If CONFIG_PCI=n, and gcc (e.g. 4.1.2) decides not to inline get_pci_function_alias_group(), the build fails with: drivers/iommu/iommu.o: In function `get_pci_function_alias_group': iommu.c:(.text+0xfdc): undefined reference to `pci_acs_enabled' Due to the various dummies for PCI calls in the CONFIG_PCI=n case, pci_acs_enabled() isn't actually ever called, but not all versions of gcc are smart enough to realize that. While explicitly marking get_pci_function_alias_group() inline would fix the build, this would inflate the code for the CONFIG_PCI=y case, as get_pci_function_alias_group() is a not-so-small function called from two places. Hence fix the issue by introducing a dummy for pci_acs_enabled() instead. Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> --- include/linux/pci.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/pci.h b/include/linux/pci.h index f68c58a93dd045b9..f4f8ee5a7362e982 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1685,6 +1685,8 @@ static inline int pci_get_new_domain_nr(void) { return -ENOSYS; } #define dev_is_pci(d) (false) #define dev_is_pf(d) (false) +static inline bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags) +{ return false; } #endif /* CONFIG_PCI */ /* Include architecture-dependent settings and functions */ -- 2.7.4