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 IS_REACHABLE to only build IOMMU-V2 support if the amd_iommu symbols are reachable by the amdkfd driver. Output a warning if they are not, because that may not be what the user was expecting.
Fixes: 64d1c3a43a6f ("drm/amdkfd: Centralize IOMMUv2 code and make it conditional") Reported-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Felix Kuehling Felix.Kuehling@amd.com --- drivers/gpu/drm/amd/amdkfd/kfd_iommu.c | 10 ++++++++++ drivers/gpu/drm/amd/amdkfd/kfd_iommu.h | 6 ++++-- 2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c index 66bbca61e3ef..7199eb833f66 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c @@ -20,6 +20,10 @@ * OTHER DEALINGS IN THE SOFTWARE. */
+#include <linux/kconfig.h> + +#if IS_REACHABLE(CONFIG_AMD_IOMMU_V2) + #include <linux/printk.h> #include <linux/device.h> #include <linux/slab.h> @@ -355,3 +359,9 @@ int kfd_iommu_add_perf_counters(struct kfd_topology_device *kdev)
return 0; } + +#else + +#warning "Moldular IOMMU-V2 is not usable by built-in KFD" + +#endif diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_iommu.h b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.h index dd23d9fdf6a8..b25365fc2c4e 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_iommu.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.h @@ -23,7 +23,9 @@ #ifndef __KFD_IOMMU_H__ #define __KFD_IOMMU_H__
-#if defined(CONFIG_AMD_IOMMU_V2_MODULE) || defined(CONFIG_AMD_IOMMU_V2) +#include <linux/kconfig.h> + +#if IS_REACHABLE(CONFIG_AMD_IOMMU_V2)
#define KFD_SUPPORT_IOMMU_V2
@@ -73,6 +75,6 @@ static inline int kfd_iommu_add_perf_counters(struct kfd_topology_device *kdev) return 0; }
-#endif /* defined(CONFIG_AMD_IOMMU_V2) */ +#endif /* IS_REACHABLE(CONFIG_AMD_IOMMU_V2) */
#endif /* __KFD_IOMMU_H__ */