(.text+0x691): undefined reference to `amd_iommu_unbind_pasid'
> x86_64-linux-ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_suspend':
> kfd_iommu.c:(.text+0x966): undefined reference to `amd_iommu_set_invalidate_ctx_cb'
> x86_64-linux-ld: kfd_iommu.c:(.text+0x97f): undefined reference to `amd_iommu_set_invalid_ppr_cb'
> x86_64-linux-ld: kfd_iommu.c:(.text+0x9a4): undefined reference to `amd_iommu_free_device'
> x86_64-linux-ld: drivers/gpu/drm/amd/amdkfd/kfd_iommu.o: in function `kfd_iommu_resume':
> kfd_iommu.c:(.text+0xa9a): undefined reference to `amd_iommu_init_device'
> x86_64-linux-ld: kfd_iommu.c:(.text+0xadc): undefined reference to `amd_iommu_set_invalidate_ctx_cb'
> x86_64-linux-ld: kfd_iommu.c:(.text+0xaff): undefined reference to `amd_iommu_set_invalid_ppr_cb'
> x86_64-linux-ld: kfd_iommu.c:(.text+0xc72): undefined reference to `amd_iommu_bind_pasid'
> x86_64-linux-ld: kfd_iommu.c:(.text+0xe08): undefined reference to `amd_iommu_set_invalidate_ctx_cb'
> x86_64-linux-ld: kfd_iommu.c:(.text+0xe26): undefined reference to `amd_iommu_set_invalid_ppr_cb'
> x86_64-linux-ld: kfd_iommu.c:(.text+0xe42): undefined reference to `amd_iommu_free_device'
>
> Use a stronger 'select' instead.
>
> Fixes: 64d1c3a43a6f ("drm/amdkfd: Centralize IOMMUv2 code and make it conditional")
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> ---
>  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